STUDY SUMMARY
Light therapy improves nonseasonal depression
This latest study was an eight-week, randomized, double-blind, placebo- and sham-controlled clinical trial evaluating the benefit of light therapy with and without pharmacotherapy for nonseasonal MDD.1 The investigators enrolled 122 adult patients (ages 19 to 60) from outpatient psychiatry clinics who had a diagnosis of MDD (diagnosed by a psychiatrist) and a HAM-D8 score of at least 20. Subjects had to be off psychotropic medication for at least two weeks prior to the first visit; they were subsequently monitored for one week to identify spontaneous responders and give patients time to better regulate their sleep-wake cycle (with the goal of sleeping only between 10 PM and 8 AM daily).
The investigators randomly assigned patients to one of four treatment groups:
• Active light monotherapy (10,000-lux fluorescent white light for 30 min/d early in the morning) plus a placebo pill
• Fluoxetine (20 mg/d) plus sham light therapy
• Placebo pills with sham light therapy; or
• Combined active light therapy with fluoxetine (20 mg/d).
Sham light therapy consisted of the use of an inactivated negative ion generator, used in the same fashion as a light box. All patients were analyzed based on modified intention to treat. Adherence was assessed through review of patients’ daily logs of device treatment times and through pill counts.
The primary outcome at eight weeks was the change from baseline in the Montgomery-Asberg Depression Rating Scale (MADRS), a 10-item questionnaire with a worst score of 60.9 Secondary outcomes were treatment response (≥ 50% reduction in MADRS score) and remission (MADRS score ≤ 10) at the final eighth-week visit. MADRS scoring was used because of its sensitivity to treatment-induced changes and its high correlation with the HAM-D scale.
At the end of eight weeks, the mean changes in MADRS scores from baseline were: light monotherapy, 13.4; fluoxetine monotherapy, 8.8; combination therapy, 16.9; and placebo, 6.5. The improvement was significant in the light monotherapy treatment group and in the combination therapy group, compared with the placebo group, and in the combination group, compared with the fluoxetine treatment group; improvement was not significant for the fluoxetine treatment group compared with the placebo group, however.
The treatment response (≥ 50% MADRS improvement) rate was highest in the combination treatment group (75.9%), followed by light monotherapy (50%), placebo (33.3%), and fluoxetine monotherapy (29%). There was a significant response effect for the combination versus placebo treatment group.
Similarly, there was a higher remission rate in the combination treatment group (58.6%) than in the placebo, light monotherapy, or fluoxetine treatment groups (30%, 43.8%, and 19.4%, respectively). Combination therapy was superior to placebo in treatment response (≥ 50% reduction in the MADRS score) and remission (MADRS ≤ 10), with numbers needed to treat of 2.4 and 3.5, respectively.
By the end of the eight-week study period, 16 of 122 patients had dropped out. Two reported lack of efficacy, five reported adverse effects, and the remainder cited administrative reasons, were lost to follow-up, or withdrew consent.
WHAT’S NEW
New evidence on a not-so-new treatment
We now have evidence that bright light therapy, either alone or in combination with fluoxetine, is efficacious for increasing the remission rate of nonseasonal MDD.
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