Patients with chronic pain syndromes frequently exhibit symptoms including nightmares, intrusive and recurrent recollections, and symptoms of increased arousal associated with posttraumatic stress disorder, (PTSD). This study's purpose was to determine the prevalence of PTSD-like symptoms in a population of FMS patients seeking treatment from a pain center. The researchers also set out to evaluate the relationship between the symptoms of FMS, PTSD-like symptoms and disability. Considering the impact of PTSD symptoms the authors hypothesized that FMS patients with higher levels of PTSD-like symptoms would report greater disability, pain, affective distress, and greater difficulties in adapting to chronic pain when compared to FMS sufferers that did not report similar levels of PTSD-like symptoms.

Subjects were ninety-three consecutive patients referred to a university based pain treatment center FMS program. The average age of the patients was 46 years, and the patients were predominately female (98%). This group's demographics were comparable to the demographics of FMS patients seeking treatment from rheumatologists and pain medicine specialists. Patients were subject to a comprehensive FMS evaluation, and completed self-report questionnaires measuring disability, PTSD-like symptoms, and psychosocial responses to their pain condition. The researchers assigned the subjects to one of two groups, labeled either PTSD+ or PTSD- based on the level of self-reported PTSD-like symptoms.

Fifty-six percent of the patients reported levels of PTSD-like symptoms that were clinically significant and comprised the PTSD+ group. They reported levels of disability, life interference, emotional distress, and pain that were significantly greater than the levels reported by the PTSD- group. Over eighty-five percent of PTSD+ patients exhibited significant disability, compared to fifty percent of the PTSD- group. The PTSD- also fared better than the PTSD+ group when the researchers looked at coping ability.
The authors comment on the possible underlying mechanism that links FMS and PTSD.

"Although the psychological sequelae of PTSD are relatively well delineated, the long-term effects of such symptoms on physical disorders are still relatively unexplored. One could argue that those who retain elevated levels of PTSD-like symptoms beyond a reasonably expected adjustment period may have been predisposed to poor coping or impaired psychological response. In those cases, both FMS and PTSD symptoms may be a consequence of inadequate psychological resources. In effect, the predisposition to poor coping may be the underlying factor for both FMS and PTSD. Alternatively, symptoms of PTSD may make adjustment to or recovery from chronic pain more difficult. The complicating nature and burden of coping with PTSD symptoms may increase the likelihood of a pain condition becoming chronic. Although the cross-sectional nature of the current study does not permit us to draw any definitive conclusions on the causal relation between PTSD and FMS symptoms, the positive relation between these problems suggests that extra attention should be provided to FMS patients with PTSD-like symptoms."

The authors note that although PTSD+ group exhibited many of the symptoms of PTSD, there was no thorough clinical interview. Therefore, it cannot be assumed that those in the PTSD+ group would merit a diagnosis of PTSD. However, the authors assert that their results "suggest that understanding symptoms characteristic of PTSD may be particularly important in understanding FMS and that assessment of PTSD-like symptomology among FMS patients may have important clinical implications." They authors suggest future study to investigate the underlying mechanisms of the FMS and PTSD relationship.

Sherman J, Turk D, Okifuji A. Prevelance and Impact of Posttraumatic Stress Disorder-Like Symptoms on Patients With Fibromyalgia Syndrome. The Clinical Journal of Pain. 2000;16:127-134.