Autism spectrum disorder (ASD) is a complex and often misunderstood condition. Learn about autism symptoms, causes, tests to diagnose, therapies, and more.


Around 1 in 36 children in the United States has been diagnosed with autism spectrum disorder (ASD), according to the Centers for Disease Control and Prevention (CDC). People with ASD often face challenges that consume many aspects of their daily lives, from speech and communication issues to repetitive behaviors to issues with physical well-being and development.

Autism is a complex and often misunderstood condition, and many myths and misconceptions about it circulate in society. Read on for science-backed information about what the disorder is, what causes it and what doesn’t, which signs and symptoms may occur, how it’s diagnosed and treated, and why it’s important for all people to gain greater awareness of what it means to live on the autism spectrum.

What is autism?

boy with autism sits a play therapy table with his therapist while he colors

Autism affects the way the brain and nervous system develop and function. As such, it’s known as a neurodevelopmental disorder. Autism is formally called a spectrum disorder because the abilities of people with ASD and the types and severity of symptoms they experience can vary widely.

The experience of being on the autism spectrum often involves repetitive and inflexible patterns of behavior, activities, and interests. People with autism may also follow rigid routines. When these are disrupted, it can cause great distress to someone with autism, as their ability to adapt to change may be limited. These routines are referred to as repetitive and restricted behaviors (RRBs).

Some people with autism may have severe impairments when it comes to their ability to communicate and interact with others. Others may experience milder autism symptoms and live successful and fulfilled lives.

People with autism are sometimes referred to as being high or low functioning, but these terms may be inaccurate or imprecise and can be considered controversial, as some may function effectively in one facet of their lives but struggle in other areas.

It's important to remember the significance of autism being labeled a disorder rather than a disease and to recognize that people with ASD are as diverse and nuanced as any other group of people. While autism can be disabling in many ways, it can also be a meaningful and valuable part of life, informing one’s interaction with the world.

How common is autism?

Roughly 1 in 100 children worldwide has been diagnosed with autism, according to a 2022 review of studies published in Autism Research. This reflects the average rate of people known to have the disorder, although current autism rates may be underestimated as some studies have cited notably higher figures. Moreover, the rates of ASD in many low- and middle-income countries aren’t known, according to the World Health Organization (WHO).

Autism occurs across all racial, ethnic, and socioeconomic groups. In the U.S., it is diagnosed nearly four times more often among children assigned male at birth (AMAB) compared to children assigned female at birth (AFAB).

ASD rates among children in the U.S. and other countries have risen since the 1970s and most notably since the late 1990s. This may be in part due to the condition simply becoming more common. But many health experts believe that updated definitions and diagnostic criteria (more below) are most likely behind much of the rise in ASD rates, at least in the U.S.

As greater awareness, more screening, and better access to support services increase, so do the number of diagnosed cases. Additionally, Black, Hispanic, Asian American, and Pacific Islander children have historically been underdiagnosed compared to white children. Increased diagnoses in these communities have also contributed to the rise in ASD rates.

Although autism symptoms tend to manifest in early childhood, more than 5.4 million adults in the U.S. between the ages of 18 and 84 live with ASD. This equates to about 1 in 45 adults, according to findings from the CDC published in the Journal of Autism and Developmental Disorders in 2022.

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What are the different levels of autism?

“Autistic disorder” was previously one of five different types of conditions classified as pervasive developmental disorders (PDD), according to the fourth and prior editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM-4). Published and updated by the American Psychiatric Association (APA), the DSM is the standard reference used by healthcare providers (HCPs) in the U.S. to diagnose mental health disorders.

With the release of the fifth edition of the manual (DSM-5) in 2013, the APA merged four of the five PDD disorders into a single autism spectrum disorder (ASD) diagnosis. Rather than viewing these disorders as separate categories, experts recognized that autism occurs along a spectrum and that similarities exist between the various subtypes, regardless of the severity of their symptoms. A fifth PDD type, Rett syndrome, isn’t considered a type of autism because it results from a genetic mutation.

The four former PDD types that were merged into the ASD diagnosis and are no longer classified as separate disorders include:

  • Asperger’s syndrome
  • Autistic disorder
  • Childhood disintegrative disorder
  • Pervasive developmental disorder not otherwise specified (PDD-NOS)

The DSM-5 and its next revision, DSM-5-TR, replaced these previous subtypes with three levels of ASD (see below). ASD is classified based on language impairment or intellectual disability, symptom severity, and the degree of support needed by a person to address social communication issues and repetitive behaviors. ASD levels 1 through 3 indicate how much support a person with ASD needs in these areas.

In addition to determining the appropriate ASD level, when making a diagnosis, an HCP specifies if the person’s ASD occurs:

  • With or without accompanying intellectual impairment
  • With or without accompanying language impairment
  • With catatonia (a condition marked by the lack of an appropriate response to the environment, such as impaired communication or lack of movement)

An HCP will also specify if the person’s disorder is associated with:

  • A known medical or genetic condition or environmental factor
  • Another neurodevelopmental, mental, or behavioral disorder

ASD level 1: Requiring support

ASD level 1 is the mildest form of autism and what most people likely refer to when describing what was once diagnosed as Asperger’s syndrome. Although people at this level are more likely to speak using full sentences and more complex language, they typically have trouble engaging in back-and-forth conversations.

They may also find it hard to:

  • Start conversations or interact with others
  • Respond as others tend to expect. Additionally, what they say may come across as awkward, indifferent, rude, or hard for others to understand
  • Stay interested in conversations with others, which could lead to abrupt pauses mid-conversation or disinterest and indifference
  • Make or keep friends, as their words and behaviors may appear odd or possibly off-putting to some people
  • Understand other people’s emotions or perspectives, even though they have language skills that are similar to those of many of their peers
  • Understand figurative language

People who meet the criteria for ASD level 1 might also:

  • Be inflexible when it comes to their behavioral patterns and routines
  • Have a hard time coping with transitions or changing situations
  • Require help with organizing, like cleaning their room and arranging and storing clothes, shoes, and toys

ASD level 2: Requiring substantial support

ASD level 2 is the middle of the autism spectrum. People at this level might have similar but more severe characteristics compared to those in level 1 and may require more help on a daily basis.

Even with support, people at this ASD level may not communicate in a coherent manner and are more likely to respond in ways that might be interpreted by others as inappropriate or rude.

People at this level may exhibit social communication traits such as:

  • Using fewer words and speaking in short, simple sentences
  • Only discussing topics that interest them and saying little to nothing otherwise
  • Missing nonverbal communication cues, including other people’s facial expressions and body language
  • Showing unexpected social behavior during conversations, such as turning or walking away mid-conversation or simply not responding
  • Preferring to be alone, even when others try to engage them in play or conversation
  • Using echolalia (repeating words or phrases, such as from favorite television shows or movies, although they may not understand what they mean) or yelling when faced with challenges that may not be obvious to others

People with ASD level 2 might also:

  • Have a highly specific and restricted range of activities and interests
  • Appear markedly stressed when asked to change or disrupt their routines or when called upon to shift their focus (such as from topics of interest)
  • Display stimming (also known as self-stimulating), behaviors. These are repetitive motions or vocalizations to help regulate or cope with emotions or sensory input, or to show excitement. They may include repeating words or phrases, hand-flapping, lining up objects, head banging, rocking, spinning, twirling, or pacing. For people at ASD level 2, these behaviors might interfere with functioning or impact health, such as repeatedly picking at the skin, which can lead to infected or chronic wounds.

ASD level 3: Requiring very substantial support

ASD level 3 is the most severe form of autism, which requires the most support due to profound impairments that can impact communication skills, social interactions, and daily functioning.

Social traits at this level may include:

  • Severe deficits in communication skills, which may manifest as being nonverbal (a person may use signs or gestures to communicate instead), having limited verbal capabilities, using echolalia, or needing devices to help with communication
  • Preferring solitary play and other activities, showing little to no interest in making friends or interacting with their social environment, and only interacting with others when an immediate need must be met
  • Finding it exceedingly hard to participate in imaginative play with peers
  • Responding only to simple and nonverbal instructions

Repetitive or restrictive behaviors may include:

  • Extreme difficulty and distress (including angry outbursts) when called upon to change their focus, task, or daily routines or when certain sensory stimuli (such as changes in noise level) upset them
  • Stimming (self-stimulating) to the point of substantially disrupting their ability to function and complete their daily activities

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What are the signs and symptoms of autism?

Man with autism looks out of a bright window while he plays with a fidget ring

The core symptoms of autism involve difficulties with social interaction and communication and restricted and repetitive behaviors (RRBs) and interests.

