Gallagher, Catherine E.2023-11-132023-11-132022-09https://unbscholar.lib.unb.ca/handle/1882/37538Women are significantly more likely than men to present with concurrent trauma and substance use disorders (SUDs), resulting in complex clinical needs and treatment attrition (Fonesca et al., 2021). However, current interventions for co-occurring trauma and SUDs tend to confer modest benefits for trauma and little-to-no benefit for SUDs (Molina & Whittaker, 2022). Research examining transdiagnostic factors underlying the relationship between trauma exposure and substance use is in its infancy but is promising for intervention (Corace et al., 2021). Thus, the overarching goal of this dissertation was to understand how heterogeneous trauma histories of women affect their substance use, and whether the relationship between trauma characteristics and substance use could be understood via the sequential ordering of two transdiagnostic emotional vulnerability factors: 1) emotional intolerance (anxiety sensitivity, distress intolerance); and 2) emotional dysregulation (negative urgency, nonacceptance, limited strategies, difficulties with goal-directed behaviour). These goals were achieved via three Research Questions utilizing an online survey. The sample was 130 adult community-based women self-identifying as experiencing substance use problems. Research Question 1 identified three latent classes of women based on their self-reported lifespan trauma exposure: Class 1 (Low Lifetime Trauma), Class 2 (Moderate Interpersonal Trauma–Predominant Childhood Neglect), and Class 3 (High Interpersonal Trauma–Predominant Sexual Abuse). Class 3 reported the greatest interpersonal trauma exposure, frequency, and perceived functional impairment and significantly greater substance use severity. Research Question 2 examined how these latent classes differed on transdiagnostic emotion variables (i.e., emotional intolerance, emotion dysregulation). When controlling for state negative affect, classes significantly differed on emotional intolerance in the expected direction but not on emotion dysregulation. Finally, Research Question 3 found that the relationship between trauma characteristics and SUD severity was mediated by emotional intolerance then emotional dysregulation. Results suggest that as women’s lifetime interpersonal trauma increases, so does their SUD severity by way of emotional intolerance and subsequent difficulties regulating their emotions. Taken together, findings for all three Research Questions indicate that transdiagnostic interventions targeting tolerance of aversive emotions may facilitate the ability to learn and employ healthy emotion regulation strategies among women with complex interpersonal trauma histories and SUDs.x, 236electronicenhttp://purl.org/coar/access_right/c_abf2doctoral thesisBrunelle, CarolinePsychology