Bipolar disorder, previously known as manic depression, is a mental disorder that causes periods of depression and periods of abnormally elevated mood. The elevated mood is significant and is known as mania or hypomania, depending on its severity, or whether symptoms of psychosis are present. During mania, an individual behaves or feels abnormally energetic, happy, or irritable. Individuals often make poorly thought out decisions with little regard to the consequences. The need for sleep is usually reduced during manic phases. During periods of depression, there may be crying, a negative outlook on life, and poor eye contact with others. The risk of suicide among those with the illness is high at greater than 6 percent over 20 years, while self-harm occurs in 30–40 percent. Other mental health issues such as anxiety disorders and substance use disorder are commonly associated with bipolar disorder.The causes are not clearly understood, but both environmental and genetic factors play a role. Many genes of small effect contribute to risk. Environmental risk factors include a history of childhood abuse and long-term stress. About 85% of the risk is attributed to genetics. The condition is classified as bipolar I disorder if there has been at least one manic episode, with or without depressive episodes, and as bipolar II disorder if there has been at least one hypomanic episode (but no manic episodes) and one major depressive episode. In those with less severe symptoms of a prolonged duration, the condition cyclothymic disorder may be diagnosed. If the symptoms are due to drugs or medical problems, it is classified separately. Other conditions that may present similarly include attention deficit hyperactivity disorder, personality disorders, schizophrenia and substance use disorder as well as a number of medical conditions. Medical testing is not required for a diagnosis, though blood tests or medical imaging can be done to rule out other problems.Treatment commonly includes psychotherapy as well as medications such as mood stabilizers and antipsychotics. Examples of mood stabilizers that are commonly used include lithium and various anticonvulsants. Involuntary treatment in a hospital may be needed if a person is a risk to themselves or others but refuses treatment. Severe behavioral problems, such as agitation or combativeness, may be managed with short term antipsychotics or benzodiazepines. In periods of mania, it is recommended that antidepressants be stopped. If antidepressants are used for periods of depression, they should be used with a mood stabilizer. Electroconvulsive therapy (ECT), while not very well studied, may be tried for those who do not respond to other treatments. If treatments are stopped, it is recommended that this be done slowly. Many individuals have financial, social or work-related problems due to the illness. These difficulties occur a quarter to a third of the time, on average. Due to poor lifestyle choices and side effects from medications, the risk of death from natural causes such as heart disease is twice that of the general population.Bipolar disorder affects approximately 1% of the global population. In the United States, about 3% are estimated to be affected at some point in their life; rates appear to be similar in females and males. The most common age at which symptoms begin is 25. The economic cost of the disorder has been estimated at $45 billion for the United States in 1991. A large proportion of this was related to a higher number of missed work days, estimated at 50 per year. People with bipolar disorder often face problems with social stigma.