Social interaction and communication challenges

People with autism have trouble with verbal and nonverbal communication. For instance, they may not understand or properly use the following:

  • Expressions or figures of speech that aren’t meant to be taken literally
  • Eye contact
  • Facial expressions
  • Gestures
  • Spoken language (about one-third of people with autism are considered nonverbal)
  • Tone of voice

More specifically, people with ASD may:

  • Appear as if they aren’t looking or listening to people who are talking with them
  • Make little or inconsistent eye contact
  • Respond slowly (or not at all) to their name or to other verbal attempts to draw their attention
  • Rarely share emotion, enjoyment, or interest in objects or activities
  • Show facial expressions or gestures or move in ways that don’t match what they’re saying
  • Speak in a sing-song (with a pitch that goes up or down) or robotic (flat, monotone) tone of voice that lacks inflection. Some people with ASD may not speak at all
  • Talk at length about a favorite topic without allowing others the chance to respond or without recognizing that others may not be interested in what they’re saying

They may also have trouble:

  • Adjusting their behaviors to social situations, often feeling overwhelmed by them
  • Gauging personal space (maintaining a socially appropriate distance from others)
  • Making friends
  • Sharing in imaginative play
  • Recognizing their own emotions or that of others
  • Reciprocating emotions and understanding or talking about feelings
  • Seeking emotional comfort from others
  • Taking turns speaking during conversations
  • Understanding other people’s perspectives and predicting other people’s intentions

Repetitive and restrictive characteristics and behaviors

These can vary widely across the autism spectrum. Examples include:

  • Echolalia (repeating words or phrases)
  • Greater or less sensitivity to sensory input (such as from vision, touch, smell, sound, or taste), including those from lights, sounds, temperature, or textures
  • Limited or intense interest in specific subjects, including numbers, details, or facts associated with these topics
  • Manipulating objects in repetitive ways, such as flipping levers, shaking sticks, and spinning wheels
  • Playing with toys in the same manner every time
  • Ritualistic behaviors such as lining up toys or other objects, repeatedly touching these objects in a specific sequence, and getting upset when the order of these objects is disrupted
  • Resistance to change and needing to maintain routines without variations, including keeping the same daily schedule, meals, clothes, and routes to destinations
  • Staring at lights or spinning objects or focusing on parts of objects (like wheels)
  • Stimming (self-stimulating behaviors)

Other autism characteristics

Some people with ASD might also display one or more of the following symptoms:

  • Anxiety, stress, or excessive worry
  • Delayed language, movement, or cognitive skills. These may include higher-level brain functions such as learning, reasoning, judgment, and language.
  • Food aversions, often due to sensory issues such as not liking the texture or color of certain foods
  • Hyperactive, impulsive, and/or inattentive behavior
  • Irritability, aggressive behavior, or other mood or emotional reactions
  • Lack of or greater amount of fear than anticipated from a situation
  • Dyspraxia (lack of motor control and coordination, leading to issues such as clumsiness)
  • Atypical sleeping and eating habits
  • GI issues such as abdominal pain, constipation, or diarrhea

Strengths of people with autism

Although people with autism experience various challenges, they may also show strengths and talents and excel in certain areas. For instance, some people may:

  • Absorb and learn facts, figures, melodies, quotes, and other information in great detail and retain them for long periods of time
  • Communicate directly and honestly
  • Display hyperlexia (high-level reading skills that develop at an early age)
  • Exhibit extraordinary focus and concentration
  • Excel in art, music, math, or science because of their methodical and analytical approach to learning, observing, and repeating patterns as a means of acquiring knowledge
  • Express and bring ideas to life in creative and innovative ways
  • Have an enhanced sense of direction
  • Show a strong capacity for visual and auditory (listening) learning
  • Garner “niche” expertise in specific topics of interest by thoroughly studying information to a degree that others might find challenging to accomplish
  • Show resilience, strength, and composure and an ability to find alternate solutions when coping with issues and events that others might find hard to grapple with
  • Think independently, logically, and in “out-of-the-box” ways

And although people with autism may sometimes find it hard to empathize with people who don’t have the disorder, a 2022 study published in Autism Adulthood found that participants with ASD are better at empathizing with others who have the disorder compared to others who don’t have it. This points to the benefits of having people with autism work with others experiencing similar challenges, according to the study authors.

How does autism affect kids?

Autism symptoms often manifest within the first two to three years of a child’s life. But these symptoms can change as they grow. Signs and symptoms observed in infants and toddlers may differ from those observed in children aged 4 through the teen years.

Autism signs in infants and toddlers

An infant or toddler with autism might display these characteristics:

  • Appear less aware of other people around them and may not respond when someone tries to get their attention, such as by calling out their name
  • Eat a limited range of foods and get upset when they’re served items that differ from what they usually eat and drink. Food preferences are often related to routines and sensory issues.
  • React strongly to sensory stimulation (sights, sounds, smells, touch, and tastes), such as wanting to spend a long time stroking a stuffed animal because they like how it feels
  • Exhibit stimming (self-stimulating) behavior when they get excited or upset, such as flapping their hands, rocking back and forth, or making the same noise repeatedly
  • Spend a great deal of time and effort setting up toys in the same way each time they play with them
  • Start talking later than most children within their age range
  • Show little to no interest in imaginative or make-believe play with their toys, or may start doing so at a later age than most of their peers
  • Show little to no interest in playing with children their own age
  • May not smile back when others smile at them
  • Have difficulty making, or inability to make, eye contact
  • Display little to no interest in verbalizing or sharing emotions

Autism signs in children aged 4 and older

Autism in children might manifest in different ways as children get older and gain experience in different environments, such as pre-school and elementary school.

A child with autism might display these characteristics:

  • Enjoy or feel calmer when they experience certain sensory stimuli, such as being tucked tightly into bed or seeing colored lights
  • Exhibit an intense attachment to an inanimate object
  • Find it hard or impossible to communicate their needs or desires
  • Have difficulty with motor control (controlling their bodily movements)
  • Self-stimulate when they’re upset or excited, such as by flapping their hands, rocking back and forth, or repeating the same sound
  • Respond to questions by repeating them
  • Connect or get along better with adults or children who are younger or older than them rather than children their own age
  • Desire to play with other children, but find it hard to ask if they can play with them
  • Play by themselves or exclusively with one or two good friends because they have a difficult time making and keeping friends or playing in a larger group dynamic. This may involve spending time on the periphery of the group instead of being fully engaged.
  • Show little if any interest in playing or spending time with children they know outside of school
  • Speak in a different manner or tone than others, which might include speaking slower or faster or with an accent or a sing-song voice
  • Talk enthusiastically about subjects that interest them, but find it harder to talk about other people’s interests
  • Unintentionally make social mistakes. It may be difficult for people with autism to interpret social subtext, like subtle body language and vocal tone changes, which can lead to miscommunications.
  • Use longer or more complex words compared to children their age, even in relaxed situations and environments

In addition, they might:

  • Find it difficult to cope with various sensory stimuli, such noisy or crowded environments or the feeling of seams in their clothing
  • Find it hard to tell if people are joking or being nice to them, or if they’re trying to bully or hurt their feelings
  • Find it hard to cope with changes to their routine, especially if these changes are unplanned or unexpected
  • Find it hard to keep conversations going or converse with people in general
  • Find it challenging to proceed or cope with social situations that don’t have clear rules or set times, such as during free play or recess at school
  • Find spending time at parties, busy places, and other types of social situations overwhelming
  • Show little to no interest in being touched, held, or cuddled

Autism signs in teens

Children with autism continue to experience different social situations and environments as they enter the teen years, all of which can impact the signs and symptoms they manifest.

A teen with autism might:

  • Find it hard to understand and cope with the changes to their bodies they experience during puberty
  • Need to be reminded to groom every day and may be less socially motivated to do so compared to some teens without ASD. This might include having difficulty knowing when and how to use deodorant, when to put on clean clothes, how to care for acne, when and how to shave, and what to do during menstrual periods.
  • Find it challenging to deal with changing schedules during middle school and high school
  • Act or speak in a way (with facial expressions and tone of voice) that others might misunderstand or misinterpret. For example, they might make prolonged eye contact, which others may view as flirting.
  • Do well with routines, but feel anxious and distracted with any changes to those routines
  • Experience strong positive or negative reactions to certain sensory stimuli, such as feeling anxious or overwhelmed in noisy environments such as the school gym but feeling calmed by flashing, multicolored lights at a concert
  • Find it hard to imagine things or situations they have yet to experience, such as thinking about what they might be expected to do when they go to a social gathering
  • Find starting a new activity challenging but become extremely focused on it once they start it. This may involve struggling to break this focus to move on to other activities and functions, such as eating or sleeping.
  • Find talking to people with autism easier than it is to speak with others who do not have autism. This may entail having a larger circle of friends with ASD.
  • Spend a lot of time learning about specific topics and sharing their acquired knowledge with others
  • Talk at great length about topics of interest, but find it hard to talk about other people’s interests
  • Try especially hard not to make social mistakes or hurt other people’s feelings
  • Use longer or more complex words than are necessary to express their thoughts
  • Make friends with people who are older or younger than them

In addition, they might:

  • Not be able to communicate what they’re trying to convey during conversations, and may be misunderstood as a result
  • Not be able to comprehend “gray areas” or exceptions to rules, since they tend to have strong views on matters of importance to them and perceive things as definitively “right” or “wrong”
  • Not be able to tell when others are being unkind or trying to take advantage of their trusting nature
  • Not understand or pick up on social cues, such as when others would rather not talk about a subject or don’t find it interesting
  • Not understand hidden meanings when others talk with them, such as when someone’s giving them a hint or trying to tease them
  • Not know how much eye contact to use or find doing so uncomfortable
  • Not know when to talk during conversations, sometimes talking over people for fear of not being able to say what they’d like to say
  • Not know what questions to ask or how to answer them when talking with others
  • Not understand why certain jokes are funny or when people are speaking figuratively (instead of literally). This may entail not understanding sayings, phrases, or expressions that contain figurative meaning.

