Changes in pain and related health outcomes after cognitive processing therapy in an active duty military sample

This study explored the association between changes in pain and related health outcomes and posttraumatic stress disorder (PTSD) symptoms following cognitive processing therapy (CPT) in an active duty military sample. Based on the mutual maintenance model, we hypothesized that PTSD symptom reductions would be associated with improvements in pain and health symptoms following CPT. This secondary, intent-to-treat analysis included data from a parent trial of 127 active duty U.S. Army soldiers diagnosed with PTSD who were receiving variable-length CPT. We used mixed-effect regression models with repeated measures to examine whether treatment responders (i.e., individuals with a reduction of 11 points or more on the PCL-5) demonstrated improvements in pain and health outcomes posttreatment. Models included fixed effects of visit (baseline and 1-month follow-up), clinically significant PTSD improvement classification (present or absent), and the respective interaction. There were significant interactions on pain interference, F(1, 75.92) = 6.32, p  = .014; perceived life control, F(1, 95.59) = 5.17, p = .025; affective distress, F(1, 83.15) = 9.77 p = .002; mental health, F(1, 96.27) = 20.75, p < .001; physical health, F(1, 84.97) = 3.98, p = .049; and somatic symptoms, F(1, 80.64) = 6.08, p = .016. These interactions revealed that participants with clinically significant PTSD improvement following CPT also demonstrated certain better pain and health outcomes compared to nonresponders. Service members with pain and health issues in addition to PTSD who respond to CPT may also report improvements in these issues posttreatment, increasing the value of connecting them to treatment.