New brain stimulation technique improves social communication in children with autism

A new non-invasive brain stimulation technique known as rapid continuous theta burst stimulation (A-CTBS) improves social communication at a one-month follow-up and has a favorable safety profile in children with autism, a trial published from China has found. bmj Today.

The researchers say the findings suggest that A-CTBS “may be a viable and scalable therapeutic option for children with autism spectrum disorders.”

Preliminary results from a recent pilot study suggest that A-CTBS is safe and effective in increasing social communication in children with autism. A major advantage of A-CTBS is its shorter sessions than traditional brain stimulation, making it more suitable for children.

To further this work, researchers examined the effectiveness and safety of a five-day A-CTBS protocol in improving social communication among children with autism, including young children and those with intellectual disability.

The trial involved 200 children (167 boys and 33 girls) aged 4–10 with autism, admitted to three academic hospitals in China from July 2023 to October 2024, half of whom also had intellectual disability.

Children were randomized to receive active A-cTBS (intervention) or sham (control) treatment for five consecutive days (10 sessions each day). The stimulation targeted the left primary motor cortex of the brain, which is associated with movement, language and social cognition.

The researchers used the Social Responsiveness Scale (SRS-2) to measure change in social communication impairment from baseline to post-intervention and from baseline to one-month follow-up. Language improvement was also assessed using three validated measures.

A total of 193 participants completed the entire five-day intervention course. Compared with the sham group, the A-CTBS group showed significantly greater improvement in social communication from baseline to post-intervention and from baseline to one-month follow-up, with a mean difference impairment score reduction of -6.25 and -6.17, respectively.

The A-CTBS group also showed greater improvement in language abilities. This finding was supported by small effect sizes (Cohen’s d) ranging from 0.12 to 0.47, indicating differences between the two group means.

Adverse events occurred more frequently in the A-CTBS group than in the sham group (54.5% vs. 29.3%), with discomfort and scalp discomfort being the most common. All adverse events were mild to moderate and resolved spontaneously.

The researchers acknowledge some limitations of the SRS-2 measurement and potential bias from greater treatment expectancy in the intervention group. The trial also had a short follow-up of one month and more than 80% of the participants were boys.

However, they point out that the inclusion of young children and people with intellectual disability supports the broader applicability of the protocol, and the consistent effect in sensitivity analyzes provides greater confidence in their findings.

As such, they say that their results suggest that A-CTBS “can be a viable, effective, and scalable therapeutic option for children with autism spectrum disorders, including those with intellectual disability” and that their protocol “represents a major advance toward equitable autism care worldwide.”

In an associated editorial, Hong Kong researchers agree that the findings look promising, but advocate cautious optimism.

They note that while “A-CTBS should not replace psychosocial support or educational adaptations,” it “could become an important component of a multimodal pathway for children with autism with significant social communication difficulties,” provided it is “further replicated and thoughtfully integrated with behavioral care.”