How does autism affect adults?

The way people experience autism in adulthood may differ from that of childhood. Experiencing different environments, life events, and circumstances coupled with coping strategies that may have been developed over the years can affect how autism presents in adulthood. It’s worth remembering that autism is a spectrum, and while some adults with autism can live independently and flourish, others will need significant support throughout their lives.

An adult with autism might:

  • Be deeply knowledgeable or feel passionate about certain topics or hobbies
  • Find it challenging to communicate effectively during interviews. This includes providing details about their skills and capabilities, making it harder to land a job.
  • Find it harder than most people to keep their jobs. Someone with autism might be highly knowledgeable and able to perform the technical aspect of their job effectively, but might find it difficult to connect personally with their colleagues and supervisors.
  • Find it tough to work on projects or tasks that don’t come with clear instructions for how to complete them
  • Find dating and socializing challenging and exhausting
  • Prefer to be alone during breaks at work or school
  • Prefer engaging in structured social activities with others, such as cooking or participating in a shared hobby or interest
  • Like spending time with others but find social functions that don’t have set rules or timetables difficult to manage, since they aren’t sure what to do or how to conduct themselves in these situations
  • Often feel misunderstood and may inadvertently express their feelings in a way that upsets others
  • React in a positive or negative way to certain sensory stimuli, such as enjoying the sense of comfort and calmness that using a weighted blanket might bring but staying away from certain types of clothing because they don’t like the texture or feel
  • Stim (self-stimulate) or repeat the same motions to feel calm

In addition, they might:

  • Find it hard to contain involuntary outbursts or noises such as repetitive throat-clearing
  • Find it difficult to cope with changes to their daily routines
  • Find it hard to empathize with other people’s perspectives and not understand why people don’t see matters or situations the same way they do
  • Find it challenging to engage in and understand small talk, finding it awkward or wearisome to talk about topics that seem unimportant
  • Have trouble making sense of certain rules or ways of doing things, leaving them feeling anxious and frustrated

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How is autism different from other conditions?

Asperger’s and autism (autistic disorder)

Autism (autistic disorder) and Asperger’s syndrome both fall under the broader diagnosis of ASD and are no longer classified as separate disorders according to the DSM-5, DSM-5-TR, and the WHO’s International Statistical Classification of Diseases and Related Health Problems edition 11 (ICD-11). (The ICD is used by WHO member countries across the globe.)

That said, an Asperger’s diagnosis was previously given to people on the milder end of the spectrum who were considered “high functioning.” That’s because symptoms in people with Asperger’s tend to be more subtle. Although the diagnosis is no longer used, many people diagnosed with the condition still strongly and positively identify with being an “Aspie.” (Before you refer to someone as an “Aspie,” check with them directly to ask their preference.)

While autism and Asperger’s share some common characteristics, there are significant differences. One of the most prominent differences is that people with Asperger’s have “neurotypical” language development and intelligence, meaning their brains develop and function in ways that are typical or similar to those without a neurodevelopmental condition.

In fact, people diagnosed with Asperger’s tend to have average or above-average intelligence. As such, the disorder may sometimes be referred to as ASD without intellectual or language impairment. In contrast, people with autism may have more profound cognitive issues, including language delays and speech impairments.

People with Asperger’s may also have interests or hobbies they focus on, but these may not interfere with their daily lives. In comparison, people with autism may display intense interest in certain hobbies, enthusiasms, and routines.

Although both disorders can impact social skills, the degree to which autism affects a person’s social skills may be much greater compared to someone with Asperger’s. Though it may be difficult for people with Asperger’s to communicate and interact with others, it’s often easier for them to make and maintain friendships compared to people with autism. Those with autism also have a harder time understanding social cues, nonverbal communication, and figurative language.

Because people with Asperger’s tend to have milder symptoms and show fewer neurodevelopmental impairments, they may have been diagnosed at a later age than people with autism. But people with Asperger’s often still need support. Early intervention can greatly benefit people with ASD, no matter which previous diagnosis they had or which level they may be on the spectrum.

Autism and attention-deficit/hyperactivity disorder (ADHD)

Although the symptoms of autism may overlap with those of ADHD, there are distinct differences between them. The DSM-5 and DSM-5-TR classify both conditions as neurodevelopmental disorders and recognize that they may occur at the same time.

The defining characteristics of people with ASD include communication and social interaction challenges coupled with restricted or repetitive behaviors. On the other hand, people with ADHD may have persistent issues with attention, hyperactivity, and impulsivity.

Attention span: Many people with autism have highly specific interests and may be fully absorbed in them for hours. They may find it hard, however, to focus on tasks that don’t interest them. People with ADHD tend to have a short attention span, even when they’re engaged in a meaningful activity or one that piques their interest.

That said, people with ADHD may also be hyperfocused, which is defined as being fixated on a specific event or topic. Although this symptom may not be included in diagnostic manuals such as the DSM-5 or DSM-5-TR, it’s an ADHD symptom recognized by HCPs.

Communication: People with autism often have a hard time expressing emotions, and though they may be able to empathize with others, they may have a tougher time conveying their understanding of other people’s feelings. They may not use or detect communication cues, such as gestures, eye contact, and other types of body language. People with ADHD, meanwhile, may behave and speak impulsively and continuously, often interrupting and not gauging how what they’re saying impacts others.

Routines: People with autism prefer rigid structure and familiarity to their routines. Changes or disruptions to these can be highly stressful. Structured routines may be much harder for people with ADHD to follow. They can become easily bored or distracted, which can lead to impulsive behaviors, especially in school settings or other structured environments.

Symptoms with age: Symptoms of autism and ADHD can differ as people age. For instance, some symptoms (such as social reciprocity, or the ability to engage in back-and-forth conversation) may improve as people with autism get older and acquire better social skills. Other symptoms of autism, such as rigid behavioral patterns and routines, may remain the same over time. Hyperactive-impulsive symptoms tend to be more common in young children with ADHD, whereas inattention tends to occur more often in older children.

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What causes autism?

Scientists have yet to determine what exactly causes autism, although research suggests that factors such as the interaction of genes and the environment influence its development.

Is autism genetic?

Although genetics can play a role in the development of autism, only 40 to 80 percent of cases have been linked to genetic causes. These include cases in which associated genetic syndromes—such as Down syndrome, fragile X syndrome, and tuberous sclerosis complex—are involved. Many other gene variations, combined with environmental factors (such as parental age, birth complications, and others that have not been identified), determine an individual's risk of developing ASD.

Many of the genes linked to ASD play a role in brain development. More specifically, the proteins made by these genes may affect the production, growth, and organization of neurons (nerve cells). Some of these genes impact how many neurons are made while others play a role in the way neurons communicate with one another. Other genes linked to ASD help regulate gene or protein activity associated with brain development.

How these genes specifically affect the development of ASD isn’t exactly known. Some studies point to early brain development, when their effect may be seen in an excess of neurons and overgrowth in the outer surface of the brain.

These differences in neuron and brain development occur in the frontal and temporal lobes of the cortex, which help regulate emotions, language, and social behavior. It’s thought that these changes account for the differences in cognitive functioning, communication, and socialization observed in people with autism.

Are biological siblings at greater risk for autism?

Having one biological child with autism raises the risk of the next child also having autism by 20 percent. If two biologically related siblings develop autism, the risk that a third child will develop ASD goes up by about 32 percent.

Do vaccines cause autism?

There is no credible, science-backed evidence that childhood vaccinations cause autism. In the 1990s, concerns about the measles-mumps-rubella (MMR) vaccine and its possible contribution to autism began to spread among the press and the public at large.

These concerns were based on a 1998 report published in The Lancet by Andrew Wakefield and colleagues claiming that the MMR vaccine may make children more prone to ASD. Despite the small sample size (12 children), weak study design, and conclusion based on speculation, the study received enormous publicity.

