Light Therapy Highly Effective for Major Depression

The combination of bright light therapy plus an antidepressant significantly improves nonseasonal major depressive disorder, and light therapy alone is more effective than antidepressant monotherapy, a randomized, placebo-controlled trial suggests.

"I've studied bright light therapy in winter depression for a long time, but we always thought that winter depression was different from nonseasonal depression," Raymond Lam, MD, University of British Columbia, Vancouver, Canada, told Medscape Medical News.

"So this was the first study that was placebo-controlled, and I think that while light therapy could be used on its own for some patients, more severely ill patients need combination therapy, whether that combination be an antidepressant plus psychotherapy or psychotherapy plus light therapy or light therapy plus an antidepressant."

The study was published online November 18 in JAMA Psychiatry.

The trial randomly assigned 122 patients to light therapy alone for 30 minutes a day; a placebo device, which was a negative ion generator; the combination of light therapy plus fluoxetine (multiple brands), 20 mg a day; or a negative ion generator plus placebo. Approximately 30 patients were enrolled in each of the four treatment groups.

Patients had a score of 20 or higher on the Hamilton Depression Rating Scale at baseline. The mean duration of the current major depressive disorder episode ranged from a low of 45 weeks in the placebo group to a high of 90 weeks in the combination group.

Major depressive disorder (MDD) affects at least 5% of the population, with a lifetime prevalence estimated at 14%. It is the second-ranked cause of disability worldwide and is associated with impairment in quality of life, increased risk of mortality, and societal burden. Treatments for MDD include psychotherapies and antidepressants, but remission rates remain low despite adequate treatment and more therapeutic options are needed.

Light therapy, an effective treatment for seasonal affective disorder (SAD), may also be appropriate for MDD. Bright light is a safe, well-tolerated, nonpharmacological treatment that can be used alone or combined with medications. Light can correct disturbed circadian rhythms, which have been implicated in the pathophysiology of MDD. Previous meta-analyses of light therapy for nonseasonal MDD, however, have yielded only equivocal and conflicting evidence for efficacy. Two more recent systematic reviews both concluded that the quality and methods of the identified studies were too heterogeneous to conduct a meta-analysis. They each found insufficient evidence for efficacy of bright light monotherapy, although 1 review found low-quality evidence for bright light as adjuvant treatment to antidepressants.

The mean Montgomery-Asberg Depression Rating Scale (MADRS) score at week 0 was approximately 22 in all treatment groups.