Exploring Social Cognition Decline Across Alzheimer'S Disease Severity: Insights From A Comparative Analysis

The detection of subtle behavioral signs in early stages of Alzheimers Disease (AD) is of great importance to start clinical investigation. Memory and reasoning problems are usually more commonly reported by relatives than those associated with Social Cognition (SC). This study focusing on deficits in SC as a behavioral marker of Alzheimers Disease (AD) investigated: (1) selective impairments in SC domains according to stage of disease; (2) if impairments were better explained by nonsocial cognitive dysfunctions. Sixty-five elderly distributed into groups according to the Mini-Mental State Examination (Healthy, Mild cognitive impairment, Mild-AD, Moderate-AD) participated in the study. All underwent the Edinburgh Social Cognition Test (ESCoT), which investigates the cognitive and affective domains of Theory of Mind, as well as interpersonal and intrapersonal understanding of social norms. The nonsocial cognitive battery included traditional tests of episodic memory, executive functions, verbal fluency and language comprehension. Mediation analysis was performed to understand the influence of nonsocial cognitive skills in SC impairment among groups. Results revealed prominent losses in SC in moderate AD regardless of memory- skills. Theory of mind was a crucial link between social and nonsocial cognitive abilities. Executive functioning, verbal fluency and language comprehension mediated group-related cognitive declines effects on SC impairment. These findings underscore the complex interplay between cognitive domains in AD and suggest that selective impairments of SC highlight is as potential a marker for tracking the progression of the disease.