Seasonal affective disorder among psychiatric nurses in Aberdeen

The Seasonal Pattern Assessment Questionnaire was posted to psychiatric nurses in Aberdeen, and 443 (73% of eligible subjects) responded. The rate of Seasonal Affective Disorder (SAD) was 2.9% and for subsyndromal SAD (S-SAD) was 9.5%. When rates were age and sex adjusted to the Aberdeen population aged 15 to 64, this yielded a prevalence of 1.9% for SAD and 7.2% for S-SAD. As in other studies, there was a preponderance of young female sufferers, but being married appeared to be protective. Comparisons with epidemiological studies elsewhere lead to the conclusion that population rates of winter depression relate to a combination of genetic susceptibility/selection, latitude of residence and geographical mobility.