Evaluation of repetitive transcranial magnetic stimulation for treatment-resistant major depression and the impact of anxiety symptoms on outcome

Abstract

Objective: The aim of this study was to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in patients with treatment-resistant major depression and to explore the relationship between the outcome and comorbid anxiety symptoms. Methods: The study was performed on 36 patients with treatment-resistant major depression. Patients received 15 rTMS sessions to their left dorsolateral prefrontal cortex with 110% motor threshold intensity, 20 Hz frequency, and 1000 pulses per day over a three-week period with the same stimulation parameters. Patients were assessed using Sociodemographics Form, the Montgomery–Asberg Depression Rating Scale (MADRS), and the Hamilton Anxiety Rating Scale (HAM-A) at baseline both before initiating rTMS treatment and on the first day following their last rTMS treatment session. Results: Decreased scores in patients’ MADRS and HAM-A (including subscales) were statistically significant with large effect sizes (r > 0.5) after rTMS treatment. Pretreatment HAM-A total scores and HAM-A somatic subscale scores were significantly higher in those who responded to rTMS (p = .046, p = .048). There were negative correlations between post-treatment MADRS scores and pretreatment HAM-A somatic and psychic subscale scores. Conclusions: While the main limitations of the study are its design and small sample size, the findings suggested that comorbid anxiety symptoms, particularly somatic anxiety, could predict the response to rTMS in treatment-resistant major depressive disorder.

Keywords

• Transcranial magnetic stimulation
• depression
• anxiety
• somatic