Researchers at the National Center of Neurology and Psychiatry (NCNP) in Tokyo have opened a single‑arm, 12‑week pilot trial testing combined transcranial and intranasal photobiomodulation (PBM) in patients with schizophrenia. The study is registered in the Japan Registry of Clinical Trials (jRCTs032240756) and approved by the NCNP Clinical Research Review Board (CR24‑003).

Trial design, endpoints and measures

The study will recruit up to 25 participants with schizophrenia and below‑average cognitive performance. Participants will receive on‑site PBM three times per week for 20 minutes across 12 weeks. The primary endpoint is safety and tolerability; secondary outcomes include cognitive function measured by the MATRICS Consensus Cognitive Battery (MCCB), mismatch negativity (MMN) from EEG, and frontal hemodynamics by near‑infrared spectroscopy (NIRS). Assessments occur at baseline, 3 months (end of intervention) and 6 months. The protocol sets a 20% dropout allowance.

The protocol is explicitly exploratory. Its sample size calculation used an assumed MCCB change of 3 points, a standard deviation of 6, an effect size of 0.5, two‑sided α = 0.10 and 70% power, yielding a target of 20 participants before adding the dropout margin.

Device, dosing and safety focus

The intervention uses the Vielight Neuro Gamma 4 system. The planned stimulation is 810 nm near‑infrared light pulsed at 40 Hz with a 50% duty cycle for 20 minutes per session. The protocol specifies energy densities of 60 J/cm2 over the frontal area and 15 J/cm2 each for the occipitoparietal and intranasal sites. Output power densities are listed as 100 mW/cm2 (frontal) and 25 mW/cm2 (occipitoparietal and intranasal).

Because PBM devices like Vielight are marketed as low‑risk wellness devices, the study focuses first on adverse events, session‑by‑session tolerability and adherence. The team will record side effects using a predefined checklist before and after each session and will code events with MedDRA. Participants will continue usual medications under physician supervision; concurrent rTMS or tDCS is not explicitly excluded.

The protocol notes one prior randomized PBM trial in schizophrenia that found no cognitive benefit and frames this work as a safety and feasibility step to inform future controlled studies.

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Tags: photobiomodulation, schizophrenia, Vielight Neuro Gamma, MATRICS (MCCB), near-infrared

Topics: Non-invasive brain stimulation, Neuromodulation, Wearable neurotech