Childhood Trauma, PTSD, and Substance Use: The mediating role of positive and negative urgency

Abstract

Childhood trauma and posttraumatic stress disorder (PTSD) are highly comorbid with substance use. This co-occurrence may be explained by increased levels of positive urgency and negative urgency (i.e., impulsive actions in response to intense positive/negative emotions) in those with trauma exposure and/or PTSD. This study aimed to clarify how childhood trauma subtypes, PTSD symptom clusters, and urgency relate to substance use/problems, and whether urgency facets mediate the relationship between specific PTSD symptom clusters and substance use/problems. A sample of 299 participants (Mage = 27.39, SD = 12.46; 61.5% female) was recruited from the University of New Brunswick and through a crowdsourcing platform. In hierarchical regressions, PTSD avoidance symptoms emerged as a significant predictor of nicotine problems and polysubstance use. CTQ physical neglect predicted cannabis problems, nicotine and alcohol use frequency, and polysubstance use. Negative urgency predicted alcohol use frequency, while positive urgency predicted polysubstance use. In mediation analyses, negative urgency fully mediated the relationship between PTSD avoidance, intrusion, and hyperarousal symptoms and alcohol problems. Positive urgency partially mediated the association between all PTSD symptom clusters and polysubstance use. Clinically, these findings suggest that PTSD symptoms are implicated especially in alcohol problems and polysubstance use, but that contributors to this substance use pattern are distinct. Negative urgency appears to be a target of intervention for individuals with PTSD symptoms and alcohol problems, while positive urgency may be more important for individuals with PTSD symptoms who experience polysubstance use.