Co-Occurring PTSD and Substance Use Disorder influence on therapy outcome?

As many clinicians are aware, PTSD and Substance Use Disorder (SUD) commonly co-occur.  As a result, it is important for clinicians to understand how these two disorders effect treatment. In a recent study Bountress et al. (2018) examined this question.  Their results are interesting.

In their article, Bountress et al. (2018) compared treatment outcomes for the treatment of PTSD using Prolonged Exposure Therapy. They compared by order of onset of the problem. The two groups examined were, (A) PTSD before SUD and (B) SUD before PTSD.

They found no significant associations between order of onset and baseline symptomatology. In other words, the PTSD symptoms were essentially similar across the groups at baseline.

Another finding was that participants with PTSD first were significantly more likely than participants with SUD first to report higher levels of PTSD symptoms at the end of treatment.

They suggested that one possible explanation could be that participants (average age of 40.3 years) who developed PTSD first had PTSD longer than individuals who developed SUD first. Thus, the PTSD was more entrenched or chronic. They indicated that this group may benefit from a longer duration of treatment.

The good news out of all of this? The SUD before PTSD group had the greatest PTSD symptom reductions.  Co-morbid SUD may not be a hindrance to PTSD treatment.

In their sample those in the primary PTSD group experienced PTSD onset at about age 24 and SUD onset at 32; Based on the average age of 40.3 years they had PTSD for 8 years before the SUD and 16 years before therapy for the PTSD.

Those in the primary SUD group experienced SUD onset at age 24 and PTSD onset at age 31, so they had SUD for 16 years and PTSD for 9 years before therapy for their PTSD.


Bountress, K. E., Badour, C., Flanagan, J., Gilmore, A. K., & Back, S. E. (2018). Treatment of Co-Occurring Posttraumatic Stress Disorder and Substance Use: Does Order of Onset Influence Outcomes?. Psychological Trauma: Theory, Research, Practice, and Policy. 2018 Nov;10(6):662-665. doi: 10.1037/tra0000309