What causes attention deficit hyperactivity disorder (ADHD)?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

The causes of attention deficit hyperactivity disorder (ADHD) are still not completely understood. The condition does seem to run in families and so is often thought to be inherited. Other factors, such as prenatal and childhood exposure to certain toxic substances like lead; brain injuries; smoking, drug, or alcohol use by expectant mothers; and low birth weight are also possible causes.

One of the first questions a parent will ask me is “What did I do wrong? Did I cause this?” There is no evidence that ADHD is caused by lapses in child rearing, reactions to vaccines, or giving in to countless requests for sugar-loaded cookies. I tell parents to forget their inner blame game and focus on finding the best possible way to help their child. Let researchers try to discover the cause for ADHD. And they’re trying hard. Scientists believe genetic and environmental factors may play a role, and studies show that many children with ADHD have a close relative who also has the disorder. Experts also know that kids with ADHD have chemical changes in their brain and that certain areas of the brain are about 5 to 10 percent smaller in size and activity than normal.

Other studies about the cause of ADHD point to links with smoking during pregnancy, premature delivery, very low birth weight, and injuries to the brain at birth. Some research suggests a link between excessive early TV watching and attention issues. (That’s one of the reasons the AAP says that children under two should not have any screen time, that means no computers, TV, DVDs, or video games, and that kids two and older should watch no more than one to two hours a day of nonviolent, quality TV.)

From The Smart Parent's Guide: Getting Your Kids Through Checkups, Illnesses, and Accidents by Jennifer Trachtenberg.

The Smart Parent's Guide: Getting Your Kids Through Checkups, Illnesses, and Accidents

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The Smart Parent's Guide: Getting Your Kids Through Checkups, Illnesses, and Accidents

What to Do When You Don't Know What to Do! "Moms and dads need expert guidelines, especially when it comes to their kids' health. This book reveals the inside strategies I use myself-I'm a parent, too!-to avoid critical, common blunders where it matters most: in the ER, pediatrics ward, all-night pharmacy, exam room, or any other medical hot spot for kids. These tips could save your child's life one day. Even tomorrow." -Dr. Jen Making health care decisions for your child can be overwhelming in this age of instant information. It's easy to feel like you know next to nothing or way too much. Either way, you may resort to guessing instead of making smart choices. That's why the nation's leading health care oversight group, The Joint Commission, joined forces with Dr. Jennifer Trachtenberg on this book: to help you make the right decisions, whether you're dealing with a checkup or a full-blown crisis. The Smart Parent's Guide will give you the information you need to manage the pediatric health care system. Dr. Jen understands the questions parents face—as a mom, she's faced them herself. She walks you through everything: from how to choose the best ER for kids (not adults) to when to give a kid medicine (or not to) to how pediatricians care for their own children (prepare to be surprised). Her goal is your goal: to protect the health of your children. There simply is nothing more important.

Doctors and scientists aren’t sure what causes attention deficit hyperactivity disorder (ADHD). What they do know is that in people with ADHD, the brain works differently than it does in people without the condition. This makes it hard for people with ADHD to behave exactly the way other people do. The other thing known for a fact is that living with ADHD is tough.

Dr. Iris M. Rodriguez-Ocasio, MD

80% of ADHD cases are thought to have a polygenic basis. Neuroimaging, neuropharmacology, and neurophysiology studies have shown that there is a probability of a biologic basis.

Constance Mofunanya, DNP
Pediatric Nursing Specialist

Attention deficit/hyperactivity disorder (ADHD) in children is a syndrome of inattention, hyperactivity and impulsivity. According to DSM-IV, there are 3 types of ADHD, predominantly inattentive, predominantly hyperactive-impulsive, and combine. The predominantly hyperactive-impulsive type occurs 2 to 9 times more in boys, but the predominantly inattentive type occurs with equal frequency in both boys and girls. ADHD is classified as a developmental disorder and is considered a disruptive behavior disorder. It is estimated that 3 to 10% of school agers are affected by ADHD. ADHD has no known single or specific cause. Possible causes include genetic, bio-chemical, sensorimotor, physiologic, and behavioral factors. Risk factors includes but not limited to, head trauma, birth weight less than 1000g, lead exposure, prenatal exposure to alcohol, cocaine and tobacco.

Despite extensive research, scientists still do not know what causes Attention Deficit Hyperactivity Disorder. Researchers, however, have ruled out some causes-such as a child's surrounding and upbringing.

Environmental factors may make a case of ADHD more pronounced, but do not cause the disorder.

Research has shown refined sugars and food additives have little or no effect on behavior.

There does seem to be a strong hereditary component to ADHD, and it is believed that prenatal exposure to alcohol and cigarettes may worsen the condition.

Continue Learning about ADD/ADHD Causes

What Causes Attention Deficit Hyperactivity Disorder (ADHD)?
What Causes Attention Deficit Hyperactivity Disorder (ADHD)?
Does Attention Deficit Hyperactivity Disorder (ADHD) Run In Families?
Does Attention Deficit Hyperactivity Disorder (ADHD) Run In Families?
Minimize Side Effects from ADHD Medications
Minimize Side Effects from ADHD Medications

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.