Furthering the role of immune system disorders in the development of mental disorders, recent research links infections that children contract during their childhood with increased risk of mental disorders during childhood and adolescence. The first study of its kind shows that high temperatures, sore throats and infections during childhood can increase the risk of suffering from a mental disorder as a child or adolescent. This study followed all children born in Denmark between 1 January 1995 and 30 June 2012. The researchers have looked at all infections that have been treated from birth and also at the subsequent risk of childhood and adolescent psychiatric disorders.

The study showed that children who had been hospitalized with an infection had an 84 per cent increased risk of suffering a mental disorder and a 42 per cent 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.

The study has just been published in JAMA Psychiatry and is a part of the Danish iPSYCH psychiatry project.

The study concludes that infections and the inflammatory reaction that follows afterwards can affect the brain and be part of the process of developing severe mental disorders. This can, however, also be explained by other causes, such as some people having a genetically higher risk of suffering more infections and mental disorders.

The new knowledge 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 for which the researchers have shown a correlation. This is the assessment of senior researcher on the study, Research Director Michael Eriksen Benrós from the Psychiatric Centre Copenhagen at Copenhagen University hospital.

“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,” he explains.