Efficacy and safety of noninvasive brain stimulation for ADHD: a systematic review and meta-analysis of double-blind randomized controlled trials across international English and Chinese databases.
Huiru Cui, Guosheng Wang, Shuyi Wang et al.
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In 30 seconds
This systematic review and meta-analysis examined double-blind, parallel-group randomised trials of noninvasive brain stimulation (NIBS) for clinical ADHD symptoms, including studies from China. Across 15 studies (17 comparisons; 746 participants), NIBS improved symptoms compared with sham stimulation (SMD=-1.12, 95% CI -2.05 to -0.19, p = 0.031), although heterogeneity was high (I²=94%). Subgroup findings suggested possible benefit from high-frequency rTMS over the right prefrontal cortex using a figure-8 coil; tDCS and TNS did not show significant efficacy. Dropout rates and adverse events did not differ significantly between groups.
Key findings
- Across 15 studies (17 comparisons; 746 participants), NIBS improved ADHD symptoms versus sham (SMD=-1.12, 95% CI -2.05 to -0.19, p = 0.031).
- Symptom results were highly heterogeneous (I²=94%).
- Subgroup analysis suggested possible benefit from high-frequency rTMS with a figure-8 coil over the right prefrontal cortex; tDCS and TNS showed no significant efficacy.
- Dropout rates and adverse events did not differ significantly between active and sham stimulation.
Why it matters
The pooled findings suggest that brain stimulation may reduce ADHD symptoms and was generally well tolerated in the included trials. However, substantial heterogeneity and the lack of significant efficacy for tDCS and TNS make the overall result difficult to translate into a uniform treatment expectation. The review therefore adds evidence of potential benefit while underscoring uncertainty about which approaches are effective.
What to keep in mind
The pooled symptom estimate had high heterogeneity (I²=94%), and the authors conclude that evidence remains insufficient to support routine clinical use.