SAD is estimated to affect more than 10 million Americans. Bright light therapy, where special light boxes are used to treat the depression associated with seasonal affective disorder (SAD), is particularly effective when administered first thing in the morning.

The authors recommend that bright-light exposure be scheduled immediately on awakening in the treatment of most patients with seasonal affective disorder.

A number of previous trials have found light therapy -- exposure to bright artificial light -- more effective in treating SAD than sham or "placebo" therapy. But past studies have come to conflicting conclusions regarding the relative effects of morning and evening light therapy. While many findings suggest that morning therapy is most effective, a few suggest morning and evening therapy are equally effective.

Archives of General Psychiatry 1998;55:863-864,875-882,883-889,890-896.

COMMENT: This is the time of the year where we need to crank out the full spectrum lights. This series of three studies seems to provide compelling evidence that the best time for light therapy is in the morning. I am not a strong advocate of light box therapy however, but I believe that exposure to full spectrum lights in the environment all day long are probably better.

A few points to remember: One can NOT have an incandescent full spectrum bulb. Neodymium bulbs are color corrected and not much better than regular bulbs but much more expensive. Do not be fooled. Fluorescent bulbs are the only one that produce full spectrum light. When searching for them there are a few things to remember about the four foot bulbs as I believe all the compact full spectrum fluorescent come from the same garage. The long bulbs, however are different.

Full sunlight is characterized as having a rating of 5500 with a CRI (color retention index) of 100. That would be perfect. The closer to 5500 the better, higher numbers are not better here, one wants 5500. I have seen bulbs that are 5700 with a CRI of 91. If anyone finds a better bulb, please let me know.