12 Purpose in Life, Loneliness, and Subjective Cognitive Decline in an Ethnically Diverse US Sample
Authors: Pluim Celina F. , Anzai Juliana A. U. , Martinez Jairo E. , Munera Diana , Garza-Naveda A. Paola , Vila-Castelar Clara , Guzmán-Vélez Edmarie , Ramirez-Gomez Liliana , Bustin Julian , Serrano Cecilia M. , Babulal Ganesh M. , Oliveira Maira Okada de , Quiroz Yakeel T. 
Published: December 2023

Objective:Subjective cognitive decline (SCD), the self-reported experience of worsening cognitive abilities (Jessen et al., 2014), is associated with increased risk of developing Alzheimer’s disease and Mild Cognitive Impairment. Modifiable factors such as purpose in life (PiL), the experience of living a meaningful life where one’s life goals are attainable or being achieved (Boyle et al., 2009), and loneliness, an individual’s perceived social isolation (Luhmann & Hawkley, 2016), are known to be associated with SCD. These relationships are understudied among ethnically diverse groups. Using an online survey, we examined associations between PiL, loneliness and SCD in older ethnically diverse individuals living in the US.Participants and Methods:870 older adults (126 Latino, 74 Black, 33 Asian, and 637 White; average age=67.0 [7.6]) completed an online survey including the Life Purpose Questionnaire, the Gierveld Loneliness Scale, and the Everyday Cognition scale (ECog), which measures subjective cognitive concerns in memory, language, executive function, and divided attention. Chi-square tests and analyses of variance were conducted to assess group differences in SCD and demographic/lifestyle predictors. Multiple regressions and correlations were conducted to assess the relationships between ethnicity and PiL with SCD, and the moderating effect of race/ethnicity. Multiple regressions and correlations were conducted to identify sociodemographic and lifestyle predictors of SCD in each study group.Results:White participants were older (p<.001), and White and Asian groups had higher levels of education (p=.009) compared to Latinos. The White group had a higher proportion of female (p=.016) and middle-income (p=.019) respondents. Black participants had higher PiL (p=.035) and lower loneliness (p=.047) compared to White participants; there were no group differences in ECog ratings (p=.143). Regression results indicated that higher PiL associated with lower SCD in the whole sample (β=-.435, p<.001). The interaction between PiL and ethnic group was significant (β=.078, p=.025), suggesting the relationship between PiL and SCD was strongest in White participants, followed by Asian, then Latino, and finally Black participants. In Latinos, female sex (β=-.281, p=.004) and higher PiL (β=-.240, p=.034) predicted lower SCD ratings. In White participants, higher PiL (β = -.394, p < .001), and lower loneliness (β = .128, p = .003) predicted lower SCD ratings. Correlation analyses revealed no significant associations with SCD in the Black group, although the correlation between loneliness and SCD was trending (r=.222, p=.063). In the Asian group, greater PiL was associated with lower SCD ratings (r=-.439, p=.011).Conclusions:Our findings suggest that PiL may be protective against SCD, particularly in Latino, Asian, and White adults. Differential predictive factors of SCD were also identified for our study groups, suggesting certain groups may benefit from specific targeted interventions. Overall, findings suggest that interventions geared toward increasing PiL and/or mitigating loneliness may help reduce SCD and the risk of cognitive decline in older adults in the US. As the current study was cross-sectional and faced sample size limitations in Asian and Black groups, future studies should include longitudinal assessment of these associations with larger and more representative samples to confirm our findings.