Age-at-onset and schizophrenia: reversed gender effect.
OBJECTIVE
This study seeks an explanation for reversed gender effect on age-at-onset (AAO) in schizophrenia. The hypothesis is older AAO in males would be detected in a sample where higher infant mortality (IMR) prevailed.


METHODS
Case records of International Classification of Diseases-10 (ICD-10) schizophrenia patients from two states (n=70 each) with an IMR of 13 and 67 per thousand were reviewed and AAO was obtained by using the recorded age and duration of illness.


RESULTS
In the sample from the state with lower IMR, AAO did not differ between the two sexes. However, men had older AAO than women in the state with fivefold higher IMR.


CONCLUSIONS
Gender differences in AAO may be a function of perinatal complications. In places where infants with perinatal complications are less likely to survive, hence high IMR, a small group of potentially youngest AAO schizophrenic males may be eliminated thus changing the gender effect on AAO.
Gangadhar
B N
BN
Department of Psychiatry, NIMHANS, Bangalore 560 029, India. bng@nimhans.kar.nic.in
Panner Selvan
C
C
Subbakrishna
D K
DK
Janakiramaiah
N
N
D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology; D017678:Sex Distribution