Scientists have hypothesized that humans infected with the parasite toxoplasma gondii, or toxo for short, are two times more likely to develop schizophrenia than an uninfected human. After further investigation, their theory may be accurate.

If one is infected by toxo, it does not mean they will become schizophrenic, but they will experience a change in behavior. The goal of the toxo parasite is to live inside a cat, notes The Atlantic. It does this by infecting their food source, rats, and alters the part of the rats brain that controls fear, anxiety, and sexual arousal. The parasite causes the rat to become sexually attracted to the smell of cat urine. So, when toxo infects humans, it causes shrinkage in the cerebral cortex, which is found in many schizophrenia patients.

In one recent study by E Fuller Torrey and Dr. Robert H. Yolken, they found that people who have owned cats since childhood are more likely to be diagnosed with schizophrenia, reports CBS News. “In schizophrenia, the evidence of an association with T. gondii is overwhelming,” commented the authors of the study. The evidence being built up by scientist strongly supports the correlation between schizophrenia and toxo.

Although this research has gained current Internet fame, scientists have been studying the behavioral impacts of toxo since the 1980s. The man who brought toxo to the public’s attention is Jaroslav Felgr. He believed that there was something inside him that was manipulating his personality. His behavior was described as reckless or dangerous. Felgr found himself crossing busy streets, “and if cars honked at me, I didn’t jump out of the way,” notes The Atlantic. People did call Felgr crazy, and he started to agree with them. Still, he felt something was off and decided to get his blood tested. Sure enough, he was infected. The effects of toxo can be subtle or it can be deathly. The public can no longer ignore the effects of this parasite.

Here is a thought…if toxo makes rats attracted to cats, does it make human’s attracted to cats? Maybe this can explain that crazy cat lady next door.