Facial emotion recognition and empathy for pain in patients with type 2 diabetes mellitus

Objective: Type 2 diabetes mellitus (T2DM) is associated with cognitive decline, but its impact on social cognition remains poorly understood. This study investigated whether individuals with T2DM exhibit impairments in facial emotion recognition and empathy for pain, two domains crucial for daily interpersonal functioning that are often overlooked in neuropsychological assessments. Method: Seventy-six participants (37 with T2DM and 39 matched healthy controls) completed two validated social cognition tasks: a dynamic Facial Emotion Morphing Test and an empathy-for-pain task involving 25 animated scenarios (intentional, accidental, and neutral harm). Groups were matched for age, sex, and education. Analyses of covariance were conducted using Montreal Cognitive Assessment (MoCA) scores as covariates to control for global cognitive status. Results: Compared to controls, individuals with T2DM showed significantly lower overall emotion recognition accuracy (η_p² = 0.10) and fear recognition accuracy (η_p² = 0.06). In the empathy-for-pain task, they exhibited reduced intentionality comprehension (η_p² = 0.05, d = 0.73), increased attribution of harmful intent (η_p² = 0.05, d = -0.60), and harsher punishment judgments (η_p² = 0.08). These effects were of medium magnitude and were not explained by demographic, cognitive, or clinical factors. Conclusions: T2DM is associated with selective impairments in social cognition, even in the absence of global cognitive decline. These findings underscore the clinical utility of assessing social cognition in patients with T2DM, as such deficits may compromise interpersonal functioning and quality of life. Incorporating ecologically valid social cognition measures into neuropsychological evaluations may support early detection of brain dysfunction in metabolic conditions and inform interventions aimed at preserving social cognitive health.