The connection between cats and mental illness is getting stronger. Researchers have discovered that cat-scratch disease is linked to schizophrenia. It is more likely that people who are diagnosed with schizophrenia are infected with Bartonella. Bartonella is a bacterium that humans can catch after being bitten or scratched by cats.
Schizophrenia is a severe and chronic mental disorder that affects how the affected persons feel, think, and behave. People suffering from this disorder often appear to have lost touch with reality. Researchers and doctors have not understood what causes the condition, but they think it is a mixture of genetics, possible viral infections, abnormalities in brain chemistry, and immune disorders. The symptoms of the ailment typically start when the affected persons are aged 16 to 30. Some children also suffer from schizophrenia, but this is rare. According to the National Institute of Mental Health, Schizophrenia’s symptoms are categorized into three:
Positive symptoms are disturbances that are added to the personality of a person. They include:
- Thought disorders (dysfunctional or unusual ways of thinking)
Negative symptoms are capabilities that the affected person loses from his or her personality. They include:
- Reduced feelings of pleasure in one’s daily life.
- Reduces the expression of emotions through voice tone or facial expression.
- Difficulty sustaining and beginning activities.
Cognitive symptoms are changes in a person’s memory or other aspects of thinking. They include:
- Trouble paying attention of focusing
- Poor ability to understand information and make decisions using the information
- Issues with working memory.
Research studies suggest that one percent of the world’s population has schizophrenia,, and around 2 million people in the United States suffer from mental disorder. In a study published in the Daily Mail (https://www.dailymail.co.uk/sciencetech/article-9406501/Health-Schizophrenia-linked-Bartonella-bacteria-cat-scratch-disease.html), researchers from the United States tested the blood of 17 people with schizophrenia for Bartonella DNA. The researchers found the bacteria in 70 percent of cases compared to just 8 percent of the healthy control group. Since the study size was limited, further work needs to be done to confirm a link. The symptoms of the cat-scratch disease include:
- Swollen lymph nodes
- Blister or bump at the site of the cat’s scratch
Cats become infected with Bartonella through fleas and ticks. For many years, scientists have thought that cats’ scratch disease was short-lived. However, the new finding suggests that the infections might persist in some people. The new study found that a bacterium known to cause the disease called cat scratch fever because cats usually spread it through scratches and bites is found in the blood of schizophrenics more frequently than in people who are not suffering from mental illness.
The research was published in March 2021 in the journal called Vector-Borne and Zoonotic Diseases. The research adds to a growing body of work that supports that when people are infected with the Bartonella bacteria, they can experience neurological issues. According to Edward Breitschwerdt, the study author, the Bartonella species plays the role of a co-factor or cause of neuropsychiatric illnesses. However, he said that much more research has to be done to clarify the preliminary results.
Breitschwerdt has studied bacteria for many years. Previously, he worked on a study about a Midwestern boy who was 14 years of age. The boy started to experiences psychosis-like symptoms after his cat scratched him. The doctor who treated the boy misdiagnosed him with schizophrenia when he was suffering from scratch cat disease. Before the teen experienced the onset of psychiatric symptoms, he was active, socially, athletically, and academically. The boy had participated in national history and government competitions and was a leading actor in school plays. He had also won an award in fencing and achieved excellent grades in his courses. Breitschwerdt reported about the study in 2019. The boy was at one time placed on a psychiatric hold for a week after he said that he was a “damned and evil son of the devil. “
Doctors examined the teen’s medical records quickly, hoping to find answers to why he was behaving bizarrely. After visiting many hospitals, the doctors found out that the teenager had a Bartonella infection. The teen recovered fully after doctors prescribed antibiotics to treat the infection. In 2020, Breitschwerdt published this study (Cat scratch’ fever may cause human madness, study says in a journal called Pathogens. In the study, 29 out of the 33 participants were infected with Bartonella and said they experienced neuropsychiatric symptoms. The findings of the study also reported evidence that a connection existed between mental disorders and the bacteria.
In a pilot study conducted in part by a UW-Madison veterinary medicine professor, the conclusion was that when a person is infected by bacteria associated with cat scratch disease, it can play a role in schizoaffective disorder and schizophrenia. In the study, researchers took blood samples from 17 individuals with schizoaffective disorder or medically managed schizophrenia and a control group of 13 individuals. They tested the individuals for Bartonella infection, which is linked to cats exposed to fleas and ticks.
Out of the 17 people who had schizophrenia, 12 had the bacteria’s DNA in their bloodstream compared to 1 of 13 people in the control group. Both groups stated that they had cats, and the pets had been exposed to fleas. By design, the research was not able to show a causal link between schizophrenia and Bartonella infection. Researchers are planning to perform a larger study to see if the preliminary results are precise. Bartonella is historically linked with cat-scratch disease, also referred to as cat-scratch fever. Until recently, doctors thought that the disease was a self-limiting, short-lived infection. Although there is an emerging understanding that neuropsychiatric illnesses like schizophrenia are disorders of brain networks, the actual causes of these disorders are not known, said the co-author of the study, Flavio Frohlich. Like other researchers, he said that the research study was the first work examining the role of Bartonella in schizophrenia. More studies need to be done to ascertain the potential role of the bacteria in causing schizophrenia.