Is light therapy an effective treatment for SAD?
More than 60 controlled studies of light therapy have been conducted by researchers around the world. Although there are general limitations to each study (e.g., small sample size, brief treatment periods), several qualitative reviews have concluded that light therapy is an effective treatment for SAD, with response rates of 60% to 90% in controlled studies. Two meta-analyses also confirm the efficacy of light therapy against plausible placebo controls. In large series, the clinical response rate for light therapy is approximately 65%. The most studied light device is the fluorescent light box. The fact that the light box has proven effective in almost every study, regardless of sample size, has placed the light box as the “gold standard” light device. Other light devices include head mounted units, or incandescent light visors. Studies of the head mounter units have shown good clinical response rates (comparable to those of light box studies) but the bright light conditions were no be
