Bright-light therapy

Domain IX · Biomedical, neuro & digital

What it is

Source note (October 2026): treatment lines are taken from the full text of the CANMAT 2023 update and the ISBD 2025 recommendations; CBT-SAD structure from Rohan et al. (2015) and the Oxford Academic chapter pages of Rohan's therapist guide. Still: whether the final NICE NG222 guideline makes any…

Format

• Phase 1: Recognition and assessment (psychotherapist, 1–2 sessions within ongoing therapy). Goal: notice a recurring seasonal pattern and gather a clear history. NHS notes a diagnosis usually requires depressive symptoms at the same time of year for at least two years. UBC warns that depressive…
• Phase 3: Initiation (medical team; therapist supports). In the Rohan trial a scripted instruction session covered device set-up and positioning, the rationale, instructions and possible side effects. ISBD describes the prescriber adapting the starting regimen where hypomania is a concern or…

Who practises it, and how they are trained or regulated

• Who delivers it and regulatory status (checked October 2026):
• United States: light boxes are not approved or regulated by the FDA specifically for seasonal affective disorder; they are sold without prescription and insurance usually does not cover them (as of October 2026 per a Mayo Clinic Health Information Library page updated January 2025). The UBC page advises a UL safety approval for US use.
• Canada: the UBC SAD clinic states light devices are not well regulated in Canada and advises CSA-approved devices with a UV filter that have been tested in scientifically valid studies.

Evidence status, as the guide reports it

• Bright-light therapy (BLT) means sitting daily in front of a device that gives bright, diffuse, UV-filtered white light, usually a light box, to treat depression with a seasonal (winter) pattern and, as an adjunct, some non-seasonal and bipolar depressions. Sources describe it as a chronobiological…

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?
• Does it involve fasting, a special diet or 'detox'? Have you discussed this with your doctor?
• 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?
• 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

• clients enjoying elevated energy and not wanting to report it.
• overselling ("it's just a lamp") or dismissing it; correct both.
• activities that depend on good weather; build indoor and dark-evening options.
• pressure from others, financial strain, or a client hoping you will choose for them.
• the client starting with an online purchase before review; respond with information, not prohibition.

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.