title: Depression subtypes and 5-year risk of dementia and Alzheimer disease in patients aged 70 years.
abstract: OBJECTIVE
  The objective of this study was to estimate several subtypes of depressive disorders as risk factors for dementia and Alzheimer disease (AD) specifically.
  
  
  METHODS
  This is a population-based cohort study using a sample of 451 non-demented older people. Adjusted Cox proportional hazard models were calculated to determine the association of depression with dementia or AD development after 5 years. Baseline evaluation included the Cambridge Mental Disorders of the Elderly Examination (CAMDEX). Depressive disorders (major episode [MD] and minor depressive disorders [MDDIS]) were assessed following DSM-IV criteria and further classified according to the age at onset (early versus late onset). In turn, all late-onset depressions were grouped as with or without depression-executive dysfunction syndrome (DEDS). Dementia (and dementia subtypes) diagnoses were made using the CAMDEX. When the patients were deceased, the Retrospective Collateral Dementia Interview was used.
  
  
  RESULTS
  Late-onset depressions (both MD and MDDIS) were associated with increased dementia (hazard ratio [HR] = 2.635; 95% CI = 1.153-6.023; and HR = 2.517; 95% CI = 1.200-5.280, respectively), and AD (HR = 6.262; 95% CI = 2.017-19.446; and HR = 4.208; 95% CI = 1.828-9.685, respectively) after adjustment by age, gender, marital status, education, cognitive impairment, executive function and stroke history. A second model revealed that only late-onset depressions with DEDS increased the risk for both dementia (late-onset MD with DEDS: HR = 6.262; 95% CI = 2.017-19.446; late-onset MDDIS with DEDS: HR = 4.208; 95% CI = 1.828-9.685) and AD (late-onset MD with DEDS: HR = 7.807; 95% CI = 1.567-38.894; late-onset MDDIS with DEDS: HR = 6.099; 95% CI = 2.123-17.524).
  
  
  CONCLUSIONS
  Late-onset depressive episodes with DEDS are risk factors for dementia and AD development, regardless of the severity of the depression.
authors.affiliation: Research Unit, Institut d'Assistència Sanitària, Salt, Girona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Vilalta-Franch
authors.forename: Secundino
authors.initials: S
authors.lastname: López-Pousa
authors.forename: Jordi
authors.initials: J
authors.lastname: Llinàs-Reglà
authors.forename: Laia
authors.initials: L
authors.lastname: Calvó-Perxas
authors.forename: Javier
authors.initials: J
authors.lastname: Merino-Aguado
authors.forename: Josep
authors.initials: J
authors.lastname: Garre-Olmo
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology*; D015331:Cohort Studies; D003704:Dementia / Q000453:epidemiology*; D003866:Depressive Disorder / Q000145:classification* / Q000453:epidemiology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D015995:Prevalence; D016016:Proportional Hazards Models; D012307:Risk Factors; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology