A Comparison of Group Cognitive Behavioural Therapy (CBT) and Structured Activity Group for Adults With Attention Deficit Hyperactivity Disorder (ADHD)

Overview

Many adults with attention deficit hyperactivity disorder (ADHD) experience difficulties with inattention, planning and impulsivity that impacts work and social life negatively also after treatment with medication. There are various psychological treatments aiming to improve these symptoms, but it is not known if they work or not. The goal of this clinical trial is to evaluate group cognitive behavioural therapy (CBT) for adults with attention deficit hyperactivity disorder (ADHD) in comparison to an active control group consisting of a discussion and activity group. Previous research suggests that group CBT works about equally well as other structured group activities. The main questions the researchers aim to answer are if group CBT work better than activity groups to: * Improve symptoms of ADHD * Improve general mental health and life quality * Improve every-day functioning The researchers also want to learn if group CBT or activity groups work better for some people with ADHD depending on individual characteristics such as • type of symptoms, age, gender or co-occurring psychiatric diagnoses. The comparison is a manualised structured activity group given at the same number of sessions and same group size. All participants will visit our clinics at 12 occasions. They will: * Fill in questionnaires before and after the group intervention, and online after 6 and 12 months * Do cognitive testing before and after the intervention

Despite medical treatment, many adults with ADHD experience residual symptoms that negatively affect work performance and social life. Hence, several psychological interventions targeting these symptoms have been developed, but the treatment effects are still unclear due to lack of controlled clinical trials. In this single-blind randomised controlled clinical trial, we will evaluate the effects of group CBT based on Safren's manual "CBT for ADHD/Mastering Your Adult ADHD" (Safren SA et al, Behav Res Ther, 2005), compared to an active control group. The control intervention is a manualised activity group that contains the same non-specific therapeutic elements as the treatment but no active CBT components. For dose equivalence, activity groups will be given with the same same number and length of sessions, and the same frequency, as the treatment conditions. Since therapist experience is known to influence outcomes, the activity groups will be held by staff with equivalent training and experience to those giving the treatment groups. Consenting patients assessed eligible for treatment will be randomly assigned to treatment or control group using a standard digital randomisation generator with an allocation of 1:1. Patients and clinicians rating outcomes will be blind to group assignment. Pre- and post intervention, and at 6 months and 12 months follow-up, the patient's ADHD symptoms, symptoms of anxiety and depression and general functioning will be assessed by experienced clinicians and with validated self-rating scales. Treatment fidelity and expectation will be compared for the therapy and control groups and adverse events will be registered. An exact power calculation for estimation of sample sizes cannot be performed since effect sizes are not known. Based on a previously published studies of Safren's CBT individually administered, and general consensus of what is a clinically meaningful improvement in psychological treatments for other psychiatric diagnoses, we expect that 60 patients per arm will be sufficient for detection of clinically relevant effect sizes of approximately Cohen's d 0.3-0.4. A statistician will make a blind Bayesian stop analysis (Svensson JE et al, J Cereb Blood Flow Metab, 2021) for every 20-25 patients, and based on the results we can decide to halt the study if sufficient power has been achieved earlier than after 60 patients. Full attrition analysis with intention to treat (ITT) analysis will be performed to investigate and minimize attrition bias.