Improving methodologies for the treatment of child and adolescent disorders: introduction.

This special issue grew out of a workshop sponsored by the National Institute of Mental Health, the MacArthur Foundation, and the Child and Adolescent Psychosocial Interventions Consortium. The goals of the workshop are outlined. The contents of the special issue are then described: definitions of psychotherapy and its mechanisms of action, developmental issues in psychotherapy research, methodologies for the treatment of anxious youth, measurement of change in interventions, predicting the outcome of treatment, and advancing the efficacy and effectiveness of psychosocial treatments. Finally, some areas that need to be addressed in the future are discussed, such as process research, the effects of comorbidity on outcomes, intensity, and duration, and transferability of treatments.