RESUMEN
OBJECTIVE: Childhood trauma (CT) is associated with a range of psychopathologies, including psychosis. However, evidence on underlying mechanisms remains limited. The study aimed to investigate whether CT impacts on youth mental health by modifying sensitivity to stress in daily life. METHOD: The experience sampling method (ESM) was used to measure momentary stress, negative affect and psychotic experiences in 99 adolescents and young adults (43 help-seeking service users, 16 siblings and 40 controls). Before ESM assessments, CT and depressive, anxiety and psychotic symptoms were assessed. RESULTS: Stress sensitivity, that is, the association between momentary stress and (i) negative affect and (ii) psychotic experiences, was modified by physical and emotional abuse and, partially, emotional and physical neglect, but not sexual abuse in service users and controls. While there was strong evidence for increased stress sensitivity in service users when high vs. low levels of CT were compared, a pattern of resilience was evident in controls, with attenuated, or no differences in, stress sensitivity in those with high vs. low CT levels. Less consistent findings were observed in siblings. CONCLUSIONS: Stress sensitivity may be an important risk and resilience mechanism through which CT impacts on mental health in youth.