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

Abstract

Background: Up 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.

Methods: Participants 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 (20Hz) rTMS applied to the right dorsal lateral prefrontal cortex (DLPFC).

Results: By 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 4weeks 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.

Limitations: Relatively small sample size of the ACTIVE group as well as the SHAM procedure may limit the generalizability of the results.

Conclusions: Thus, 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.

Keywords: Anxiety disorders; Electrophysiology; GAD.