Depressive, Bipolar and Related Disorders Depressive, Bipolar, and Related Disorders encompass a range of mental health conditions characterized by significant mood disturbances. These disorders are characterized by an irritable, depressed, elevated, or expansive mood, or by a loss of interest or pleasure in all or almost all activities, causing a clinically significant decline in functioning. Symptoms and signs may include, but are not limited to, feelings of hopelessness or guilt, suicidal ideation, a clinically significant change in body weight or appetite, sleep disturbances, an increase or decrease in energy, psychomotor abnormalities, disturbed concentration, pressured speech, grandiosity, reduced impulse control, sadness, euphoria, and social withdrawal.