Adult ADHD is a serious risk factor for co-occuring psychiatric disorders and negative psychosocial consequences. Given this background, instead of or in addition to psychopharmacological treatment there is a need for effective psychotherapeutic treatment options for adults with ADHD. Previous trials on psychotherapeutic concepts were based on cognitive behavioural and/or dialectical behavioural approaches and showed significant effects. In a pilot study, our structured skills training group program for adult ADHD led to significant symptomatic improvements (Hesslinger et al. 2007). The following study evaluated the program’s effectiveness, feasibility and patient acceptability in a multicentre setting (N = 72, Philipsen et al. 2007). The therapy was well tolerated and led to significant improvements of ADHD, depressive symptoms and personal health status (p < 0.001). Patients regarded the program topics “behavioural analyses”, “mindfulness” and “emotion regulation” as the most helpful. As in our initial study, patients in the multicentre study rated the group setting as highly effective. This might be explained as result of greater peer support and the opportunity of learning from positive role models (e.g. during homework discussion). Following our staged approach, we are currently running a large randomized multicentre placebo-controlled study for the evaluation of the efficacy of this structured group program in adult ADHD that has been approved by the German Federal Ministry of Research and Education. In this study we compare the effects of purely medical management, specific psychotherapy, and the combination of both, comparable with the Multimodal Treatment Study of Children with ADHD (MTA).