An Umbrella Review of the Links Between Adverse Childhood Experiences and Substance Misuse: What, Why, and Where Do We Go from Here?

BACKGROUND AND OBJECTIVES: A wealth of research has identified adverse childhood experiences (ACEs; abuse, neglect, violence or disorder in the home) as a strong risk factor for substance misuse. Synthesis of the existing evidence is critical to shape policy and inform directions for future research. Existing reviews have focused on specific substances or substance use outcomes (eg, disorder), and do not include discussion of the mechanisms that operate between ACEs and substance misuse. The current umbrella review aims to synthesize reviews on the relationship between ACEs and substance misuse, review the evidence on the mechanisms linking these, identify existing gaps in our knowledge, and discuss critical directions for future research, practice, and public policy. METHODS: Two electronic databases (PsycINFO and Medline) were searched for reviews published between 1998 and 2022 on the link between ACEs and substance misuse. Twenty articles met eligibility criteria and were qualitatively synthesized. RESULTS: Results overwhelmingly demonstrated an elevated risk of substance misuse or disorder, among adolescents and adults exposed to ACEs. Research on the mechanisms that explain this link highlights a multitude of potential intervention targets, with childhood stress propelling a cascade of effects across neurobiological, endocrine, immune, metabolic, and nervous systems, impacting psychosocial and cognitive functioning. Nonetheless, the literature is subject to limitations surrounding potential unmeasured cofounders and causality, as well as decontextualizing childhood adversity from broader structural issues that influence the link between ACEs and substance misuse. Research, policy, and practice that seek to holistically understand and address the relationship between ACEs and substance misuse within the broader social determinants of health is crucial.