ipRGC as a Potential Biomarker for Predicting Transcranial Magnetic Stimulation Treatment Response in Major Depressive Disorder

This research explores the potential of retinal ganglion cells (RGCs), particularly intrinsically photosensitive RGCs (ipRGCs), as biomarkers for predicting response to transcranial magnetic stimulation (TMS) in treatment-resistant depression (TRD). We also aim to assess the impact of TMS treatment on RGCs and ipRGCs in TRD patients, investigating associations with clinical improvements and cognitive status. A clinical trial involving 44 patients with treatment-resistant depression (TRD) will be conducted. All participants will receive rTMS targeting the dorsolateral prefrontal cortex (DLPFC). Data will be collected pre- and post-intervention, as well as at a 2-month follow-up, using multiple outcome measures, including the post-illumination pupil response (PIPR). The project seeks to confirm the effectiveness of TMS and the potential of RGCs/ipRGCs as predictors of treatment response, thereby facilitating the development of personalized treatment strategies for TRD patients undergoing rTMS therapy.

NCT Number	NCT07474974
Lead Sponsor	Polytechnic Institute of Porto Collaborators: Hospital de Sao Joao, Porto
Conditions	Depression - Major Depressive Disorder, Treatment Resistant Depression
Enrollment	44 participants
Start Date	2026-03-15
Primary Completion	2027-04-30 (estimated)
Study Completion	2027-07-31 (estimated)
Updated on ClinicalTrials.gov	2026-08-06