Sad during the winter? Lighten up

J. Murray Howard

By Cathy Seigerman

As winter approaches, some people may feel more tired and depressed. It might not all be related to the holiday season and its accompanying stresses.

Chalk some of it up to "seasonal affective disorder," or SAD for short, a type of depression that can occur as the amount of natural light decreases. Artificial light therapy can help.

The onset of SAD correlates with shorter periods of daylight and is more common in northern latitudes. "The body's internal clock doesn't run at 24 hours and needs to be reset by light each day," said Dr. Mark Rapp of U.Va. Psychiatric Services. "As the amount of available daylight declines during the winter, the clock may not be reset correctly, and body rhythms are thrown out of sync. As a result, you feel lousy."

People with SAD "may gain weight because they crave carbohydrates or sugary foods, and sleep excessively," he said. "They also may become socially withdrawn or irritable, and unable to concentrate. Typically, they feel worse in the morning than in the evening, the reverse of the non-seasonal depression pattern."

An estimated 10 million Americans complain of SAD, and women tend to be more susceptible to it than men.

Some scientists also link SAD with production of a hormone called melatonin, which the body produces more of in darkness. It causes people to become drowsy, and some researchers suspect people with SAD release more melatonin than others. Other chemicals produced in the brain, serotonin and dopamine, also may play a role.

Some practical and effective therapies that can help reduce SAD symptoms include getting regular aerobic exercise, taking walks outside on your lunch hour, eating fewer calories and not getting too stressed out, Rapp said. "These techniques help with all types of depression, and are especially recommended during the holiday season."

One treatment for SAD is a box that shines artificial bright light from fluorescent tubes or incandescent bulbs. Exposure to this type of light therapy for half an hour to an hour daily seems to work for some people. Recent studies suggest that it is both safe and effective, with few possible side effects, which are mostly mild, he said. Light therapy is not advisable for people with retinal problems or people who take medications that cause sensitivity to light. Anyone considering buying a light therapy box should consult a physician first.

"Bright light therapy may be more effective in producing full remission of symptoms of SAD than established antidepressants," Rapp said.