PHOTObiomodulation for REsistant Depression Study: An Open-Label Pilot Trial on Transcranial Photobiomodulation for...

Area of Science:

• Neurology
• Psychiatry
• Biomedical Engineering

Background:

• Treatment-resistant depression (TRD) poses a significant clinical challenge, necessitating novel therapeutic strategies.
• Transcranial photobiomodulation (tPBM) is an emerging noninvasive neuromodulation technique with potential antidepressant effects.
• Evaluating the efficacy and safety of whole-brain tPBM in TRD patients is crucial for advancing treatment options.

Purpose of the Study:

• To assess the acute effects of a whole-brain tPBM protocol on depressive symptoms in TRD patients.
• To evaluate the safety and tolerability of the tPBM intervention.
• To determine clinical response and remission rates following tPBM treatment.

Main Methods:

• A prospective, open-label, single-arm pilot trial involving 29 adult TRD outpatients.
• A standardized whole-brain tPBM protocol using a near-infrared light helmet (810 nm) was administered three times weekly for 4 weeks.
• Primary outcome: clinical response (≥50% reduction in Montgomery-Åsberg Depression Rating Scale [MADRS] scores) at 4 weeks.

Main Results:

• Significant reduction in MADRS scores from baseline (35.5 ± 6.9) to post-treatment (22.9 ± 11.2) (p < 0.001).
• Clinical response rates were 40.9% (per-protocol) and 31.0% (intention-to-treat).
• Mild-to-moderate adverse events, primarily headaches (50.0%), were reported by 63.6% of participants; no serious adverse events occurred.

Conclusions:

• A 4-week whole-brain tPBM protocol demonstrated clinically meaningful antidepressant effects in TRD patients.
• The tPBM protocol was well-tolerated, supporting its feasibility as a noninvasive neuromodulation strategy.
• Larger, randomized, sham-controlled trials are recommended to confirm efficacy and optimize tPBM parameters for TRD treatment.