The prospective association of adolescent loneliness and low resilience with anxiety and depression in young adulthood: The HUNT study

Background Loneliness is a recognized risk factor for anxiety and depression, yet research on its interaction with low resilience remains sparse, particularly across the adolescent-to-adult transition. This study investigates how adolescent loneliness, both independently and in interaction with low resilience, influences anxiety and depression in young adulthood. Methods This study utilized longitudinal data from The Trøndelag Health Study (HUNT) to track adolescents (13–19 years) from Young-HUNT3 (2006-08) through to HUNT4 (2017-19). Loneliness was assessed via a single-item measure, while resilience was estimated using the Resilience Scale for Adolescents. Anxiety and depression outcomes at the 11-year follow-up were measured using the Hospital Anxiety and Depression Scale. Multivariate logistic regression analyses were done to analyze the associations. Moreover, interaction effects were evaluated using relative excess risk due to interaction (RERI). Results Loneliness during adolescence independently predicted anxiety and depression in young adulthood. Adolescents experiencing both loneliness and low resilience showed notably higher risks compared to other groups (highly resilient adolescents without loneliness [reference], highly resilient adolescents with loneliness, and adolescents with low resilience and low loneliness). The combined effect of loneliness and low resilience exhibited a synergistic interaction on the additive scale, although it was not statistically significant (RERI 0.13, 95% CI -2.39-2.65). Conclusion Adolescent loneliness and low resilience independently predict anxiety and depression in young adulthood. The interaction between loneliness and low resilience further heightens these risks. This underscores the importance of early interventions that focus on resilience-building during adolescence and reducing the impacts of loneliness on mental health.