A 2015 review of light therapy for depressive symptoms concluded that methodological problems make it hard to say whether this treatment was effective.
The verdict changed in 2016, however, when JAMA Psychiatry published an ambitious, eight-week study by Lam et al. This investigation compared two treatments for Major Depressive Disorder (MDD), and used two placebos.
Specifically, patients were randomized to receive:
- Light and Antidepressant Combination Treatment: light therapy (exposure to 10,000-lux fluorescent white light early in the morning for 30 minutes), plus Prozac (fluoxetine), 20 mgs
- Light Only: light therapy plus placebo pills
- Antidepressant Only: Prozac, 20 mgs, plus a negative ion generator which was inactivated, but hummed as if were working
- Placebos: placebo pills and the inactivated negative ion generator
The results were clear: Light therapy, and the combination of light therapy and an antidepressant, were superior to the antidepressant alone by a large margin.
Michael Terman, PhD, a professor in the psychiatry department of Columbia University, and president of the non-profit Center for Environmental Therapeutics, said:
This is the most impressive clinical trial of light therapy I have seen, whether for SAD (seasonal affective disorder) or non-SAD.
It ran for eight weeks, longer than earlier studies, it used two types of placebo control, and it pitted the response against standard antidepressant medication.
If light had proved ineffective, or only weakly effective by comparison with fluoxetine, it would have consigned light therapy to the dustbin. The dramatic opposite result turns the tables on the choice of somatic treatment for major depression. 10,000 lux light therapy upon awakening – or by implication, a walk outdoors if the sun is up – now can be recommended to patients with recurrent depression, many who will respond without recourse to drugs.
More generally, this study confirms what Thomas R. Insel, MD, former director of NIMH, concludes about antidepressants. While they may help some patients achieve remission, the “bottom line is that these medications appear to have a relatively small effect in patients broadly classified as having depression.” Other, perhaps nonpharmacologic, tools are needed.
What Does This Mean for You as a Patient?
Many patients may not respond optimally to antidepressants. If so, your health care provider can use light therapy with you as an adjunct to medication, or even consider light therapy as the sole therapy.
Further, if you are being treated for major depressive disorder for the first time, you might consider light therapy as the treatment of choice, not just for seasonal affective disorder, but for any affective disorder with a depressive component. Then, if that does not work sufficiently, you may add antidepressants, or other treatments.
To find out about the practical aspects of light therapy, read Light Therapy for Beginners, or the many scholarly papers in Seasonal Affective Disorder and Light Therapy and Later Demonstrations of Light Therapy for Psychiatric Disorders.