(PS4-A14) Impulsivity as a Mediating Factor Between Adverse Childhood Experiences and Posttraumatic Stress Disorder

Adverse childhood experiences (ACEs) are associated with many negative health outcomes including increased vulnerability for posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) (Contractor et al., 2018; Junglen et al., 2019). Yet, not everyone who experiences ACEs goes on to develop PTSD. There have been various attempts to characterize this relationship. Impulsivity has gained interest as a potential mediator. The UPPS-P model conceptualizes impulsivity as a multi-dimensional construct encompassing five facets: lack of premeditation, lack of perseverance, sensation seeking, positive urgency, and negative urgency (Whiteside & Lynam 2001). These subconstructs have theoretical connections to PTSD symptomatology. For example, the tendency to act rashly when experiencing negative emotionality (negative urgency) may be a compensatory mechanism to regulate negative affect prominent in PTSD (Roley et al., 2017). Previous research has helped elucidate how PTSD and impulsivity are interrelated (e.g., Contractor et al., 2018), but less has been done within the context of SUD. The purpose of this study is to examine whether impulsivity acts as a mediator between ACEs and PTSD symptoms in a sample of adults seeking inpatient treatment for SUD. We hypothesized that negative urgency would mediate the relationship between ACEs and PTSD symptoms. Eighty-four patients (M=39 years, SD=13, 54% white) enrolled in an acute residential treatment episode for SUD were consented to participate. Participants completed a series of questionnaires including the UPPS-P, the Adverse Childhood Experiences Questionnaire, and the PTSD Checklist for DSM-5 (PCL-5) (Felitti et al., 1998; Blevins et al., 2015) to measure impulsivity, ACEs, and PTSD symptoms, respectively. Data were analyzed in STATA using a bias-corrected bootstrap structural equation model (SEM) to examine whether impulsivity (total and subscales) mediates the relationship between ACEs and PTSD symptoms. Average PCL-5 score was 38.63 (SD=23.62, 0-77), with 58.33% meeting threshold for a provisional diagnosis of posttraumatic stress disorder (PCL score > 30). The mean number of ACEs was 5.54 (SD=5.46, 0-17). The mean total UPPS score was 11.59 (SD=2.22, 5-20). Subscale scores ranged from 1.82 (SD=0.66) for lack of perseverance to 2.78 (SD=0.87) for negative urgency. ACEs score was a significant direct predictor of PTSD in all models. Lack of premeditation emerged as a significant partial mediator of this association. The indirect effect of ACES to PTSD through lack of premeditation was 0.49 (z=2.07; p=0.04). Neither the total UPPS-P score nor any other subscales were found to mediate the relation between ACES and PTSD. These finding suggest that an individual’s propensity towards lack of premeditation partially explains the relationship between ACEs and PTSD symptoms within a sample of SUD patients, supporting previous research (Kim & Choi, 2020). We did not find that negative urgency mediated this relationship, possibly because direct effects may have overshadowed more subtle indirect effects. Further research is needed to examine how impulsivity interacts with ACEs and PTSD in various populations to continue to characterize the relationship and better treatment.