A Systematic Review of Psychosocial Interventions for Adults with Autism Spectrum Disorders

Background:   While numerous studies evaluate psychosocial interventions for children with Autism Spectrum Disorders (ASD), relatively few investigate the efficacy of psychosocial interventions for adults with ASD. This is concerning given that a large cohort of people who were diagnosed with autism as children and will soon transition to adulthood and need efficacious intervention and services. However, no systematic reviews or meta-analyses of the literature examining psychosocial interventions for adults with autism exist. Consequently, remarkably little is known about the evidence-base for psychosocial interventions in this population.

Objectives:   Describe and quantify the current and existing evidence base for psychosocial interventions for adults with ASD in order to guide future research and treatment.

Methods:   A systematic review of the literature on psychosocial interventions for adults with ASD was conducted. A comprehensive search of the literature between January 1950 and September 2011 was completed. Studies were examined and included in this review if they were conducted using a longitudinal design (i.e., single case study, non-controlled trial, comparison study, randomized-controlled trial) and (1) reported quantitative findings, (2) included participants ages 18 and older, and (3) included participants with ASD. In order to ascertain the relative effectiveness of the psychosocial interventions described in the studies, effect size (d) was calculated using mean change divided by pooled standard deviation. Of the 1217 studies found in an extensive literature search, only 13 evaluated the efficacy of psychosocial interventions for adults with ASD.

Results:   The 13 studies found in this review represented highly diverse research methodologies and modalities of intervention. A total of five studies were single case studies, three studies were comparison studies, two studies were randomized-controlled trials, and one study was an uncontrolled trial. Five studies evaluated applied behavior analysis, four studies evaluated social cognition training, and two evaluated other types of community-based interventions. As a whole, the studies identified had modest sample sizes of no more than 71 participants, with over three-quarters of studies having less than 20 participants. Effect sizes (d) for included studies ranged from 0.14 to 3.59. Due to the small number of studies on psychosocial interventions for adults with ASD, we were unable to conduct a meta-analysis of the adult ASD literature. As a consequence, clear estimates of effect size for different types of psychosocial interventions are unavailable. Effect sizes should also be interpreted with caution, especially for studies with small sample sizes, which comprised the majority of studies.

Conclusions:   This body of research represents a positive and promising direction for psychosocial interventions for adults with ASD. However, both the amount and quality of research is limited by underpowered studies with limited internal validity for documenting intervention efficacy. This indicates that future research on interventions for adults with ASD is greatly needed, specifically on studies that employ more comprehensive and methodologically rigorous interventions designed to target core information processing deficits.