Sex differences in neuropsychological functioning among schizophrenia patients.
OBJECTIVE
Evidence from the literature addressing sex differences in cognition in schizophrenia remains equivocal, with some researchers suggesting that male schizophrenia patients are more impaired than female subjects, while others report no significant sex differences in cognitive functioning. The aim of the present study was to investigate whether the differential pattern of cognitive performance observed in healthy men and women is preserved in male and female schizophrenia patients.


METHODS
Ninety-six schizophrenia patients (56 men) were compared with 62 age- and gender-ratio matched healthy controls (31 men), on a battery of neuropsychological tests that assessed basic cognitive abilities: attention, working memory, abstraction, inhibition, fluency, verbal learning and memory, visual memory, visuospatial skills, and psychomotor speed.


RESULTS
As a group, schizophrenia patients were significantly impaired in each of the cognitive domains assessed, with the exception of psychomotor speed. The effect of sex was significant for verbal learning and memory, wherein women outperformed men. No significant group x sex interactions were found in any cognitive domains, indicating that the female advantage typically observed in verbal learning and memory remained the same in the schizophrenia patients.


CONCLUSIONS
The degree of cognitive impairment is the same for male and female schizophrenia patients. Those sex differences found among the patients were typical of the healthy population as well. Therefore, differential decrements in basic cognitive domains do not appear to account for the favourable course of schizophrenia in women relative to men.
Bozikas
Vasilis P
VP
First Department of Psychiatry, Hospital Papageorgiou, Ring Road Thessaloniki. N. Efkarpia, GR-54603 Thessaloniki, Greece. vbozikas@ned.auth.gr
Kosmidis
Mary H
MH
Peltekis
Apostolos
A
Giannakou
Maria
M
Nimatoudis
Ioannis
I
Karavatos
Athanasios
A
Fokas
Kostas
K
Garyfallos
George
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000453:epidemiology*; D012720:Severity of Illness Index; D017678:Sex Distribution; D014706:Verbal Learning; D055815:Young Adult