Loneliness During Adolescence and Subsequent Health and Well-Being in Adulthood: An Outcome-Wide Longitudinal Approach.

Purpose: Intergovernmental organizations, such as the World Health Organization, policymakers, scientists, and the public alike are recognizing the importance of loneliness for health/well-being outcomes. However, it remains unclear if loneliness in adolescence shapes health/well-being in adulthood. We examined if increase in loneliness during adolescence was associated with worse health/well-being in adulthood, across 41 outcomes.

Methods: We conducted a longitudinal study using data from Add Health-a prospective and nationally representative cohort of community-dwelling U.S. adolescents. Using regression models, we evaluated if an increase in loneliness over 1 year (between Wave I, 1994-1995 and Wave II, 1996) was associated with worse health/well-being outcomes 11.37 years later (in Wave IV, 2008; N = 11,040) or 20.64 years later (in Wave V, 2016-2018; N = 9,003). Participants were aged 15.28 years at study onset and aged 28.17 or 37.20 years during the final assessment.

Results: Participants with the highest (vs. lowest) loneliness had worse outcomes on 4 (of 7) mental health outcomes (e.g., higher likelihood of depression (relative risk= 1.25, confidence interval [CI] = 1.06, 1.49, p = .010), 3 (of 4) psychological well-being outcomes (e.g., lower optimism [β = -0.12, 95% CI = -0.23, -0.01, p = .030]), 2 (of 7) social outcomes (e.g., lower romantic relationship quality (β = -0.10, 95% CI = -0.19, 0.00, p = .043), one (of 13) physical health outcomes (e.g., higher likelihood of asthma (relative risk= 1.24, 95% CI = 1.01, 1.53, p = .041), and 0 (of 9) health behavior outcomes and 0 (of 2) civic/prosocial outcomes.

Discussion: These findings suggest the promise of testing scalable loneliness interventions and policies during adolescence to better determine their impact on various outcomes.