A new study by Danish scientists has shown that autoimmune disorders and infections increase the risk of developing mental illness such as depression. The study involved more than 3 million people. It has been found that people hospitalized with various infections have a 62% greater chance of getting a mood disorder. In patients hospitalized with autoimmune diseases, the risk of developing the disorder increases by 45%. The number of hospitalizations also affected the development of mental disorder. For those who were hospitalized three times with infections during the study, the risk of mood disorder was doubled, and for those who were hospitalized seven times, the risk was tripled.
The results of scientific work confirm the hypothesis that inflammation or infection, or autoimmune diseases, can affect the brain in such a way that the risk of mood disorder increases. According to scientists, infections are the cause of mental illness in 12% of cases. Previous studies have shown that people suffering from depression and at higher risk for autoimmune diseases have a lower number of immune T cells.
There are also many other factors affecting the psyche that were not considered in this study, such as smoking and socio-economic status. Future research should help establish a causal relationship and establish whether infections are actually the cause of mental disorders. In addition, research should help to understand the mechanism at the biological level.