Unipolar Depression & Bipolar Depression Differences

Medically reviewed by Karen Foster, LPC
Updated April 19, 2024by BetterHelp Editorial Team

Depression is a complex mental health disorder that encompasses several different conditions, including major depression, also known as unipolar depression. Depression also exists in other mood disorders, such as bipolar I disorder and bipolar II disorder.

The difference between unipolar and bipolar depression is significant. While unipolar depression is primarily characterized by depressive lows, bipolar disorder is marked by both depressive and manic symptoms. The most significant difference that differentiates bipolar depression is the presence of mania, also known as manic or hypomanic episodes. These episodes often lead to elevated mood, excitability, and other highs that aren’t typically present in major depression.

In this article, we will give you an overview of these two disorders, describe depression, and discuss their differences in detail, including the common symptoms and diagnostic criteria from The Diagnostic and Statistical Manual of Mental Disorders.

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Depression symptoms: Unipolar and bipolar

Before discussing the difference between unipolar depression and bipolar disorder, we're going to provide an overview of the conditions. While the depressive symptoms are similar between the two, there are also some differences that we'll discuss later. A major depressive episode is characterized by a persistent feeling of sadness or irritable mood for at least two weeks, along with other symptoms such as tiredness loss of interest, and guilty or intense feelings. The most important overall distinction to keep in mind is that bipolar disorder includes mood episodes with manic symptoms that are not typically present in major depression. The risk of both disorders may increase when an individual has a family history of mental health conditions. For example, those with a family history of bipolar disorder may be at a higher risk for both unipolar depression and bipolar disorder.

Unipolar depression

Unipolar depression, more commonly known as major depressive disorder or major depression, is characterized by The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria that focus on one prolonged mood episode at the depressive pole, without moving between highs and lows. The major symptom of unipolar depression is a persistent feeling of sadness, along with other symptoms associated with low mood.

According to The Diagnostic and Statistical Manual of Mental Disorders, the symptoms of unipolar depression include the following:

  • Feeling sad
  • Loss of interest in activities for an extended time
  • Irritability
  • Sudden weight loss or lack of appetite
  • Trouble concentrating
  • Disruptions in sleep
  • Lack of energy
  • Guilty intense feelings
  • Suicidal or morbid thoughts

If you or someone you know is experiencing suicidal thoughts, help is available. The 988 Suicide & Crisis Lifeline can be reached 24/7 by chatting with a representative or calling or texting 988.


Usually, for a unipolar depression diagnosis, symptoms need to have persisted for two weeks and represent a departure from how the individual felt before the major depressive episode. 

Bipolar disorder depression

Bipolar disorder is a mental health condition in which an individual experiences fluctuations in mood, from depressive lows to manic highs. The lows also known as bipolar depression, are characterized by symptoms that are present in many depressive disorders, including unipolar depression. The highs, referred to as manic episodes, are characterized by feelings of elation, high energy, and pleasure-seeking behavior that are very different from symptoms of a depressive episode. In certain forms of bipolar disorder, less severe manic episodes, called hypomania, can occur. There are three different types of bipolar disorder, each with specific criteria: 

  • Bipolar I – includes manic episodes that last for seven days or more and depressive episodes that last for two weeks or more.
  • Bipolar II – includes hypomanic episodes that last for four days or more and depressive episodes that last for two weeks or more.
  • Cyclothymic disorder – includes symptoms of mania and depression that persist but do not rise to the level required for a bipolar II diagnosis.

Symptoms of manic episodes include:

  • Feelings of hopefulness and elation
  • Talking and thinking rapidly
  • High energy levels
  • Disrupted sleep patterns
  • Taking more risks
  • Increased sense of self-importance
  • Irritability
  • Experiencing hallucinations

Symptoms of depressive episodes include:

  • Feelings of sadness and hopelessness
  • Lack of energy
  • Loss of interest in activities
  • Difficulties with concentration
  • Disrupted sleep patterns
  • Fluctuations in weight
  • Slow movement and speech
  • Suicidal thoughts

Unipolar depression vs bipolar depression

The most significant difference between bipolar disorder and unipolar depression is the presence of manic episodes in bipolar disorder. But are symptoms of depression experienced during depressive episodes of bipolar disorder similar to those experienced during major depression? There is some debate in the scientific community as to whether depression manifests itself differently in the two disorders, potentially due to previously functioned diagnostic criteria or the influence of medical conditions on symptoms. However, an unusual sense of similarity in depressive symptoms across both unipolar and bipolar disorders remains a topic of interest. 

Research shows that the existence of manic symptoms can affect how depressive episodes of bipolar disorder look compared to unipolar depression. Notably, people with bipolar disorder can experience mixed episodes—in which symptoms of both depressive and manic episodes are present—that can make the depression aspect of the disorder look different than unipolar depression.

