Phenomena associated with contemporary charismatic religious sects raise questions about the combined impact of group influence and intensely held beliefs on group members' psychological functioning. The author considers the stages of membership in these sects, with emphasis on psychiatric aspects of conversion, long-term membership, and leaving. He discusses options for psychiatric intervention, including psychotherapy, conservatorships, and deprogramming. Systems theory is used to provide a psychological model for the relationship between group influence in these sects and current conceptions of individual psychopathology and normal adaptation.