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

Abstract

There is a paucity of information concerning the prevalence and detection of seasonal affective disorder (SAD) in UK populations. To determine the prevalence, detection and current treatment of SAD within a general population sample. The study was conducted in conjunction with the Outcomes of Depression International Network (ODIN) project, a large European study of depression. At the North Wales arm of the project, 1999 adults were randomly selected from a health authority database and screened by post for SAD with the Seasonal Patterns Assessment Questionnaire (SPAQ). Those scoring above cut-off were offered diagnostic interview, after which diagnosis of SAD according to DSM-IV criteria could be made. The prevalence rate of SAD was calculated to be 2.4% (95% CII.4-1.3). The majority of identified cases had not previously received a diagnosis of SAD from their general practitioner, although over half had been diagnosed with other forms of depression and had been prescribed antidepressant medication. Although SAD was found to be common in this general population sample it appeared to be largely underdiagnosed and/or misdiagnosed.