Anosognosia in Alzheimer's Pathology: Validation of a New Measure.

Abstract

Two studies were performed to validate a brief measure of cognitive insight and compare it to an empirical model - the Cognitive Awareness Model (CAM). A pilot study included 31 (52% male; Mage = 69.42) patients from an outpatient neuropsychological assessment clinic. Seven patients were diagnosed with likely Alzheimer's dementia (AD), 15 mild cognitive impairment (MCI), and 9 no diagnosis (i.e., cognitively normal; CN). The Cognitive Coding Form (CCF) and several other measures were administered. Study 2 entailed archival data extraction of 240 patients (80 CN, 80 MCI, and 80 AD; 53.3% female; Mage = 72.8) to examine whether the CCF predicts memory (Wechsler Memory Scale - IV) and executive functioning (Trail-Making Test B). The pilot study found preliminary evidence of convergent and discriminant validity for the 8-item CCF. Study 2 confirmed that both patient-reported cognitive concerns (F(2,237) = 10.40, p < .001, ω2 = .07, power = .99) and, more strongly, CCF informant-patient discrepancy scores (F(2,237) = 24.52, p < .001, ω2 = .16, power = .99) can distinguish CNs from those with MCI and AD. A regression indicated that depression (5.5%; β = -.38, p < .001) and TMT-B (13%; β = -.43, p < .001), together accounted for 18.5% of the variance in insight (R2 = .19, F(2,219) = 26.10, p < .001), supporting the CAM. These studies establish an efficient measure of insight with high clinical utility and inform the literature on the role of insight in predicting performance in those with Alzheimer's pathology.