Do We Become More Lonely With Age? A Coordinated Data Analysis of Nine Longitudinal Studies.

Loneliness is a pervasive experience with adverse impacts on health and well-being. Despite its significance, notable gaps impede a full understanding of how loneliness changes across the adult life span and what factors influence these changes. To address this, we conducted a coordinated data analysis of nine longitudinal studies encompassing 128,118 participants ages 13 to 103 from over 20 countries. Using harmonized variables and models, we examined loneliness trajectories and predictors. Analyses revealed that loneliness follows a U-shaped curve, decreasing from young adulthood to midlife and increasing in older adulthood. These patterns were consistent across studies. Several baseline factors (i.e., sex, marital status, physical function, education) were linked to loneliness levels, but few moderated the loneliness trajectories. These findings highlight the dynamic nature of loneliness and underscore the need for targeted interventions to reduce social disparities throughout adulthood.

Longitudinal Associations Between Multimorbidities and Patient-Reported Quality of Life.

OBJECTIVES: The global prevalence of multimorbidity is increasing as the population ages. As individuals get older, they are likely to develop multiple chronic conditions, and nearly two-thirds of older adults in the United States are estimated to experience 2 or more chronic conditions. The present preregistered study examined whether multimorbidity was associated with longitudinal changes in health-related quality of life (i.e., anxiety, depression, and physical function) and whether these associations were moderated by sociodemographic factors (i.e., sex, race, marital status, income, insurance, and education). METHODS: Data come from the Health Literacy and Cognitive Function Among Older Adults Longitudinal Study (LitCog), a prospective cohort study of English-speaking older adults (N = 900). At each measurement occasion, participants reported anxiety, depression, and physical function using the Patient Reported Outcomes Information System, chronic conditions, and sociodemographic characteristics. We employed multilevel growth models to estimate changes in health-related quality of life, with multimorbidities as a predictor and sociodemographics as covariates. RESULTS: Results indicated that individuals with multiple chronic conditions reported persistently high levels of anxiety and depression, and worse physical function. We found evidence for racial health disparities, such that individuals who identified as non-White experienced worse health-related quality of life as multimorbidities increased, relative to White participants. DISCUSSION: These results contribute to the current conversation about the long-term impacts of structural and systemic barriers experienced by minoritized groups. We further discuss the public health implications of multimorbidity in older adulthood.