Research Patterns in the Treatment of Adults With Problem Behavior and Intellectual and Developmental Disabilities: A Quantitative Systematic Review.

Research featuring adults with intellectual and developmental disabilities who engage in problem behavior has outlined various treatment approaches. The current quantitative systematic literature review identified and coded 76 peer-reviewed and gray literature articles published between January 2002 and September 2022. Following article identification and coding, we calculated effect size estimates (i.e., Tau Baseline Corrected) and assessed the methodological rigor of included articles. Through this work, we uncovered 42 unique multi-protocol treatments (i.e., treatments incorporating multiple therapeutic elements). Multi-protocol treatments were associated with larger effect sizes (more effective) compared to single-protocol treatments. The average methodological rigor score associated with peer-reviewed works was 1.6 (out of 4), while gray literature works scored 1.2. We offer commentary in response to these outcomes, alongside recommendations for future research to address the many avenues of inquiry that appear to remain largely neglected (e.g., component analysis to evaluate individual treatment elements and their efficacy).