Prevalence of winter depression in Denmark.

An unselected cohort of 3556 subjects in Copenhagen was asked to complete the Seasonal Pattern Assessment Questionnaire (SPAQ) for estimating the presence of seasonal affective disorders (SAD or winter depression). Completed questionnaires were received from 1794 subjects in total. About 12% of the respondents had a Global Seasonality Score (GSS) high enough to indicate the presence of SAD. Among those respondents without SAD, women and younger people were found to be much more sensitive to seasonal and weather changes than men and older people, respectively.