Am J Psychiatry 1992; 149:1070-1074
Copyright © 1992 by American Psychiatric Association
Are males more likely than females to develop schizophrenia?
WG Iacono and M Beiser
Department of Psychology, University of Minnesota, Minneapolis 55455.
OBJECTIVE: This study was undertaken to determine whether the incidence of
schizophrenia is equivalent for males and females. METHOD: An attempt was
made to identify every first-episode case of psychosis in a large Canadian
city over a period of 2 1/2 years. A comprehensive referral network was
established that included hospital and community settings where psychotic
persons might appear. More than 300 potential subjects were identified, 175
of whom underwent a structured psychiatric interview and were assigned
diagnoses according to five different diagnostic systems. RESULTS: The
incidence of schizophrenia was two to three times higher among males than
among females. Even though the use of different diagnostic systems yielded
slightly different risk rates, the elevated risk for males remained
consistent. There were no differences between the sexes in the incidence of
affective psychosis. In comparison with schizophrenia, the incidence rates
for mood disorders with psychotic features were sometimes lower and
sometimes higher, depending on the diagnostic system used. CONCLUSIONS: The
findings, coupled with reports in the past 10 years from other
investigators, challenge the conventional belief that the incidence of
schizophrenia is the same for the two sexes.
