Trauma-related guilt, shame, and trauma type among patients with co-occurring PTSD and SUD

Background: Substance use disorder (SUD) frequently co-occurs with posttraumatic stress disorder (PTSD). Feelings of shame and guilt are associated with either disorder but have not been studied in patients with both disorders. Index trauma characteristics are associated with PTSD severity and trauma-related shame. This study examines the effects of trauma-related guilt and shame, and index trauma on SUD and PTSD severity in a clinical sample of individuals with co-occurring SUD and PTSD. Methods: Participants were SUD-treatment-seeking patients with co-occurring PTSD (N = 209) who completed the Clinician-Administered PTSD scale for Diagnostic and Statistical Manual of Mental Disorders (DSM-5; CAPS-5), Alcohol Use Disorder Identification Test (AUDIT), Drug Use Disorders Identification Test (DUDIT), Trauma-Related Guilt Inventory (TRGI) and Trauma-Related Shame Inventory (TRSI). Regression analyses examined the predictive values of PTSD severity, trauma-related guilt, and shame on alcohol and drug use problems, and the predictive values of trauma-related guilt and shame on PTSD severity. One-way ANOVA and follow-up t-tests examined the effects of index trauma on PTSD severity and trauma-related shame. Results: PTSD severity was significantly associated with drug use disorder (DUD) severity and showed a curvilinear relationship to alcohol use disorder (AUD) severity. Trauma-related guilt was not significantly associated with SUD severity, while trauma-related shame was significantly associated with DUD severity (but not AUD severity). Both trauma-related guilt and shame were significantly associated with PTSD severity; however, only trauma-related shame showed an independent association. Interpersonal (especially sexual) index traumas were associated with increased trauma-related guilt and shame, while childhood index traumas were associated with increased PTSD severity. Conclusions: Trauma-related guilt and shame might be important focus points in PTSD treatment, but for SUD problems, this study only showed an association between trauma-related shame and drug use problems. Trauma-related shame seems to be a more important treatment focus point than trauma-related guilt in the treatment of PTSD. It becomes particularly relevant for interpersonal index traumas (especially sexual trauma). Childhood traumas require attention in SUD-PTSD co-occurrence, given the higher severity of PTSD.