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

Abstract

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.

Community Brief

Why is this an important issue?

Existing research on the effectiveness of cognitive behavioral therapy (CBT) in autism has predominantly focused on pediatric populations, leaving a critical gap in understanding its effects in adults. No previous systematic review has reported specific results on the effects of CBT in autistic adults.

What is the purpose of the study?

The purpose was to conduct a systematic review to evaluate the effects of CBT specifically in autistic adults. In addition, we assessed the certainty of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation methodology.

What did the authors do to review the literature?

We developed a systematic search strategy combining the terms “Autism,” “Cognitive Behavioral Therapy,” “Adult,” and their respective synonyms. We applied this strategy to the PubMed/MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases.

What studies did the authors find?

We selected a total of 11 articles, corresponding to 10 randomized controlled trials (RCTs). Five of these were conducted in the United Kingdom, two in Sweden, and the remaining three in the United States, Japan, and South Korea. The total sample size was 537 autistic people; the mean age ranged from 19.7 to 45.7 years, and the proportion of male participants ranged from 38.1% to 90%.

In summary, what did those studies show?

In summary, CBT probably results in an important reduction in alexithymia at <6 months of follow-up (moderate-certainty evidence). For all other outcomes, such as depression, anxiety, social anxiety, obsessive-compulsive symptoms, functioning, quality of life, mental health symptom severity, autistic traits, and all-cause discontinuation, the certainty of the evidence was very low. The available data suggest that CBT may reduce depression and anxiety and may improve quality of life, while it may have little to no effect on the remaining outcomes. Most RCTs had small sample sizes and a high risk of bias.

What are the remaining gaps in the literature?

The effect of CBT remains unclear for symptoms such as depression, anxiety, social anxiety, severity of mental health symptoms, obsessive-compulsive symptoms, functioning, autistic traits, all-cause discontinuation, and quality of life due to the very low certainty of the available evidence.

Based on this review, what do the authors recommend?

More robust and methodologically rigorous RCTs are needed to better understand the role of CBT in this population and to inform clinical practice.