Repetitive transcranial magnetic stimulation in substance use disorders is safe and tolerable: A Systematic review of 141 clinical trials including 4299 participants.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive neuromodulation intervention investigated as a treatment for substance use disorder (SUD) and its co-occurring disorders. As the number of rTMS SUD clinical trials increase, the safety and tolerability profile should be assessed. In this systematic review, we investigate adverse events (AEs) of rTMS in individuals with SUD and factors that may influence their occurrence. METHODS: We performed a systematic PubMed search to identify all controlled trials of rTMS in SUD published up to January 2025. Eligible studies were assessed, and safety information was extracted for analysis. RESULTS: A total of 141 clinical trials with 4299 participants were included in their active arms. rTMS trials recruited participants who were engaged in active substance use, were in the pre-treatment phase, in early recovery, or in sustained recovery. Twenty-two studies explicitly reported no AEs. Sixty-nine studies reported only mild AEs, while only six studies reported moderate AEs. Thirty-five studies did not report safety-outcomes/AEs. As expected, participants reported mild and temporary AEs such as headaches, pain or discomfort under the coil, or dizziness. Only nine studies reported serious AEs (7 studies in active TMS and 2 in sham TMS). Importantly, no seizures attributable to active rTMS were reported in these SUD samples. CONCLUSION: Overall, rTMS in SUD samples is safe and well-tolerated regardless of recovery stage and substance. Most reported side effects were mild, self-limiting, and tolerable. However, AE reporting was incomplete, as 35 of 141 trials reported no safety data, limiting conclusions to reported outcomes. This evidence supports the safety of rTMS as a potential stand-alone or adjunctive treatment for SUD.