Exploring the Efficacy of Dialectical Behaviour Therapy and Methylphenidate on Emotional Comorbid Symptoms in Adults with Attention Deficit/Hyperactivity Disorder: Results of the COMPAS multicentre randomized controlled trial

This study evaluated the efficacy of dialectical behaviour group therapy (GPT) vs. individual clinical management (CM) and methylphenidate (MPH) vs. placebo (PLB) on emotional symptoms in adults with ADHD. This longitudinal multicentre RCT compared four groups (GPT+MPH, GPT+PLB, CM+MPH, and CM+PLB) over five assessment periods, from baseline to week 130. Emotional symptomatology was assessed using SCL-90-R subscales. Of 433 randomized participants, 371 remained for final analysis. At week 13, GPT+MPH group showed smaller anxiety reductions than CM groups, but differences disappeared at subsequent assessments. Emotional symptom improvements were significantly predicted by reduction in core ADHD symptoms in all groups except GPT+MPH group. The unexpected lack of between-group differences may be explained by a 'floor effect', different intervention settings (group vs. individual), and psychotherapy type. Multiple regression analyses suggest a more specific effect of combined interventions (GPT+MPH). Implications for clinical practice are discussed.