Photobiomodulation

Domain IX · Biomedical, neuro & digital

What it is

What it is: photobiomodulation (also called low-level light or laser therapy, and marketed as "red light therapy") is the application of red or near-infrared light from a laser or LED device. In the transcranial form, light is aimed through the scalp and skull with the aim of acting on the brain.

Format

• An open-label pilot (Monteiro et al., 2026; 29 outpatients with treatment-resistant depression; no control group) reported an intention-to-treat response rate of 31.0% and remission of 6.9%, and says sham-controlled trials "are warranted to confirm efficacy".
• Decision support: usually 1–2 sessions, built into ongoing therapy. Goal: an informed choice that keeps established care in place. Move on once the client has the facts, has the questions to ask the prescriber or study team, and has agreed a plan for monitoring.

Who practises it, and how they are trained or regulated

• This is not a phased therapy, so the framework describes (a) where the method stands in regulation and evidence and (b) the phases of the psychotherapist's involvement.
• United States, devices for the brain or mental health: NIH-funded trial consent forms state that the near-infrared device used is FDA-cleared for muscle aches and joint pain, "not, however, FDA approved to treat depression" (NCT04366258), and not cleared for mild cognitive impairment (NCT04784416); both call the procedures experimental. Alzforum (May 2024) lists FDA status for Alzheimer's disease, mild cognitive…
• US consumer "wellness" route: FDA's General Wellness guidance (final, January 2026) covers low-risk products that promote a healthy lifestyle and are not intended to diagnose, cure, mitigate, prevent or treat disease. According to a law-firm summary, a product is not low-risk if it uses technology that poses a safety risk without specific controls. Whether a given light device qualifies depends on the product and…

Evidence status, as the guide reports it

• Ji et al. (2024, Frontiers in Psychiatry): a meta-analysis of 11 RCTs (407 participants) concluding that PBM reduces depression symptoms, with GRADE certainty rated moderate for depression and very low for sleep. The authors list as limitations small samples, unclear blinding in some trials, and…

Questions to explore with your client

• What drew you to it, and what are you hoping it will change?
• Does it involve any substance, plant preparation, remedy or supplement? Has your doctor or prescriber been told, especially about any medication you take?
• Is it a group, retreat or community? How do they respond if someone wants to leave or raises a concern?
• How do you and the practitioner understand what is happening, in spiritual or cultural terms? Is that a source of comfort, worry, or both?
• Does it use a device, heat, cold, water or a physical procedure? Has a medical professional checked that it is safe for you?
• Who runs it, and what training or registration do they hold?
• What actually happens in a session or meeting, and how often?
• What does it cost, and is there pressure to commit to more?
• How do you feel afterwards, in the hours and days that follow?
• Does it fit with, or clash with, the work we do here?

What practitioners of it watch for

• hopelessness after a failed "last hope". Working: the plan is used and updated.
• escalating use when no effect is felt. Working: the client seeks medical review.
• abrupt stopping, secrecy. Working: the client brings the decision to the prescriber.
• splitting (team as hopeful, therapist as sceptic). Working: one shared plan and clear contacts.
• guilt or pressure from parent networks. Working: the decision is taken with the child's doctor.

When to involve someone else

• New or worsening physical symptoms, or advice to stop or change prescribed medication: involve the client's doctor or prescriber.
• Signs of coercion, isolation from family and friends, escalating costs or secrecy: discuss openly and consider safeguarding.
• A crisis or thoughts of suicide: follow your crisis protocol. In the US, call or text 988; in the UK and Ireland, Samaritans on 116 123.

Drawn automatically from the guide's own sections. Stay curious: neither endorse nor dismiss what the client values, and check anything that matters against the full guide and its sources. Not medical advice.