Heart rate deceleration tracks antidepressant response to accelerated dorsomedial prefrontal intermittent theta-burst stimulation in major depression

Identifying accessible, low-cost biomarkers of treatment response remains a key challenge in personalizing transcranial magnetic stimulation (TMS) therapy for major depressive disorder (MDD). We tested whether stimulation-evoked heart rate deceleration (HRD) predicts antidepressant response to accelerated intermittent theta-burst stimulation (iTBS) of the dorsomedial prefrontal cortex (dmPFC). Thirty-two patients with MDD received accelerated bilateral dmPFC-iTBS delivered with a double-cone coil.

Heart rate was sampled continuously at 1-second intervals using a low-cost chest-strap sensor, and HRD was quantified as the relative change from a 1-minute pre-stimulation baseline to the mean heart rate across the stimulation window. Response was defined as a 50% or greater reduction in 17-item Hamilton Depression Rating Scale score. Response and remission rates were 65.6% and 56.3%, respectively.

Responders showed greater HRD than non-responders (Cohen’s d = 1.40). HRD discriminated responders with an area under the curve of 0.905; a 2% cutoff yielded 90.5% sensitivity and 81.8% specificity. Each 1% increase in HRD was associated with approximately 2.5-fold higher odds of response.

Stimulation-evoked HRD tracked antidepressant response and is compatible with modulation of a prefrontal-autonomic network; it warrants evaluation in larger sham-controlled studies as a pragmatic, bedside-accessible candidate marker of response. The trial was registered retrospectively at ClinicalTrials.gov (identifier NCT07615387 first posted 29/05/2026). This research was conducted as part of the medical residency thesis of Dr.

The preliminary clinical findings of this study were presented as an oral presentation at the 16th International Congress on Psychopharmacology & Child and Adolescent Psychopharmacology/Psychotherapy (ICP 2025) and were subsequently published as an abstract in the official congress proceedings.Two further analyses from the same cohort, a heart–brain coupling measurement obtained in a separate session and presented at the 4th International and 28th National Clinical Education Symposium of the Psychiatric Association of Turkey (Antalya, April 2026), and resting-state EEG data in preparation, address distinct questions and do not overlap with the present report.This study was funded by Scientific Research Projects Coordination Unit of İstanbul University-Cerrahpasa Rectorate, Istanbul, Turkey [grant number 37949]. The funding source had no role in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication. This study was funded by Scientific Research Projects Coordination Unit of İstanbul University-Cerrahpaşa Rectorate, Istanbul, Turkey [grant number 37949].

Present address: Council of Forensic Medicine, Ministry of Justice, Istanbul, Turkey Department of Psychiatry, Cerrahpaşa Faculty of Medicine, Istanbul University– Cerrahpaşa, Istanbul, Turkey Ali Tarık Altunç, Yusuf Çiçek, Ahmet Torun, Sarp Yoldaş & Burç Çağrı Poyraz Department of Psychiatry, Bakırköy Prof. Mazhar Osman Mental Health and Neurological Diseases Education and Research Hospital, Istanbul, Turkey Brain and Cognition Research Center (BEYKOG), İstanbul Medipol University, Istanbul, Turkey Besikcizade Center for Medicine and Human Sciences (BETIM), Istanbul, Turkey The authors declare no competing interests. The study protocol was approved by the Clinical Research Ethics Committee of Istanbul University-Cerrahpaşa (Approval No: E-83045809-604.01-1014334; June 12, 2024) and was conducted in accordance with the Declaration of Helsinki.