Adverse Childhood Experiences, Personality Traits of Impulsivity and Substance Use during Young Adulthood

Background and purpose
The influence of adverse childhood experiences (ACEs), which often include childhood exposure to maltreatment and household dysfunction, on substance use behaviors during young adulthood has been widely documented. Few studies have examined the pathways linking ACEs to substance use. A vulnerability marker for the increased substance use among young ACEs victims such as impulsivity (e.g., lack of perseverance, negative urgency) remains to be explored. The current study examined whether individual differences in personality traits of impulsivity were critical factors that mediate the relationship of exposure to ACES on drug dependence symptoms, alcohol-related problems, and tobacco use in young adulthood. Since the majority of young people suffer not just one but several types of ACEs, we used patterns of ACEs in exploring the pathways from ACEs to substance use.

Methods
The present study used a community sample of young adults (N=335). Participants were recruited through community advertisements targeting young adults, ages 18-25. Latent class analysis (LCA) was first conducted to identify groups or classes of young individuals with similar patterns of ACEs. Exposure to ACEs included thirteen childhood exposure to violence and adversities. They include childhood emotional, physical and sexual abuse, emotional and physical neglect, intimate partnership violence, household substance use, family mental health, incarcerated family members, property crime, and gang violence. We used multiple structural equation models (SEM) to specify the roles of four related, but different impulsivities (i.e., negative urgency, premeditation, perseverance, sensation seeking) in linking ACEs patterns to problematic substance use, including drug dependence symptoms, alcohol-related problems, and tobacco use.

Results
Our LCA found that the 4-class solution described the optimal number of ACEs typologies (LMRT (p= .03); BLRT (p<.001)). The 4-class solution exhibited high entropy (85%), and the average posterior class membership probability scores were excellent across groups (.88 - .95). Four distinct classes include: Low ACEs (56% of the sample), Household Dysfunction/Community Violence (14%), Emotional ACEs (14%), and High/Multiple ACEs (16%). The final SEM analyses fit the data well (CFI > .95; RMSEA ≤ .04). Our SEM analyses indicated indirect effects for the High Multiple ACEs class through pathways to negative urgency on drug dependence symptoms, alcohol-related problems, and current tobacco use, respectively.  We also found that the paths from ACEs to lack of perseverance to problematic substance use were also statistically significant only for the High Multiple ACEs class.

Discussion and implications
The present study found that negative urgency and lack of perseverance played a significant role in linking ACEs to problematic substance use among a poly-victimized class. The results of this research suggest that personality traits of impulsivity would be potentially useful targets to prevent problematic substance use among young people who have exposure to multiple ACEs.