What Is Bipolar Disorder? Bipolar disorder, formerly called manic depression, is a mental illness that brings severe high and low moods and changes in sleep, energy, thinking, and behavior. Bipolar disorder is a mental health condition that affects a person’s mood, energy, activity and thought; it is characterized by manic (or hypomanic) and depressive episodes. Bipolar disorder is characterized by episodes of mania or hypomania and depression. Bipolar disorder is a lifelong mental health condition with episodes of high energy (mania or hypomania) and low mood (depression). Symptoms may disrupt your sleep, activities and daily life. Key signs of bipolar disorder include distinct periods of elevated mood (mania or hypomania) and periods of depression, which can impact energy, sleep, behavior, and overall well-being. Bipolar disorder, formerly called manic depression, is a mental health condition that causes extreme mood swings. These include emotional highs, also known as mania or hypomania, and lows, also known as depression. Bipolar disorder, formerly manic depression, causes extreme mood shifts ranging from mania to depression. Learn symptoms, diagnosis, treatment, and more. Find out about bipolar disorder, including symptoms, how it's diagnosed and treatments. Information on bipolar disorder including symptoms, causes, diagnosis, treatment options, and resources to find help for yourself or others. Learn about NIMH research on bipolar disorder. Find resources on the signs and symptoms of bipolar disorder, types, and potential treatments and therapies.