Abstract
Adverse childhood experiences (ACEs) are identified with increased risk of adult mental health difficulties and negative impacts on wellbeing. However, there is a need to go beyond simple associations and identify candidate mechanisms underpinning the ACEs-mental health relationship. Further methodological heterogeneity points to issues around the operationalisation of ACEs and the importance of modelling data using robust research designs. The aim of the current review was to synthesize studies that utilised formal mediation and/or moderation analyses to explore psychological and social variables on the pathway between clearly defined ACEs (as measured by the ACE questionnaire and CTQ) and common mental health outcomes (depressive, anxiety, PTSD symptoms) across community samples aged over 18. A total of 31 papers were retrieved for critical appraisal. The majority of the studies explored factors mediating/moderating the link between child adversity and depression, and less on anxiety and trauma. Most mechanisms were tested in only single studies, limiting the consistency of evidence. Evidence indicated that the mechanisms underlying associations between ACEs and adult mental health are likely to reflect multiple intervening variables. Further, there are substantial methodological limitations in the extant literature including the proliferation of causal inferences from cross-sectional designs, and both measurement and conceptual issues in operationalizing adversity. Consistent transdiagnostic mechanisms relevant to common mental health problems were identified, including perceived social support, emotion regulation, and negative cognitive appraisals/beliefs. Further research using longitudinal design is required to delineate the potential contribution of the identified mechanisms.