Factors that may increase your risk of seasonal affective disorder include:

  • Being female. Seasonal affective disorder is diagnosed more often in women than in men, but men may have symptoms that are more severe.
  • Living far from the equator. Seasonal affective disorder appears to be more common among people who live far north or south of the equator. This may be due to decreased sunlight during the winter, and longer days during the summer months.
  • Family history. As with other types of depression, those with seasonal affective disorder may be more likely to have blood relatives with the condition.
  • Having clinical depression or bipolar disorder. Symptoms of depression may worsen seasonally if you have one of these conditions.
Sep. 22, 2011