Residential PTSD treatment outcomes during cognitive processing therapy for veterans with and without recent histories of cannabis use.

Prior evidence has suggested that cannabis use is associated with greater posttraumatic stress disorder (PTSD) symptom severity and worse outcomes following trauma-focused treatment. However, lack of high-quality randomized studies necessitates the use of clinical data to clarify the relationship between cannabis use and PTSD treatment to help inform clinical practice. A total of 114 veterans completed cognitive processing therapy in a residential PTSD treatment program. Differences in treatment response between cannabis users and nonusers were evaluated for measures of PTSD, depression, and posttraumatic growth using analysis of covariance to control for pretreatment scores and other drug use. At baseline, cannabis users reported higher levels of PTSD symptom severity relative to nonusers but reported similar levels of depression and posttraumatic growth. Significant differences between groups in the amount of change were not observed on any of the measures from before to after treatment; however, the total sample reported significant improvements in all measures of interest. These results suggest that PTSD treatment outcomes for cannabis users may be similar to nonusers when use is stopped during treatment. Additional data are needed regarding whether outcomes remain similar at follow-up, whether cannabis users maintain abstinence after treatment, and the impact of resumed cannabis use on PTSD symptoms. (PsycInfo Database Record (c) 2021 APA, all rights reserved).