Prevalence and impact of adverse childhood experiences and extrafamilial violence: a representative survey of adults in Northern Ireland.

Introduction: Adverse childhood experiences (ACEs) are linked to poor outcomes in adulthood, but extrafamilial violence (EFV), such as bullying, community and collective violence, remains relatively under-researched. This study aimed to estimate the prevalence of both the commonly measured ACEs and EFV in Northern Ireland (NI), a postconflict region and assess the association with physical and psychological outcomes. Methods: A representative sample of 1200 adults completed a standardised assessment of childhood adversity (WHO Adverse Childhood Experiences International Questionnaire) covering 13 ACEs. Logistic regressions assessed the association between high ACE exposure (4+vs 0) and adult mental and physical health, health behaviours and service use, adjusting for age, gender and deprivation. Adjusted ORs (AORs), population attributable fractions and additional variance explained were reported. Results: When EFVs were included alongside commonly measured ACEs, 60.0% (n=719) of the NI sample reported at least one ACE and 17.6% (n=212) reported four or more. EFVs were independently associated with poor mental health outcomes, including post-traumatic stress disorder (PTSD)/complex PTSD (CPTSD) (AOR=14.8, 95% CI (6.5, 33.8)) and anxiety (AOR=7.5, 95% CI 4.9 to 11.4), contributing up to 18.3% (n=41) of anxiety cases. EFVs were also linked to substance use, chronic pain and frequent health service contact. While the most commonly measured ACEs predicted involvement in the justice system, EFVs significantly improved model fit for most health outcomes. Conclusions: EFV is a common and impactful form of childhood adversity. Including EFVs in ACE models improves predictive accuracy, particularly for mental health. ACE research and policy frameworks should be broadened to reflect the added burden of EFV.