Accelerated Deep Intermittent Theta-Burst Stimulation Obsessive-Compulsive Disorder: a Double-Blind, Randomized, Controlled Study

Abstract

Aim: The FDA-approved protocol for OCD involves six weeks of 20 Hz deep transcranial magnetic stimulation (dTMS) targeting the medial prefrontal cortex. However, the efficacy of accelerated deep intermittent theta burst stimulation (d-iTBS) targeting the same region has not yet been evaluated in randomized controlled trials. This study addresses this gap by investigating a modified, shorter-duration d-iTBS protocol. Methods: The intervention consisted of five daily sessions over two consecutive weeks, totaling 50 d-iTBS sessions. The primary outcome measures were the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Dimensional Obsessive-Compulsive Scale. Changes in clinical scores were analyzed using repeated measures ANOVA. Results: The reduction in total obsessive-compulsive symptoms (OCS) exhibited a statistically significant difference between the active and placebo groups for the GroupxTime interaction. However, this effect was not observed when examining obsessions and compulsions separately, nor across specific OCS dimensions. Reductions in depressive and anxiety symptoms did not reach statistical significance for the Group x Time interaction. Within the active treatment group, an earlier age at OCD onset was correlated with a greater reduction in total OCS. Pairwise comparisons revealed that changes in total Y-BOCS scores from pre-treatment to the treatment endpoint and from pre-treatment to two-week follow-up were not statistically significant. Nevertheless, the reduction in scores between the treatment endpoint and two-week follow-up showed a trend toward significance (p = 0.051). Conclusion: Accelerated d-iTBS targeting the mPFC appears to be effective in reducing OCD symptoms; however, its therapeutic effects may become more apparent several weeks after the completion of treatment. The present trial is registered with ClinicalTrials.gov (NCT06177470).