<p>Childhood adversity is a major risk factor for psychopathology, yet the psychological mechanisms remain unclear. One proposed mechanism is low positive affect, although the evidence remains scattered and heterogeneous. In this meta-analytic structural equation modeling study, we pooled data from 115 studies (<i>N</i> = 305,943) to examine the direct and indirect pathways linking childhood adversity, positive affect and psychopathology. Findings indicate that childhood adversity is significantly associated with low positive affect, which in turn relates to increased psychopathology symptoms. Moderator analyses reveal that these effects vary by sample characteristics, assessment methods and study quality, underscoring the complexity of these associations. These results suggest that interventions enhancing positive affect may mitigate psychopathology risk among individuals exposed to childhood adversity, offering promising new avenues for prevention and clinical practice in mental health.</p>