If you’ve been feeling down and out, it could have to do with the shortening length of daylight. Symptoms of Seasonal Affective Disorder (SAD), also known as winter depression, winter blues or seasonal depression, begin in the fall as daylight shifts and the days get shorter, a change that may be accentuated by daylight saving time.
Paul Desan, MD, director of the Yale Psychiatric Consultation Service, says the problem affects thousands of people, enough to make it an “unrecognized public health problem.” He often gets calls from physicians seeking advice on treating the problem. SAD became an accepted clinical diagnosis in the 1980s.
“Research suggests that 15 percent of people at the latitude of Connecticut have changes severe enough to consider getting treatment,” Dr. Desan says. Two percent of people at this latitude experience enough symptoms to constitute major depression. Researchers believe that shorter days and nights of fall and winter can throw off circadian rhythms—the internal sleep and wake cycle—leading to depressive symptoms. Seasonal changes usually begin to occur during early adulthood, and are four times more likely to affect women than men.
While each person may experience SAD differently, the symptoms can include:
- Increased sleep and daytime drowsiness
- Changes in energy level
- Social withdrawal
- Sadness, irritability
- Fatigue, or low energy level
- Decreased sex drive
- Diminished concentration
- Difficulty thinking clearly
- Increased appetite, especially for especially sweets and carbohydrates
- Weight gain
“Actually, if you handed out a questionnaire, 9 out of 10 people would report having at least one of these symptoms, so this is probably part of a basic human pattern,” says Dr. Desan.
Anyone whose symptoms interfere with their daily routine should consider light therapy, says Dr. Desan. While the FDA has not approved a light therapy device—and not all insurers will cover one—many doctors recommend buying a medical-grade 10,000 lux light box from a reputable manufacturer (beware of devices sold on the internet that don’t have a doctor’s approval). They tell patients to use it for 30 minutes before 8 o’clock every morning, when research has found treatment to be most effective.
“Research suggests light earlier in morning is more powerful than later in the morning, so just going outside at lunchtime and eating your lunch outdoors is probably not going to be enough,” Dr. Desan says. Symptoms of the disorder start to clear up as the spring progresses, when the days get longer again.