Differentiating Dementia From "Pseudodementia" Early in the Clinical Course: Utility of Neuropsychological Tests

Abstract

This study investigated the utility of several widely used neuropsychological tests in the distinction between dementia and "pseudodementia". Thirty-seven patients referred for this differential diagnosis because of early and subtle changes in memory underwent neuropsychological evaluation. All were reevaluated at least 6 months later. Results revealed significant associations between defective temporal orientation, visuoconstruction, and visual memory at Time 1, and the subsequent development of dementia. Overall, verbally mediated performances at Time 1 were not predictive of the eventual diagnosis; however, some verbally based performances did discriminate the groups at Time 2. The findings indicate that certain nonverbal tests are especially sensitive to early cognitive changes associated with dementia. Appropriate weighting of these measures in neuropsychological judgment may assist in the differential diagnosis of dementia versus pseudodementia. Novelty and the multidimensional nature of the discriminating tasks may account for this effect.