A randomized controlled trial evaluating integrated versus phased application of evidence-based psychotherapies for military veterans with comorbid PTSD and substance use disorders

OBJECTIVE: Recent clinical practice guidelines recommend the delivery of evidence-based psychotherapies for both substance use disorder (SUD) and posttraumatic stress disorder (PTSD) within the same treatment episode for patients with SUD/PTSD comorbidity. This randomized clinical trial evaluated the comparative effectiveness of integrating versus phasing evidence-based psychotherapies for SUD and PTSD among veterans with co-occurring SUD/ PTSD.

METHOD: 183 veterans with DSM-IV PTSD and SUD at two VA Medical Centers were randomized to one of two psychotherapies during which Motivational Enhancement Therapy [MET] for SUD and Prolonged Exposure [PE] for PTSD were either phased or integrated throughout treatment. Primary outcomes as evaluated by blinded assessors were percent days with drug use or heavy drinking and PTSD symptomology. We hypothesized integrated MET/PE (n = 95) would yield better SUD and PTSD-related outcomes at posttreatment than phased MET/PE (n = 88).

RESULTS: In intent-to-treat analyses (n=183), both treatment groups achieved clinically (d=0.46 - 1.06) and statistically significant reductions in SUD (p < 0.01) and PTSD (p < 0.01) symptomology; the time by treatment interactions were not significant. Post-hoc analyses could not confirm statistical non-inferiority; between-group effect sizes suggest a lack of clinically-meaningful differences between the two treatment approaches (d=0.08 - 0.27).

CONCLUSIONS: Our hypothesis that integrated MET/PE would result in better outcomes than phased MET/PE across a range of PTSD and SUD measures was not supported; both strategies for combining two single-disorder treatments for co-occurring SUD/PTSD yielded significant symptom reduction.