鈥� This article reviews the evidence for differing rates of depression between the sexes in the United States and elsewhere during the last 40 years, and then critically analyzes the various explanations offered. These explanations include the possibility that the trends are spurious because of artifacts produced by methods of reporting symptoms, or that they are real because of biological susceptibility (possibly genetic or female endocrine), psychosocial factors such as social discrimination, or female-learned helplessness.