Bipolar disorder is a mental illness characterized by alternating periods of mania and depression. Manic episodes involve elevated or irritable moods along with rapid speech, distractibility, racing thoughts, and increased goal-oriented activities lasting at least a week. Depressive episodes include persistent feelings of sadness, anxiety, guilt, and hopelessness along with sleep and appetite disturbances and fatigue. While the exact causes are unclear, genetic influences are believed to account for 60-80% of the risk. Treatments include psychotherapy to alleviate symptoms and recognize triggers and pharmacology like lithium and anticonvulsants to treat episodes and prevent relapses.