New Study Shows Link Between Infections and Lower IQs

Image by: Alessio Damato, Mikhail Ryazanov
Image by: Alessio Damato, Mikhail Ryazanov

New research has been published showing a distinct link between people who have been hospitalized due to infections also having lower IQ scores than average. The study was conducted by researchers from the University of Copenhagen and Aarhus University, led by Michael Eriksen Benrós, MD and Ph. D affiliated with the National Centre for Register-Based Research at Aarhus BSS.

The study results showed people who had been previously hospitalized due to infections had on average an IQ 1.76 lower than the average IQ. More shocking was that people who had been hospitalized with infection five or more times, had even lower IQ scores; 9.44 points lower than the average. That is a considerable drop in mental cognition. The types of infections ranged from infections in the stomach, urinary tract and even skin infections. The infections with the most impact on cognitive ability were the infections in the brain. Surprisingly however, brain infections did not have a considerably higher impact than the other infection types, meaning infections severe enough to require hospitalization all resulted in the person scoring lower on IQ tests.

The team also discovered that the immune system played a role as well. Michael Eriksen Benrós, stated “…It seems that the immune system itself can affect the brain to such an extent that the person’s cognitive ability measured by an IQ test will also be impaired many years after the infection has been cured.”.  The study was conducted over a period of 6 years, from 2006-2012 on over 190,000 subjects who were born between 1974 and 1994.

Michael Eriksen Benrós explained the what the research concludes in further detail: “Infections can affect the brain directly, but also through peripheral inflammation, which affects the brain and our mental capacity. Infections have previously been associated with both depression and schizophrenia, and it has also been proven to affect the cognitive ability of patients suffering from dementia. This is the first major study to suggest that infections can also affect the brain and the cognitive ability in healthy individuals.”
“We can see that the brain is affected by all types of infections. Therefore, it is important that more research is conducted into the mechanisms which lie behind the connection between a person’s immune system and mental health,” says Michael Eriksen Benrós.

To read more see the article released on Scientific Computing. You can also read the full published findings here in the International Journal PLOS ONE

Image by: Alessio Damato, Mikhail Ryazanov  CC SA 3.0