Abstract
Exposure to trauma increases the risk of engaging in detrimental health behaviours such as tobacco and substance use. In response, the United States Substance Abuse and Mental Health Services Administration developed Trauma-Informed Care (TIC), an organisational framework for improving the provision of behavioural health care to account for the role exposure to trauma plays in patients' lives. We adapt TIC to introduce a novel theory of behaviour change, the Trauma-Informed Theory of Individual Health Behavior (TTB). TTB posits that individual capacity to undertake intentional health-promoting behaviour change is dependent on three factors: (1) the forms and severity of trauma they have been and are exposed to, (2) how this trauma physiologically manifests (i.e., the trauma response) and (3) resilience to undertake behaviour change despite this trauma response. We define each of these factors and their relationships to one another. We anticipate that the introduction of TTB will provide a foundation for developing theory-driven research, interventions, and policies that improve behavioural health outcomes in trauma-affected populations.