title: [Mental retardation as a risk factor to develop a psychotic disease].
abstract: BACKGROUND
  One of the main aims of research on schizophrenia has been to pinpoint the early symptoms and signals of the disease before its appearance.
  
  
  OBJECTIVE
  We have examined the diagnoses previously given to patients before they were diagnosed of schizophrenia.
  
  
  METHODS
  This is a case-control study in which we used a data register including the fields of minimum basic data set (MBDS) whose time period included 1999 to 2005.
  
  
  RESULTS
  In our study, there was a 3.6% frequency of mental retardation and 2.1% one of behavioral and emotional disorders with onset usually occurring in childhood and adolescence, both diagnosed previously. The estimated odds ratio for a mentally retarded patient to suffer adult onset psychosis is 4.6 (95%CI [3.43-6.26]), schizophrenia 5.8 (95% CI [4.20-7.88]), paranoid schizophrenia 4.8 (95% CI [3.39 -6.93]), residual schizophrenia 7.0 (95% CI [4.81 -10.09]) and persistent delusional disorder 2.7 (95% CI [1.57 -4.73]).
  
  
  CONCLUSIONS
  It can be concluded from our study that there is an increased frequency of mental retardation among the pathological records of subjects who will be diagnosed with paranoid schizophrenia and residual schizophrenia in the future. This fact supports the etiological thesis of schizophrenia involving neurodevelopment disorders.
authors.affiliation: Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: M Negueruela
authors.initials: MN
authors.lastname: López
authors.forename: A Ceverino
authors.initials: AC
authors.lastname: Domíngeuz
authors.forename: J
authors.initials: J
authors.lastname: Quintero
authors.forename: M M Pérez
authors.initials: MM
authors.lastname: Rodríguez
authors.forename: A
authors.initials: A
authors.lastname: Fernández Del Moral
authors.forename: M A Jiménez
authors.initials: MA
authors.lastname: Arriero
authors.forename: M Martínez
authors.initials: MM
authors.lastname: Vigo
authors.forename: I Basurte
authors.initials: IB
authors.lastname: Villamor
authors.forename: M J Sevilla
authors.initials: MJ
authors.lastname: Vicente
authors.forename: J López
authors.initials: JL
authors.lastname: Castromán
authors.forename: R Navarro
authors.initials: RN
authors.lastname: Jiménez
authors.forename: D
authors.initials: D
authors.lastname: Zambrano-Enríquez
authors.forename: J L
authors.initials: JL
authors.lastname: González de Rivera
authors.forename: E Baca
authors.initials: EB
authors.lastname: García
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000150:complications*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult