A new non-invasive brain stimulation technique known as accelerated continuous theta burst stimulation (a-cTBS) improves social communication at one month follow up and has a favourable safety profile in children with autism, finds a trial from China published by The BMJ today.
The researchers say the findings suggest that a-cTBS may be “a viable and scalable therapeutic option for children with autism spectrum disorder.”
Preliminary results from a recent pilot study suggest that a-cTBS is safe and effective for enhancing social communication in children with autism. A key advantage of a-cTBS is its shorter sessions compared with conventional brain stimulation, making it more suitable for children.
To build on this work, the researchers investigated the effectiveness and safety of a five day a-cTBS protocol in improving social communication among children with autism, including younger children and those with intellectual disability.
The trial involved 200 children (167 boys and 33 girls) aged 4-10 years with autism recruited from three academic hospitals in China from July 2023 to October 2024, half of whom also had intellectual disability.
The children were randomised to receive either active a-cTBS (intervention) or sham (control) treatment for five consecutive days (10 sessions each day). The stimulation targeted the brain's left primary motor cortex, which is linked to movement, language, and social cognition.
The researchers used the Social Responsiveness Scale (SRS-2) to measure changes in social communication impairment from baseline to post-intervention and from baseline to one month follow-up. Language improvements were also assessed using three recognised measures.
A total of 193 participants completed the full five day intervention course. Compared with the sham group, the a-cTBS group showed significantly greater improvements in social communication from baseline to post-intervention and from baseline to one month follow-up, with mean difference impairment score reductions of -6.25 and -6.17, respectively.
The a-cTBS group also showed greater improvements in language abilities. This finding was supported by a small effect size (Cohen's d) ranging from 0.12 to 0.47, representing the difference between the two group means.
Adverse events were more frequent in the a-cTBS group than in the sham group (54.5% v 29.3%), with restlessness and scalp discomfort being the most common. All adverse events were mild to moderate and resolved spontaneously.
The researchers acknowledge some limitations with the SRS-2 measure and potential bias from greater treatment expectancy in the intervention group. The trial also had a short one-month follow-up and more than 80% of participants were boys.
However, they point out that the inclusion of young children and those with intellectual disability supports the protocol's broad applicability, and consistent effects across sensitivity analyses provides greater confidence in their conclusions.
As such, they say their results suggest that a-cTBS may be “a feasible, effective, and scalable therapeutic option for children with autism spectrum disorder, including those with intellectual disability” and their protocol “represents a major advancement towards equitable autism care worldwide.”
In a linked editorial, researchers in Hong Kong agree that the findings show promise, but advocate for cautious optimism.
They note that while "a-cTBS should not replace psychosocial support or educational adaptation," it "may become an important component of a multimodal pathway for children with autism with significant social communication difficulties," provided it is "further replicated and integrated thoughtfully with behavioural care."
Randomized controlled/clinical trial
People
Accelerated continuous theta burst stimulation targeting left primary motor cortex for children with autism spectrum disorder: multicentre randomised sham controlled trial
29-Apr-2026
All authors have completed the ICMJE uniform disclosure form at https://www.icmje.org/disclosure-of-interest/ and declare: this study was supported by the National Natural Science Foundation of China, the China Brain Initiative Grant, the Science and Technology Commission of Shanghai Municipality, the Shanghai Municipal Commission of Health and Family Planning, the Innovative Research Team of High-level Local Universities in Shanghai, and Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine; FL, QZ, HT, LZ, TR are the developers of a repetitive transcranial magnetic stimulation system and hold a patent (patent No ZL 2024 1 1977448.9); no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.