By Bower, B.
Science News , Vol. 167, No. 17
A new scientific era may have dawned for light therapy, a potential depression fighter that has languished in the shadows of anti-depressant medication and psychotherapy for the past 20 years.
A research review commissioned by the American Psychiatric Association in Washington, D.C., concludes that in trials, daily exposure to bright light is about as effective as antidepressant drugs in quelling seasonal affective disorder (SAD), or winter depression, and other forms of depression.
"I now tell my patients that light therapy is a reasonable depression treatment, even if the data base for this approach is relatively small," says psychiatrist Robert N. Golden of the University of North Carolina at Chapel Hill. Golden directed the new statistical review, which appears in the April American Journal of Psychiatry.
Like many mainstream psychiatrists, Golden had been skeptical of studies reporting that depression diminishes in response to daily bright-light exposure, usually administered early in the morning for 30 minutes to 1 hour. These investigations often contain serious flaws, he says, such as few participants and no groups treated with dim lights or other placebos.
The new review supported Golden's skepticism about research quality. Of 173 published light-treatment studies that his team considered, only 20 passed muster on their design and controls. Those tests lasted between 1 week and 6 weeks and typically included about 20 participants. But to Golden's surprise, pooled data from the acceptable investigations showed markedly eased SAD symptoms from both bright-light exposure after awakening and dawn simulation, in which a light box each morning provides a sleeping person with gradually intensifying illumination.
Moreover, light therapy yielded substantial relief for outpatients with mild-to-moderate depression unrelated to any season. …