Performance on the Wechsler Adult Intelligence Scale-III in Japanese patients with schizophrenia.
OBJECTIVE
Patients with schizophrenia have been reported to perform worse than non-schizophrenic populations on neuropsychological tests, which may be affected by cultural factors. The aim of this study was to examine the performance of a sizable number of patients with schizophrenia on the Japanese version of the Wechsler Adult Intelligence Scale-III (WAIS-III) compared with healthy controls.


METHODS
Performance on the WAIS-III was evaluated in 157 Japanese patients with schizophrenia and in 264 healthy control subjects.


RESULTS
All IQ scores and four indices from the WAIS-III were impaired for patients with schizophrenia compared with healthy controls. Processing Speed was markedly disturbed, approximately 2 SD below that of the healthy control group. Among the 13 subtests, Comprehension (z = -1.70, d = 1.55), Digit Symbol Coding (z = -1.84, d = 1.88), and Symbol Search (z = -1.85, d = 1.77) were profoundly impaired relative to the healthy controls.


CONCLUSIONS
These results indicate that the pattern and degree of impairment, as evaluated by the WAIS-III, in Japanese patients are similar to those previously reported in English-speaking patients and that the deficits of some neuropsychological domains relevant to functional outcomes are universally characteristic of schizophrenia.
Graduate School of Human Sciences, Osaka, Japan.
Haruo
H
Fujino
Chika
C
Sumiyoshi
Tomiki
T
Sumiyoshi
Yuka
Y
Yasuda
Hidenaga
H
Yamamori
Kazutaka
K
Ohi
Michiko
M
Fujimoto
Satomi
S
Umeda-Yano
Arisa
A
Higuchi
Yumiko
Y
Hibi
Yukako
Y
Matsuura
Ryota
R
Hashimoto
Masatoshi
M
Takeda
Osamu
O
Imura
D000328:Adult; D044466:Asian People; D003072:Cognition Disorders / Q000523:psychology*; D032882:Comprehension; D003469:Culture; D005260:Female; D006801:Humans; D007360:Intelligence; D007564:Japan; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D012565:Schizophrenic Psychology; D014888:Wechsler Scales; D055815:Young Adult
Wechsler Adult Intelligence Scale-III; cognitive impairment; cross-national difference; functional outcome; schizophrenia