SEVERITY OF COGNITIVE IMPAIRMENT IN ALZHEIMERS-DISEASE AFFECTS LIST LEARNING USING THE CALIFORNIA VERBAL-LEARNING TEST (CVLT)

Impairment in list learning is considered a primary symptom of Alzheim er's disease (AD), yet there are no published reports examining the re lationship between list learning and severity of cognitive impairment. We gave nine-item and 16-item versions of the California Verbal Learn ing Test (CVLT; Delis et al., 1987), a standardized shopping list asse ssment of memory, to 24 AD patients (mean age = 76.2 +/- 8.1; mean yea rs of education = 13.8 +/- 2.4), who were stratified into four groups based on MMSE scores (mean = 16.0 +/- 5.6). ANOVAs revealed severity e ffects for total list learning (p < 0.001), the first trial (p < 0.001 ), the last trial (p < 0.001) and short- and long-delay recall measure s. Most of these differences seemed due to floor effects. For example, the modal number of words recalled after a delay was 0 by subjects wi th MMSE scores below 21. Severity of cognitive impairment was associat ed with the proportion of intrusions such that the most severely demen ted subjects gave almost entirely intrusion responses. Surprisingly, l ist length did not significantly affect any of the free recall measure s. Our results suggest that list learning and recall seem to be lost r elatively early in AD. Measures of list recall like the CVLT may not b e useful in tracking severity of cognitive impairment over time. (C) 1 998 John Wiley & Sons, Ltd.