Heterogeneity in the Co-occurrence of Substance Use and Posttraumatic Stress Disorder: A Latent Class Analysis Approach

Objective: Posttraumatic stress disorder (PTSD) often co-occurs with substance use (SU). Although there has been independent research on subgroups of participants based on their PTSD or SU responses, rarely are PTSD-SU typologies examined consistent with a precision medicine approach (and corresponding person-centered statistical approaches). The current study examined the nature and construct validity (covariates of depression, physical aggression, verbal aggression, anger, hostility, reckless and self-destructive behaviors [RSDB]) of the best-fitting latent class solution in categorizing participants based on PTSD (PTSD Checklist for DSM-5) and alcohol/drug use responses (Alcohol Use and Disorders Identification Test Alcohol Consumption Questions, Drug Abuse Screening Test). Methods: The sample included 375 trauma-exposed participants recruited from Amazon’s Mechanical Turk online labor market. Results: Latent class analyses indicated an optimal three-class solution (low PTSD/SU, moderate PTSD/drug and high alcohol, and high PTSD/SU). Multinomial logistic regressions indicated that depression (OR = 1.22) and frequency of RSDBs (OR = 1.20) were significant predictors of the moderate PTSD/drug and high alcohol class versus the low PTSD/SU class. Depression (OR = 1.55) and frequency of RSDBs (OR = 1.19) were significant predictors of the high PTSD/SU class versus the low PTSD/SU class. Only depression (OR = 1.27) was a significant predictor of the high PTSD/SU class versus the moderate PTSD/drug and high alcohol class. Conclusions: Results provide construct validity support for three meaningful latent classes with unique relations with depression and RSDBs. These findings improve our understanding of heterogeneous PTSD-SU comorbidity patterns and highlight acknowledgment of such subtyping (subgrouping) in considering differential treatment options, treatment effectiveness, and resource allocation