Seasonal affective disorder and latitude: a review of the literature

J Affect Disord. 1999 Apr;53(1):35-48. doi: 10.1016/s0165-0327(98)00097-4.


Background: The aim of the study is to investigate the relationship between the prevalence of SAD and latitude.

Methods: An overview of the epidemiological literature on the prevalence of SAD is given and studies relevant for the latitudinal dependency of prevalence will be analyzed and discussed.

Results: The mean prevalence of SAD is two times higher in North America compared to Europe. Over all prevalence studies, the correlation between prevalence and latitude was not significant. A significant positive correlation was found between prevalence and latitude in North America. For Europe there was a trend in the same direction.

Conclusions: The influence of latitude on prevalence seems to be small and other factors like climate, genetic vulnerability and social-cultural context can be expected to play a more important role. Additional controlled studies taking these factors into account are necessary to identify their influence.

Publication types

  • Review

MeSH terms

  • Adult
  • Aged
  • Child
  • Europe / epidemiology
  • Female
  • Geography
  • Humans
  • Male
  • Middle Aged
  • North America / epidemiology
  • Prevalence
  • Seasonal Affective Disorder / epidemiology
  • Seasonal Affective Disorder / psychology*