Bright light therapy, an effective treatment for seasonal affective disorder, also is efficacious for nonseasonal major depressive disorder either as a monotherapy or with fluoxetine, a new study shows.
Dr. Raymond W. Lam of the department of psychiatry at the University of British Columbia in Vancouver, and his colleagues conducted the study by recruiting 122 patients aged 19-60 years with a DSM-IV-TR diagnosis of major depressive disorder (MDD). The participants were randomized to receive one of four interventions: 30 minutes of morning light therapy plus a placebo pill; fluoxetine plus a sham negative-ion generator; a combination of light therapy plus fluoxetine; or placebo pill plus sham ion-negative ion generator. Their results were published online Nov. 18 in JAMA Psychiatry.
The patients were evaluated by a blinded, independent evaluator by telephone. Response was measured by 50% or more reduction of the baseline Montgomery-Åsberg Depression Rating Scale (MADRS). A MADRS score of 10 or less was considered remission.
The mean change in MADRS score from the start of the study through 8 weeks was 16.9 for combination therapy, 13.4 for light therapy, 8.8 for fluoxetine, and 6.5 for placebo. The differences were noted to be significant for combination therapy vs. placebo (P less than .001) and light therapy vs. placebo (P = .006). However, they noted no significant difference between fluoxetine vs. placebo (P = .32).
Response was achieved by 75.9% for those on the combination therapy, 50% for the light therapy alone, 33.3% for placebo, and 29% for fluoxetine therapy. Remission was achieved by 58.6% for combination therapy, 43.8% for light therapy, 30% for placebo, and 19.4% for fluoxetine. The number needed to treat for response and remission in the combination-therapy group, compared with the placebo group, was 2.4 (95% confidence interval, 1.6-5.8) and 3.5 (95% CI, 2.0-29.9), respectively.
Dr. Lam and his colleagues noted that the treatments were well tolerated overall.
“The main result of this study was that both light monotherapy and the combination treatment had significant benefits, compared with a sham-placebo condition in adults with nonseasonal MDD,” they wrote.
The study was supported by a grant from the Canadian Institutes of Health Research. Dr. Lam reported several disclosures, including receiving research funds from Lundbeck and Pfizer. He also served as a consultant to and/or received honoraria from several pharmaceutical companies, including AstraZeneca, Bristol-Myers Squibb, Eli Lilly, Johnson & Johnson, Lundbeck, Otsuka, Pfizer, and Takeda. The other authors also reported multiple disclosures.