Social Functioning as a Behavioral Marker of Cognitive Decline in Older Adults
Authors:   , Split Molly , Schultheis Maria T 
Published: November 2024

Background: The increase in Alzheimer's disease and related dementia (ADRD) prevalence worldwide has led researchers to investigate novel ways to improve the early detection of ADRD, including behavioral (i.e., non-biological) markers. Changes in social functioning represent a promising behavioral marker of cognitive decline, given that social isolation is linked to cognitive decline, and patterns of social-behavioral changes are associated with ADRD. The assessment of social functioning also provides a cross-culturally relevant early detection method. The current study (1) examined the psychometric and cross-cultural properties of a previously developed and revised self-report measure (Cognitive Assessment of Social Interaction - Revised; CASI-R) in community-dwelling older adults and (2) investigated its relationship with objective executive functioning (EF) via online cognitive assessments. Methods: The study sample included three racial/ethnic groups: 52 Black non-Hispanic/Latino (nHL) adults, 52 Latino/Hispanic adults of any race, and 65 White nHL adults (n = 167). To address the first study aim, the CASI-R's internal consistency, overall factor structure, measurement invariance (MI) (i.e., configural, metric, scalar, and strict), and convergent validity were assessed using Cronbach's alpha, exploratory factor analysis (EFA), multi-group confirmatory factor analysis (CFA), and Pearson correlations, respectively. To address aim two, hierarchical linear regressions were performed with EF test scores as the primary independent variable (i.e., attention, working memory, response inhibition) and the CASI-R as the dependent variable while controlling for covariates (i.e., age, gender, race, education, personality, mood). Results: Cronbach's alpha and EFA results revealed strong internal consistency and a robust one-factor model for the CASI-R within the whole sample and three racial/ethnic groups. When assessing MI of the CASI-R across the Black nHL, Hispanic/Latino, and White nHL groups, multi-group CFA indicated the data fit full configural invariance (i.e., equivalent one-factor structure across groups), while metric, scalar, and strict invariance were not achieved; exploratory follow-up analyses revealed the Hispanic/Latino group as the potential source of the variance (i.e., model misfit). Pearson correlations confirmed the CASI-R's convergent validity with the Frontal Systems Behavior Scale (FrSBe) total score and subscales within the whole sample and three racial/ethnic groups. Finally, hierarchical regressions revealed significant associations between greater complaints of social interaction difficulties on the CASI-R and poorer performances on tasks of simple attention, working memory (marginal significance), and response inhibition over and above significant covariates. Conclusions: In summary, the CASI-R is a reliable self-report measure for assessing overall social interaction ability in Black nHL, Hispanic/Latino, and White nHL adults and is cross-culturally relevant at the factor structure level. Furthermore, clinicians may consider the elevated total scores as potential indicators of subtle difficulties with attention and response inhibition, and to a lesser degree working memory, within these three racial/ethnic groups. Although additional work is needed to clarify the factors within the Hispanic/Latino group that may be influencing their responses on the CASI-R, the current study provides strong evidence for the validity and clinical applicability of this measure in diverse populations. Findings also provide preliminary evidence for classifying social interaction ability as a potential preclinical behavioral marker of ADRD.