This widely publicized autism study was found to have significant scientific flaws, and has since been retracted by The Lancet and discredited by the medical and scientific community. The United Kingdom’s General Medical Council (GMC) also pulled Wakefield’s license to practice medicine in the U.K.

The GMC determined that Wakefield was culpable of misconduct for deliberately falsifying facts, picking and choosing data that fit the study’s hypothesis and conclusion, and subjecting children with autism and other developmental disorders to invasive tests (such as colonoscopies and spinal taps) without any clinical indication as to how these tests would benefit them.

All told, numerous subsequent, well-designed studies conducted in the U.S. and across the world haven’t found any direct evidence that vaccines cause autism. This extends to concerns about the vaccine ingredient thimerosal, which is a mercury-based preservative used to prevent germs from contaminating multidose vaccine vials (containers with more than one dose of a vaccine).

Although no studies have shown that thimerosal causes harm, the preservative was removed from routine childhood vaccines used in the U.S., Europe, and several other countries by 2001 due to these theoretical concerns. Thimerosal is still used in multidose vials containing the flu vaccine, as well as several other adult vaccines.

Despite the overwhelming scientific evidence to support the safety of vaccines, the fallout from Wakefield’s study persists. Many people remain unconvinced about the safety of vaccines, especially in children, and choose not to vaccinate as a result.

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What are the risk factors for autism?

In addition to genetics, other known risk factors for developing ASD may include:

  • Having older biological parents, including a birthing parent age 35 or older (although more research is needed to confirm this connection)
  • Very low birth weight, defined as weighing less than 3 pounds, 4 ounces (1.5 kilograms)
  • Prenatal infections such as rubella (German measles) and cytomegalovirus (virus related to the herpes viruses that cause chickenpox and mononucleosis)
  • Prenatal use of valproic acid (an anti-seizure drug) and thalidomide. Thalidomide is a drug now used to treat multiple myeloma and Hansen’s disease (a chronic infectious bacterial disease once known as leprosy), but was previously used to treat morning sickness in the late 1950s and early 1960s

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What are the possible complications of autism?

The challenges associated with social interactions, communication, and behavior in people with autism might lead them to have issues with:

  • Academic success and learning
  • Bullying
  • Employment
  • Family stress
  • Living independently
  • Social isolation

Health conditions associated with autism

People with autism may have other physical and mental health conditions that need to be assessed and treated. Some conditions may occur alongside ASD. These are referred to as comorbidities (conditions that tend to coexist or appear at the same time as another condition).

Comorbid conditions that may occur with (but aren’t necessarily specific to) autism include:

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How is autism diagnosed?

Boy sits in a play therapy room with a child psychologist during an evaluation for an autism diagnosis

Some people with autism can be diagnosed as early as 18 months of age, and in some cases, signs may be noticed before 12 months of age, according to the APA. Determining if a person has autism can be challenging, as there are no medical tests (such as lab work, brain imaging scans, or genetic tests) that can diagnose the disorder.

Children with suspected autism symptoms may be evaluated by healthcare specialists with expertise in diagnosing and treating ASD. This team might include HCPs such as a:

  • Child psychologist: An HCP with a doctorate degree in psychology who specializes in diagnosing and treating mental health, behavioral, social, and developmental issues in children
  • Developmental-behavioral pediatrician: A medical doctor who specializes in assessing and treating children with special needs such as autism
  • Neuropsychologist: A psychologist who specializes in understanding the relationship between the brain and cognitive, behavioral, and emotional functioning
  • Psychiatrist: A medical doctor who specializes in diagnosing and treating mental, emotional, and behavioral conditions

Autism may also be diagnosed by just one HCP with ASD expertise. Specialists aren’t always available or accessible in some areas of the U.S., in which case a child’s primary HCP may work with early intervention professionals or school staff to check for ASD.

Teachers and daycare specialists—who often spend substantial time with kids who have ASD—are often trained to evaluate developmental milestones and recognize ASD. Though they cannot diagnose the disorder, teachers can play a big role in referring kids for diagnosis and additional support.

This evaluation usually includes the HCP obtaining the child’s personal and family medical history and conducting physical and neurological exams. The HCP will also test the child’s cognitive, communication, language, and social skills, as well as discuss the child’s behavior, symptoms, and other concerns a parent or caregiver might have.

The evaluation provides information about the child’s level of functioning along with their strengths and challenges. It also helps pinpoint if the child has ASD or if another health condition could be the cause of or contributing to the child’s symptoms. The evaluation also looks for associated health issues that must be evaluated and treated.

According to the CDC, steps involved in diagnosing autism include:

Developmental monitoring of childhood milestones

This is an ongoing process in which the child’s parent or other caregiver watches the child grow and discusses the child’s skills and abilities with the child’s HCP. This helps determine whether the child has met key developmental milestones, which are skills, functions, and abilities that most children reach by various ages. Behavior, learning, motor skills, play, and speech are among the milestones monitored.

The CDC provides a checklist that parents, early childhood education specialists, or other caregivers can use to track a child’s developmental milestones. The child’s HCP (such as a doctor or nurse) will also participate in developmental monitoring during appointments such as routine well-child visits.

Developmental screening for ASD

This next step involves a more formal and in-depth look at how the child is developing, which may be integrated into a routine well-child visit. The American Academy of Pediatrics (AAP) recommends that all children receive developmental and behavioral screening at 9, 18, and 30 months of age.

The AAP also recommends that all children be screened for ASD during well-child visits when they’re 18 and 24 months old. Developmental screening may also occur during other HCP visits, such as when the caregiver has concerns that the child may have ASD due to suspected symptoms or if the child is at high risk for the disorder (such as if they have a biological sibling or parent with autism).

Although the DSM-5 and DSM-5-TR are commonly used by HCPs in the U.S. to diagnose mental and behavioral conditions, other tests might also be used if the person’s symptoms and characteristics don’t quite fit the manual’s diagnostic criteria for ASD.

Developmental screening might entail the use of standardized tests that compare the child to other children of the same age. These might include questions about the child’s language, motor, and cognitive skills, as well as behaviors and emotions. Examples of these screening tests include the:

  • Ages and Stages Questionnaires SE-2 (ASQ-SE2): A parent/caregiver-completed questionnaire that looks at communication, gross motor skills, fine motor skills, and problem solving
  • Communication and Symbolic Behavior Scales (CSBS): A one-page checklist completed by a parent/caregiver when their child is between 6 and 24 months old
  • Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F): A commonly used 20-question, parent/caregiver-completed test used to assess early social communication skills and other signs of autism in toddlers ages 16 to 30 months
  • Parents’ Evaluation of Developmental Status (PEDS): A 10-question form for parents/caregivers to answer
  • Screening Tool for Autism in Toddlers and Young Children (STAT): A 20-minute, interactive developmental screening tool consisting of 12 activities that assess communication, imitation skills, and play

Developmental diagnosis of ASD

If screening points to developmental delays or potential autism symptoms, further testing and evaluation by a specialist, such as a child psychologist, might be needed to confirm or rule out ASD. Some of these tests might entail the specialist observing the child’s behavior while other tests require parents/caregivers to describe the child’s behaviors.

A battery of autism-specific tests might be used, such as the:

  • Autism Diagnostic Observation Schedule, Second Edition (ADOS-2): This test provides the option of using one of five different modules, depending on the individual’s age, for HCPs to observe unstructured social occasions called “presses” and to rate spontaneous and prompted social interactions, communication, and behavior. The test can be used for people aged 12 months and up, including adults.
  • Autism Diagnostic Interview, Revised (ADI-R): This test evaluates reciprocal social interaction, communication, language, and restricted and repetitive interests and behaviors. It is appropriate for children and adults aged about 18 months and older.
  • Childhood Autism Rating Scale, Second Edition (CARS-2): This is a 15-question test that helps HCPs distinguish between ASD and other conditions in children aged 2 and up.
  • Gilliam Autism Rating Scale, Third Edition (GARS-3): This test incorporates DSM-5 criteria to help identify autism in people aged 3 to 22 and to estimate the severity of the disorder. It can be completed by parents/caregivers, teachers, or HCPs.

Other tests

Specialists may also recommend tests to help confirm or rule out autism or other health conditions that might be contributing to symptoms. These tests may include DNA testing for genetic diseases, and visual and audio tests to rule out vision and hearing impairments. Occupational therapy screening can assess the person’s ability in areas such as learning, play, self-care, and interactions with their environment, and identify any obstacles that hinder daily activities.

The AAP also stresses the importance of testing for conditions that commonly occur alongside ASD, including health conditions such as seizures and other behavioral or developmental conditions like ADHD, anxiety, and other mood disorders.

