Gender and age at onset in schizophrenia: impact of family history.
OBJECTIVE
The 1-year prevalence of schizophrenia was studied in a limited geographical area of Reunion Island (Indian Ocean) to assess the impact of family history of schizophrenia on the well-known association between gender and age at onset.


METHODS
The population of schizophrenic patients meeting the DSM-III-R criteria for schizophrenia (N = 663) was identified and divided according to the presence of another schizophrenic patient among the first- and second-degree relatives.


RESULTS
As previously reported, the median age at onset differed between the sexes: the males had an earlier onset (mean age = 27.8 years) than the females (31.5 years). Comparison of the ages at onset according to family history revealed that onset was later for female subjects with a negative family history than for the three other groups (i.e., males with or without a family history and females with a family history). No difference emerged in the comparison of the ages at onset of the males and females with a positive family history.


CONCLUSIONS
Comparison of schizophrenic patients with familial versus sporadic disorder confirms the absence of a gender effect for age at onset in the subgroup with familial disorder. This approach also demonstrates the existence of a subgroup composed of affected females having late onset and no family history of schizophrenia.
Laboratoire d'épidémiologie génétique (Institut National de la Santé et de la Recherche Médicale Unité 155), Université de Paris VII, France.
P
P
Gorwood
M
M
Leboyer
M
M
Jay
C
C
Payan
J
J
Feingold
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D002648:Child; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017508:Reunion / Q000453:epidemiology; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology*; D012737:Sex Factors