Thirty minutes of bright light each morning beat placebo for non seasonal depression
In a double blind trial of 122 outpatients, 10,000 lux light for 30 minutes each morning for eight weeks beat placebo (d = 0.80): 43.8% in remission against 30.0%. Fluoxetine alone did not beat placebo here; light plus fluoxetine did best.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: Small trial, about thirty per arm, wide confidence intervals, eight weeks only. The fluoxetine-versus-placebo null is underpowered and should not be read as the drug failing in general; the combination that included fluoxetine did best. Modified intention-to-treat analysis. Light boxes cost money, and outdoor light was not what was tested.
Bright light is an accepted treatment for winter depression. This trial asked whether it works for the ordinary kind.
Significant findings
Lam, Levitt, Levitan and colleagues randomised 122 adults aged 19 to 60 with at least moderately severe non seasonal major depression, in academic outpatient psychiatry clinics, to one of four arms for eight weeks: a 10,000 lux light box for 30 minutes each early morning plus a placebo pill (32 people); fluoxetine 20 mg a day plus an inactive ion generator as the sham light (31); both active treatments (29); or placebo pill plus sham light (30). The trial was double blind.
Depression scores fell by 13.4 points with light, 8.8 with fluoxetine, 16.9 with the combination and 6.5 with placebo. "The combination (effect size [d] = 1.11; 95% CI, 0.54 to 1.64) and light monotherapy (d = 0.80; 95% CI, 0.28 to 1.31) were significantly superior to placebo in the MADRS change score, but fluoxetine monotherapy (d = 0.24; 95% CI, -0.27 to 0.74) was not superior to placebo."
Remission at eight weeks: placebo 30.0%, fluoxetine 19.4%, light 43.8%, combination 58.6%. "All treatments were generally well tolerated, with few significant differences in treatment-emergent adverse events."
The other direction
This is one trial of 122 people, with about 30 in each arm, and the intervals are wide. The antidepressant's failure to beat placebo here is one small trial's result, not a verdict on the drug, and the combination arm, which included the drug, did best of all. Nothing in this row is a reason to start, stop or change a medication; that is a conversation with a prescriber.
What this does not show
A 10,000 lux box was tested, not a bright morning outdoors. The trial ran eight weeks and does not say what happens after.
Worth asking
Is thirty minutes of bright light in the morning something worth adding to what I am already doing?
Source
Efficacy of bright light treatment, fluoxetine, and the combination in patients with nonseasonal major depressive disorder: a randomized clinical trial — Lam RW, Levitt AJ, Levitan RD, Michalak EE, Cheung AH, Morehouse R, Ramasubbu R, Yatham LN, Tam EM (2016)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1001/jamapsychiatry.2015.2235
DOI: 10.1001/jamapsychiatry.2015.2235
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Funding not disclosed
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 122
- Preregistered
- Yes
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 24, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 68 out of 100 on our published rubric. One caveat travels with that badge: Small trial, about thirty per arm, wide confidence intervals, eight weeks only. The fluoxetine-versus-placebo null is underpowered and should not be read as the drug failing in general; the combination that included fluoxetine did best. Modified intention-to-treat analysis. Light boxes cost money, and outdoor light was not what was tested. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Efficacy of bright light treatment, fluoxetine, and the combination in patients with nonseasonal major depressive disorder: a randomized clinical trial — Lam RW, Levitt AJ, Levitan RD, Michalak EE, Cheung AH, Morehouse R, Ramasubbu R, Yatham LN, Tam EM (2016). Published in: Top-tier peer-reviewed journal. DOI: 10.1001/jamapsychiatry.2015.2235. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Funding not disclosed. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.