The Asymmetric Moderating Role of Intolerance of Uncertainty in the Longitudinal Reciprocal Associations between Sleep Disturbance and Internalizing Symptoms: A Two-wave Study among 54,240 Adolescents

The reciprocal relationships between sleep disturbance and internalizing symptoms (e.g., anxiety and depression symptoms) have been widely explored in both cross-sectional and longitudinal studies. Although intolerance of uncertainty (IU) is recognized as a risk factor for both sleep disturbance and internalizing symptoms, its role in their longitudinal reciprocal associations remains unclear. To address this gap, a two-wave longitudinal study was conducted with 54,240 Chinese adolescents, who provided self-reported data on sleep disturbance, internalizing symptoms, and IU. Results revealed significant longitudinal reciprocal associations between sleep disturbance and internalizing symptoms, with IU exacerbating these relationships. Notably, the moderating effect of IU was asymmetric, exerting a stronger influence on the prediction of internalizing symptoms through sleep disturbance than vice versa. Beyond its direct impact on sleep disturbance and internalizing symptoms, IU was shown to intensify their longitudinal reciprocal relationship for the first time. These findings underscore the need for early screening and timely intervention for IU in adolescents. Moreover, the asymmetric moderating effect also suggests that sleep disturbance and IU may have synergistic effects on internalizing symptoms, highlighting the importance of prioritizing IU-based assessments and interventions for adolescents experiencing sleep disturbance.