Childhood Mistreatment, PTSD, and Substance Use in Latinx: The Role of Discrimination in an Omitted-Variable Bias

Childhood mistreatment (CM) has been associated with adult posttraumatic disorder (PTSD) and substance use disorders (SUDs) in the general population. Few studies have examined the role of PTSD in the CM-SUD association among Latinx. This cross-sectional study evaluated a theory-driven conceptual model with a specific focus on the impact of perceived discrimination, which may interfere with these associations.

Using a nationally representative sample and structural equation modeling (SEM), the study evaluated the mediation of PTSD in the CM-SUD link, adjusting for or omitting discrimination and other sociodemographic variables that are known predictors of Latinx behavioral health. Multi-subsample analyses were then conducted to review nativity differences (US-born = 924.43% and immigrant = 1630.57%).

The fully specified final model (model 1, covariates adjusted) failed to show a significant mediation of PTSD in the tested link, but a direct detrimental effect group of discrimination, for all Latinx. The mediation was only supported, when treating discrimination and other covariates as omitted variables (model 5), which also showed additional direct and indirect effect of CM on SUD. In subsample analyses, models of US-born and immigrant-Latinx subpopulations were identical but showed nativity differences when omitting covariates.

When discrimination and other covariates were fully adjusted, Latinx exposed to trauma were more likely to develop SUD in adulthood, regardless of when traumatic exposure occurred. This unexpected finding challenges theories explaining the CM-SUD connection, suggesting possible model misspecifications of parametric SES; namely, omitting the unique impact of perceived discrimination in Latinx can lead to biased results. From a clinical standpoint, both trauma and discrimination must be addressed when assessing Latinx behavioral health.