Psychotherapy with persons who have mental retardation: an evaluation of effectiveness.

Studies of psychotherapy with persons who have mental retardation were examined. Studies conducted during a 30-year period were rated by an expert consensus panel and classified with regard to the nature of the research and outcome and effectiveness domains. We conducted a meta-analysis on a small number of the studies and found a wide range of research designs, types of interventions, and participants. The evaluation also pointed to a moderate degree of change in outcome measures and moderate effectiveness in terms of benefit to clients with mental retardation. We conclude that psychotherapeutic interventions should be considered as part of overall treatment plans for persons with mental retardation.