Your cat's litter box could be a source of explosive anger -- and not for the obvious reasons.
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A new study suggests that people prone to explosive bouts of rage might be under the influence of toxoplasmosis, an illness caused by a parasite found in cat feces and undercooked meat.
Folks diagnosed with intermittent explosive disorder (IED) are more than twice as likely to carry Toxoplasma gondii, the parasite that causes toxoplasmosis, said lead researcher Dr. Emil Coccaro.
"If you've got someone with aggression problems, you might check them for toxoplasmosis," said Coccaro, chair of psychiatry and behavioral neuroscience at the University of Chicago.
"People who blow up have a real problem. It's not just a character problem or bad behavior. There's something underneath that's driving it."
Coccaro noted that because this study was not a clinical trial, the results don't establish a direct cause-and-effect link. He also added that not everyone who tests positive for toxoplasmosis will have aggression issues.
Intermittent explosive disorder involves recurrent and impulsive outbursts of verbal or physical aggression that are disproportionate to the situations that caused the anger.
"They've got a short trigger, and when they're threatened by something, they blow up," Coccaro said.
IED is thought to affect as many as 16 million Americans, more than bipolar disorder and schizophrenia combined, the study authors said.
Coccaro and his colleagues suspected that toxoplasmosis might be linked to some cases of intermittent explosive disorder.
Toxoplasmosis is typically a relatively harmless parasitic infection. About a third of all humans have been infected, the researchers said. Newborns and people with compromised immune systems are most at risk for a severe toxoplasmosis infection, which can cause damage to the brain, eyes or other organs, according to the U.S. Centers for Disease Control and Prevention.
However, toxoplasmosis might also affect the brains of otherwise healthy carriers. Previous research has tied the parasite to an increased risk of suicide and suicidal behavior, which involve the same sort of impulsive and aggressive traits as intermittent explosive disorder, Coccaro said. ■