Research

Hormonal

Exposure to bright light (7,000–10,000 lux) for 30–60 minutes daily, particularly in the early morning, is an effective, non-invasive intervention for treating Seasonal Affective Disorder (SAD) and non-seasonal depression.

Use a medical-grade light therapy lamp delivering 7,000–10,000 lux. Sit about 20-35 cm away for 30-60 minutes every morning. You do not need to stare directly at the light; just keep your eyes open and you can read or work. If you have eye conditions like retinal detachment or take photosensitizing drugs, consult a doctor first. Consistency is key: daily use yields the best results.

GoodSupportsHIGH confidence
BLT is nowadays established as first-line treatment for SAD [61, 75] leading to an amelioration of symptoms after a few days of treatment. Light therapy is also effective as second-line treatment for non-seasonal depression, although it usually takes longer (2–5 weeks) than in SAD to achieve a therapeutic effect [2, 75, 87].
Christine Blume et al. · Somnologie - Schlafforschung und Schlafmedizin · 2019

Why this rating

The paper cites it as 'first-line treatment' and 'well-controlled' in multiple contexts, though it is a review of existing literature rather than a single primary trial.

Source

Effects of light on human circadian rhythms, sleep and mood

Christine Blume et al. · Somnologie - Schlafforschung und Schlafmedizin · 2019

DOI 10.1007/s11818-019-00215-x

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DOI resolved against Crossref · corpus check 2026-06-10

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