Psychoneuroimmunology is the study of the physiological interactions between the nervous system and immune functions within the body. This discipline can trace its origins back to the mid 1800’s to ideas that were more superstition than science. However, in recent years, solid scientific data has shown how the brain and various psychological states can greatly modulate the immune system. Now, a team of investigators at Harvard University Medical School have just published data describing a strong association between trauma exposure and posttraumatic stress disorder (PTSD) in civilian women with an increased risk of developing the autoimmune disorder systemic lupus erythematosus (SLE).
Findings from the new study—published today in Arthritis & Rheumatology in an article entitled “Association of Trauma and Posttraumatic Stress Disorder with Incident Systemic Lupus Erythematosus (SLE) in a Longitudinal Cohort of Women”— contributes to a growing body of evidence that various psychosocial traumas and associated stress responses may lead to autoimmune disease.
In the current study, the investigators focused on the association of trauma exposure and PTSD symptoms with the development of SLE over 24 years of follow-up in a cohort of women in the U.S. From the data gathered among the 54,763 women in the study, the researchers found a nearly three-fold elevated risk of SLE among women with probable PTSD and more than two-fold higher risk of SLE among women who had experienced any traumatic event compared with women not exposed to trauma.
“We were surprised that exposure to trauma was so strongly associated with risk of lupus—trauma was a stronger predictor of developing lupus than smoking,” explained lead study investigator Andrea Roberts, Ph.D., a research associate in the department of social and behavioral sciences at the Harvard T.H. Chan School of Public Health. “Our results add to considerable scientific evidence that our mental health substantially affects our physical health, making access to mental health care even more urgent.”
The authors described their analysis, stating that “incident SLE with ≥4 American College of Rheumatology criteria was ascertained by self-report and confirmed by medical record review. PTSD and trauma exposure were assessed with the Short Screening Scale for DSM-IV [Diagnostic and Statistical Manual of Mental Disorders, 4th edition] PTSD and the Brief Trauma Questionnaire. Women were categorized as having: no trauma, trauma and no PTSD symptoms, subclinical PTSD (1–3 symptoms), or probable PTSD (4–7 symptoms).”
Using these criteria as a base, the researchers also assessed whether other health risk factors such as smoking, body mass index (BMI), or use of oral contraceptives were underlying factors contributing to the increased SLE risk in women.
The results from their study showed that “during follow-up, 73 cases of SLE occurred. Compared to women with no trauma, probable PTSD was associated with increased SLE risk (HR4–7 symptoms =2.94, 95% CI=1.19–7.26, p<0.05). Subclinical PTSD was associated with increased SLE risk, though this did not reach statistical significance (HR1–3 symptoms =1.83, 95% CI=0.74-4.56, p=0.19). Smoking, BMI and OC [oral contraceptive] use slightly attenuated associations (e.g., probable PTSD adjusted HR=2.62, 95% CI=1.09-6.48, p<0.05). Trauma exposure, regardless of PTSD symptoms, was strongly associated with incident SLE (HR=2.87, 95% CI=1.31, 6.28, p<0.01).”
This research not only lends weight to the strong connection between trauma and immune system but underscores the larger association between a patient’s mental state and overall health.