Autism spectrum disorder diagnostic criteria

The DSM-5 and DSM-5-TR criteria for diagnosing ASD in children point to difficulties with social communication and interactions. The HCP conducting the assessment must be certain these deficits aren’t caused by developmental delays alone. To be diagnosed with ASD, a person must have difficulties associated with:

  • Social-emotional reciprocity, including trouble with back-and-forth conversation, sharing interests with others, and expressing and/or understanding emotions
  • Nonverbal communication used for social interaction, such as eye contact and body language, along with issues using and understanding nonverbal communication such as facial expressions and gestures
  • Developing and maintaining relationships with others (apart from their caregivers), which includes having a lack of interest in others along with difficulties responding to social contexts and sharing imaginative play with others

In addition, the person must exhibit at least two of these four restricted and repetitive behaviors, interests, or activities:

  • Repetitive speech, motor movements, echolalia, and use of phrases
  • Rigid adherence to routines, ritualized verbal or nonverbal behavior patterns, and extreme resistance to change. This may involve following the same route to school, repeating the same questions, and eating the same food because of its color or texture. Even small changes to any of these routines causes great distress.
  • Intense, highly focused, and restricted interests, such as being strongly attached to certain objects and interests
  • Increased or decreased reactivity to sensory input or unusual interest in sensory aspects of the environment. This may include a fascination with spinning objects, no reaction to pain, or a strong dislike for loud noises.

These symptoms must also impair daily functioning. ASD is diagnosed based on the person’s current and past functional capacities. The APA’s updated observational criteria allow HCPs to diagnose people whose autism symptoms don’t clearly manifest until adolescence or adulthood, although they may have shown some signs of the disorder earlier in their lives.

Diagnosing autism in adults

Along with conducting a thorough physical and neurological exam and going over their family and medical history, HCPs mainly diagnose adults with ASD by observing and interacting with them. They also consider the person’s past and present symptoms to determine if they’re in line with those commonly observed in others with autism.

Although there aren’t any ASD diagnostic criteria geared toward adults only, DSM-5 (and DSM-5-TR) criteria may be adapted for this age group. Certain autism-specific tests, such as ADOS-2 and ADI-R, may also be used to screen for ASD in adults.

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How is autism treated and managed?

Current ASD treatments aim to manage autism symptoms that impede daily functioning. Because people with autism have different strengths and face different challenges associated with the disorder, each treatment plan must be tailored to each person’s needs. This usually involves a team-based approach, with active participation by members of the person’s healthcare and social service teams, parents or caregivers, and educational professionals.

As people with autism approach and enter adulthood, they may need additional services to maintain health, support daily functioning, and assist with social and community engagement. These might include assistance with continuing education and job training, as well as with securing employment, housing, and transportation.

Treatments for ASD might involve:

Behavioral therapies for autism spectrum disorder

These ASD therapies aim to change behaviors by helping people understand what occurs before and after the behavior. Commonly used in school, healthcare, and home settings and designed and supervised by professionals certified in behavioral analysis, these interventions have the most evidence supporting their use in treating autism symptoms.

An example is applied behavioral analysis (ABA), which takes a step-by-step approach to teach cognitive, behavioral, and social skills to people with autism. In the U.S., ABA may be offered by some schools and covered by health insurance as part of an individualized educational plan (IEP) for students with autism.

ABA applies common principles of behavioral therapy (such as positive reinforcement of desired behaviors), often intensively, to help children with autism develop skills they’re not developing on their own and to decrease aggressive or harmful behaviors, such as self-injury. Small improvements are reinforced and built upon to develop, change, or improve certain behaviors.

ABA helps people develop, change, and improve skills associated with:

  • Academics
  • Daily living and self-care (such as showering and grooming)
  • Work
  • Language and communication
  • Reading
  • Punctuality
  • Social interaction

Examples of ABA teaching methods include:

Discrete Trial Training (DTT): This structured approach uses step-by-step instructions to teach desired behaviors and responses. DTT breaks skills into small components. During the process, trainers use tangible rewards (such as a small toy) to reinforce desired behaviors and responses while ignoring undesired behaviors.

Pivotal Response Training (PRT): Using play-based therapy and initiated by the person with autism, PRT targets pivotal areas of a person’s development, including:

  • Initiation of social interactions
  • Motivation
  • Response to multiple cues
  • Self-management

PRT aims to develop language and communications skills, increase positive social behaviors, and reduce disruptive stimming (self-stimulating) behaviors.

Early Start Denver Model (ESDM): Developed based on the principles of ABA, this behavioral therapy is used in children with autism aged 12 to 48 months. EDSM employs “joint activity routines” to boost cognitive, language, and social skills, including building positive and fun relationships with others.

These include participating in play activities and daily routines that teach children to take initiative and facilitate social engagement and social learning. Conducted in home, school, or clinical settings, these joint activities mimic exchanges that occur during early development between children and their caregivers.

Applied behavioral analysis controversy

ABA is widely used by schools and therapists and the techniques it employs may greatly improve the quality of life for some children with ASD and their families, perhaps especially when ASD is moderate to severe (levels 2 and 3). That said, some have questioned its methods and goals.

Some critics of ABA contend that it is grounded in an antiquated premise. That is, the approach focuses on making people with autism unlearn common autistic behaviors with the goal of making them more socially acceptable or indistinguishable from their peers. This goal of “normalcy,” critics argue, may further contribute to the stigma that surrounds autism. As the Autistic Self Advocacy Network (ASAN) points out, autism is another form of neurodiversity, and people with autism should be respected as naturally different rather than being viewed as abnormal or in need of fixing.

ABA may also involve practicing skills (such as eye contact) for many hours. Mastering particular skills can tax neurotypical people of any age, critics argue, but particularly children who have issues regulating thoughts and emotions. Another criticism: ABA may try to reduce stimming behaviors such as flapping hands or twirling, which some people with autism use to calm themselves. This can be viewed by some as denying children with ASD the opportunity to self-soothe and possibly even gain a level of emotional independence.

As the leading form of therapy for children with autism, ABA has helped many enhance their communication skills, stem dangerous behaviors, improve the ability to care for themselves, and more. But the divergence between ABA’s potential benefits and perceived harms has spurred mixed feelings among some parents and caregivers. Some staunchly oppose this form of therapy for their children or regret using it, while others stand firmly behind it.

ABA may work for some but not for others. It’s important to discuss all autism treatment options with your child’s HCP and decide which ones may best suit their individual needs.

Whichever form of therapy is employed, it’s important that interventions focus on areas such as social-emotional development and improve a child’s ability to understand and relate to the world around them. As much as possible, therapeutic goals must also build on each child’s strengths, respect their interests, and allow them to engage with society in ways that are meaningful and beneficial to them.

Developmental therapies for autism spectrum disorder

Often combined with behavioral interventions, these ASD approaches aim to improve a broad range of developmental skills, including those associated with language and physical functions.

The most common developmental therapies for ASD include:

Speech therapy for autism

Speech therapy (ST) helps improve verbal, nonverbal, and social communication, with the goal of facilitating more useful and functional communication in people with autism. ST aims to improve spoken language, help people with ASD learn nonverbal skills such as sign language, or learn to communicate using alternative means such as pictures or devices such as tablets.

Speech therapists may help people with ASD:

  • Make clearer speech sounds and regulate tone of voice
  • Match emotions with the corresponding facial expressions
  • Match pictures with their meaning
  • Strengthen the muscles in the mouth, jaw, and neck
  • Understand nonverbal cues such as body language
  • Respond properly to questions
  • Use speech apps on electronic devices

Occupational therapy for ASD

Occupational therapy (OT) helps people with autism develop and improve cognitive, motor, physical, and social skills. An OT treatment plan might focus on learning strategies, play skills, and self-care, as well as managing sensory issues.

The plan may involve developing and improving skills associated with:

  • Bathing and grooming
  • Dressing oneself
  • Eating
  • Fine motor skills such as coloring, cutting with scissors, and writing
  • Using the restroom

Some occupational therapists may also help with swallowing and feeding difficulties some people with ASD might have. And OTs might employ sensory integration therapy to help prevent sensory overload (known as hyperresponsive or excessive reactions to sensory stimuli) and hyporesponsiveness (limited or no response to sensory stimuli).

Educational interventions for autism spectrum disorder

These ASD interventions are designed to help kids with ASD succeed academically. A primary example of this includes the Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) program.

TEACCH structures the learning environment of people with autism to boost the capacity for learning. It was developed to create a highly structured learning environment, which capitalizes on strengths and preferences people with ASD often have, including visual skills and consistency.

The approach helps promote independence along with communication, coping, social, and other life skills. Children are evaluated, after which the teacher arranges the classroom structure to accommodate their unique needs and learning style.

