Verbal memory tests in the differential diagnosis of depression and dementia: discriminative power of seven test variations.

The many tasks for the assessment of verbal memory differ widely in features of presentation and retrieval. In this study, seven common memory tasks (immediate and delayed free recall, randomized presentation, selective reminding, serial recall, recognition after short and long delay) were compared for their discriminative power between depressed, demented, and healthy elderly subjects. Tasks that require little cognitive capacity were hypothesized to be particularly useful to differentiate the patient groups. Demented and depressed patients demonstrated deficits on all tests, the demented being more severe. Only recognition after long and short delay, and delayed recall distinguished demented from depressed patients. Delayed retrieval tasks were more useful to discriminate patient groups than tasks that require little cognitive capacity.