A new study shows that fevers, sore throats and infections during childhood can increase the risk of also suffering from a mental disorder as a child or adolescent.

According to researchers, the study’s findings expand the understanding of the role of the immune system in the development of mental disorders.   

For the study, researchers followed all children born in Denmark between Jan. 1, 1995, and June 20, 2012, totaling more than 1 million children.

The researchers looked at all infections treated from birth and also at the subsequent risk of childhood and adolescent psychiatric disorders.

“Hospital admissions with infections are particularly associated with an increased risk of mental disorders, but so too are less severe infections that are treated with medicine from the patient’s own general practitioner,” said Dr. Ole Köhler-Forsberg from Aarhus University and Aarhus University Hospital’s Psychoses Research Unit.

The study showed that children who had been hospitalized with an infection had an 84 percent increased risk of suffering a mental disorder and a 42 percent increased risk of being prescribed medicine to treat mental disorders.

Furthermore, the risk for a range of specific mental disorders was also higher, including psychotic disorders, OCD, tics, personality disorders, autism and ADHD, according to the study’s findings.   

“This knowledge increases our understanding of the fact that there is a close connection between body and brain and that the immune system can play a role in the development of mental disorders,” he said. “Once again research indicates that physical and mental health are closely connected.”

“We also found that the risk of mental disorders is highest right after the infection, which supports the infection to some extent playing a role in the development of the mental disorder,” he added.

The study’s findings could have importance for further studies of the immune system and the importance of infections for the development of a wide range of childhood and adolescent mental disorders, according to the researchers.

“The temporal correlations between the infection and the mental diagnoses were particularly notable, as we observed that the risk of a newly occurring mental disorder was increased by 5.66 times in the first three months after contact with a hospital due to an infection and were also increased more than twofold within the first year,” said research director Dr. Michael Eriksen Benrós from the Psychiatric Centre Copenhagen at Copenhagen University Hospital.    

Benrós, the senior researcher on the study, added that it first and foremost corroborates the increasing understanding of how closely the body and brain are connected.

The study was published in JAMA Psychiatry.

Source: Aarhus University