Teen's sudden-onset schizophrenia may be linked to cat bacteria

A teen boy suddenly became psychotic, and bacteria from a cat scratch may have been the culprit

A case study from NC State connects teen's sudden-onset schizophrenia to a bacteria found in animals
March 27, 2019 

Teen turns inexplicably homicidal

When pathogens leap from animals to humans, bizarre things can happen. A case study from North Carolina State University details the transformation of a socially-active teen with good grades into someone his parents didn’t recognize: suicidal, homicidal and psychotic.

The 14-year-old boy had been infected with Bartonella henselae, the bacteria associated with cat-scratch fever.

“This situation turned his family’s life upside down,” said Dr. Breitschwerdt, a veterinarian at NC State.

In October of 2015, the boy started feeling depressed and suicidal. His psychosis (unpredictable rage outbursts, hallucinations) caused him to drop out of school. He was afraid he would hurt his family and believed he was an “evil, damned son of the devil.” By December, his mother quit her full-time job to take care of him.

The boy’s doctors prescribed a range of drugs including antipsychotics, mood stabilizers and anti-depressants. After four hospitalizations (including an 11-week stint at a psychiatric hospital) and extensive testing, his condition had not improved.

In the summer of 2016, his parents noticed lesions that resembled stretch marks on his legs and armpits. They weren’t the sort of stretch marks associated with significant weight gain or loss. Seven months later, a doctor connected the lesions to Bartonella, a type of bacteria that’s caused similar lesions in the past. The boy started antibiotics and his father got in touch with Breitschwerdt, who has more than 30 years of experience researching Bartonella.
The boy's parents found stretch-mark-like lesions on his body

Breitschwerdt was able to find the pathogen in the boy’s blood. The pathogen could have jumped from one of the family’s two cats. After several rounds of antibiotics, the boy’s psychotic symptoms disappeared, and by the Fall of 2017 he was back in school.

“I’ve been emailing with the father, and he’s looking at colleges now,” said Breitschwerdt.

Breitschwerdt said it’s extremely difficult to claim that Bartonella caused this boy’s condition with just one case study, but the incident shows that more studies are needed on the association between mental disorders and infections.

“It’s never easy to determine the cause of psychiatric conditions,” he said. “We need a very good study to answer more questions.”

An Emerging Threat 

Infections like those from Bartonella are called zoonosis, or diseases that crossover from animals to humans. Many of these diseases are classified as “emerging” and aren’t well understood. About 75 percent of emerging diseases come from animals (think AIDs, rabies, Lyme disease, Trachoma etc.,). Bloodsuckers like ticks, fleas and mosquitos carry Bartonella, and transfer it to animal hosts. From there, the bacteria can jump to humans via animal bites, scratches or open wounds.

The Bartonella species are difficult to study, because they hide in the body. They aren’t always located in the blood, so blood tests may not detect them. Often, they’re in such low concentrations that they’re hard to identify.

There are more than 30 different varieties of the bacteria, but B. henselae is the most well-known, because of its association of cat-scratch fever, a mild, flu-like illness that clears up quickly. North Carolina has a high incidence rate of cat scratch fever.

But there’s evidence linking B. henselae to more severe health issues like heart infections, eye disorders and nervous system damage. This case study could mean that Bartonella can lead to mental illness as well.

More questions to answer

The medical community still doesn’t understand the cause of many mental disorders like depression, anxiety, and schizophrenia. Dr. Greenberg, the pediatric psychiatrist that reviewed the case, says it’s tricky to diagnose caused, because most diseases have multiple factors.

“It’s all a matter of interplay,” she said. “It’s not just environment and genetics, it’s everything. I’m not saying infections cause everything, but they might cause a lot more problems than people realize.”

Greenberg specializes in the connection between infectious diseases and psychiatric illness. She says that pediatricians and general practitioners aren’t taught about the intricacies of infectious diseases.

“We’re still learning about it, and there needs to be a lot more research on it,” she said.

Breitschwerdt said it’s going to take interdisciplinary teams to tackle questions surrounding emerging diseases. “That approach to chronic and poorly understood diseases will allow us to advance treatment.”

—Rossie Izlar

Rossie Izlar is a digital producer on the UNC-TV Science team.