Effects of Cognitive Behavioral Therapy in Autistic Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Autism is a neurodevelopmental disability characterized by differences in communication, social interaction, and behavior. Cognitive behavioral therapy (CBT) is a promising intervention for autistic people, yet research mainly focuses on children. Objective: To assess the effects of CBT in autistic adults. Methods: We performed a systematic review. We conducted searches in PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. We included randomized controlled trials (RCTs) evaluating CBT in autistic adults (≥16 years). We performed study selection, data extraction, and risk of bias assessment in duplicate. We conducted meta-analyses using random-effects models. We determined the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation methodology. Results: We included 10 RCTs ( n = 537). Most RCTs had small sample sizes and a high risk of bias, and most meta-analyses showed heterogeneity. For alexithymia, CBT probably caused an important reduction (1 RCT; MD: −5.30 points; 95% confidence intervals: –10.87 to + 0.27; moderate certainty of the evidence) at less than 6 months post-treatment. Regarding other outcomes at less than 6 months, CBT may reduce depression and anxiety and improve quality of life; however, it may have little to no effect on social anxiety, functioning, obsessive-compulsive symptoms, mental health symptom severity, and all-cause discontinuation. For autistic traits, CBT may lead to an increase in scores. The evidence for these latter outcomes remains very uncertain (very low certainty of the evidence). Conclusion: CBT showed very uncertain effects across most outcomes in autistic adults. CBT probably reduced alexithymia at less than 6 months post-treatment. These findings are limited by methodological issues in the included RCTs, such as small sample sizes and high risk of bias. Overall, evidence on the effect of CBT in autistic adults remains limited, highlighting the need for more rigorous research to inform clinical practice.