Modelling the Mediating and Moderating Mechanisms Linking Adverse Childhood Experiences to Adult Mental Health Outcomes in the South South Geopolitical Zone

Adverse childhood experiences (ACEs) are robustly associated with adult mental health deterioration, but the mediating and moderating mechanisms of this relationship remain insufficiently characterised within sub-Saharan African populations. This study modelled the mechanisms linking adverse childhood experiences to adult mental health outcomes in the South South geopolitical zone of Nigeria. A large-scale epidemiological survey design was used, with 900 adults aged 25 to 45 years selected through multistage probability sampling from Bayelsa, Delta, and Cross River States. The ACE Questionnaire (adapted for Nigerian cultural contexts), the Patient Health Questionnaire-9 (PHQ-9), the General Anxiety Disorder Scale (GAD-7), and measures of social support, coping self-efficacy, and community belonging were administered. Conditional process analysis (PROCESS macro, Models 14 and 58) was applied for mediated moderation analysis. Findings identified trauma-specific coping self-efficacy and social support as the strongest mediators of the ACE-mental health relationship. Community belonging moderated the mediated pathway, with high belonging buffering the impact of ACEs on mental health even when coping self-efficacy was low. Multiple ACE types demonstrated additive rather than synergistic mental health effects. The study provides an original mechanistic model for ACE-mental health pathways in the South South zone, with direct implications for trauma-informed counselling programme design and community mental health advocacy. Keywords: adverse childhood experiences, mental health, mediation, moderation, South South Nigeria.