The mediational role of close teacher-student relationships in the link between loneliness and academic achievement: A longitudinal study in junior high school students

Loneliness is a well-documented risk factor for adolescents’ psychosocial and academic adjustment. However, the mechanisms through which loneliness is related to school performance remain unclear, as most prior studies have relied on cross-sectional designs. Drawing on the evolutionary theory of loneliness, this study tested whether teacher–student closeness (TSC) mediates the longitudinal association between loneliness and academic achievement (AA). Participants were 314 Italian junior high school students (M age = 12.28, SD age = 0.83; 51.9% female) assessed at two time points during the 2024–2025 academic year. Latent autoregressive cross-lagged panel models, controlling for sex, age, and cultural possessions, showed that loneliness at T1 predicted lower TSC at T2, whereas TSC at T1 predicted higher AA at T2. The direct effect of loneliness on AA was non-significant, but the indirect effect via TSC was significant. Findings suggest that loneliness may indirectly undermine academic achievement by weakening TSC.