Background. The differential diagnosis of early dementia
of
the Alzheimer's type from depression
in the elderly is often made difficult by the presence of significant
memory impairment in depressed
patients. The Delayed Word Recall test (DWR) was developed to facilitate
the early diagnosis
of Alzheimer's disease. The DWR involves: (a) repeated
elaborate encoding of ten separate
words; (b) a filled delay; (c) delayed free recall. A
recognition memory test has also been
recently developed. The available evidence suggests impressive sensitivity
and specificity when
the DWR has been used to separate patients with early Alzheimer's
disease from very well matched controls.
Methods. In the present study, the DWR was evaluated with
regard to its ability to separate a
group of 50 patients with early Alzheimer's disease from 50 elderly
patients with major depression in a between-subjects experimental design.
Results. For both free recall and recognition indices, the
between-group overlap was large.
Using recommended cut-off scores for the detection of Alzheimer's
disease,
44% of the depressed patients would have been misclassified as demented
based on their free recall scores, and
48% of the depressed patients would have been misclassified on the basis
of their recognition scores.
Conclusion. We conclude that the DWR is not specific enough
to clearly distinguish patients
with early Alzheimer's disease from elderly patients
with major depression.