This article reports a secondary analysis of past therapy outcome meta-analysis. Fifteen meta-analysis provided effect sizes from 56 studies in previous reviews that met 1 of 3 increasingly stringent levels of criteria for clinical representativeness. The effect sizes were synthesized and compared with results from the original meta-analyses. Effect sizes from more clinically representative studies are the same size at all 3 criteria levels as in past meta-analyses. Almost no studies exist that meet the most stringent level of criteria. Results are interpreted cautiously because of controversy about what criteria best capture the notion of clinical representativeness, because so few experiments have tested therapy in clinical conditions, and because other models for exploring the generalizability of therapy outcome research to clinical conditions might yield different results.

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.

No abstract

No abstract