title: Sudden death of father or sibling in early childhood increases risk for psychotic disorder.
abstract: OBJECTIVE
  To determine if exposure to a severe, acute stressor during early development is associated with an increased incidence of schizophrenia and bipolar disorder compared to exposure to a chronic stressor.
  
  
  METHODS
  We identified all those born in Helsinki between 1960 and 1990 whose father or sibling died between their conception and 5-years-of-age through linking two national registers: the Finnish Population Register and the Cause of Death Register. The reason for the death was also extracted from the Cause of Death Register. A third register, the Finnish Hospital Discharge Register, was used to determine psychiatric outcomes in adulthood.
  
  
  METHODS
  11,855 individuals whose father or sibling had died before they were 5-years-old. In total, 129 individuals had an ICD 8, 9 or 10 diagnosis of schizophrenia and 165 had a diagnosis of bipolar disorder. 6136 individuals had a father or sibling who died from a sudden, external cause (e.g. accident or suicide) and 5719 individuals had father or sibling who died from a non-external, illness-associated cause.
  
  
  RESULTS
  Sudden loss of a father or sibling led to a significantly greater risk of developing bipolar disorder or schizophrenia in adulthood compared to loss of a father or sibling from illness. These associations are independent of sex, parental history of psychiatric illness, age at exposure to loss and age at follow-up.
  
  
  CONCLUSIONS
  Our findings are in keeping with accumulating evidence which indicates that exposure to stress during early development can increase the risk of psychotic illness among those exposed.
authors.affiliation: Department of Psychiatry and Psychology, Royal College of Surgeons in Ireland, Dublin, Ireland. maryclarke@rcsi.ie
authors.forename: Mary C
authors.initials: MC
authors.lastname: Clarke
authors.forename: Antti
authors.initials: A
authors.lastname: Tanskanen
authors.forename: Matti O
authors.initials: MO
authors.lastname: Huttunen
authors.forename: Mary
authors.initials: M
authors.lastname: Cannon
mesh_terms: D001714:Bipolar Disorder / Q000453:epidemiology / Q000209:etiology*; D002675:Child, Preschool; D003643:Death; D003645:Death, Sudden / Q000453:epidemiology; D005220:Fathers; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008016:Life Change Events; D008297:Male; D012042:Registries; D012306:Risk; D012559:Schizophrenia / Q000453:epidemiology / Q000209:etiology*; D035781:Siblings