Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of depression and abnormally elevated mood, lasting days to weeks, and in some cases months. If the elevated mood is severe or associated with psychosis, it is called mania; if it does not significantly affect functioning, it is called hypomania. During mania, an individual behaves or feels abnormally energetic, happy, or irritable, and often makes impulsive decisions with little regard for the consequences. There is usually sleep disturbance during manic phases. During periods of depression, the individual may experience crying, have a negative outlook, and demonstrate poor eye contact. An estimated 15–20% of those with BD die by suicide. Approximately 30–60% attempt suicide during their lifetime. Among those with BD, 40–50% overall and 78% of adolescents engaged in self-harm.