Near-infrared Transcranial Laser Therapy in Subjects With Major Depressive Disorder

Brief Summary

Major depressive disorder (MDD) is a leading cause of disability worldwide, and many patients do not achieve adequate benefit from current treatments. Transcranial photobiomodulation (tPBM) is a non-invasive neuromodulation technique that delivers near-infrared (808 nm) light through the scalp to frontal brain regions involved in mood regulation. Preclinical and early clinical studies suggest that tPBM may improve symptoms of depression and enhance cortical function. This randomized, sham-controlled, parallel-group trial evaluates the efficacy, safety, and neural effects of tPBM in adults with MDD. Participants are assigned to one of four groups: Continuous Wave, Medium Dose (CW), Continuous Wave, Low Dose (CW\_LOW), Pulsed Wave (PW), or Sham treatment. Interventions are delivered 3 times a week for 6 weeks (total of 18 sessions) to bilateral frontal scalp sites (AF3/F3 and AF4/F4). The primary outcome is change in depressive symptoms measured by the Hamilton Depression Rating Scale (HAMD-17) from baseline to the end of treatment (Week 6, Visit 18). Secondary outcomes include changes in self-reported depression scales (QIDS, SDQ), regional brain glucose metabolism measured by FDG-PET, and resting-state EEG markers. Safety and tolerability are assessed throughout the trial, including adverse events, scalp/site reactions, and suicidality screening. This study will provide proof-of-concept evidence for the clinical efficacy and mechanistic effects of tPBM in major depression and will inform the design of larger, multicenter clinical trials.