Unipolar depression: what is it?

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Robert Roy Britt 

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Robert Roy Britt 

last updated: Apr 23, 2021

3 min read

Unipolar depression is another name for major depressive disorder (MDD), a condition characterized by periods of intense sadness. Often, the term unipolar depression is used to distinguish the condition from bipolar depression, in which a person goes through a stark mix of depressing lows and manic highs that come in waves. Unipolar depression is common, affecting about 10% of adults in the United States in a given year, and some 21% at some point in their lives (Hasin, 2018). There are treatment options available for unipolar depression, and they include things like cognitive-behavioral therapy (CBT), medications, and more.


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Symptoms of unipolar depression

Unipolar depression is more than just being sad or blue for a few days. The symptoms of unipolar depression often affect a person's ability to function on a day-to-day basis, affecting sleep, eating habits, cognitive function, and performance in work or school.A diagnosis of unipolar depression, or MDD, is made if a person has at least five of the following symptoms for at least two consecutive weeks (American Psychiatric Association, DSM-5, 2013):

  • Sadness or depressed mood most of the day

  • Loss of interest or pleasure in normal activities

  • Weight gain or loss

  • Poor sleep or oversleeping

  • Fatigue or loss of energy

  • Pacing, fidgeting, or other purposeless activity

  • Slowed movement or speech

  • Guilt or a sense of worthlessness

  • Difficulty thinking, concentrating, or making decisions

  • Recurring thoughts of death or suicide

Clinical depression can make it difficult to manage these symptoms and might lead a person to feel a sense of self-loathing.

Unipolar vs. bipolar depression

The depressive symptoms of unipolar depression and the depression associated with the lows of bipolar disorder are essentially the same. But while unipolar depression is characterized by just lows, bipolar disorder causes periodic swings from similar lows and sadness to feelings of extreme elation or excitement. People in the upswings of bipolar disorder, also known as manic phases, may feel like they can do anything (even things that are dangerous) or may spend large sums of money or engage in risky behavior. The feelings of elation can also suddenly turn to confusion, or even anger.

Highs can come with extreme irritability for some people, and there can be stretches of feeling more balanced between the upswings and downswings. There's no universally set cycle, and some people will experience highs and lows at the same time (Jain, 2021). 

As opposed to unipolar disorder, bipolar disorder is marked by more short-term mood changes. Most people with bipolar disorder spend more time in the depressed phase than the manic phase (Tondo, 2017). 

While unipolar depression can emerge at any point in life, bipolar disorder typically shows up during teen years or early adulthood. There are two main types (American Psychiatric Association, 2013):

  • Bipolar I: Manic episodes last at least a week or are so severe that hospitalization is required. Depressive stretches typically last two weeks, and symptoms of the manic and depressive phases sometimes overlap.

  • Bipolar II: Similar cycles, but manic episodes are not full blown and are referred to as hypomanic episodes.

Some people experience a third variation marked by longer cycles, lasting two years or more, with less severe symptoms.Because both unipolar and bipolar depression are characterized by periods of depression, some people are initially diagnosed with unipolar depression (MDD) and then may later experience a manic episode, resulting in a change in their diagnosis from unipolar to bipolar depression. This misdiagnosis can lead to many patients receiving the wrong treatments (Rosenberg, 2017).If you are experiencing symptoms of depression and your healthcare provider suspects that you have major depressive disorder, it's important to mention any periods of extreme elation that you've experienced in the past so your provider can give you the best treatment available.

Treatments for unipolar depression

Treatments for unipolar and bipolar depression are similar in some respects and often include a combination of medication and talk therapy. Sometimes cognitive behavioral therapy can help a person acknowledge negative thoughts and behaviors and try to change them. 

While people with unipolar depression often benefit from antidepressants, someone with bipolar disorder usually needs mood stabilizers or antipsychotic drugs (such as olanzapine, risperidone) as well. Bipolar disorder is a lifelong condition requiring continued treatment. Healthcare providers often prescribe antidepressant medication to treat depressive episodes in bipolar disorder, and combine that drug with a mood stabilizer to prevent triggering a manic episode (NIH, n.d.). The gold standard treatment for bipolar disorder is a mood stabilizer called lithium, and some studies have found that 50%-70% of people treated with lithium have reduced symptoms of mania (Jain, 2021).

While mental health is a spectrum and symptoms of various conditions can differ from person to person, any changes in your mood or emotional welbeing that are making it difficult for you to function on a daily bases are a good reason to seek professional help.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

April 23, 2021

Written by

Robert Roy Britt

Fact checked by

Felix Gussone, MD

About the medical reviewer

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.