Category: Addictive Behaviors
An established body of work indicates a strong associations between posttraumatic stress symptoms (PTSS) and substance use. While much of this work has focused on the influence of PTSS on alcohol use, there is growing interest in links with other substances (e.g., cannabis, methamphetamine). Indeed, recent work has taken a more nuanced approach to understanding the influence of PTSS on other substances, suggesting that specific symptoms (e.g., hyperarousal) are associated with different substance use outcomes. Drawing from the self-medication model, these data suggest that individuals may use different substances to manage different symptoms and/or use similar substances (e.g., anxiolytics) to cope with greater severity of specific symptoms. Unfortunately, much of this work has examined these relations in isolation (e.g., alcohol or cannabis). As such, our understanding of PTSS-polysubstance use is limited – concerning, given the high prevalence of polysubstance use in the general population.
Empirical work has found that individuals using other substances, in addition to alcohol, report more severe PTSS in comparison to both alcohol- and other substance-only users. While associations between a) general PTSS severity and b) single-substance and/or unspecified polysubstance use are useful for laying a theoretical framework, more research examining specific symptoms and specified polysubstance use is needed. The current study aims to extend the literature by examining differences in severity of specific PTSS symptoms between users of two of the most common and accessible anxiolytic drugs in the United States – alcohol and cannabis.
A final sample of 157 (Mage = 20.63; 76% female) college drinkers that met criteria for a provisional diagnosis of PTSD were divided into two groups: alcohol-only (n = 69) and alcohol and cannabis (n = 88). Profile analysis evaluated for a main effect (mean difference) and parallelism (different patterns) between groups on the four PTSD symptoms clusters (cluster level). Profile analyses and follow-up univariate ANOVAs compared groups by specific symptoms (symptom level).
Cluster level analyses found a main effect and departure from parallelism (ps < .001) between groups. Symptom level analyses found differences between groups on negative cognition and hyperarousal symptoms (ps < .001), but not re-experiencing or avoidance symptoms (ps > .10). Univariate analyses showed users of both substances reported significantly greater severity of intrusive thoughts, event amnesia, negative beliefs, negative feelings, loss of interest, feeling disconnected, negative affect, irritability, risk taking, concentration issues, and sleep problems than alcohol-only users (all p < .05, η2: .028-.127).
Overall, individuals using cannabis, in addition to alcohol, reported significantly more negative cognition and hyperarousal symptoms. This generally supports an ‘additive’ self-medication model, suggesting that individuals use multiple substances with similar neurological effects to deal with more severe, specific symptoms. Conversely, these findings may suggest that the use of more substances exacerbates the severity of symptoms. Theoretical and clinical implication will be discussed.
Nathan Kearns– Doctoral Student, University of North Texas, Denton, Texas
Anabel Potts– University of North Texas
Renee Cloutier– PhD Student/NIDA Predoctoral Fellow, University of North Texas, Texas
Darian Chambers– University of North Texas
Heidemarie Blumenthal– University of North Texas