While ethnocultural differences in risk of tardive dyskinesia (TD) have bee
n suggested, no previous studies have examined whether this factor also pla
ys a role in lack of awareness of TD. This study examined this question in
an Asian population with schizophrenia. Six hundred seven patients in a sta
te mental hospital in Singapore were assessed using the Abnormal Involuntar
y Movement Scale (AIMS) and the Simpson-Angus Rating Scale. Of the 607 pati
ents, 242 (39.9%) met criteria for TD, and 163 (67.4%) patients were not aw
are of the presence of TD. No significant differences in terms of age, gend
er, and duration of illness mere found between those aware of their TD and
those not aware. Daily neuroleptic doses and scores for the AIMS and Simpso
n-Angus Rating Scale were significantly different, although after logistic
regression, only the Simpson-Angus Rating Scale scores remained significant
. The finding that a large proportion of our patients lacked awareness of t
heir TD is consistent with other reports in the West and provides evidence
that this feature is characteristic of the illness rather than of a specifi
c ethnocultural group. We found an association between lack of awareness an
d greater severity of extrapyramidal symptoms (EPS), suggesting that there
may be a subtype of TD in which lack of awareness and greater vulnerability
of developing EPS are features.