Abstract
This systematic review examines the relationship between social cognition (SC) and social behavior in patients with neurodegenerative diseases. Social behavioral changes impact both patients and caregivers, contributing to increased caregiver burden and institutionalization risks. SC impairments are common in different neurodegenerative diseases and are assumed to underlie social behavioral changes. However, it has not been systematically investigated how SC and social behavior relate to each other, over all neurodegenerative patient groups. A systematic search was performed in the PubMed and PsycINFO databases from inception and extraction up to September 5th, 2023. Analyzing 21 studies, including assessment of the relationship between SC and social behavior with performance-based measures for SC and proxy ratings of social behavior, little evidence was found for a consistent association between SC impairments and social behavior. Weak associations were identified between better emotion recognition and fewer behavioral symptoms r = -.23 CI [-0.42, -0.02] and better emotion recognition and less apathy symptoms r = -.24 CI [-0.46, 0.01]. Disinhibition was more frequently associated with SC aspects than agitation or irritability. Furthermore, affective theory of mind (ToM) was more often associated with social behavior than cognitive ToM. However, the heterogeneity between studies with regard to what aspects of SC and social behavior were measured and with what instruments, and the low number of studies, limit definitive conclusions. This review underscores the need for future research employing standardized, reliable, and ecologically valid measures to more accurately assess the assumed association between SC and social behavior in neurodegenerative diseases.