By Donald Levy, MD
Medical Director, Osher Clinical Center
In late fall, as the days shorten and the temperature drops, some animals begin gathering food for the winter and some go into hibernation. Many people note a change in their behavior and mental outlook during this natural change of season; perhaps a slight downturn in mood, a tendency to eat more carbohydrates and to gain a little weight. For some (1-10%), these symptoms occur annually and may become pronounced and disabling—severe enough to describe a syndrome called seasonal affective disorder, or SAD.
The symptoms of SAD may include depression, fatigue, sleepiness, carbohydrate craving, weight gain and loss of libido. The biochemical aspects of this condition are not fully understood, but include a shift in the circadian rhythm, abnormal secretion of melatonin from the pineal gland and abnormal serotonin metabolism.
Symptoms of S.A.D.
loss of libido
A number of therapies can be effective in relieving the symptom of SAD. One well studied and interesting therapy involves the use of bright light (and more recently, specific wavelengths of light, such as the blue end of the spectrum). Bright light therapy is interesting in that it is simple, effective, well-researched and involves no medications.
This form of treatment involves exposure to an appropriate dose of artificial bright white (10,000 LUX) for about 30 minutes every morning. Some people need a little more or less, and some require a second “dose” later in the day. The eyes must be open, but one may read or work on a hobby during the “treatment”. It is not necessary to look directly at the light. The light is best delivered by a specially-designed lamp that emits clear, glare-free, non-ultraviolet light.
What is the best way to begin? First, consult a physician or licensed mental health therapist to confirm that the symptoms are consistent with SAD. Next, purchase a quality product. In the past, quality lamps cost more than $400.00, but are now available for less than ½ that price. For example, on Amazon.com one can find the Northern Light Technologies products, which include a light that may be used as a desk lamp year round (about $210.00). Another product by Daylight sells for about $145.00.
For additional, reliable information, a good book to read is Winter Blues, Fourth Edition: Everything You Need to Know to Beat Seasonal Affective Disorder by Norman Rosenthal, MD. Doctor Rosenthal was the first to identify SAD as a clinical syndrome while working at the National Institute of Mental Health.
For those with SAD, light therapy may truly brighten what can feel like a long dark winter.