Response rate underreports improvement in patients with major depressive disorder and comorbidities treated with repetitive transcranial magnetic stimulation (rTMS)

Abstract

To study the efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) in Major Depressive Disorder (MDD) including comorbidities of Generalized Anxiety Disorder (GAD), Post-Traumatic Stress Disorder (PTSD), and Borderline Personality Disorder (BPD). We compared response and remission rates to a single question patient-reported outcome (PRO). A retrospective review of patients completing rTMS from 1/2009-2/2021. Standard response (≥50% reduction in Patient Health Questionnaire-9 [PHQ-9]) and remission (PHQ-9 ​< ​5) definitions were used. The PRO was a single yes/no question “Did you feel rTMS was helpful?” rTMS parameters were 10 ​Hz, 3000 pulses/session, 120% of motor threshold over the left dorsolateral prefrontal cortex (DLPFC). Student’s t-test was used to compare PHQ-9 baseline, endpoint, and change scores with and without comorbidities. Response, remission, and PRO were analyzed using chi-square or Fisher’s Exact tests. Logistic regression examined gender and age predictors. 84 patients were analyzed, with comorbidities of GAD (52.4%), PTSD (13.1%), and BPD (15.5%). Response and remission rates were 42.9% and 16.7%, respectively. The PRO was 61.9%. There were no significant differences in these rates with versus without comorbidities. In post-hoc analysis, gender was not a predictor for better outcomes, and older patients were more likely to experience remission than younger patients. Retrospective study, small sample size of PTSD and BPD. Comorbidities did not influence response and remission rates. The standard response rate underreported the patient’s perceived improvement. The patient’s point of view should be taken into account when discussing the clinical use of rTMS for MDD. • In our sample, rTMS for depression had response and remission rates of 42.9% and 16.7%. • Comorbidity of GAD in about half the patients did not reduce these rates. • Comorbidity of PTSD and BPD did not reduce the rates either but the limitation was a small sample. • Single question patient-reported outcome of response was 61.9%, higher than formal response rate.