Official recommendations

In the 20 years since the initial discovery of light therapy and circadian rhythms, thousands of studies involving several thousand participants have demonstrated the validity of light therapy for the treatment of these chronobiological disturbances.^{1 2} Dozens of medical journals report on the efficacy of light therapy (See footnotes below for a partial list). The National Institute of Health as well as major research universities and medical associations have established light therapy as a mainstream treatment.^{3 4 5 6 7 8} These studies have been confirmed through multiple independent replications of placebo-controlled trials. Most northern US hospitals, and all Canadian hospitals have Winter Blues clinics.

Treatment of choice

Reviews in Archives of General Psychiatry, JAMA and other medical journals recommend light therapy as the treatment of choice for Winter Blues.^{9 10 11 12 13} Light is generally recommended first because of the quick response and high response rate. Most patients respond within a week. Although some studies show response rates as high as 90%, large clinical trials show response rates of 65% and 75%.^{14 15} Another reason light is preferred is that it is more effective than other treatments and side effects are more benign and better tolerated.^{16 17} One recent journal concluded,

"[Light] meets 3 essential criteria for use in clinical practice: (1) specific antidepressant efficacy as gauged against placebo controls, (2) lack of clinically significant ocular changes, and (3) a favorable side effect profile."¹⁸

Official recommendations

Winter Blues and its treatment are described in the DSM IV.¹⁹ Light therapy is also recommended by the Society for Light Treatment and Biological Rhythms (SLTBR),²⁰ the U.S. Public Health Service Agency for Health Care Policy and Research,^{21 22} American Psychiatric Association,²³ and the American Academy of Sleep Medicine (for sleep disturbances).²⁴ The American Medical Association is currently reviewing recommendation guidelines for its Recognition Program.²⁵