Each child is given a visual schedule of their daily activities (such as a wall chart). Verbal instructions are reinforced with physical demonstrations along with visual aids and instructions. As a child becomes more skilled, their environment becomes less structured to help facilitate independence. Although TEACCH is mainly used in the classroom setting, it can also be used in home or community settings.

Social-relational interventions for autism spectrum disorder

These autism treatments help foster social skills and forge emotional connections. Examples of these interventions include:

Floor time therapy for people with autism

Also called the Developmental, Individual Difference, Relationship-Based (DIR) model of intervention, floor time therapy sessions can take place in the living room, playground, office, and other settings where open-ended play and interaction are possible. The approach may help children with autism of any age connect with others on their own terms while using their interests and passions to foster and facilitate social engagement, as well as symbolic and logical thinking.

They interact and engage in play at the person’s developmental level, allowing the person with autism to take the lead. DIR-trained therapists teach caregivers and other family members how to guide the person into progressively complex interactions, a process that’s called “opening and closing circles of communication.”

Floor time aims to help the person reach six milestones that support emotional and intellectual growth:

  1. Self-regulation and interest in the world
  2. Intimacy (engagement in relationships)
  3. Back-and-forth communication
  4. Complex communication
  5. Emotional ideas
  6. Emotional thinking

Relationship Development Intervention (RDI) for people with autism

This parent- or caregiver-led approach focuses on helping people with autism develop social skills, think flexibly, understand different perspectives, and learn to engage and form connections with others. It involves activities that increase the person’s interest, motivation, and ability to participate in social interactions.

The six objectives of RDI include:

  1. Emotional referencing: The ability to learn from the emotional and subjective experiences of other people
  2. Social coordination: The ability to observe and control one’s behavior to effectively participate in social relationships
  3. Declarative language: The ability to use language and nonverbal communication to express curiosity, invite others to interact, share perceptions and feelings, and coordinate actions with others
  4. Flexible thinking: The ability to adapt and shift plans as circumstances change
  5. Relational information processing: The ability to put things into context and solve problems that lack clear-cut or “right and wrong” solutions
  6. Foresight and hindsight: The ability to anticipate future possibilities based on past experiences

Social-skills training for people with autism

This might include tactics such as sharing “social stories” to describe what to expect in social situations. Or it might involve a more structured approach such as social skills therapy, which is usually conducted in a group setting.

This gives people with ASD a safe environment to practice social skills. Learning how to collaborate, share information, and take turns asking and responding to questions are among the social and communication activities group members practice during sessions.

Psychological therapies for autism spectrum disorder

These therapies can help people with autism better cope with anxiety, depression, and other mental health issues. Cognitive behavioral therapy (CBT) is a form of talk therapy that may help children and adults with ASD expand their ability to recognize emotions in others and interact and cope better in social situations.

It helps them better understand and forge connections between thoughts, feelings, and behaviors. During sessions, CBT-trained therapists help people with ASD change the way they think about certain situations with the goal of changing the way they react to them.

Medicines for autism spectrum disorder

Certain medications can help manage some of the symptoms associated with ASD, especially those related to behavior. It’s important to note that these medicines don’t work in the same way or as effectively for everyone with autism.

Be sure to discuss the risks and benefits of each potential therapy with the person’s HCP to ensure they’re safe to use and that they don’t interact with any medicines (or herbs or dietary supplements) the person might already take.

Medicines used to treat autism symptoms tend to work best when used alongside other interventions such as behavioral therapies. In other words, medication usually complements rather than replaces other autism treatment strategies.

Examples of medicines used to treat autism symptoms or its coexisting conditions include:

Antipsychotics for autism

Also referred to as psychoactive or neuroleptic medicines and typically used to treat psychotic disorders such as schizophrenia, these medicines may help reduce autism symptoms such as irritability, repetitive and self-harming behaviors, and tantrums, while minimizing withdrawal and aggression. Two second-generation (or atypical) antipsychotics approved by the U.S. Food and Drug Administration (FDA) for use in children with ASD include:

  • Aripiprazole for children aged 6 to 17
  • Risperidone for children aged 5 and older

Some first-generation (or typical) antipsychotic medicines may also be prescribed off-label for severe behavioral symptoms. Prescribing off-label means an HCP is prescribing a medicine for a purpose that hasn’t been approved by the FDA as specified on the medicine’s product label. It's a common and often effective practice.

Examples of typical antipsychotics prescribed off-label for behavioral issues associated with autism include chlorpromazine, haloperidol, and fluphenazine. These are prescribed with great caution due to a higher risk of long-term side effects, including a condition that causes involuntary body and facial movement called tardive dyskinesia.

Antidepressants for autism

Some antidepressants may be used to treat conditions that coexist with autism, such as depression, OCD, and anxiety. Selective serotonin reuptake inhibitor (SSRI) antidepressants may also decrease the frequency and intensity of repetitive behaviors, improve eye contact, and reduce anxiety, irritability, tantrums, and aggression.

The FDA has approved the following selective SSRIs for use in children or teens:

  • Escitalopram for depression in children aged 12 and older
  • Fluoxetine for depression in children aged 8 and older
  • Fluvoxamine for OCD in children aged 8 and older
  • Sertraline for OCD in children aged 6 and older

Serotonin and norepinephrine reuptake inhibitors (SNRIs) may also be prescribed, although not as often as SSRIs. For instance, the SNRI duloxetine is an FDA-approved treatment for anxiety in children and teens.

Tricyclic antidepressants (TCAs) can also treat depression and OCD but may also be prescribed off-label to improve behaviors such as hyperactivity and irritability. TCAs are the oldest type of antidepressants but are prescribed less often due to a higher risk of side effects and overdose. Examples of TCAs used in people with autism include amitriptyline, clomipramine, and desipramine.

When other antidepressants, such as SSRIs, aren’t effective or can’t be taken due to side effects, other antidepressants may be considered such as the:

  • Norepinephrine/dopamine-reuptake inhibitor (NDRI) bupropion, which is FDA-approved to treat depression in adults, but may be prescribed off-label for depression and ADHD in children
  • Serotonin partial agonist reuptake inhibitor (SPARI) vilazodone, which is FDA-approved as a treatment for depression in adults but may be prescribed off-label for depression and anxiety in children
  • Tetracyclic antidepressant (TeCAs) mirtazapine, which is FDA-approved to treat depression in adults, but may be prescribed off-label for depression in children

Anticonvulsants for autism

Also called seizure medicines, anticonvulsants may be prescribed for a person with ASD who also has a seizure disorder such as epilepsy. Examples of anticonvulsants prescribed for seizures include:

  • Carbamazepine
  • Clonazepam
  • Diazepam
  • Divalproex
  • Lamotrigine
  • Levetiracetam
  • Oxcarbazepine
  • Phenytoin
  • Topiramate
  • Valproic acid

Stimulants for autism

It’s common for people with autism to have ADHD, both of which can produce overlapping symptoms such as hyperactivity, inattention, and impulsivity. As such, ADHD medicines such as stimulants might be prescribed when people have both conditions.

Examples of stimulants used for coexisting ADHD and ASD include:

  • Methylphenidate (more commonly known by its brand name Ritalin), which is FDA-approved for treatment of ADHD in children aged 6 and older
  • Mixed amphetamine salts (more commonly known by its brand name Adderall), which is FDA-approved to treat ADHD in children aged 3 and older

Extended-release versions of these medicines, such as methylphenidate HCL, are also available. The challenge lies in finding a stimulant that’s effective with side effects that are tolerable to the person with ASD and that doesn’t make symptoms worse. Worsening symptoms may be an issue for some people, as some stimulants such as methylphenidate and methylphenidate HCL have been known to cause irritability and exacerbate aggressive behaviors.

Melatonin to treat sleep disturbances in people with ASD

Sleep disturbances (such as insomnia, delayed sleep onset, and excessive daytime sleepiness) are common in people with autism. The lack of quality sleep can worsen ASD symptoms such as aggressiveness, self-harm, hyperactivity, inattention, repetitive behaviors, and problems with sociability. To help with sleep issues such as insomnia, the person’s HCP might recommend an over-the-counter sleep supplement such as melatonin.

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When to see a healthcare provider for autism

If you suspect your child may have ASD, be sure to discuss your concerns with your child’s HCP. Although autism symptoms tend to appear early in life, when and how these symptoms first manifest and progress can vary.

Some signs and symptoms of autism may be subtle and easily missed and not every sign will be present in every child. Moreover, some children may show a few of the characteristics of ASD without actually having the disorder.

