This RCT-study proposes the evaluation of an intensive educational intervention tailored for adults with Attention Deficit Hyperactivity Disorder (ADHD) in community mental health centers (CMHCs). Given the prevalent challenges of prolonged waiting lists and low patient engagement in CMHCs, the research seeks to assess the efficacy of this intervention in enhancing patient engagement, self-efficacy, satisfaction with the information and overall health outcomes. The intervention, developed collaboratively with user representatives, combines a brief group-based educational sessions with standard clinical care. The primary hypotheses posit that this approach will lead to increased patient satisfaction with the treatment, patient self-efficacy, and activation compared to conventional treatment. Additionally, it aims to improve patients' satisfaction with information received. The study will employ a ITT analysis to assess the intervention's effects against usual treatment practices in outpatient settings. The anticipated outcome is a significant improvement in level of patient satisfaction, level of self-efficacy and level of satisfaction with the received information for patients with ADHD, potentially informing clinical practices and optimizing care for adults with ADHD.