May 22, 2015
May 19, 2015—Toronto, Ontario, Canada— Light therapy, both as monotherapy and in combination with fluoxetine, has been found to be efficacious in the treatment of patients with nonseasonal major depressive disorder. This result of a double-blind, randomized, placebo-controlled trial was presented at the 168th Annual Meeting of the American Psychiatric Association from May 16 – 19.
Raymond Lam, MD, of the University of British Columbia, Vancouver, Canada, explained that bright light therapy is an evidence-based treatment for seasonal depression, but limited evidence supports its efficacy in nonseasonal major depressive disorder. Dr. Lam and his team determined the efficacy of light therapy, alone and in combination with fluoxetine, in nonseasonal major depressive disorder.
Three Canadian centers participated in this 8-week trial. Entry criteria included Diagnostic and Statistical Manual of Mental Disorders 4 criteria for major depressive disorder of at least moderate severity. Active medical illness or substance use, bipolar disorder, seasonal major depressive disorder, and treatment resistance were excluded.
Patients were randomly assigned to one of four interventions: (1) active light monotherapy (active 10,000 lux fluorescent white light box for 30 minutes daily) plus placebo pill; active antidepressant monotherapy (placebo inactive negative ion generator for 30 minutes daily plus fluoxetine 20 mg); combined light and antidepressant (active light box plus fluoxetine); or placebo (placebo inactive negative ion generator plus placebo pill).
The primary outcome measure was change in Montgomery-Åsberg Depression Rating Scale score, with secondary outcomes of response (≥50% reduction) and remission (≤12).
A total of 131 patients were screened and 122 randomized. The overall probability of change in score on the Montgomery-Åsberg Depression Rating Scale was significant, with post hoc tests showing that light monotherapy (P = .025) and light + fluoxetine combination (P = .001) were superior to placebo, while fluoxetine monotherapy was not.
The light + fluoxetine combination was also superior to fluoxetine monotherapy (P = .028). Similarly, the combination of light + fluoxetine was superior to both placebo and fluoxetine monotherapy for response and remission rates, and light monotherapy was superior to placebo.
Dr. Lam concluded that light therapy, both as monotherapy and in combination with fluoxetine, was found to be efficacious in the treatment of patients with nonseasonal major depressive disorder. The combination of both light and fluoxetine appeared to confer the greatest efficacy.