Light Therapy for Nonseasonal Depression?

Steven Dubovsky et al.
2015-12-03
Normalization of circadian rhythms may be a reason for the apparent usefulness of artificial bright light.

To investigate the potential usefulness of artificial bright light in nonseasonal depression, investigators in Canada randomized 122 medication-free patients with moderately severe, nonpsychotic, nonbipolar major depression to one of four 8-week, double-blind treatments: fluoxetine (20 mg) + 30 minutes of bright light (10,000 lux) in the mornings, pill placebo + bright light, fluoxetine + light placebo (inactive negative-ion generator), or double placebo (pill + ion generator). No patients had seasonal affective disorder.

On the primary outcome (reduction of depression), only the active combination and bright light alone were significantly superior to placebo (effect sizes, 1.11 and 0.80, respectively). In secondary analyses, the combination of active treatments (but not either one alone) was significantly better than placebo in producing response and remission (numbers needed to treat, 2.4 and 3.5, respectively).