The course and characteristics of the different types of bipolar disorder have profound implications for its long-term prognosis and treatment. Patients with bipolar I disorder are symptomatically ill nearly half the time and have a high probability of relapse. Bipolar II disorder is more chronic, more depressive, and associated with more neuroticism and emotional instability between episodes than bipolar I. Impaired psychosocial functioning and a high risk for suicide are common to all types of bipolar disorder. The illness can be stabilized through pharmacotherapy and by patients maintaining orderly patterns of life activities and using psychotherapy, psychoeducation, and mood charting. Adherence to pharmacotherapy increases the duration of remission. Physicians can help improve adherence by selecting medications with simple dosage regimens and educating patients and families about the disorder and what to expect from medications.