Adapted Dialectical Behavior Therapy Skills Group for Adults with Intellectual and Developmental Disabilities: A Quasi-Experimental Trial

Adults with mild to moderate Intellectual Disabilities (ID) experience cognitive and environmental challenges that increase risk for problem behavior and development of depressive symptoms. Self-regulation of emotion has been linked to these challenges and is a promising leverage point of intervention, addressed by Dialectical Behavior Therapy (DBT; Linehan, 1993). This study explored if one DBT-informed intervention, the Skills System adapted for adults with ID (Brown, 2011), reduces problem behavior and depression while enhancing self-efficacy of emotion regulation in a postsecondary education setting. The 12 modules each covered twice a week for the duration of a 16-week semester, covered the four DBT skill sets: mindfulness, interpersonal effectiveness, emotion regulation, and distress tolerance. Thirty-one participants were assigned according to programmatic factors to either the Skills System or a waitlist condition who received the intervention in the spring semester. Informant-report of problem behavior and depressive behaviors and self-report of depressive symptoms, self-efficacy of emotion regulation, and satisfaction with life were obtained for all participants who completed the study (17 Skills System and 14 waitlist participants) at the first and last weeks of the fall and spring semesters. There were no statistically significant group differences for problem behavior, informant- and self-reported depression and self-efficacy of emotion regulation. Within group change from pre- to post-intervention was examined with a larger sample by collapsing the data of both groups also revealing no statistically significant difference in mean scores from pre- to post-intervention. Post-hoc analyses revealed that the sample of participants with elevated depression scores endorsed a significant reduction in self-report depression from pre- to post-intervention. Discussion of the non-significant findings from this quasi-experimental study raises questions about the active component of DBT-based interventions for adults with ID. One possibility is that offering a single cycle as opposed to more than one cycle over 12 months as seen in prior research may not have been adequate to effect significant change. It is also possible that these findings are suggestive that the skills-group without individual DBT-informed therapy may be inadequate to effect significant change. Limitations to this study are discussed and highlight some of the challenges and future suggestions for conducting quasi-experimental research with adults with ID and comorbid behavioral and mental health concerns.