Differences Between Bipolar Disorder and Major Depression

Bipolar disorder and major depression both cause depressive symptoms but are distinct conditions.

While the depressive episodes of bipolar disorder may cause symptoms that overlap with MDD, these are different conditions that require different approaches to treatment

Medically reviewed in December 2021

Bipolar disorder and major depressive disorder (MDD) are mood disorders that cause depressive symptoms. Both can be categorized as serious mental illnesses and can severely impact a person’s quality of life, overall health, and day-to-day functioning.

However, bipolar disorder and MDD are distinct conditions that require different approaches to treatment.

Here, we will look at the important difference between symptoms of MDD and symptoms of bipolar disorder.

Symptoms of MDD
MDD is also known as major depression and clinical depression. It is characterized by persistent feelings of sadness and a significant loss of interest in activities. It directly impacts how a person thinks, feels, and behaves.

Symptoms of MDD can include:

  • Feelings of hopelessness and despair
  • Lack of desire to participate in activities that used to be enjoyable or pleasurable
  • Sleeping too much or too little
  • Changes in appetite
  • Significant weight loss or weight gain
  • Inability to concentrate or make decisions
  • Physical pain unrelated to other health conditions
  • Thoughts of self-harm

To be diagnosed with MDD, symptoms must be present every day, for most of the day, for at least two consecutive weeks.

However, depression is a different experience for everyone. Symptoms can vary in intensity, how long they last, and how they impact a person’s life. Depression may also feel different on different days or at different times. Some days might be better than others, but depression causes moods to remain consistently low.

Symptoms of bipolar disorder
Bipolar disorder is defined by extreme shifts in mood. People with bipolar disorder also experience episodes of depression, with symptoms like those described above.

However, they also experience episodes of mania, or extreme emotional highs. Symptoms of mania can include:

  • Feelings of elation—described as feeling “high” or “wired”
  • Being unusually talkative and speaking more quickly than usual
  • Racing thoughts
  • Increased energy or agitation
  • Loss of appetite
  • Inflated sense of self-importance
  • Risky behaviors or lack of judgment

These episodes can affect energy levels, concentration, and a person’s ability to accomplish daily tasks. People with bipolar disorder may also experience episodes of hypomania, which refers to episodes of mania with less severe symptoms.

These extreme moods may not happen in a predictable cycle and can even be experienced at the same time, which is called a mixed state or an episode of mixed features. During these episodes, a person may have a lot of energy—but at the same time feel hopeless or sad.

Unlike bipolar disorder, people with MDD do not experience symptoms of mania.

Episodes can last for several hours, days, weeks, or even months. It’s also important to note that people with bipolar disorder can experience periods without symptoms of mania or depression.

Getting a diagnosis
While the depressive episodes of bipolar disorder may cause symptoms that overlap with MDD, it’s important to remember that these are different conditions that require different approaches to treatment—and getting the correct diagnosis is extremely important.

If you or a loved one have symptoms like those described above, your best source of information will be a healthcare provider, who can help you find out what is causing your symptoms and help you find an appropriate treatment plan.

Medically reviewed in December 2021.

Cedars Sinai. "Overview of Mood Disorders."
Johns Hopkins Medicine. "Mood Disorders."
T.S. Evans, N. Berkman, et al. "Disparities Within Serious Mental Illness." Agency for Healthcare Research and Quality, 2016. Technical Briefs, No. 25.
National Institute of Mental Health. "Bipolar Disorder."
American Psychiatric Association. "What is Bipolar Disorder?"
Cleveland Clinic. "Bipolar Disorder."
MedlinePlus. "Bipolar Disorder."
Word Health Organization. "Depression."
Laura Goldman. "What is depression and what can I do about it?" MedicalNewsToday. November 22, 2019.
National Alliance on Mental Health. "Depression."

Featured Content


Major Depressive Disorder Symptoms

A quick guide to understanding the symptoms of depression.

Caring for Yourself While Caring for Someone With Depression

Being a caregiver for someone with major depression can take its toll on you. Learn how avoid caregiver depression.

What Is Major Depressive Disorder?

Major depressive disorder is a serious mental illness that can impact every area of a person’s life and health.

Steps to Seeking Treatment for Major Depression

Three strategies for seeking treatment for this serious mental illness.

How to Recognize Major Depression in Loved Ones

Help a friend or family member by learning the signs of major depression.