Exposure to bright light-the treatment of choice for seasonal affective disorder, or SAD-may also help people with other mental health conditions including bulimia nervosa, antepartum depression and nonseasonal depression, preliminary research finds.

"The latest news is that light therapy is just as effective as antidepressants in treating nonseasonal depression-it's truly exciting," says Columbia University psychologist Michael Terman, PhD, a SAD researcher who uses both light and medications to treat patients. "The findings almost make me say that it's only by happenstance that light therapy was discovered and developed in the context of SAD."

That said, the literature in the area is still sparse, emphasizes Dan Oren, MD, a veteran SAD researcher at Yale University.

"No one has done any solid head-to-head comparisons that prove that one form of treatment is better than another in treating nonseasonal depression," he notes.

The excitement is the result of several studies that are emerging on the topic, including a meta-analysis in the April 2005 American Journal of Psychiatry (Vol. 162, No. 4, pages 656-662), by University of North Carolina at Chapel Hill psychiatrist Robert Golden, MD, and colleagues concurring that bright light treatment is effective both for SAD and for nonseasonal depression.

"Effect sizes [are] equivalent to those in most antidepressant pharmacotherapy trials," the authors write.

Meanwhile, a 2004 meta-analysis conducted for The Cochrane Collaboration, a not-for-profit organization that prepares systematic reviews of health-care therapies, found that light therapy offered help for nonseasonal depression, especially when administered during the first week of treatment, in the morning and as an adjunct to antidepressants. A revision of that meta-analysis is currently under way, Terman notes, indicating that light therapy plus medications is probably the best approach.

-T. DeAngelis