Do post-traumatic pain and post-traumatic stress symptomatology mutually maintain each other? A systematic review of cross-lagged studies

After traumatic exposure, individuals are at risk of developing symptoms of both pain and post-traumatic stress disorder (PTSD). Theory and research suggest a complex and potentially mutually maintaining relationship between these symptomatologies. However, findings are inconsistent and the applied methods are not always well suited for testing mutual maintenance. Cross-lagged designs can provide valuable insights into such temporal associations, but there is a need for a systematic review to assist clinicians and researchers in understanding the nature of the relationship. Thus, the aim of this systematic review was to identify, critically appraise, and synthesize results from cross-lagged studies on pain and PTSD symptomatology to assess the evidence for longitudinal reciprocity and potential mediators. Systematic searches resulted in 7 eligible studies that were deemed of acceptable quality with moderate risk of bias using the cohort study checklist from Scottish Intercollegiate Guidelines Network. Furthermore, synthesis of significant pathways in the cross-lagged models showed inconsistent evidence of both bidirectional and unidirectional interaction patterns between pain and PTSD symptomatology across time, hence not uniformly supporting the theoretical framework of mutual maintenance. In addition, the synthesis suggested that hyperarousal and intrusion symptoms may be of particular importance in these cross-lagged relationships, while there was inconclusive evidence of catastrophizing as a mediator. In conclusion, the findings suggest an entangled, but not necessarily mutually maintaining relationship between pain and PTSD symptomatology. However, major variations in findings and methodologies complicated synthesis, prompting careful interpretation and heightening the likelihood that future high-quality studies will change these conclusions.