Bipolar disorder, which is also known as manic-depressive disorder, is a mental illness that causes extreme mood swings. These mood swings consist of emotional highs (manic or hypomanic episodes) and lows (depressive episodes). There are three main types of bipolar disorder: bipolar I, bipolar II, and cyclothymic disorder. People with bipolar disorder often experience decreased quality of life and overall functioning. Among all mental illnesses, bipolar disorder has the highest suicide rate.^[1][2][3]

People with bipolar I experience manic episodes. Common symptoms during manic episodes – which last ≥1 week – include an unusual increase in self-esteem, a decreased need for sleep, feeling unusually important, racing thoughts, increased energy, and risky behaviors (spending too much money, reckless driving, etc.).

People with bipolar II experience hypomanic episodes, which are milder symptoms of mania.

People with bipolar I and II experience depressive episodes. Common symptoms during depressive episodes – which last ≥2 weeks – include feeling sad or hopeless, losing interest in previously enjoyable activities, increased or decreased appetite, excessive fatigue, and suicidal thoughts.

There may also be mixed episodes where both manic and depressive symptoms co-occur.

People with cyclothymic disorder experience symptoms of both hypomanic and depressive episodes, but don’t meet the criteria for these episodes. ^[4][3]

A thorough evaluation by a mental health provider is required to identify bipolar disorder. Two commonly-used sets of diagnostic criteria are those in the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association, and the International Classification of Disease (ICD), published by the World Health Organization.

Treatment focuses on managing acute episodes (manic, hypomanic, and depressive) and on providing maintenance care to prevent acute episodes from recurring. A combination of medication and psychotherapy is often used.

Medications such as mood stabilizers, antipsychotics, and antidepressants are commonly used. However, antidepressants should not be used in people with a history of rapid cycling (≥4 acute episodes within a year).^[4][5]

Fish oil and N-Acetyl-Cysteine seem to be particularly helpful for depressive episodes.^[6][7] Coenzyme Q10, Folic acid, zinc, and probiotics also show some promise for treating bipolar disorder.^[7]

Numerous psychotherapy modalities, including cognitive behavioral therapy, family-focused therapy, interpersonal social rhythm therapy, and mindfulness, may be helpful in addition to medication. However, the form of psychotherapy chosen should be specific to the individual's unique needs.^[8][5]

People with bipolar disorder may also benefit from neuromodulation treatments such as Electroconvulsive Therapy (ECT) or repetitive Transcranial Magnetic Stimulation (rTMS). Although electroconvulsive therapy has shown to be an effective treatment, there is limited research on using rTMS.^[9]

Bright light therapy can also help reduce symptoms of depression in people with bipolar disorder.^[10]

According to observational studies, people with bipolar disorder are less likely to follow a Mediterranean dietary pattern and tend to consume less seafood. Some studies also found that diets rich in essential fatty acids correlate with improved symptoms of bipolar disorder. Because most of the research is observational, more rigorous studies are required to assess the relationship between diet and bipolar disorder.^[7]

The exact cause of bipolar disorder is unknown. It does, however, appear to be influenced by psychosocial, genetic, and biological factors.^[2]