title: Paternal age and schizophrenia: a population based cohort study.
abstract: OBJECTIVE
  To investigate the association of paternal age at conception with the risk of offspring developing schizophrenia.
  
  
  METHODS
  A population based cohort study.
  
  
  METHODS
  Sweden.
  
  
  METHODS
  754,330 people born in Sweden between 1973 and 1980 and still alive and resident in Sweden at age 16 years.
  
  
  METHODS
  Hospital admission with schizophrenia or non-schizophrenic, non-affective psychosis.
  
  
  RESULTS
  After adjustment for birth related exposures, socioeconomic factors, family history of psychosis, and early parental death the overall hazard ratio for each 10 year increase in paternal age was 1.47 (95% confidence interval 1.23 to 1.76) for schizophrenia and 1.12 (0.98 to 1.29) for non-schizophrenic non-affective psychosis. This association between paternal age and schizophrenia was present in those with no family history of the disorder (hazard ratio for each 10 year increase in paternal age 1.60, 1.32 to 1.92), but not in those with a family history (0.91, 0.44 to 1.89) (P = 0.04 for interaction).
  
  
  CONCLUSIONS
  Advancing paternal age is an important independent risk factor for schizophrenia. The stronger association between paternal age and schizophrenia in people without a family history provides further evidence that accumulation of de novo mutations in paternal sperm contributes to the overall risk of schizophrenia.
authors.affiliation: Academic Unit of Psychiatry, Cotham House, University of Bristol BS6 6JL.
authors.forename: Attila
authors.initials: A
authors.lastname: Sipos
authors.forename: Finn
authors.initials: F
authors.lastname: Rasmussen
authors.forename: Glynn
authors.initials: G
authors.lastname: Harrison
authors.forename: Per
authors.initials: P
authors.lastname: Tynelius
authors.forename: Glyn
authors.initials: G
authors.lastname: Lewis
authors.forename: David A
authors.initials: DA
authors.lastname: Leon
authors.forename: David
authors.initials: D
authors.lastname: Gunnell
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D001724:Birth Weight; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D010331:Paternal Age; D010375:Pedigree; D016016:Proportional Hazards Models; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D012621:Seasons; D013548:Sweden / Q000453:epidemiology