After participating in this educational activity, the physician should be better able to 1. Identify the biological role of oxytocin in forming attachments. 2. Evaluate the relationship between various neuropsychiatric disorders and oxytocin. 3. Identify clinical implications of using oxytocin to treat various neuropsychiatric disorders. Oxytocin is a peptide hormone integral in parturition, milk letdown, and maternal behaviors that has been demonstrated in animal studies to be important in the formation of pair bonds and in social behaviors. This hormone is increasingly recognized as an important regulator of human social behaviors, including social decision making, evaluating and responding to social stimuli, mediating social interactions, and forming social memories. In addition, oxytocin is intricately involved in a broad array of neuropsychiatric functions and may be a common factor important in multiple psychiatric disorders such as autism, schizophrenia, and mood and anxiety disorders. This review article examines the extant literature on the evidence for oxytocin dysfunction in a variety of psychiatric disorders and highlights the need for further research to understand the complex role of the oxytocin system in psychiatric disease and thus pave the way for developing new therapeutic modalities. Articles were selected that involved human participants with various psychiatric disorders and that either compared oxytocin biology to healthy controls or examined the effects of exogenous oxytocin administration.