The prevalence of seasonal affective disorder (SAD) in The Netherlands

Since the description of SAD the prevalence of this disorder has been of particular interest. The more so, because early studies, indicated the correctness of the on theoretical grounds - expected interaction between latitude and prevalence rate of SAD. More eleborate prevalence studies, mainly in the USA indeed showed a positive correlation between prevalence rate and latitude. In Europe, only few studies have appeared. Although the results of most of these studies are preliminary and research-methods and criteria vary across studies, tentative conclusions are that the prevalence rates in Europe are considerably lower than in the USA, but that there is a similar trend in the direction of an increase of prevalence at higher latitudes.8"10 In the present study, the prevalence of SAD in the Netherlands is investigated.