title: Affective disorders and risk of developing dementia: systematic review.
abstract: BACKGROUND
  Affective disorders are associated with cognitive disturbances but their role as risk factors for dementia is still not fully investigated.
  
  
  OBJECTIVE
  To evaluate the risk of developing dementia in individuals with a history of affective disorder.
  
  
  METHODS
  We conducted a systematic review of case-control and cohort studies addressing the risk of developing dementia in people with affective disorders. To the best of our knowledge, this is the first systematic review that has included studies evaluating this risk specifically in people with bipolar disorder.
  
  
  RESULTS
  Fifty-one studies were included. Most of the studies found an increased risk for developing dementia in individuals with depression. Greater frequency and severity of depressive episodes seem to increase this risk. The evidence is contradictory regarding whether there is a difference in risk in people with early- or late-onset depression. The few available risk estimates for dementia in people with bipolar disorder suggest an even higher risk than for those with depression.
  
  
  CONCLUSIONS
  Affective disorders appear to be associated with an increased risk of developing dementia, and one that is dependent on clinical and demographic variables. Depression may be both a prodrome and a risk factor for dementia. Future research should aim to elucidate the mechanisms that mediate these links.
authors: Department of Mental Health and CEDOC, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, FCM, UNL, Campo Mártires da Pátria, 130, 1169-056 Lisbon, Portugal. jalvesdasilva@fcm.unl.pt
authors: Joaquim
authors: J
authors: da Silva
authors: Manuel
authors: M
authors: Gonçalves-Pereira
authors: Miguel
authors: M
authors: Xavier
authors: Elizabeta B
authors: EB
authors: Mukaetova-Ladinska
mesh_terms: D017668:Age of Onset; D001714:Bipolar Disorder / Q000453:epidemiology; D003704:Dementia / Q000453:epidemiology*; D004812:Epidemiologic Methods; D006801:Humans; D019964:Mood Disorders / Q000453:epidemiology* / Q000523:psychology; D062706:Prodromal Symptoms; D017678:Sex Distribution