Consider having your child evaluated by their HCP if at any point you have concerns about ASD or if you notice the following signs:

  • By 6 months old they make little to no eye contact or share few if any big smiles and other warm and happy expressions
  • By 9 months old they don’t mimic sounds or facial expressions
  • By 12 months old they babble, coo, gesture (such as pointing, reaching, showing, or waving) only a little or not at all
  • By 16 months old, they say few if any single words
  • By 24 months old, they say few if any meaningful and spontaneous two-word phrases (without imitating or repeating)

It’s also important for your child to see their HCP at any age if they:

  • Lose language or social skills they previously developed, or if their language development is delayed
  • Avoid eye contact
  • Prefer to play or be alone
  • Find it hard to understand or relate to other people’s feelings
  • Repeat the same words or phrases (echolalia)
  • Resist changes to their routine or surroundings (for example, if even minor changes cause distress)
  • Show restricted interests or are intensely focused on a few topics, activities, or hobbies
  • Self-stimulate when they’re anxious, upset, excited, or happy
  • Are hyperresponsive or hyporesponsive (overrespond or under respond) to various types of sensory input (such as colors, lights, smells, sounds, tastes, and textures)

Questions to ask your child’s healthcare provider

If your child is diagnosed with autism, it’s a good idea to ask your child’s HCP any questions you might have about the disorder. Examples include:

  • What signs, symptoms, or behaviors support your diagnosis?
  • Can you explain the screening tests that were used to diagnose my child? How did they do on these tests?
  • Will other evaluations be needed to confirm the diagnosis or help with planning treatment?
  • Which autism treatments do you recommend for my child and why?
  • Will treatment include medication? If so, how long do they need to take it?
  • How often will my child need to attend therapy sessions?
  • Will insurance cover all my child’s therapy sessions and visits with specialists?
  • Is my child eligible for government aid?
  • What level of support will my child need at home, school, and in the community?
  • Will my child require special assistance at school? Do they need to be enrolled in a special education program?
  • Will my child be able to participate in activities such as sports, music, and arts classes?
  • Are there any lifestyle changes that complement my child’s autism treatment plan?
  • Will my child eventually develop enough socially to function independently?
  • Can you recommend any community resources for people with autism and their family members?
  • Are there support groups for people with ASD and their family members?
  • Do you have any recommendations or resources for explaining the autism diagnosis to my child?
  • Where can I get additional credible information about autism?

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What is the outlook for people with autism?

Because people can experience ASD differently, it’s difficult to predict how their lives will proceed. Some people will require intense support, whereas others with autism spectrum disorder will learn to live and thrive independently.

Early diagnosis and intervention for autism can have long-term positive effects on symptoms and life skills. These early intervention programs may include:

  • Parent/family training to support and teach families how to care for and work with children on the spectrum
  • Hearing impairment services
  • Nutrition services
  • Speech, occupational, and physical therapy services

ASD interventions can start before or around preschool age, as early as 2 to 3 years old (although the average age of diagnosis is still over 4 years old). A young child’s brain is more “plastic” during this age range, meaning it’s still forming and more likely to be malleable compared to older children and adults. Brain plasticity raises the likelihood that autism treatments will be successful over the long term.

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Living with autism

Mixed group of children and teens with autism prepare for a team match by joining together in a huddle

Living with autism spectrum disorder may be challenging and stressful for the person and their family members. Although getting the proper treatments and support services can greatly benefit people with ASD, the following tips may help people and their family manage the disorder:

  • Keep all appointments with their HCP.
  • Work closely with members of the person’s healthcare team and be sure you understand the purpose of each of the interventions recommended and provided.
  • Tell others who need to know about the person’s ASD (and associated conditions), which includes working with the person’s HCP and schools to develop and implement their educational plan and modify it as needed.
  • Check for educational resources for your child, including talking with their teacher or school principal.
  • Be sure the person wears a medical alert bracelet or necklace in case they wander and can’t communicate their needs. Have them carry an emergency form that includes key contact information and communication symbols they can understand.
  • Reach out for support from local community services, which might include speaking with a trusted spiritual advisor, getting mental health counseling, or joining a support group.
  • Connect with other parents, caregivers, or family members who have a loved one with autism.
  • Take mental and physical breaks from caring for your loved one as needed, which includes allowing trusted friends and other family members to temporarily take over care. Consider accessing the National Respite Network to help find local respite care services.

Autism and exercise

It’s important for people with ASD to get regular physical activity as much as possible. In addition to the physical health benefits, exercise helps improve:

  • Communication skills and provides opportunities for social interaction
  • Muscular strength and endurance, which allows people to engage in socially oriented activities such as recreational sports and games
  • Balance, body coordination, visual-motor control, and other mobility skills

Tips to promote regular physical activity in people with autism include:

Starting small, building up, and making activity part of their routine: Encourage shorter periods of physical activity at first, with chunks of activity spaced throughout the day. Try:

  • Walking the dog or walking to school or work (or at least part of the way)
  • Getting active as a family when TV commercials play or between episodes, using break times for brisk activities such as jumping jacks or pushups
  • Walking together to the park or playground after meals

Because people on the spectrum often prefer to keep routines, aim to build a regular and predictable structure into their daily physical activity program.

Building motor skills: Make these skill-building activities fun by encouraging the person to:

  • Vary movements such as by hopping, jumping, running, or skipping
  • Play with various equipment such as balls, bats, gloves, and racquets, which give them the chance to throw, catch, kick, and strike

Trying different types of physical activity: Examples include playing table tennis, swimming, riding bikes or horses, or jumping on the trampoline. Try to encourage activities that support fitness, social interaction (such as tennis), and independence (such as yoga, perhaps by following a yoga class on video).

Modeling the activity and engaging friends and family: Be a role model for your loved one, which includes being physically active on a regular basis yourself. Use visual aids such as task cards and live or video demonstrations to help them learn these activities.

Getting in touch with organizations that run recreational sports programs: In some cases, you may need to share insight with organization members on how to communicate, motivate, and teach your loved one about these activities. Some organizations might be geared toward people with special needs and may already know how to employ these strategies.

Autism and nutrition

Repetitive and restrictive behaviors along with sensory issues can affect eating habits and food choices. People with ASD may only eat a limited selection of foods or may be overly sensitive to the color, smell, taste, or texture of certain foods. These might include a strong dislike for certain nutrient-rich foods such as some fruits and vegetables or foods they find too soft or slippery.

As a result, they may not eat enough calories or be deficient in certain nutrients. They may also get constipated, especially if they don’t get enough fluids, fiber, or physical activity.

Some medicines taken to manage autism symptoms may also affect appetite. Stimulants can decrease appetite, which can affect growth and development.

Other medicines used with ASD can increase appetite and the absorption of various vitamins and minerals. Be sure to discuss these and other medication side effects with the person’s HCP, and what you might do to manage them.

The Academy of Nutrition and Dietetics recommends these strategies to help bolster nutrition in people with ASD:

Prepare for pickiness. Try tackling sensory issues outside of the kitchen, which may include having the person accompany you to the grocery store to choose a new food. If possible, learn more about the food when you get home, including how it grows, by doing research together on the internet.

Decide together how to prepare the food and encourage them to participate in making it. Don’t stress if your child doesn’t want to eat it afterwards. Getting familiar with new foods in a low-pressure, positive way may help them eventually become a more flexible eater.

Make mealtimes routine. Making meals as predictable and routine as possible and serving meals around the same times each day can ease anxiety and stress for people with ASD. Let them pick a favorite food to include with each meal, too.

You may also need to adjust the environment to make mealtimes less stressful. For instance, if someone with ASD is sensitive to lights or sounds, turn these down. Or let them choose where to sit at the table.

Seek guidance from a registered dietitian nutritionist (RDN). Be sure to consult with an RDN before making significant changes to the person’s meal plan, as some of these changes might lead to side effects and nutrient deficiencies. An RDN can also help determine any nutritional risks based on how your loved one eats and answer questions you might have about the safety and effectiveness of various eating plans, nutrition therapies, and supplements. An RDN can help you develop a healthful eating plan or share sample menus that support the nutritional needs of people with autism.

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Why is autism awareness important?

The United Nations has declared April 2 each year World Autism Awareness Day to help people with ASD live full and meaningful lives as integral members of society. Autism awareness offers a variety of benefits:

  • Helps boost self-acceptance, confidence, and mental health for people with autism
  • Helps people with autism feel included and valued and less isolated and misunderstood
  • Helps people with autism gain access to necessary treatments (including early interventions for ASD) and the support they need at home, school, work, within their communities, and in other facets of their lives
  • Helps people with autism become better integrated into their communities and expands their continuing education and job opportunities

Autism awareness also increases the public’s understanding and embrace of people with ASD. It also makes it less likely that they’ll make assumptions or believe stereotypes and misinformation about people with the disorder. This supports inclusivity within society and helps people with ASD and their families feel supported and empowered.

What can be done to increase autism awareness?

