Understanding the link between trauma & problematic substance use: Does diagnosis trump experience?

​Brittany Skelding, Dr. David Speed, and Dr. Caroline Brunelle
Department of Psychology, University of New Brunswick
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​It has been suggested that that the consistent link between childhood trauma and problematic substance use may be explained by the self-medication hypothesis, which posits that individuals consume substances to dampen the secondary symptoms of having experienced trauma. However, little research has distinguished between the likelihood of using substances problematically following a trauma-related diagnosis (i.e., post-traumatic stress disorder) versus the experience of traumatic events without receiving a diagnosis. The current study utilized data from the Canadian Community Health Survey (N = 21,917) to investigate this distinction. A logistic regression revealed a significant interaction between PTSD and traumatic events without a clinical diagnosis on the likelihood of using substances problematically (p = .038, OR = .684, 95% CI [.479, .973]). Specifically, having PTSD may initially lead to a higher likelihood of using substances problematically as compared to having no clinical diagnosis; however, as the frequency of childhood traumatic events an individual experiences rises, disordered substance use increases as well, matching that of individuals with a clinical diagnosis. These findings suggest that substance use interventions in the context of trauma are necessary regardless of PTSD diagnosis and intensity of services should match the level of exposure to trauma.