Stress disorders affect many other body functions, including neural networks that have an impact on immune function. Researchers used a national Swedish registry to identify whether stress disorders are associated with subsequent autoimmune disease.
Large stressors in life are inevitable and most individuals are exposed to them at one point or another. While most individuals bounce back and recover, many people develop severe stress disorders after life-altering events. Individuals who develop stress disorders also go on to experience an assortment of other effects, including disruptions in the brain network, which have also been shown to affect other body functions such as immune functions. This could ultimately lead to increased susceptibility to disease and autoimmune disease.
Limited evidence in humans
Autoimmune disease has been linked to stress disorders in animal models, but the evidence in humans is limited. Evidence available in humans has been restricted to samples involving military men with post-traumatic stress disorder, so the samples sizes have been too small and incomplete.
Researchers from Iceland, Sweden, and the United States collaborated in a study to determine the association between stress disorders and the risk of autoimmune disease. Their findings, recently published in the journal JAMA, show some interesting results.
The researchers used a nationwide Swedish registry which followed individuals from 1981 to 2013 who had received a stress disorder diagnosis during this time. The researchers were able to control for family factors by using a sibling based comparison approach. The average age of the diagnosis of a stress disorder was 41 years.
Higher risk of developing autoimmune diseases
They found that compared to individuals that had not been exposed to stress, those who has been exposed and developed stress disorders were at a higher risk for developing autoimmune diseases. This association also held true in the comparison with siblings who had not been exposed to stress.
Interestingly, the use of drugs that help with stress disorders, such as serotonin reuptake inhibitors, especially during the first year following the diagnosis of stress disorder showed a decreased risk of autoimmune disease. Due to the large data set and the different statistics that were performed on this data, these were significant.
Findings help pave the path to prevent or decrease autoimmune diseases
In conclusion, this cohort of the Swedish population revealed that a diagnosis of a stress disorder was associated with an increased risk of developing an autoimmune disease later on in life. This is a good start to understanding ways to improve stress disorders initially to potentially prevent or decrease autoimmune disease later in life. Further studies will be needed to understand what the mechanism to this association is and how it is biologically relevant.
Written by Ingrid Qemo, PhD
Reference: Song, H., Fang, F., Tomasson, G., et al. 2018. Association of stress-related disorders with subsequent autoimmune disease. JAMA. 319 (23): 2388-2400