Am J Psychiatry 1991; 148:1164-1171
Copyright © 1991 by American Psychiatric Association
The influence of major depression on clinical and psychometric assessment of senile dementia of the Alzheimer type
EH Rubin, DA Kinscherf, EA Grant and M Storandt
Alzheimer's Disease Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110.
OBJECTIVE: The performance on standard clinical and psychometric
assessments of eight elderly individuals with major unipolar depression
alone and seven with depression plus mild senile dementia of the Alzheimer
type was compared with that of 41 nondepressed subjects suffering from very
mild senile dementia of the Alzheimer type, 66 with mild senile dementia of
the Alzheimer type, and 83 age-matched subjects without senile dementia.
METHOD: Subjects with depression alone, depression plus mild senile
dementia of the Alzheimer type, and very mild and mild senile dementia of
the Alzheimer type met strict inclusionary and exclusionary criteria. A
90-minute semistructured interview, including several brief standardized
clinical scales, was used to assign a Clinical Dementia Rating to each
subject according to published guidelines, and each subject was given a
2-hour psychometric test battery. Data were analyzed by one-way
multivariate analysis of variance to ascertain if there was an effect of
group on clinical and psychometric test scores. RESULTS: The eight
depressed subjects without concurrent dementia performed as well as the 83
nondepressed subjects without dementia on most clinical measures; however,
their performance on most psychometric measures closely resembled that of
the 41 nondepressed subjects with very mild dementia. The performance of
the seven subjects with depression plus mild dementia was comparable to
that of the 66 nondepressed subjects with mild dementia on most clinical
and psychometric measures. CONCLUSIONS: Although depressed subjects
performed as well as subjects without dementia on many clinical
assessments, psychometric testing was not able to distinguish depressed
subjects from those with very mild senile dementia of the Alzheimer type.
This demonstrates the need for careful psychiatric evaluation before
interpreting deficits on psychometric tests as indicating the presence of
very mild senile dementia of the Alzheimer type.
