Reductions in PTSD Severity Precede Reductions in Pain Intensity Among Veterans Receiving Intensive Treatment

Objective: Chronic pain often co-occurs with posttraumatic stress disorder (PTSD). The mutual maintenance hypothesis proposes that there may be shared underlying mechanisms of symptoms of pain exacerbating PTSD, and vice versa. The association between PTSD and pain intensity remains understudied. To elucidate the relationship, the present study examined the temporality of changes in PTSD severity and pain intensity in veterans undergoing intensive PTSD treatment. Method: Data from 332 veterans undergoing intensive 2-week cognitive processing therapy- (CPT-) based treatment (ITP) with adjunctive components (i.e., mindfulness, art therapy). Random intercepts cross-lagged panel models (RI-CLPMs) were used to examine within-subjects relationships between pain intensity and PTSD severity over the course of the program. Results: Veterans experienced large PTSD severity reductions (Essg = 1.20; p < .001) and small pain severity reductions (Essg = 0.21; p < .001) over the course of treatment, despite pain not being a treatment target. RI-CLPMs revealed that PTSD severity significantly predicted subsequent pain severity. Results indicate the absence of a bidirectional relationship in that changes in pain intensity did not predict later PTSD severity improvement during the ITP. Time trends for both PTSD severity and pain intensity were generally consistent with respect to baseline demographic characteristics. Conclusion: Our findings support the mutual maintenance regarding the association between PTSD and pain intensity. Future research should investigate temporal associations in other evidence-based PTSD treatments and formats and evaluate the long-term impacts of PTSD treatment on pain intensity.