Study Finds PTSD Symptoms Associated With Chronic Back Pain

Authors of a study in Vietnam War-era US veterans (each of whom had an identical twin who also was a veteran) have concluded that posttraumatic stress disorder (PTSD) symptoms are associated with an increased incidence of chronic back pain (CBP). The authors also concluded that although PTSD symptoms are a risk factor for chronic back pain, there are factors that can be modified, potentially preventing the development of chronic back pain in these at-risk veterans.

Citing several primary sources, Pradeep Suri and colleagues, from VA Puget Sound Health Care System in Seattle, Washington, explained the importance of this issue. The authors wrote: "Military Veterans have a high prevalence of both PTSD and back pain. PTSD is comorbid with chronic pain in 47% to 59% of United States (US) military veterans in outpatient pain clinics and post-deployment clinics, where the back is the most common individual location of chronic musculoskeletal pain. Much remains unknown about the relationship between PTSD and back pain. The association between PTSD and back pain may be due to causal links between these two conditions or their correlates, raising the possibility that treatment of one condition might prevent or improve symptoms of the other."

The authors used data from monozygotic twins who were both veterans, thus keeping genetic factors and early family environment from confounding the results.

Suri et al. wrote, "...[T]o date, no published studies have used genetically informative samples that permit the examination of whether PTSD symptoms are a risk factor for future CBP independent of genetic factors and the early family environment."

The longitudinal co-twin control study by Suri et al drew upon data and survey responses of 342 individual veterans (171 monozygotic twin pairs).

These veterans had participated in a large-scale study of PTSD that included a baseline survey conducted between 2010 and 2012. A follow-up survey was sent between 2015 and 2017 to all 171 monozygotic twin pairs in which both co-twins in the pair had no history of chronic back pain at baseline, but only one of the twins in the pair met criteria for having current symptoms of PTSD symptoms. To determine this disparity within a twin pair, the authors looked for pairs in which 1 twin had a score of less than 30 on the PTSD Symptom Checklist, and the other twin had a score of 30 or higher.

The 227 male veterans who completed the 5-year follow-up included 91 monozygotic twin pairs, with a mean age of 62 years. In that follow up, 40% of the veterans who had the score of 30 or higher at baseline went on to report incidence of chronic back pain. Among the veterans with a score of 30 or higher, 60% reported chronic back pain. (See: Suri P, Boyko EJ, Smith NL, et al. Post-traumatic stress disorder symptoms are associated with incident chronic back pain. Spine. 2019; 44(17):1220-1227.)

Editors' note: For more about the treatment of PTSD within pain management, please read "Use of Stellate Ganglion Block to Treat Posttraumatic Stress Disorder: A Narrative Review," by Dharti Patel, MD, Daniel Amor, MD, and Paul Shekane, MD, in the October 2019 issue of Topics in Pain Management, vol. 35, no. 4, pages 1-7.