A new study partially conducted by researchers at the University of Pittsburgh found that those with the herpes simplex virus 1, which typically causes cold sores, displayed reduced cognitive function.
The researchers studied people in India with and without herpes and with and without schizophrenia. They looked at their cognitive functions using a computerized battery and assessed different aspects of top processes.
Vishwajit Nimgaonkar, a professor of psychiatry and human genetics at the University of Pittsburgh worked on the study. He said those they tested didn’t do as well as others without the virus on tests of mental function, attention and memory.
He said it was previously believed that the virus’s only effects were cold sores, and in some people, eye infections. Seeing the effects it sometimes had on patients with schizophrenia, he was led to do this research through work with psychiatric patients with herpes.
“Whether or not you had a psychiatric diagnosis like schizophrenia, if you had been exposed to this virus, you did less well than if you were not exposed to this virus,” he said.
Those without schizophrenia were affected as well.
Herpes Simplex Virus 1 is pretty common, but the rate of infection tends to increase as people get older. If you are in your 40s or 50s, the likelihood that someone is infected is more than 50 percent.
Once you have this virus, the body cannot get rid of it. The virus tends to cause what is called “latent infection” in sensory nerves. That means the virus is present but doesn’t present any symptoms.
If people have a compromised immune system, the virus can more easily get into the brain.
“What we think might be happening is that even with so-called healthy people, some of the virus might be entering the brain and then sort of hiding there and causing damage on a small scale,” he said.
Nimgoankar stressed that they haven’t really proven this — they are just releasing a correlation that adds new questions about how viruses affect our brains.
The study was published in the Journal of Psychiatric Research last month.