Understanding Historical Trauma for the Holistic Care of Indigenous Populations: A Scoping Review.

Historical trauma refers to the collective depredations of the past that continue to affect populations in the present through intergenerational transmission. Indigenous people globally experience poorer health outcomes than non-Indigenous people, but the connections between Indigenous people's health and experiences of historical trauma are poorly understood. To clarify the scope of research activity on historical trauma related to Indigenous peoples' health, we conducted a scoping review using Arksey and O'Malley's method with Levac's modifications. Seventy-five articles (1996-2020) were selected and analyzed. Key themes included (a) challenges of defining and measuring intergenerational transmission in historical trauma; (b) differentiating historical trauma from contemporary trauma; (c) role of racism, discrimination, and microaggression; (d) questing for resilience through enculturation, acculturation, and assimilation; and (e) addressing historical trauma through interventions and programs. Gaps in the research included work to establish mechanisms of transmission, understand connections to physical health, elucidate present and past trauma, and explore epigenetic mechanisms and effects ascribed to it. Understanding first what constitutes historical trauma and its effects will facilitate development of culturally safe holistic care for Indigenous populations.