Effects of traumatic events and PTSD on response to substance use disorder treatment

Traumatic events and posttraumatic stress disorder (PTSD) are highly prevalent in substance users, and are associated with significantly more psychiatric distress, and medical and social impairment. These findings have led many to speculate that patients who enter treatment with significant traumatic event history or PTSD will have higher rates of drug use or leave treatment sooner than patients without such a history. Despite strong theoretical links between traumatic events, PTSD, and substance use, research to date has not found a consistent effect of traumatic events or PTSD on treatment response. However, earlier studies may have been limited by several methodological features. First, the failure to use an empirically-validated measure of either traumatic events or PTSD will result in an incorrect estimate of their impact. Second, assessments conducted too far apart in time will dilute the power to find relationships between traumatic events, PTSD symptoms and substance use. A third problem is that psychiatric problems naturally fluctuate over time and research that measures them at only one time-point may not detect a significant relationship. Fourth, there are several unstudied potential mediators of the effect of traumatic events and PTSD on treatment response. Finally, there is growing evidence for high rates of new traumatic event re-exposures occuring during treatment that seem likely to affect patients' response to treatment. The next wave of research should use more sophisticated methods, designs, and analyses to more fully evaluate the effect of traumatic events and PTSD on substance use disorder treatment.