Comparison of treatment outcomes for veterans with posttraumatic stress disorder with and without comorbid substance use/dependence.

Most of the attention to the treatment of patients who have comorbid Substance Use/Dependence Disorder (SUD) and Posttraumatic Stress Disorder (PTSD) has focused on SUD outcomes. This study focuses on the PTSD outcomes of comorbid patients as compared to those with PTSD only. Altogether 8599 Veterans admitted to VA specialized inpatient/residential PTSD programs were assessed for PTSD and SUD symptoms at admission and four months following discharge. Two samples were drawn sequentially in separate phases due to unexpected results in the first sample: 4966 in the first sample and 3633 in the second sample. In the first sample, dually diagnosed Veterans had significantly better PTSD outcomes than Veterans diagnosed with PTSD only. The differences could be attributed primarily to improvement in comorbid SUD symptoms. These results were replicated in the second sample. The results suggest that there may be a synergistic effect operating in the treatment of the two comorbid disorders.