University of Virginia Health System

AVOID SAD SYMPTOMS DURING WINTER MONTHS

Seasonal Affective Disorder -- SAD for short -- is a type of depression that can occur as winter approaches and the amount of natural light decreases.

As the days get shorter, people with SAD often feel depressed and tired, said Dr. Rapp of University of Virginia Psychiatric Services. They may gain weight because they crave carbohydrates or sugary foods and sleep excessively. They also may become socially withdrawn or irritable, and are unable to concentrate.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.

The onset of SAD correlates with decreased day length 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, Rapp said. As the amount of available daylight declines during the winter, the clock may not be reset correctly, and body rhythms are thrown out of synch. As a result, you feel lousy.

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 you can use to reduce SAD symptoms include getting regular aerobic exercise, taking daytime walks on your lunch hour, eating fewer calories and not getting too stressed out, Dr. 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, Rapp said. Bright light therapy may be more effective in producing full remission of symptoms of SAD than established antidepressants, he said.

Light box side effects appear to be mild and few, and include headache, eye or vision problems and, more rarely, nausea, anxiety and agitation. Light therapy is not advisable for people with retinal problems or people who take medications that cause sensitivity to light. If you are considering buying a light therapy box, consult your doctor first.

November 5, 1999