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.
Gorwood
P
P
Laboratoire d'épidémiologie génétique (Institut National de la Santé et de la Recherche Médicale Unité 155), Université de Paris VII, France.
Leboyer
M
M
Jay
M
M
Payan
C
C
Feingold
J
J
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