Autoimmune diseases more often affect people with stress disorders
A major study shows an association between stress-related disorders and subsequent autoimmune diseases such as arthritis, celiac disease and type 1 diabetes.
Almost everyone experiences some major trauma or severe stress at one time or another. Losing a close friend, going through a painful divorce, suffering a serious accident, or being subjected to violence or abuse are all significant life stressors.
Many people manage to recover from such deep hurtful experiences. But some develop stress disorders, such as post-traumatic stress disorder (PTSD) or adjustment disorder, which bring about a number of changes in the body. And these changes can in turn affect the immune system.
So it’s conceivable that stress disorders might increase the risk of autoimmune diseases, which occurs when people’s immune systems begin to attack their body.
According to research results in 2017, people with PTSD more often contracted the autoimmune disease lupus than people without PTSD.
Now a new study of these links has emerged, this time from a group of researchers from Sweden and Iceland.
41 different autoimmune diseases
Huan Song from the University of Iceland and his colleagues used data from Swedish health records.
They identified more than 100 000 people with stress-related disorders and more than 120 000 of their healthy siblings. In addition, researchers found data from a group of over one million healthy Swedes with the same age and gender composition as the group with stress disorders.
The researchers sought to answer the question, “How many people in each group had one or more autoimmune diseases ten years later?”
Song and his team looked up cases of 41 different autoimmune diseases, including type 1 diabetes, lupus, psoriasis, multiple sclerosis, inflammatory bowel disease and celiac disease.
The results showed that people with stress-related disorders were at greater risk for autoimmune diseases than both their siblings and other healthy participants.
Slight increase in risk
Among the participants with stress disorders, researchers found autoimmune disease in 9.1 cases per 1000 person-years. Among siblings the rate was 6.5 per 1000 person-years, and the group of other healthy individuals had 6.0 cases per 1000 person-years.
What these results show is that not everyone with an autoimmune disease had stress disorders, but that such illnesses were somewhat more common among people with stress disorders.
The result is consistent with certain previous studies. One study, for example, showed that war veterans who reported symptoms of PTSD had a greater risk of developing certain autoimmune diseases.
Many factors to consider
However, the study cannot say anything definitive about what leads to what.
It’s possible that the changes brought about in the body by stress disorders are part of what triggers autoimmune diseases. However, people with stress disorders may more often change their way of life in such a way that the risk of other diseases increases.
What is clear is that neither stress nor any other single factor can explain why someone ends up with an autoimmune disease. Most likely many factors play in.
In connection with an earlier study of posttraumatic stress and lupus, Professor Eystein Husebye from the University of Bergen’s K. G. Jebsen Center for Autoimmune Diseases stated that studies have shown that many autoimmune diseases are linked to 50 to 100 genes that either protect a person or increase their risk.
We also know that environmental factors like smoking, viral infections and changes in the bacterial flora inside and outside the body may play in.
Stress-related disorders probably constitute just one of many pieces in this multifaceted puzzle.
-------------------------------------
Read the Norwegian version of this article at forskning.no.
