Wechsler memory scale–fourth edition (WMS–IV) in the neuropsychological evaluation of patients diagnosed with probable Alzheimer’s disease

Abstract

There is a scarcity of research concerning Wechsler Memory Scale–Fourth Edition (WMS–IV) findings in Alzheimer’s disease (AD). We provide information, beyond that in the test manual, concerning the power of the scale to detect AD-associated memory deficits. Participants were 87 individuals with diagnoses made according to criteria specified in the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5): 31 probable neurocognitive disorders due to AD and 33 patients with depression. Twenty-three elderly controls were also studied. The depressed and control participants had similar demographics as well as test scores and therefore were blended into a single control group (n = 56). AD patients were significantly impaired on the four WMS–IV indexes relative to controls, and the index pattern of performance differed across groups. Delayed Memory Index was a significant weakness in AD, whereas the Visual Memory Index was the lowest mean for controls. Sensitivity, specificity, hit rate, positive predictive value, and negative predictive value were strong to excellent for each index when a cutoff of 1.5 SDs below the normative mean was used to separate ADs and controls. Receiver operating characteristics curve analyses yielded excellent area under the curve statistics that ranged from .970 for the Visual Memory Index to .999 for the Delayed Memory Index. A supplementary analysis yielded similar results when the AD group was divided into mild (n = 10) and major (n = 21) subgroups.