Repetitive negative thinking serves as a transdiagnostic bridge between childhood trauma and depressionRepetitive negative thinking links childhood trauma to depression

Childhood trauma is a major risk factor for depression; however, not every affected individual develops clinically significant depressive symptoms. This underscores the importance of identifying transdiagnostic mechanisms that account for vulnerability and resilience. Repetitive negative thinking (RNT), which includes both rumination and worry, has recently been framed as a more general cognitive process that may help clarify how early adverse experiences contribute to the emergence and persistence of depression. This narrative review integrates current evidence regarding RNT as a possible transdiagnostic link connecting childhood trauma to depression, with particular focus on its interactions with emotion regulation flexibility, stress sensitization, and neurocognitive processes underlying self-referential cognition, cognitive control, and threat processing. Findings from developmental psychopathology, cognitive neuroscience, and affective science indicate that childhood trauma is often associated with persistent RNT, diminished regulatory flexibility, and increased sensitivity to stress—factors that are each independently related to depressive symptoms. Emerging evidence also suggests that these mechanisms are likely interrelated and may collectively increase susceptibility to depression across diagnostic categories. Nonetheless, substantial variability in trauma features, developmental timing, outcome measures, and study designs along with the dominance of cross-sectional research, limits the ability to draw definitive causal conclusions. Taken together, the existing literature indicates the value of a transdiagnostic perspective while highlighting important methodological and conceptual shortcomings. Future longitudinal and mechanistic studies are required to specify causal pathways and to test whether interventions aimed at RNT and related regulatory processes can meaningfully enhance the prevention and treatment of depression associated with trauma.