This paper reviews the epidemiological research evidence on the role of socio-economic factors in the origins and disease experience of schizophrenia and major depression. The studies were conducted in different countries over many years. Although their findings are divided in their support of either the social causation or the drift hypothesis, all of them agree that persons with these disorders are at high disadvantage in society. Several factors for this have been identified. These studies provide the rationale for community-based interventions that have to be guided by principles of equity in the distribution of resources and grounded in biopsychosocial models of care that comprehensively answer the needs of the affected populations.