This time of year is the peak of "SAD season." S-A-D, or Seasonal Affective Disorder, is a form of depression associated with seasonal variation in light. About two percent of Americans suffer from SAD, and women, children and older adolescents are more susceptible to the condition. John Beyer, assistant clinical professor of psychiatry and director of the Mood and Anxiety Clinic at Duke University Medical Center, says SAD symptoms are much like those of other forms of depression, with two exceptions. "People with Seasonal Affective Disorder during the winter tend to have increased sleep, kind of like bears hibernating. And instead of having decreased appetite and weight loss, people with Seasonal Affective Disorder tend to gain weight or have increased appetite, especially for carbohydrates, sweets and sugars." Beyer says antidepressants can help, and phototherapy, typically in the form of a special fluorescent lightbox, is effective in about 65 percent of cases. "The exposure for about 30 minutes to two hours significantly reduces the incidence of Seasonal Affective Disorder for people who have this common problem. The good news is that we can identify it. The better news is that we can treat it." I'm Cabell Smith for MedMinute.