Effects of repetitive transcranial magnetic stimulation on obsessive-compulsive disorder: a systematic review,...

The objective of this study was to provide updated evidence on the efficacy of repetitive transcranial magnetic stimulation in obsessive-compulsive disorder, to assess its sustained effects, and to identify moderators of treatment response.

A systematic review and meta-analysis of randomized controlled trials was conducted of publications up to September 2024. The searches included the Cochrane Library, MEDLINE, Web of Science, Scopus, PsycINFO, and Embase databases. The risk of bias was assessed with RoB 2, and effect sizes were calculated using mean differences (MD) in Yale-Brown Obsessive-Compulsive Scale scores. Subgroup analyses were used to evaluate protocol variations, while the role of moderators was explored through meta-regression.

A total of 31 trials were included. The analysis revealed substantial reductions for treatment over the left dorsolateral prefrontal cortex (MD: -4.63; 95%CI -7.73 to -1.52) and the medial prefrontal/anterior cingulate cortex (MD: -3.92; 95%CI -6.93 to -0.90). Frequencies ranging from < 1 Hz to > 5 Hz were found to be effective, whereas continuous theta burst stimulation was not as efficacious. Repeated repetitive transcranial magnetic stimulation reduced Yale-Brown Obsessive-Compulsive Scale scores (MD: -3.30; 95%CI -4.55 to -2.04), although below the minimal clinically important difference (4.9 points). The number needed to treat for a response was 6, and the dropout rates were comparable to those in the sham group, indicating good tolerability. There was no significant change in scores from post-treatment through follow-up, indicating the effect was maintained (MD: 0.07; 95%CI -0.60 to 0.75; I 2 = 0%; p = 0.83). In contrast, analysis of the overall effect from baseline to follow-up confirmed that the treatment had a significant and sustained benefit (MD: -3.17; 95%CI -4.68 to -1.65; I 2 = 64%; p < 0.0001). Baseline severity moderated outcomes, while coil type and neuronavigation did not.

According to our analysis, repetitive transcranial magnetic stimulation is an effective treatment for obsessive-compulsive disorder, particularly when administered to specific targets and at specific frequencies. Nevertheless, the mean clinical impact was negligible. These findings indicate the need for optimized protocols and pragmatic maintenance strategies.