Designed for both group psychotherapy researchers and clinicians, this comprehensive, thoroughly referenced volume examines those aspects of treatment which produce beneficial effects. The authors discuss the clinical lore, theoretical advances, and empirical research on ten factors which are the basis for effective group psychotherapy: insight, interaction, acceptance, self-disclosure, catharsis, guidance, universality, altruism, vicarious learning, and the instillation of hope. They emphasize the implications of these findings for the clinical practice of group psychotherapy.