Prospective Pathways Among Rumination, Depression, and Insomnia in Youth.

A growing body of research suggests sleep disturbances and depressive symptoms do not just co-occur but influence each other over time. While emerging evidence supports a bidirectional relationship, developmental pathways between sleep problems and depression remain understudied in youth. Rumination may serve as a potential modifiable cognitive mechanism linking these conditions. However, rumination's role in these developmental pathways remains largely unexplored, particularly across childhood and adolescence. This study employed a cross-lagged panel model (CLPM) to investigate prospective associations among sleep, depression, and rumination and test mediation effects. Participants were 364 youth aged 8 to 16 participating in three yearly assessments. A distinct pattern emerged in which rumination predicted later depression, and depression predicted later insomnia. Insomnia did not significantly predict later depression and was not associated with rumination. Examination of indirect effects identified support for a mediational pathway from rumination to insomnia through depression. Although prior research has framed early insomnia symptoms as a risk factor for later depression, the present investigation highlights an alternative developmental pathway. Results suggest that depressive rumination contributes to later depression which in turn contributes to later insomnia among youth. These findings may inform prevention and early intervention efforts by identifying rumination as a potential target to mitigate risk for depression and insomnia.