Background: Transcranial magnetic stimulation (TMS) is a promising noninvasive brain stimulation intervention. Transcranial magnetic stimulation has been proposed for obsessive-compulsive disorder (OCD) with auspicious results.
Objective: To assess the efficacy of TMS for OCD in randomized clinical trials (RCTs).
Methods: Systematic review using MEDLINE and EMBASE from the first RCT available until March 11, 2016. The main outcome was the Hedges g for continuous scores for Yale-Brown Obsessive Compulsive Scale in a random-effects model. Heterogeneity was evaluated with the I and the χ test. Publication bias was evaluated using the Begg funnel plot. Metaregression was performed using the random-effects model modified by Knapp and Hartung.
Results: We included 15 RCTs (n = 483), most had small-to-modest sample sizes. Comparing active versus sham TMS, active stimulation was significantly superior for OCD symptoms (Hedges g = 0.45; 95% confidence interval, 0.2-0.71). The funnel plot showed that the risk of publication bias was low and between-study heterogeneity was low (I = 43%, P = 0.039 for the χ test). Metaregression showed no particular influence of any variable on the results.
Conclusions: Transcranial magnetic stimulation active was superior to sham stimulation for the amelioration of OCD symptoms. Trials had moderate heterogeneity results, despite different protocols of stimulation used. Further RCTs with larger sample sizes are fundamentally needed to clarify the precise impact of TMS in OCD symptoms.