title: Gender differences in age at onset of schizophrenia.
abstract: OBJECTIVE
  To evaluate the gender differences in age at onset of schizophrenia.
  
  
  METHODS
  Prospective case control study.
  
  
  METHODS
  Department of Psychiatry, Aga Khan University Hospital, Karachi between January to December 2002.
  
  
  METHODS
  Sixty patients admitted consecutively to psychiatry ward and meeting the inclusion criteria were enrolled for the study. Age at onset of illness was defined as age at onset of gross psychotic symptoms, age at first contact with psychiatrist and age at index admission. Statistical method included two independent samples t-test. Data was dichotomized into those with family history of schizophrenia versus those without family history of illness and then Chi-square test of association was applied.
  
  
  RESULTS
  The mean age of onset of illness was 23.96 years in females and 24.13 years in males. In all other measures used to assess the onset of illness, females were overrepresented at the younger age group. 56.7% patients had a family history of psychotic disorder. Among them the mean ages at onset of illness were 20.59 years in females and 21.85 years in males ( c 0.04 df =58). The illness occurred at a younger age in those with positive family history of schizophrenia (21.22 years) than those without it (25.14 years) with dissipation of gender difference in the former.
  
  
  CONCLUSIONS
  There was no significant gender difference in age at onset of disorder in this study. Family history of schizophrenia appears to be the most significant factor that eliminates the gender differences in age at onset of schizophrenia.
authors.affiliation: Department of Psychiatry, The Aga Khan University Hospital, Karachi, Pakistan. haider.naqvi@aku.edu
authors.forename: Haider
authors.initials: H
authors.lastname: Naqvi
authors.forename: Murad Moosa
authors.initials: MM
authors.lastname: Khan
authors.forename: Abul
authors.initials: A
authors.lastname: Faizi
mesh_terms: D000328:Adult; D017668:Age of Onset; D005260:Female; D006801:Humans; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D011446:Prospective Studies; D012189:Retrospective Studies; D012559:Schizophrenia / Q000453:epidemiology*; D017678:Sex Distribution