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

Objective: Two studies were performed to validate a brief measure of cognitive insight and compare it to an empirical model - the Cognitive Awareness Model (CAM).

Method: 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).

Results: 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.

Conclusions: 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.