There is also evidence that depressive episodes of bipolar disorder are more often characterized by dysregulation, or difficulty managing emotional responses. This can make it more difficult to react in a healthy way when one experiences external stressors (e.g., divorce, car accident, loss of job). Additionally, studies show that individuals who live with unipolar depression experience more anxiety than those who live with bipolar depression.

Further research has shown that the slowing of thoughts, speech, and movement commonly exhibited by those with depression may be more pronounced in depressive episodes of bipolar disorder than in major depression. Those who live with bipolar disorder may also have more psychotic symptoms during depressive episodes, including hallucinations and loss of touch with reality. Additionally, bipolar depression may produce more frequent sleep disturbances and mood changes early in the morning. The fact that there are also three different types of bipolar disorder adds further complexity to the distinctions between the two conditions. 

Want to learn more about different mental health disorders?

Unipolar depression and bipolar depression treatment

Bipolar disorder and unipolar depression have many of the same methods of treatment, though there are some important differences as well. The first-line treatment for both disorders is often a combination of medication and therapy, typically cognitive behavioral therapy (CBT). 

Cognitive behavioral therapy

The most widely used form of psychotherapy is cognitive behavioral therapy. CBT works by helping individuals identify and replace negative thought patterns that could lead to maladaptive feelings and behaviors, such as those often exhibited in mood disorders such as bipolar disorder and unipolar depression. 

In a meta-analysis of studies on the effectiveness of CBT for bipolar disorder, researchers found that treatment can improve symptoms, help participants adhere to treatment, and enhance quality of life. The review specifically noted the efficacy of therapy in conjunction with medication, which is a common combination for those with unipolar and bipolar depression.

Another meta-analysis, which combined findings from 115 studies, concluded that CBT is also beneficial for symptoms of major depression, with researchers stating that there’s “no doubt that CBT is an effective treatment for adult depression.” 


Medication for both bipolar disorder and unipolar depression will often include an antidepressant to address depressive symptoms. Common antidepressants for those who experience bipolar and unipolar symptoms include:

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Serotonin and norepinephrine reuptake inhibitors (SNRIs)
  • Monoamine oxidase inhibitors (MAOIs)
  • Tricyclic antidepressants (TCAs)
  • Serotonin antagonists and reuptake inhibitors (SARIs)

Medication for bipolar disorder can be more complicated as it often needs to address both manic and depressive symptoms. Sometimes a combination of medications is necessary to ensure symptoms of one episode are not brought on by medication meant to address the other. Common medications for bipolar disorder include:

  • Mood stabilizers
  • Antipsychotics
  • Antidepressant-antipsychotic

The information in this article is not intended to be used as medical advice. Always consult with a medical professional before starting or stopping medication. 

Navigating mental health disorders with therapy

There is a large body of evidence pointing to online therapy as a useful method of treating mental health conditions like bipolar disorder and unipolar depression. In a wide-ranging analysis of peer-reviewed articles, researchers found that online therapy platforms, through both web- and smartphone-based treatment, could help individuals manage symptoms of bipolar disorder. The review specifically noted that online therapy could promote education, hopefulness, and a proactive approach to treatment. 

Online therapy can provide you with clarity when it comes to navigating complex mental health concerns. Working with a licensed therapist at BetterHelp, you can learn about and manage symptoms of unipolar depression and bipolar disorder. With BetterHelp, you can get care remotely, through video call, voice call, or in-app messaging. Additionally, you’ll have the option of reaching out to your mental health professional outside of sessions. If you’re experience symptoms of a manic or depressive episode—or have other concerns that you’d like to relay as soon as they arise—you can send your therapist a message, and they will respond when they’re able. 

A qualified professional can help you process emotions related to major depression, bipolar disorder, or other mental health conditions. Read below for reviews of BetterHelp therapists from those who have sought help for similar concerns in the past.

Therapist reviews

"Dr. Love has been great in helping me through a rough patch in life and helping me manage my bipolar disorder. She's kind, responsive, and down-to-earth. She makes talking with her comfortable and easy. Talking with her has been one of the best decisions I've made in a long time."

"Tim has given me some amazing insights to contemplate. He has offered me different ways of viewing my problems and approaching them. He has given me concrete tools to use to manage my stress and improve my depression. He is incredibly responsive and helpful. I'm blown away by how much I like this platform and how helpful Tim has been."

While bipolar disorder and unipolar depression have many symptoms, the two conditions differ in important ways. One important characteristic that both disorders have, however, is their treatability. If you’re living with symptoms commonly associated with major depression, bipolar disorder, or another concern, consider connecting with a licensed therapist online. You deserve thorough, supportive care as you take the next step on the path toward improved mental well-being.
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