Social Cognition in Patients with Amnestic Mild Cognitive Impairment and Mild Dementia of the Alzheimer Type.

BACKGROUND Social cognition (SC) is a core criterion for neurocognitive disorders. However, findings in patients with amnestic mild cognitive impairment (aMCI) and dementia of the Alzheimer type (DAT) are inconsistent. OBJECTIVE We report assessments of emotion recognition (ER), affective and cognitive theory of mind (ToM) in young (YC) and older controls (OC) compared to aMCI and DAT. METHODS 28 aMCI, 30 DAT, 30 YC, and 29 OC received tests of SC and a comprehensive neuropsychological assessment. Analysis of covariance was used to determine group differences. Multiple regression models were applied to identify predictors for each SC task. RESULTS In controls, OC performed worse in ER and both ToM tasks compared to YC except for one subtest. No significant differences were found between OC and patients concerning ER and affective ToM. In cognitive ToM, differences between OC and patients depended on content and cognitive load with significant impairment in DAT compared to OC. A cognitive composite score predicted SC in OC, but not in patients. Associations of SC with single cognitive domains were found in all groups with language and complex attention as best predictors. Not all variance of SC performance was explained by variance in cognitive domains. CONCLUSION Lower performance on SC tasks in OC versus YC was confirmed, although not all tasks were equally affected. With progressive cognitive impairment, cognitive ToM is more impaired than ER or affective ToM. SC seems to be at least partly independent of other cognitive domains, justifying its inclusion in batteries for dementia diagnostic.