Trajectories of Isolation and (A)Loneliness with AOD Use, 2019-2027: A National Egocentric Network Study of US Adults - This project will significantly advance understanding of the longitudinal links between interpersonal connection, alcohol use, cannabis use, and other drug (AOD) use through the analysis of novel longitudinal data that includes assessment of multiple aspects of interpersonal connection over eight consecutive years. There are well-established links between isolation, loneliness and all-cause mortality and morbidity, but longitudinal study of the links between interpersonal connection and health behaviors, which may represent a primary pathway linking to mortality, is relatively sparse due to the lack of longitudinal data. This project will explore multiple aspects of interpersonal connection for adults ages 30-80: social isolation, loneliness, and the relatively new concept of aloneliness. Isolation is assessed using novel egocentric network data and standard isolation measures. Loneliness and aloneliness are assessed using validated scales. Mental well-being is implicated as a mediating link between interpersonal connection and health behaviors, and is assessed though depression and anxiety. This study will generate the largest longitudinal data on adult interpersonal connection and AOD use. The fields of substance use research and prevention may see substantial benefit from this project’s use of novel methodological techniques to develop longitudinal models elucidating the ways in which adult interpersonal connection is linked to AOD use. Specifically, we will: 1) examine the cumulative, interactive, and reciprocal effects of multiple dimensions of interpersonal connectedness with substance use (accounting for mental well-being) over time; 2) examine the role of network churn, network structure, and network AOD use on interpersonal connectedness and individual AOD use, as well as predictors of churn and structure; and 3) explore potential heterogeneity by demographics in the associations of SI/L/A, network characteristics, and AOD use, all of which have been understudied in the interpersonal connection literature. To do so, we will extend and increase an existing nationally representative sample of 1,771 adults ages 30-80 (at 2019 baseline), collected by the same team, with four additional annual waves of data, resulting in 10 waves of data from 2019-2027 for all key measures, and increased measures 2024-2027. We will primarily apply innovative multivariate latent growth models with structured residuals methods, which estimate 2+ latent growth models at the same time while simultaneously estimating and disentangling between- and within- persons variability over time. Moreover, this model allows for the estimation of reciprocal relations among outcomes and mediated (indirect) paths, at the within-persons level; in this case trajectories of AOD use and multiple aspects of interpersonal connections.
