What is bipolar disorder?
Formerly known as manic depression, bipolar disorder is a chronic mood disorder that is characterized by dramatic shifts in mood, thinking patterns, energy levels, and behavior. Individuals with bipolar disorder will typically experience alternating periods of depression and periods of abnormally elevated mood, referred to as mania. These periods can last multiple days to multiple months, and often have periods of stable mood or euthymia in between. The symptoms of depressive and manic phases differs from person to person, and can vary over time. Episodes may not follow a set pattern, and individuals can experience the same mood state in between periods of euthymia multiple times before experiencing the opposite mood.
During depressive episodes, symptoms are similar to those of major depressive disorder. Individuals may experience persistent feelings of sadness, irritability, anhedonia, and changes in eating or sleeping habits. The first few episodes are more likely to be depressive if onset of the disorder occurs at an early age.
During manic episodes, individuals exhibit increased energy of psychomotor activity, resulting in a highly elevated or irritable mood. To be defined as a manic episode, behaviors must significantly impair the individual’s ability to work or socialize. Manic periods must last at least one week and often continue for three to six months when left untreated. In severe cases, psychotic symptoms may be present, including grandiose delusions that can sometimes lead to violent behavior.
Some forms of bipolar disorder feature a more mild form of mania known as hypomania. Hypomanic episodes last at least four days and consist of similar criteria as mania, but may not significantly interfere with the ability to work or socialize, and does not feature psychotic symptoms. Sometimes, overall functioning increases during hypomanic episodes; some individuals exhibit increased creativity, whereas others show poor judgment or irritability. Typically, individuals find it difficult to see the effects their actions have on those around them, and may often deny that anything is wrong even when confronted by family or friends.
In some cases, individuals experience mixed affective episodes. A mixed state features symptoms of both mania and depression occurring simultaneously, such as having grandiose thoughts while experiencing excessive guilt or feeling suicidal. Individuals who experience mixed states have a higher risk for suicidal behavior, as depressive emotions are often paired with mood swings or low impulse control. Mixed bipolar episodes also frequently occur with comorbid anxiety disorders.
Bipolar disorder affects about 1 percent of the global population. It often co-occurs with other mental disorders, including anxiety, substance use disorders, attention deficit hyperactivity disorder, and personality disorders. Some medical conditions are also more common in people with bipolar disorder, which may be partly related to health risks associated with treatment medications. This includes obesity, type 2 diabetes, migraine headaches, and metabolic syndrome. These contribute to a death risk that is two times higher in people with bipolar disorder compared to the general population.
