title: Prevalence and correlates of major depressive disorder and dysthymia in an eleven-year follow-up--results from the Finnish Health 2011 Survey.
abstract: BACKGROUND
  Up-to-date epidemiological data on depressive disorders is needed to understand changes in population health and health care utilization. This study aims to assess the prevalence of major depressive disorder (MDD) and dysthymia in the Finnish population and possible changes during the past 11 years.
  
  
  METHODS
  In a nationally representative sample of Finns aged 30 and above (BRIF8901), depressive disorders were diagnosed with the Composite International Diagnostic Interview (M-CIDI) in 2000 and 2011. To account for nonresponse, two methods were compared: multiple imputation (MI) utilizing data from the hospital discharge register and from the interview in 2000 and statistical weighting.
  
  
  RESULTS
  The MI-corrected 12-month prevalence of MDD was 7.4% (95% CI 5.7-9.0) and of dysthymia was 4.5% (95% CI 3.1-5.9), whereas the corresponding figures using weights were 5.4% (95% CI 4.7-6.1) for MDD and 2.0% (95% CI 1.6-2.4) for dysthymia. Women (OR 2.33, 95% CI 1.6-3.4) and unmarried people (OR 1.54, 95% CI 1.2-2.0) had a higher risk of depressive disorders. There was a significant increase in the prevalence of depressive disorders during the follow-up period from 7.3% in 2000 to 9.6% in 2011. Prevalences were two percentage points higher, on average, when using MI compared to weighting. Hospital treatments for depressive disorders and other mental disorders were strongly associated with nonparticipation.
  
  
  CONCLUSIONS
  The CIDI response rate dropped from 75% in 2000 to 57% in 2011, but this was accounted for by MI and weighting.
  
  
  CONCLUSIONS
  Depressive disorders are a growing public health concern in Finland. Non-participation of persons with severe mental disorders may bias the prevalence estimates of mental disorders in population-based studies.
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland. Electronic address: niina.markkula@helsinki.fi.
authors.forename: Niina
authors.initials: N
authors.lastname: Markkula
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Suvisaari
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland; Turku University Hospital, Finland.
authors.forename: Samuli I
authors.initials: SI
authors.lastname: Saarni
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland; University of Tampere, School of Health Sciences, Tampere, Finland.
authors.forename: Sami
authors.initials: S
authors.lastname: Pirkola
authors.affiliation: National Institute for Health and Welfare, Department of Health, Functional Capacity and Welfare, Helsinki, Finland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Peña
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland.
authors.forename: Suoma
authors.initials: S
authors.lastname: Saarni
authors.affiliation: Development of Work and Organizations, Finnish Institute of Occupational Health, Finland.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Ahola
authors.affiliation: Department of Adult Psychiatry, Tampere University Hospital, Tampere, Finland.
authors.forename: Aino K
authors.initials: AK
authors.lastname: Mattila
authors.affiliation: National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, P.O. Box 30, 00271 Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Viertiö
authors.affiliation: Institute for Clinical Psychology and Psychotherapy, Technical University of Dresden, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Strehle
authors.affiliation: National Institute for Health and Welfare, Department of Health, Functional Capacity and Welfare, Helsinki, Finland.
authors.forename: Seppo
authors.initials: S
authors.lastname: Koskinen
authors.affiliation: National Institute for Health and Welfare, Department of Health, Functional Capacity and Welfare, Helsinki, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Härkänen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003865:Major Depressive Disorder / Q000453:epidemiology*; D019263:Dysthymic Disorder / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence
keywords: Depressive disorders; Dysthymia; Epidemiology; Major depressive disorder; Non-participation