Impact of repetitive transcranial magnetic stimulation on generalized anxiety disorder in treatment-resistant depression

Background: Published evidence indicates the value of repetitive transcranial magnetic stimulation (rTMS) for generalized anxiety disorder in patients with treatment-resistant depression (TRD). As a part of routine clinical service, patients with TRD received right dorsolateral prefrontal cortex (DLPFC) inhibitory rTMS immediately prior to left DLPFC depression treatment delivered according to a US Food and Drug Administration protocol.

Methods: A retrospective investigation of routinely collected data between 2016 and 2018 was undertaken. Measures used were the clinician rated Clinical Global Impressions–Severity (CGI-S) scale and Hamilton Depression Rating scale (HAM-D), and the patient-rated Generalized Anxiety Disorder scale–7 (GAD-7) and Patient Health Questionnaire (PHQ-9). The outcome data of 61 patients with TRD were analyzed. The sample included patients with comorbid psychiatric diagnoses.

Results: Response and remission rates, respectively, were 17.1% and 27.3% on the GAD-7; 20.7% and 12.5% on the HAM-D; 19% and 24% on the PHQ-9; and 20% and 23.5% on the CGI-S. Post-treatment scores significantly improved on the GAD-7, HAM-D, and CGI-S scales, with medium to large effect sizes (.61, .62, and .86 respectively).

Conclusions: Results indicate the potential value of rTMS in treating anxiety in patients who are referred for rTMS for TRD. Well-designed and adequately powered randomized controlled trials are required to determine clinical recommendations.