Background: Attention-deficit/hyperactivity disorder (ADHD) is highly comorbid in adulthood. This meta-analysis was aimed at ascertaining the efficacy of different psychotherapies in improving comorbid internalizing symptoms in adults with ADHD. Method: Twenty randomized controlled trials and 12 uncontrolled pretest-posttest studies were included and combined using the inverse variance method. Risk of bias and heterogeneity assessment and moderator analyses were performed. Results: Cognitive-behavioral therapy (CBT) improved quality of life (QoL), emotional dysregulation (ED), depression, and anxiety symptoms, particularly at follow-up, which was predicted by core symptoms reduction. A significant between-group effect was obtained only on QoL, ED, and self-esteem for dialectical behavior therapy (DBT), mindfulness-based therapies (MBTs), and neurofeedback, respectively. Conclusion: Results support CBT efficacy for treating comorbid internalizing symptoms. More research is needed to determine the effectiveness of DBT, MBT, and neurofeedback. The small number of studies evaluating some therapies and the high risk of bias observed might limit these results.
Keywords: adult ADHD treatment; internalizing comorbidity; meta-analysis; nonpharmaceutical intervention.