A Latent Class Analysis of Posttraumatic Stress Disorders and Alcohol Use Symptoms Based on Type of Trauma Experienced Among Youth and Young Adults in a High-Risk Family Study

Background and Purpose: The co-occurrence of posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) is widely known, yet fewer studies have focused on whether and how specific AUD symptoms may map onto PTSD symptom clusters (hyperarousal/hypervigilance, avoidance/numbing, re-experiencing). Trauma survivors who do not meet diagnostic criteria for PTSD and AUD may suffer from symptoms of both disorders that impair functioning and quality of life. A growing body of research has used latent class analysis to delineate profiles of drinkers for prevention and treatment strategies. The purpose of this study is to extend this area of inquiry by examining the clustering of AUD and posttraumatic stress criteria with discrete forms of trauma exposure (physical and sexual assault).  

Methods: The Collaborative Study on the Genetics of Alcoholism (COGA) investigates alcohol and related disorders and has been ongoing since 1991. Drawing from the prospective cohort of COGA, we examined Black and White youth and young adults between the ages of 12-35. After descriptive and bivariate tests, we used latent class analysis to fit a model delineating profiles of trauma survivors (N = 2879) based on the type of trauma experienced, their posttraumatic stress symptoms (if any) and problematic alcohol use (if any). Variables included in each model were PTSD symptom clusters B, C, and D, AUD symptoms 1-11, and physical and sexual assault, with the model grouped by sex. We hypothesized that a three-solution model would provide the best fit to the data, with classes representing males/physical assault/high alcohol symptom endorsement/low PTSD symptom endorsement, females/sexual assault/moderate alcohol symptom endorsement/high PTSD symptom endorsement, and a third class comprised of roughly equal males and females with moderate alcohol symptom endorsement and low PTSD symptom endorsement.

Results:  Latent class analysis revealed that a three-class solution provided the best fit to the data, roughly consisting of a “Moderate Trauma/Moderate AUD Severity/No PTSD” class, with 36% endorsement by males and 47% endorsement by females; a “Low Trauma/Moderate AUD/No PTSD” class, comprised of majority males (43%); and a “High Trauma/Moderate AUD Severity/High PTSD Severity”, endorsed by 20% of males and 30% of females. The most common AUD symptoms co-occurring with PTSD clusters in Group 3 were criteria 1 (alcohol taken in larger amounts/over longer periods than intended), 6 (continued use despite problems), 8 (recurrent use in hazardous situations), and 10 (tolerance), although the percentage of endorsements differed somewhat by sex.

Conclusions and Implications: These data suggest that alcohol use patterns and PTSD symptoms may vary according to the type of trauma experienced; furthermore, these patterns are sex-specific, perhaps owing to the differential risk of physical versus sexual trauma for males and females. Future research may delineate profiles of individuals who use alcohol to cope with traumatic memories versus those whose alcohol use places them at higher risk for trauma exposure, which could have prevention and treatment implications.