Predictors of Loneliness by Age Decade: Study of Psychological and Environmental Factors in 2,843 Community-Dwelling Americans Aged 20-69 Years

Objective: Loneliness is a prevalent and serious public health problem due to its effects on health, well-being, and longevity. Understanding correlates of loneliness is critical for guiding efforts toward the development of evidence-based strategies for prevention and intervention. Considering that patterns of association between age and loneliness vary, the present study sought to examine age-related differences in risk and protective factors for loneliness.

Methods: Correlates of loneliness were examined through a large web-based survey of 2,843 participants (aged 20-69 years) from across the United States from April 10, 2019, through May 10, 2019. Participants completed the 4-item UCLA Loneliness Scale, San Diego Wisdom Scale (with the following subscales measuring components of wisdom: Prosocial Behaviors, Emotional Regulation, Self-Reflection, Acceptance of Divergent Values, Decisiveness, and Social Advising), and other scales measuring psychosocial variables. Multivariate regression analyses were conducted to identify the best model of loneliness and examine potential age-related differences.

Results: Age demonstrated a nonlinear quadratic relationship with loneliness (Wald statistic = 5.48, P = .019); levels were highest in the 20s and lowest in the 60s with another peak in the mid-40s. Across all decades, loneliness was associated with not having a spouse or partner (P < .001), sleep disturbance (P < .02), lower prosocial behaviors (P < .001), and smaller social network (P < .001). Lower social self-efficacy (P < .001) and higher anxiety (P < .005) were associated with worse loneliness in all age decades, except the 60s. Loneliness was uniquely associated with decisiveness in the 50s (P = .012) and with education (P = .046) and memory complaints (P = .013) in the 60s.

Conclusions: Our findings identify several potentially modifiable targets related to loneliness, including several aspects of wisdom and social self-efficacy. Differential predictors at different decades suggest a need for a personalized and nuanced prioritizing of prevention and intervention targets.