Repetitive transcranial magnetic stimulation of the right dorsal lateral prefrontal cortex in the treatment of generalized anxiety disorder: A randomized, double-blind sham controlled clinical trial

•We investigated rTMS in generalized anxiety disorder (GAD) from two clinical sites.•Following 25 rTMS treatments, Hamilton Anxiety Rating Scale (HARS) scores showed significant clinical improved.•HARS scores remained significantly improved at the 4-week follow-up.

BackgroundUp to 50% of people with GAD fail to respond to first-line pharmacotherapies for generalized anxiety disorder (GAD), partly due to poor treatment compliance rates and partly due to the complex physiology underlying GAD. Thus, new non-invasive techniques, like repetitive transcranial magnetic stimulation (rTMS) are being investigated.MethodsParticipants were recruited from two different mood disorder sites: Kingston, Ontario, Canada and Sofia, Bulgaria. Hamilton Anxiety Rating Scale (HARS) scores were reported from patients diagnosed with GAD following treatment with high-frequency (20 Hz) rTMS applied to the right dorsal lateral prefrontal cortex (DLPFC).ResultsBy the end of 25 rTMS treatments, the ACTIVE (n = 15) treatment group showed a clinically significant reduction in the HARS scores compared to the SHAM (n = 25) group. Hedge's g at visit 4 (following 25 rTMS treatments) was 2.1 between ACTIVE and SHAM treatments. Furthermore, at 2 and 4 weeks follow-up (after the end of treatment) HARS scores of the ACTIVE group remained stable and even slightly improved, demonstrating a sustained effect of the response.LimitationsRelatively small sample size of the ACTIVE group as well as the SHAM procedure may limit the generalizability of the results.ConclusionsThus, participants receiving rTMS treatment showed a clinically significant decrease in reported anxiety symptoms as measured by the HARS. rTMS may be a treatment options for patients treatment refractory to pharmacotherapies.www.clinicaltrials.gov: NCT00616447