title: Social class at birth and risk of psychosis.
abstract: BACKGROUND
  Individuals with psychotic disorders are represented more in the lower social classes, yet there is conflicting evidence to whether these individuals drift into the lower social classes or whether lower social class is a risk factor for developing psychosis. The aim of this study was to examine whether the social class at birth is a risk factor for developing psychosis.
  
  
  METHODS
  We included individuals with a first episode of psychosis (FEP) whose social class at birth was determined from birth records. We employed a case-control study design and also compared the distribution of the social classes at birth of the cases to that of the general population.
  
  
  RESULTS
  A total of 380 individuals with an FEP and 760 controls were included in the case-control study. The odds ratio for developing an FEP associated with social class (low vs high) was .62 (95% confidence interval (CI): .46-.85, p < .001), indicating that individuals from a lower social class at birth have a reduced risk of psychosis. Individuals born between 1961 and 1980 with an FEP were more likely to be from a higher social class at birth compared to the general population (60.8% vs 36.7%, χ(2) = 60.85, df = 1, p < .001). However, this association was not observed for those born between 1981 and 1990.
  
  
  CONCLUSIONS
  A higher social class at birth is associated with a greater risk for developing a psychotic disorder; however, this effect may show temporal variation.
authors.affiliation: University College Dublin, Dublin, Ireland DETECT Early Intervention for Psychosis Service, Dublin, Ireland Orygen, The National Centre of Excellence in Youth Mental Health, Parkville, VIC, Australia briannoelodonoghue@gmail.com.
authors.forename: Brian
authors.initials: B
authors.lastname: O'Donoghue
authors.affiliation: DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Felicity
authors.initials: F
authors.lastname: Fanning
authors.affiliation: University College Dublin, Dublin, Ireland DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Lyne
authors.affiliation: University College Dublin, Dublin, Ireland DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Laoise
authors.initials: L
authors.lastname: Renwick
authors.affiliation: DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Kevin
authors.initials: K
authors.lastname: Madigan
authors.affiliation: DETECT Early Intervention for Psychosis Service, Dublin, Ireland Department of Psychiatry, Royal College of Surgeons in Ireland, Dublin, Ireland.
authors.forename: Anthony
authors.initials: A
authors.lastname: Kinsella
authors.affiliation: University College Dublin, Dublin, Ireland.
authors.forename: Abbie
authors.initials: A
authors.lastname: Lane
authors.affiliation: DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Niall
authors.initials: N
authors.lastname: Turner
authors.affiliation: University College Dublin, Dublin, Ireland DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Eadbhard
authors.initials: E
authors.lastname: O'Callaghan
authors.affiliation: University College Dublin, Dublin, Ireland DETECT Early Intervention for Psychosis Service, Dublin, Ireland.
authors.forename: Mary
authors.initials: M
authors.lastname: Clarke
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D016017:Odds Ratio; D011618:Psychotic Disorders / Q000453:epidemiology*; D012307:Risk Factors; D012923:Social Class; D055815:Young Adult
keywords: Psychosis; schizophrenia; social class