Q: What is seasonal affective disorder, and how do I manage it?

A: Seasonal affective disorder (SAD) is a subtype of major depression marked by mood symptoms classically worsening in the late fall and winter months. It must recur for at least two consecutive years and remit as the days lengthen in the spring. One possible cause of SAD is reduced sunlight exposure disrupting your circadian rhythms, or biological clock. This impacts various neurotransmitters in the brain. SAD is far more prevalent in northern latitudes (of the northern hemisphere) where daylight may only last 3 to 6 hours in winter. Other causes of depression should be ruled out by your physician before concluding SAD is the problem. Standard antidepressants and psychotherapy may be helpful. A more specific treatment for SAD is phototherapy with broad-spectrum lights. This is not the light in a tanning bed, which can be harmful to your skin. Talk to your doctor if you think SAD may be affecting you to discuss treatment options. Unfortunately, health insurers will not pay for your "therapeutic" trip to the sunny islands to treat SAD.

-- Dr. Jon Cohen, Behavioral, Health Associates; member, Chattanooga-Hamilton County Medical Society

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