A Preliminary Investigation Of Repetitive Transcranial Magnetic Stimulation Applied To The Left Dorsolateral Prefrontal Cortex In Treatment Seeking Participants With Cannabis Use Disorder

BACKGROUND: Cannabis use disorder (CUD) is a common and consequential disorder. When applied to the dorsolateral prefrontal cortex (DLPFC), repetitive transcranial magnetic stimulation (rTMS) reduces craving across substance use disorders and may have a therapeutic clinical effect when applied in serial sessions. The present study sought to preliminarily determine whether serial sessions of rTMS applied to the DLPFC had a therapeutic effect in CUD. METHODS: This study was a two-site, phase-2, double-blind, randomized-controlled-trial. Seventy-two treatment-seeking participants (37.5% Women, mean age 30.2±9.9SD) with ≥moderate-CUD were randomized to active or sham rTMS (Beam-F3, 10Hz, 20-total-sessions, with cannabis cues) while undergoing a three-session motivational enhancement therapy intervention. The primary outcome was the change in craving between pre- and post-treatment (Marijuana Craving Questionnaire Short-Form—MCQ-SF). Secondary outcomes included the number of weeks of abstinence and the number of days-per-week of cannabis use during 4-weeks of follow-up. RESULTS: There were no significant differences in craving between conditions. Participants who received active rTMS reported numerically, but not significantly, more weeks of abstinence in the follow-up period than those who received sham rTMS (15.5%-Active; 9.3%-Sham; rate ratio = 1.66 [95% CI: 0.84, 3.28]; p=0.14). Participants who received active rTMS reported fewer days-per-week of cannabis use over the final two-weeks of the follow-up period (Active vs. Sham: −0.72; Z=−2.33, p=0.02). CONCLUSIONS: This trial suggests rTMS is safe and feasible in individuals with CUD and may have a therapeutic effect on frequency of cannabis use, though further study is needed with additional rTMS-sessions and a longer follow-up period.