Two models have dominated portrayals of depression. The medical model views depression as a disease that has distinct symptoms with predictable courses and outcomes. It typically relies on brain-related explanations and responses, although many adherents also use social and psychological causes and treatments. A second model conceives of depression as the result of external stressors, loss events, and other problems of living that naturally subsides when these conditions improve. In this view, optimal responses lie in addressing the social conditions that underlie depressed states. In this essay, we examine how each edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) since DSM-III in 1980 has blurred the medical and social approaches and conceived of all sorts of depressive symptoms as needing medicinal responses. Although the distinction between the social and medical types is often difficult to make, it is an essential first step in developing accurate conceptions of the two sides of depression.