Each autumn, as the days grow shorter, millions of people get the blues. They may experience mild to severe depression, weight gain, lethargy, a desire to sleep more, and an increased appetite or cravings for carbohydrates such as cakes and cookies. Almost magically in spring, their symptoms wane. They feel energized, sociable, and generally happy. Their malady: seasonal affective disorder, or SAD, a form of depression most likely to occur in winter.
For about 5 percent of people, the condition is severe enough to interfere with daily activities, work, and relationships, says Norman E. Rosenthal, M.D. Another 15 percent experience milder symptoms known as subsyndromal SAD (S-SAD).
Scientists have studied SAD as a psychological disorder since the 1980s, when Dr. Rosenthal, formerly of the National Institute of Mental Health, named the illness. Researchers don't fully understand what causes SAD, only that it is connected to light received by the brain through the eyes. One theory is that light affects the hormone melatonin, which peaks in the brain at night and regulates your internal body clock. Another is that light tinkers with the neurotransmitter serotonin, a mood-regulating chemical in the brain.
There is no test for SAD. Diagnosis is based on the cluster of symptoms, which usually begin around October and fade around April and appear for two or more consecutive winters.
Because other conditions such as low thyroid functioning can mimic SAD, talk with your doctor before attempting to treat yourself, especially if you are severely depressed. Some home remedies may complement treatment. If your symptoms are mild, try a few of these tips.
Severe seasonal affective disorder can be helped by antidepressants such as selective serotonin reuptake inhibitors, or SSRIs. See a doctor if your symptoms are getting in the way of your work or relationships, says Norman E. Rosenthal, M.D.
Also get help if you feel despair about the future or are suicidal, or if you have major sleep or eating changes, such as a weight gain of 15 or 20 pounds.
"It's a matter of degree and a matter of dysfunction, versus unpleasantness or inconvenience," Dr. Rosenthal says. If self-help strategies aren't effective, seek guidance as well.
Don't use light therapy without consulting your physician and your eye doctor, says Brenda Byrne, Ph.D. Some medications may make your eyes sensitive to light.
Brenda Byrne, Ph.D., is a psychologist and director of the seasonal affective disorder program of the light research program at Jefferson Medical College of Thomas Jefferson University in Philadelphia.
Norman E. Rosenthal, M.D., is a clinical professor of psychiatry at Georgetown University in Washington, D.C., and a former senior researcher at the National Institute of Mental Health. He is the medical director of Capital Clinical Research Associates and the author of Winter Blues: Seasonal Affective Disorder and The Emotional Revolution.
Andrew Weil, M.D., is a clinical professor of medicine and director of the program in integrative medicine at the University of Arizona in Tucson. He is the author of several books, including 8 Weeks to Optimum Health; Natural Health, Natural Medicine; and Healthy Aging.