Quality of Life, Social Networking, and Mental Health: Generational Differentiation and Uniqueness in the Context of South Korea

<b>Background/Objectives</b>: Mental health disparities across generations are a growing concern in rapidly changing societies. While health-related quality of life (HRQoL) and social networking are widely recognized as determinants of psychological well-being, less is known about how their effects differ across age groups. This study investigates the generational patterns in the relationship between HRQoL, social networking, and mental health in South Korea. <b>Methods</b>: We analyzed data from the nationally representative 2023 Community Health Survey (South Korea). HRQoL, social networking activity, and self-reported mental health outcomes (stress and depression) were assessed. Multivariate models were used to test main effects and interactions, with stratification by generational cohorts. <b>Results</b>: Across all models (i.e., all age groups), good HRQoL strongly predicts lower depression (PHQ-9 scores), showing coefficients ranging from -1.20 to -1.48, <i>p</i> < 0.001. Social networking activity also predicts reduced depressive symptoms, with significant effects from the thirties onward (e.g., -0.317 in the 30s, -0.507 in the 50s, -0.424 in the 70s +; all <i>p</i> < 0.001). However, the interaction term between HRQoL and social networking activity yields unexpected findings. The interaction becomes positive and significant, with coefficients that increase steadily by age: 0.388 in the 40s, 0.472 in the 50s, 0.533 in the 60s, and 0.638 in the 70s + (all <i>p</i> < 0.001). Using stress (1 = high-level, 0 = low-level) as the outcome variable, with the same set of covariates, it replicates the findings similar to those obtained when PHQ-9 as the outcome variable. <b>Conclusions</b>: The results suggest that the protective role of HRQoL and social networking is not uniform across generations. In South Korea, relative deprivation and social comparison may intensify with age, amplifying the psychological burden despite higher quality of life or social participation. These findings highlight the need for mental health interventions and policy responses that account for generational differences in the social determinants of well-being.