Do what you can to increase your understanding of autism. Steps might include:

  • Attending an autism awareness event to learn more about the disorder and to show your support for people living with ASD
  • Supporting the work of nonprofit autism organizations, which may include making donations to help fund further research that advances understanding and treatments for ASD
  • Talking with your friends and family about autism, and sharing what you’ve learned about how it can affect people’s lives
  • Volunteering your time with ASD organizations, whether fundraising, helping to plan events, or providing respite care

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Featured autism articles

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Aishworiya R, Valica T, Hagerman R, Restrepo B. An update on psychopharmacological treatment of autism spectrum disorder. Neurotherapeutics. 2022;19(1):248-262.

Altogether Autism. Strengths and Abilities in Autism. Accessed August 16, 2023.

American Academy of Pediatrics. Developmental Surveillance and Screening. Last updated November 14, 2022.

American Academy of Pediatrics. Screening Tool Finder. Accessed July 7, 2023.

American Autism Association. Diagnosis for Autism Spectrum Disorder as an Adult. Published July 28, 2020.

American Autism Association. What Is Autism? Accessed July 7, 2023.

American College of Obstetricians and Gynecologists. Tobacco, Alcohol, Drugs, and Pregnancy. Last reviewed December 2021.

American Psychiatric Association. What Is Autism Spectrum Disorder? Accessed June 29, 2023.

Ansel K. Nutrition for Your Child With Autism Spectrum Disorder (ASD). Published April 1, 2022.

Autism Research Institute. Screening & Assessment. Accessed June 28, 2023.

Autism SA. What Is the Difference Between Autism and Asperger’s? Accessed July 7, 2023.

Autistic Self Advocacy Network. About Autism. Accessed August 16, 2023.

Autistic Self Advocacy Network. What We Believe. Our Motto: What is “Nothing About Us Without Us”? Accessed August 17, 2023.

Centers for Disease Control and Prevention. Accessing Services for Autism Spectrum Disorder. Last reviewed March 10, 2022.

Centers for Disease Control and Prevention. ASD, Digestive Issues, and Pica. Last reviewed April 7, 2022.

Centers for Disease Control and Prevention. Autism and Developmental Disabilities Monitoring (ADDM) Network: Data & Statistics on Autism Spectrum Disorder. Last reviewed April April 4, 2023.

Centers for Disease Control and Prevention. Diagnostic Criteria. Last reviewed November 2, 2022.

Centers for Disease Control and Prevention. Autism and Vaccines. Last reviewed December 1, 2021.

Centers for Disease Control and Prevention. Key Findings: CDC Releases First Estimates of the Number of Adults Living with Autism Spectrum Disorder in the United States. Last reviewed April 7, 2022.

Centers for Disease Control and Prevention. Measles Cases and Outbreaks. Last reviewed June 9, 2023.

Centers for Disease Control and Prevention. Screening and Diagnosis of Autism Spectrum Disorder. Last reviewed March 31, 2022.

Centers for Disease Control and Prevention. Screening and Diagnosis of Autism Spectrum Disorder for Healthcare Providers. Last reviewed December 6, 2022.

Centers for Disease Control and Prevention. Signs and Symptoms of Autism Spectrum Disorder. Last reviewed March 28, 2022.

Centers for Disease Control and Prevention. Symptoms and Diagnosis of ADHD. Last reviewed August 9, 2022.

Centers for Disease Control and Prevention. Treatment and Intervention Services for Autism Spectrum Disorder. Last reviewed March 9, 2022.

Centers for Disease Control and Prevention. What Is Autism Spectrum Disorder? Last reviewed December 9, 2022.

Child Mind Institute. The Controversy Around ABA: Why Some Parents and Advocates Find Fault With the Therapy. Last reviewed/updated January 31, 2023.

Children’s Hospital of Philadelphia Research Institute. Diagnostic Criteria for Autism Spectrum Disorder in the DSM-5. Last updated June 9, 2020.

Children’s Hospital of Philadelphia Research Institute. What Questions Should I Ask After an Evaluation? Last updated June 18, 2020.

Cleveland Clinic. Autism Spectrum Disorder. Last updated February 26, 2023.

Cope R, Remington A. The Strengths and abilities of autistic people in the workplace. Autism Adulthood. 2022;4(1):22-31.

Dietz PM, Rose CE, McArthur D, Maenner M. National and state estimates of adults with autism spectrum disorder. J Autism Dev Disord. 2020;50(12):4258-4266.

Duchan D. The Applied Behavior Analysis Controversy: Normalizing or Cruel? Nursing Clio. Published May 5, 2022.

Eunice Kennedy Shriver National Institute of Child Health and Human Development. Early Intervention for Autism. Last reviewed April 19, 2021.

Eunice Kennedy Shriver National Institute of Child Health and Human Development. Medication Treatment for Autism. Last reviewed April 19, 2021.

Galli J, Loi E, Visconti LM, et al. Sleep disturbances in children affected by autism spectrum disorder. Front Psychiatry. 2022;13:736696.

General Medical Council. Fitness to Practice Panel Hearing. Published January 28, 2010.

GI Society: Canadian Society of Intestinal Research. Andrew Wakefield’s Harmful Myth of Vaccine-induced “Autistic Enterocolitis.” Accessed August 17, 2023.

Groen Y, Priegnitz U, Fuermaier ABM, et al. Testing the relation between ADHD and hyperfocus experiences. Res Dev Disabil. 2020;107:103789.

Hatch B, Kadlaskar G, Miller M. Diagnosis and treatment of children and adolescents with autism and ADHD. Psychol Sch. 2023;60(2):295-311.

Hyman SL, Levy SE, Myers SM; COUNCIL ON CHILDREN WITH DISABILITIES, SECTION ON DEVELOPMENTAL AND BEHAVIORAL PEDIATRICS. Identification, evaluation, and management of children with autism spectrum disorder. Pediatrics. 2020;145(1):e20193447.

Kim JY, Choi MJ, Ha S, et al. Association between autism spectrum disorder and inflammatory bowel disease: A systematic review and meta-analysis. Autism Res. 2022;15(2):340-352.

Leader G, Abberton C, Cunningham S, et al. Gastrointestinal symptoms in autism spectrum disorder: A systematic review. Nutrients. 2022;14(7):1471.

Maurer JJ, Choi A, An I, Sathi N, Chung S. Sleep disturbances in autism spectrum disorder: Animal models, neural mechanisms, and therapeutics. Neurobiol Sleep Circadian Rhythms. 2023;14:100095.

MedlinePlus. Autism Spectrum Disorder. National Library of Medicine. Last updated October 21, 2021.

Merck Manual Consumer Version. Quick Facts: Autism. Last updated September 2022.

Miller C. Medication for Kids With Depression. Child Mind Institute. Last reviewed or updated July 26, 2022.

Mugai S, Faizy RM, Saadabadi A. Autism Spectrum Disorder. StatPearls [Internet]. Last updated July 19, 2022.

National Institute of Mental Health. Autism Spectrum Disorder. Last reviewed February 2023.

Nationwide Children’s Hospital. What Is Asperger’s Syndrome? Accessed July 7, 2023.

NHS. Other Conditions That Affect Autistic People. Last reviewed October 4, 2022.

NHS Inform. Autism Spectrum Disorder (ASD). Last updated February 9, 2023.

Ozsahin I, Mustapha MT, Albarwary S, Sanlidag B, Ozsahin DU, Butler TA. An investigation to choose the proper therapy technique in the management of autism spectrum disorder. J Comp Eff Res. 2021;10(5):423-437.

Pepperdine Graduate School of Education & Psychology. Debunking 7 Common Myths About ABA Therapy. Published August 29, 2022.

Sefen JAN, Al-Salmi S, Shaikh Z, AlMulhem JT, Rajab E, Fredericks S. Beneficial use and potential effectiveness of physical activity in managing autism spectrum disorder. Front Behav Neurosci. 2020;14:587560.

Sulkes SB. Autism Spectrum Disorders. Merck Manual Consumer Version. Last updated September 2022.

The Spectrum. What Is the Difference Between Asperger’s and Autism? Accessed July 7, 2023.

Toscano CVA, Ferreira JP, Quinaud RT, Silva KMN, Carvalho HM, Gaspar JM. Exercise improves the social and behavioral skills of children and adolescent with autism spectrum disorders. Front Psychiatry. 2022;13:1027799.

United Nations. World Autism Awareness Day 2 April: Background. Accessed June 28, 2023.

Vahabzadeh A. Expert Q&A: Autism Spectrum Disorder. American Psychiatric Association. Accessed June 29, 2023.

World Health Organization. Autism. Last updated March 29, 2023.

World Health Organization. ICD-11 for Mortality and Morbidity Statistics: 6A02 Autism Spectrum Disorder. Last updated January 1, 2023.

Yu Y, Ozonoff S, Miller M. Assessment of autism spectrum disorder. Assessment. 2023;10731911231173089.

Zeidan J, Fombonne E, Scorah J, et al. Global prevalence of autism: A systematic review update. Autism Res. 2022;15(5):778-790.

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