LIGHT IS the first treatment in psychiatry to evolve directly out of modern neuroscience. Yet paradoxically, the biological psychiatry establishment has regarded light therapy with a certain disdain and relegated it to the edge of the paradigm—not molecular enough, a bit too Californian-alternative, a bit too media overexposed, merely a placebo response by mildly neurotic middle-aged women who don't like nasty drugs.
But light is as effective as drugs, perhaps more so. Three articles in this issue provide the best evidence to date that light is an effective antidepressant in seasonal affective disorder (SAD).1- 3 Placebo response4 and nonspecific factors5 are an issue in all clinical trials: for light therapy, "blindness" is not simply an oxymoron. Many psychiatrists are unaware that the advantage of antidepressant drugs over placebo in controlled trials is so small that only multicenter studies can answer questions of relevance.4,6- 7 That 2 single centers1- 2 in large, controlled, blind trials are able to show that light therapy works better than a convincing placebo is therefore extremely important.