is a mood disorder, characterized by feelings of sadness and worthlessness, disturbance in sleep and appetite, and a pervasive sense of hopelessness. A biopsychosocial approach best reveals its complexities: depression is biological in origin, symptom, and treatment, though psychological and social factors affect the vulnerability to depression and protection from it.
Mood disorders can be classified as unipolar or bipolar. Bipolar disorders include both periods of depression and periods of elation, grandiosity, and high energy of…