Prevalence of seasonal depression in a prospective cohort study

Eur Arch Psychiatry Clin Neurosci. 2019 Oct;269(7):833-839. doi: 10.1007/s00406-018-0921-3. Epub 2018 Jul 18.


The prevalence of autumn/winter seasonality in depression has been documented in the longitudinal Zurich cohort study by five comprehensive diagnostic interviews at intervals over more than 20 years (N = 499). Repeated winter major depressive episodes (MDE-unipolar + bipolar) showed a prevalence of 3.44% (5× more women than men), whereas MDE with a single winter episode was much higher (9.96%). A total of 7.52% suffered from autumn/winter seasonality in major and minor depressive mood states. The clinical interviews revealed novel findings: high comorbidity of Social Anxiety Disorder and Agoraphobia within the repeated seasonal MDE group, high incidence of classic diurnal variation of mood (with evening improvement), as well as a high rate of oversensitivity to light, noise, or smell. Nearly twice as many of these individuals as in the other MDE groups manifested the syndrome of atypical depression (DSM-V), which supports the prior description of seasonal affective disorder (SAD) as presenting primarily atypical symptoms (which include hypersomnia and increase in appetite and weight). This long-term database of regular structured interviews provides important confirmation of SAD as a valid diagnosis, predominantly found in women, and with atypical vegetative symptoms.

Keywords: Affective disorders; Comorbid disorders; Seasonality; Zürich longitudinal cohort study.

MeSH terms

  • Adult
  • Agoraphobia / epidemiology*
  • Comorbidity
  • Databases, Factual
  • Depressive Disorder, Major / epidemiology*
  • Female
  • Humans
  • Interview, Psychological
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Phobia, Social / epidemiology*
  • Seasonal Affective Disorder / epidemiology*
  • Switzerland / epidemiology
  • Young Adult