A self-guided internet-delivered intervention for adults with ADHD: Results from a randomized controlled trial

Background: Attention-deficit/hyperactivity disorder (ADHD) in adulthood, with an estimated prevalence of 2-3 %, is associated with several challenges in daily life functioning. Still, the availability of evidence-based psy-chological interventions for adults with ADHD is limited. Interventions delivered over the Internet on smart-phones or personal computers may help to increase the availability of and access to effective psychological interventions.Objective: This study reports on the efficacy of a self-guided psychological Internet-delivered intervention on severity levels of ADHD symptomatology and quality of life in adults with ADHD. Methods: Adults with a self-reported ADHD diagnosis (N = 120) were included in a randomized controlled trial with two arms: 1) self-guided Internet-delivered intervention for managing symptoms and impairments related to ADHD (n = 61); 2) online psychoeducation module (control group, n = 59). The primary clinical outcome was severity levels of ADHD as measured with the Adult ADHD Self-Report Scale. Secondary outcomes were quality of life as measured with the Adult ADHD Quality of Life scale and stress as measured with the Perceived Stress Scale. Measures were obtained at three time points: before (baseline), immediately after (8 weeks) and 3 months after the intervention. The secondary objective of the study was to explore user satisfaction with and adherence to the intervention.Results: Linear Mixed Model analysis revealed moderate to large between group effect-size improvements on self-report measures of ADHD symptomatology (d = 0.70) and quality of life (d = 0.53). Importantly, effects were maintained at 3-month follow-up (d = 0.76 and d = 0.52). In terms of adherence, 29 % completed all modules, while 59 % completed at least five modules (out of 7). Treatment satisfaction was adequate, with n = 34 (79 %) indicating that they were very satisfied or satisfied with the intervention, and n = 37 (88 %) indicating that they would recommend the intervention to a friend.Discussion: The study demonstrated the efficacy of a self-guided Internet-delivered intervention by showing reliable and statistically significant improvements in self-reported ADHD symptomatology and quality of life. The intervention may be suitable for better managing ADHD symptoms in primary care and as a low intensity intervention population wide. Trial registration: ClinicalTrials.gov, Identifier NCT04726813, January 27, 2021.