Social factors are crucial to the genesis, maintenance, and outcome of psychiatric disorders. In the first chapter, the authors provide an account of the history of social psychiatry. They identify early thinking about mental disorder, and link it to subsequent developments originating in the scientific traditions of the West. They argue that social psychiatry is a history of ideas about the social understanding and causation of mental ill health, and that these ideas are capable of assessment and refutation. They emphasize the central importance of its scientific basis, and assert that progress has been the result of an insistence on the development of a rigorous set of definitions, methods, and assessment tools. These are necessary in order to capture both hypothesized independent variables (social measures of various sorts, such as life events, family relationships, and social support), and dependent variables (measures of mental disorder or of specific mental symptoms or attributes). Such measures must be valid and reliable. Consequently, it has been possible to establish accurate case finding and to identify specific types of social influence. It has also been possible to formulate causal hypotheses and investigate mechanisms of action. By clarifying the effect of social factors on the emergence of acute episodes of disorder and on the process of recovery, social psychiatry has, in turn, enabled the progression of targeted social and psychological interventions.