A chart-based study of theta burst stimulation for depression at a tertiary care center

Since the demonstration of the non-inferiority of theta-burst stimulation (TBS) as compared to conventional rTMS for the treatment of depression [1], TBS is increasingly being used clinically worldwide. At our center, TBS largely replaced conventional rTMS as the first choice since July 2016 [2]. Here, we describe clinical characteristics and determinants of response to TBS in 86 individuals with depressive disorders (including single episode, recurrent depressive disorder, and bipolar affective disorder) who received TBS between July 2016 and February 2020. These patients were referred for therapeutic TMS and were not part of any clinical trial. Each patient received bilateral TBS protocol over the dorsolateral prefrontal cortex (DLPFC) (1800-pulses each of 10-min intermittent-TBS to left DLPFC and 2-min continuous-TBS to the right at 90%e100% of resting motor threshold, RMT) based on a previous clinical trial [3]. Localization of DLPFC was done using the manual method, 7 cm anterior to the motor hotspot. We reviewed patient records for sociodemographic and clinical profile, pre/post-TMS clinician-rated 17-item Hamilton Depression Rating Scale (HDRS) scores, and TMS records, including safety and tolerability. The Institute’s Ethics Committee reviewed and approved the study protocol. The mean age of the patients was 42.88 ± 15.6 years and 64%weremales. The commonest indications were augmentation of antidepressant (AD) medications, treatment resistance ( 2 AD failures), and non-feasibility of ECT (refusal of consent/high risk of complications due to medical comorbidities). The median duration of the ongoing episode (DOE), duration of illness (DOI), and age at onset (AAO) were 9.5 months, 8 years, and 28 years respectively. Of 86 patients, 17 (20%) had bipolar depression and 11 (12.8%) had psychotic symptoms. Forty-nine (57%) did not have prior history of AD failures, 27 (31.4%) had 1 2 and 10 (11.6%) had >2 AD failures. Thirty-six patients (41.9%) had a comorbid medical diagnosis (commonest being hypertension, diabetes mellitus, and hypothyroidism) and 23 (26.7%) had a