Who Is Affected?

Geographic location seems to play the most pivotal role in the occurrence of SAD. Incidence is most common in the higher latitudes (closer to the poles) where winter extremes last a longer portion of the year. The “extremes” include shorter days, colder weather that makes it difficult to get outside, greater occurrence of overcast days, and morning routines taking place prior to sunrise due to time changes. The incidence of SAD increases with latitude up to a point but is not most severe at the poles.

70-80% of those diagnosed with SAD are women with onset most frequently occurring in the 30’s. A family member with a diagnosed depressive disorder is common amongst 55% of those with SAD and 34% report a family member with a history of alcohol abuse.

Teenagers have been diagnosed with SAD but the disorder’s occurrence declines in those over 50 years of age. The elderly have a low rate of incidence despite the obvious tendency to stay indoors and be more reclusive during the winter months.