Seasonal affective disorder: prevalence, detection and current treatment in North Wales

Background There is a paucity of information concerning the prevalence and detection of seasonal affective disorder (SAD) in UK populations. Aims To determine the prevalence, detection and current treatment of SAD wi thin a general population sample. Method The study was conducted in conjunction with the Outcomes of Depressi on International Network (ODIN) project, a large European study of depressi on. At the North Wales arm of the project, 1999 adults were randomly select ed from a health authority database and screened by post for SAD with the S easonal Patterns Assessment Questionnaire (SPAQ). Those scoring above cut-o ff were offered diagnostic interview, after which diagnosis of SAD accordin g to DSM-IV criteria could be made. Results The prevalence rate of SAD was calculated to be 2.4% (95% CI 1.4-1. 3). The majority of identified cases had not previously received a diagnosi s of SAD from their general practitioner, although over half had been diagn osed with other forms of depression and had been prescribed antidepressant medication. Conclusions Although SAD was found to be common in this general population sample it appeared to be largely underdiagnosed and/or misdiagnosed.