This article provides an overview of psychiatric and mental health research on religion. First, conceptual models of religion and of mental health used throughout this literature are described. Second, published empirical research in this field is summarized, including findings from epidemiologic, clinical, and social and behavioral investigations. Third, promising theoretical perspectives for understanding a putative religionmental health connection are elaborated. These are based on respective behavioral, biological, psychodynamic, and transpersonal interpretations of existing research findings.