After nearly a century of practice, there is still no consensus among researchers and clinicians as to the definitions of such basic group therapy concepts as "structure," "development," and "self-help. " Ironically this is due, in part, to the ubiquity of group practice across a wide range of therapeutic disciplines and schools of thought. Because of this, most reviews of group therapy tend to be intensely specific, the research they report reflecting only a very narrow slice of the vast knowledge base that has developed over the past century. A book whose time has come at last, Handbook of Group Psychotherapy goes a long way toward helping to establish the scientific foundations of group therapy. At the same time, it helps to foster a long needed collaborative relationship between scientists and clinicians who study and practice group therapy. The information it contains was garnered from hundreds of articles scattered throughout more than 160 publications catering to a wide range of general and specific interests in psychotherapy. As a consequence, it offers researchers and clinicians a unique opportunity to take a hard look at all important empirical data on what group therapy is and what it does. Over the course of eighteen chapters, some of the leading contributors to the field, internationally, review and summarize the available data and present their findings on group therapy process and outcome. And along the way conceptual parameters are revised, viable new definitions are proposed, and important new questions are raised and pondered. Crucial theoretical and clinical concerns covered include: client and therapist variables and pregroup structure; communication and therapeutic paradigms; interpersonal and intrapersonal mechanisms; applications for special groups and special dysfunctions such as eating disorders and drug addiction; and many more. Handbook of Group Psychotherapy affords clinicians and researchers instant access to all important empirical data on group therapy process and outcome. It is an indispensable resource for clinical psychologists, family practitioners, psychiatrists, social workers, counselors, and all those who practice that important therapeutic modality.