Effect of traumatic event reexposure and PTSD on substance use disorder treatment response

Background: A remarkably high rate of traumatic event reexposure has been demonstrated in community-based substance users which negatively impacts their substance use disorder (SUD). The rate and effect of such reexposure in treatment is unknown. Despite increasing evidence that a diagnosis of posttraumatic stress disorder (PTSD) has little influence on long-term SUD treatment outcomes, it is possible that PTSD symptom fluctuations could have effects. Methods: This prospective longitudinal study examined the rate and effect of traumatic event reexposure and PTSD symptoms in 169 male and female methadone maintenance patients with a comorbid psychiatric disorder who were participating in a parent study. Traumatic events and PTSD symptoms were tested for association with drug use, treatment interruption, and counseling adherence in the same month, one month later, and two months later. Results: Approximately 18% of patients were reexposed to a traumatic event each month during the 12-month study. Reexposure was associated with about twice the risk of treatment interruption in the same month and one month later. Every 10% increase in PTSD symptom severity was associated with a 36% increased risk of treatment interruption two months later. No effects were seen on drug use or counseling adherence. Conclusions: SUD patients have a relatively high rate of traumatic event reexposure. Both traumatic events and PTSD symptoms are associated with increased risk of treatment interruption, resulting in SUD patients leaving treatment at precisely the time they could benefit from treatment support.