Comparative efficacy of repetitive transcranial magnetic stimulation protocols for obsessive-compulsive disorder: A network meta-analysis

Background: Repetitive transcranial magnetic stimulation (rTMS) has been found to be helpful for the treatment of obsessive -compulsive disorder (OCD). However, the relative efficacy of different rTMS protocols is unclear. Objective: To conduct a systematic review and network meta -analysis (NMA) of published literature to compare the relative efficacy of different rTMS protocols for decreasing Yale -Brown Obsessive Compulsive Severity (YBOCS) scores in patients with OCD. Method: Relevant articles published between 1985 to September 2023 were searched from the Cochrane Central Register of Controlled Trials, PubMed and PsycInfo. Double or single -blinded randomized controlled studies conducted on patients with OCD comparing an active rTMS protocol with either another active or sham rTMS protocol were included. Network meta -analysis (NMA) was conducted using a frequentist approach. Standardized mean difference (SMD) of change in Y-BOCS scores was calculated employing Hedge's g. Pairwise metaanalysis using random effects model was conducted which was extended to the NMA using restricted maximum likelihood estimation procedure. Surface under the cumulative ranking (SUCRA) probabilities were used to rank the interventions. Results: Excitatory rTMS of the bilateral dorsolateral prefrontal cortex (DLPFC), inhibitory rTMS of right DLPFC, inhibitory as well as excitatory rTMS of bilateral medial prefrontal cortex/anterior cingulate cortex (mPFC/ACC) and inhibitory rTMS of bilateral supplementary motor area (SMA) were superior to sham stimulation. The DLPFC and mPFC/ACC protocols had a higher probability of being among the top -ranked interventions. The majority of studies had a modest sample size and at least some concerns in the risk of bias assessment. Conclusion: rTMS targeting either the medial or lateral prefrontal cortices is a promising intervention for resistant OCD. There is a need to confirm these findings in large systematic studies.