'Cat Scratch' Bacteria May Cause Violent Psychosis And Depression, Study Finds

Evidence is starting to show that certain bacteria carried and spread by cats can have alarming effects on people's brains. In a recent study, researchers have detailed a group of people with psychiatric illnesses who simultaneously displayed signs of infection from a bacteria called Bartonella, including skin lesions.

Edward Breitschwerdt, the study's lead author, says that these bacteria could “potentially be causing a tremendous amount of undiagnosed disease worldwide.” The authors also note that although there is a lot of evidence showing a correlation between bacteria and brain health, it is still not enough to conclude that there is a direct cause-and-effect link between the two.

Last year, there was a case report on a 14-year-old boy who suffered from violent psychosis and delusional episodes in 2015. The symptoms began suddenly, according to the report, and despite lengthy treatments and various approaches, none were effective.

In 2016, however, doctors noticed that the boy had lesions that resembled stretch marks along his thighs and armpits. After running some tests, the results showed that he was carrying a chronic bloodstream infection caused by the bacteria Bartonella hensealae, and so the doctors started giving him antibiotic therapy.

Upon treating the infection caused by the bacteria, the boy's schizophrenia-like symptoms also ceased, allowing him to resume his normal life and attend college.

Breitschwerdt and his team have recently released a follow-up on their report from earlier this month, which featured 33 patients with similar neuropathic symptoms and suspected exposure to Bartonella bacteria.

Results revealed that 29 of the 33 patients had Bartonella infection. In said patients, researchers found Bartonella antibodies and also traces of the bacteria in the tests they ran on the subjects. Out of the 29 patients, 24 who had the infection also possessed skin lesions which allegedly developed shortly after their other symptoms began.

A list of the neuropathic symptoms found in these patients includes sleep disorders, confusion, anger issues, anxiety, depression, and headaches including migraines.

"The rod-shaped Bartonella bacteria are somewhat strange, even among their own kind. They can survive and replicate inside other cells, much like viruses — in people, they usually choose the cells that live inside or line our blood vessels," according to an article in Gizmodo.

By living inside blood vessels, these bacteria are able to hide, allowing them to evade conventional tests and become harder to detect.