When the weather gets cold and the days grow short, half a million people around the world fall into a depression called Seasonal Affective Disorder (SAD). “SAD can be severely debilitating; it adversely affects the sufferer’s ability to work and socialize,” says Stephen Ilardi, author of The Depression Cure: The Six Step Program to Beat Depression Without Drugs. Subsyndromal Seasonal Affective Disorder (SSAD), a less-severe version, makes many more people sad and sluggish, with less mental clarity and less restful sleep, Ilardi says.
Winter’s light deprivation affects sleep, energy and hormone levels, Ilardi says, and the winter sun’s rays are too shallow to penetrate skin and stimulate your body to make vitamin D, an important brain nutrient. By the end of winter, many Americans are vitamin D-deficient. (Vitamin D supplements can be effective against SAD. Most adults require 1,000 to 2,000 international units (IU) a day in winter to keep blood levels in the optimal range, Ilardi says.)
How do I know if I have SAD?
People with SAD notice a severe change in mood in winter months. Symptoms include energy loss, intensely sad moods, social withdrawal, oversleeping, difficulty concentrating, feelings of worthlessness, appetite changes and intense carbohydrate cravings that lead to weight gain.
Who gets SAD?
SAD is more prevalent in cold climates. People with jobs that keep them inside, with a history of depression and other mood disorders, and with Mediterranean, Middle Eastern or African ancestry are more vulnerable to SAD, Ilardi says. “People whose ancestors were from Iceland and the Arctic Circle have a shockingly low rate of SAD. It’s likely due to the natural selection process; people with genes that protect them from SAD chose to stay in colder climates, and people who were affected negatively by the climate migrated away, or produced fewer offspring.”
What can I do?
Bright light therapy has been shown to be as effective as antidepressants in treating SAD. “Light therapy is fast-acting with fewer side effects. People using light therapy will usually see improvement within five days, versus two to four weeks with antidepressants,” Ilardi says.
The Columbia University Winter Depression program recommends daily exposure to a light box of 10,000 lux (100 times brighter than indoor lighting) for 15 minutes to two hours, once or twice a day depending on the patient’s needs.
Vitamin D supplements can be effective against SAD. Most adults require 1,000 to 2,000 international units (IU) a day in winter to keep blood levels in the optimal range, says Stephen Ilardi, Ph.D.