I had tics for a couple of years after a series of strep infections when I was a little kid. This impact of strep was common knowledge then; my pediatrician told us that strep was the likely cause of the tics. Didn’t know there were other infectious causes of symptoms….
Young children who had infections were more likely to develop mental disorders such as schizophrenia, eating disorders, and autistic spectrum disorder in subsequent years, according to a nationwide study in Denmark.
Among more than 1 million Danish children, those who had been hospitalized for severe infection had an 84% increased risk of being diagnosed with a mental disorder before age 18 (HR 1.84, 95% CI 1.69-1.99) and a 42% increased risk of filling a psychotropic medication prescription (HR 1.42, 95% CI 1.37-1.46), reported Ole Köhler-Forsberg, MD, of Aarhus University Hospital in Risskov, Denmark, and colleagues.
Those who had received medication such as antibiotics for their infections also had a higher risk of developing a mental disorder (HR 1.40, 95% CI 1.29-1.51) and of filling a psychotropic prescription (HRR 1.22, 95% CI 1.18-1.26), Köhler-Forsberg and colleagues wrote in JAMA Psychiatry.
The relationship was a dose-response association, with children who had more infections and more severe infections having a higher risk of developing a mental disorder. The risk was also highest between 0 to 3 months after the infection, researchers found.
“This does not mean that infections do lead to a mental disorder, but the bigger take-home message is that there is an intimate relationship between the body and the brain,” Köhler-Forsberg told MedPage Today. “In some way, infections, or their effect on the immune system, do have an effect on the brain.”
In an accompanying editorial, Vivian Labrie, PhD, and Lena Brundin, MD, PhD, both of the Van Andel Research Institute in Grand Rapids, Michigan, wrote that the study was “compelling” and “strongly supports” the assumption that severe infection and the use of anti-infective agents may result in the onset of mental illness.
Brundin told MedPage Today that previous studies have demonstrated that the downstream effects of inflammation caused by infection could have profound effects on the brain. Immune cells and cytokines passing the blood-brain barrier could create an inflammatory response, which has been linked with psychiatric symptoms such as depression, she said. The association could also be attributed to certain infections in a more direct way, for example, when the parasite Toxoplasma gondii integrates itself into brain cells and disrupts the production of dopamine.