Repetitive Transcranial Magnetic Stimulation (rTMS): A Large-Scale Retrospective Clinical Data Analysis Indicating rTMS as Effective Treatment for Generalized Anxiety Disorder (GAD)

Abstract

Background: Typical success rates of rTMS reported in the literature indicate remission and response rates of approximately 45% and 68%, respectively, for Major Depressive Disorder (MDD) (Dunner, Aaronson, Sackeim, Janicak, Carpenter, Boyadjis, & Lanocha, 2014). To date, rTMS is FDA-cleared only for MDD and Obsessive Compulsive Disorder (OCD). This report aims to compare patient response rates reported in the literature to those of a multi-location organization consisting of three clinics, and demonstrates the efficacy of rTMS in treating not only MDD but also GAD. Comorbitiy of the two disorders is so prevalent that some authors suggest that GAD and MDD should be conceived and treated as a single disorder, while others suggest the two disorders should remain as distinct diagnoses, and one a comorbidity of the other (MacNamara, Kotov, & Hajcak 2015). GAD occurs prior to MDD in 54% of cases (Galyamina, Kovalenko, Smagin, & Kudryavtseva, 2017) causing impairment by causing feelings of excessive worry, irritability or restlessness and may include somatic responses such as nausea, palpitations, and insomnia. Methods: A total of 401 patients with a clinical diagnosis of MDD were treated with rTMS at the dorsolateral prefrontal cortex. Remission rates and response magnitudes were compared using an evaluative case report design, and patient data spanning the three clinical locations. Left hemisphere targets received either high-frequency rTMS (120% of MT, 10 Hz for 18 minutes) or intermittent Theta-Burst (120% of MT, 5 Hz for 3:08 minutes). Right hemisphere targets received rTMS (110% or 120% of MT, 1 Hz for 15 minutes) or continuous Theta-Burst (110% of MT. 5 Hz for 39 seconds). Bilateral treatment protocols varied in combinations of standard rTMS and Theta-Burst. Patient progress was monitored using the Patient Health Questionnaire-9 (PHQ-9) for depression and Generalized Anxiety Disorder-7 (GAD-7) for anxiety. Results: In standard with this organization's clinical definitions, patients were considered in remission for scores of 5 or lower for PHQ-9 and GAD-7, for MDD and GAD respectively. For remission rates, 40.40% of patients reported a PHQ-9 score of 5/27 or lower according to the PHQ-9, and 44.03% of patients reported 5/21 or lower, according to the GAD-7. Conversely, response rates (indicated by a fifty percent or greater decrease in scores) were 59.71% for GAD7, and 67.42% for PHQ-9. Conclusion: In this retrospective analysis of three clinics’ outcomes, remission and response outcomes for GAD were similar to outcomes for MDD, indicating that rTMS shows significant efficacy for GAD treatment. A large, sham-controlled, randomized clinical trial controlling for protocols, and demographics is needed to determine TMS for GAD is an effective treatment. Conflicts of Interest: All data was collected from clinics belonging to NeuroStim TMS Centers. Funding: Funding for this study was provided by NeuroStim TMS Centers. References Dunner, D. L., Aaronson, S. T., Sackeim, H. A., Janicak, P. G., Carpenter, L. L., Boyadjis, T., & Lanocha, K. (2014). A multisite, naturalistic, observational study of transcranial magnetic stimulation for patients with pharmacoresistant major depressive disorder: durability of benefit over a 1-year follow-up period. The Journal of clinical psychiatry, 75(12), 1394-1401. Galyamina, A. G., Kovalenko, I. L., Smagin, D. A., & Kudryavtseva, N. N. (2017). Interaction of Depression and Anxiety in the Development of Mixed Anxiety/Depression Disorder. Experimental Studies of the Mechanisms of Comorbidity (review). Neuroscience and Behavioral Physiology, 47(6), 699–713. https://doi.org/10.1007/s11055-017-0458-3 MacNamara, A., Kotov, R., & Hajcak, G. (2015). Diagnostic and Symptom-Based Predictors of Emotional Processing in Generalized Anxiety Disorder and Major Depressive Disorder: An Event-Related Potential Study. Cognitive Therapy and Research, 40(3), 275–289. https://doi.org/10.1007/s10608-015-9717-1