Antibiotics were associated with the highest risk of a subsequent diagnosis of mental illness in children

According to health experts, some antibiotics are known to go into the brain, so they might have some direct impact. Study have found that of all medications given to the children for their infections, antibiotics were associated with the highest risk of a subsequent diagnosis of mental illness. But more "judicious use of antibiotics" could decrease some of that risk.

However, it doesn't mean that every child who develops an infection will become mentally ill.

"You should rest assured that the great majority of these kids are not going to go on and develop a mental illness," says McIntyre. After all, infections are necessary for the normal development of the immune system.

That said, parents should be on the lookout for signs of anxiety, behavioral problems or any other potential symptoms of mental illness following an infection, notes Köhler-Forsberg. If they notice anything in their child, they should immediately seek help, he adds.

"If a child should be so unlucky to develop any mental problems, then we know that [in most cases] when it gets detected early and treated in a good way, then the child will get better again," he says.