Most people have heard of SAD, or Seasonal Affective Disorder, which is a fancy term for depression that typically has its onset in late fall or early winter a period when the days are getting shorter.
In many cases, treatment with exposure to bright light and/or anti-depressive medications can ameliorate the symptoms. In a recent study investigators sought to determine whether such treatments would be effective for cases of non-seasonal depression.
Led by Dr. Raymond W. Lam of the Department of Psychiatry, University of British Columbia, Canada, several researchers devised a randomized, double-blind, placebo- and sham-controlled, eight-week study in adults aged 19-60 years. All had non-seasonal major depressive disorder. At the beginning and end of the study, each participant completed a Depression Rating Scale, and the difference between the scores was the primary guide to the effectiveness of treatments.
The 122 participants were randomly assigned to one of four treatment groups as follows:
- (1) exposure to a fluorescent light box for 30 minutes early each morning, plus a placebo pill
- (2) exposure to an inactive negative ion generator for 30 minutes per day, plus the anti-depressant fluoxetine (20 mg/day)
- (3) combination of light exposure, plus the active drug
- (4) inactive negative ion generator, plus a placebo pill.
The greatest changes in the Rating Scale at the end of the study were seen in the third group above, the one treated with the combination of both light and drug. The group experiencing the second-most change was the one treated only with light. Some response to the respective treatments was achieved by about three-fourths of the combination group (group 3), and about half of the light treatment group (group 1).
The authors noted that the combination of the two active treatments light and drug were the most effective in terms of both the Rating Scale and the rate of response to treatment. Thus, adding light exposure to drug treatment even in cases that are not associated with seasonal changes may increase the effectiveness of drug treatments. Further replication of these results would increase our confidence in them, of course.