Anger issues? Blame your cat. Or at least a cat parasite that is often carried in your furry friend’s feces. If you have uncontrollable bouts of anger, rage disorder or an explosive temper, a new study says you may have experienced a brain infection brought on from the common parasite Toxoplasma gondii, which causes the parasitic disease Toxoplasmosis.
Reports Scientific American on March 27: “In the study of more than 350 adults, those with a psychiatric disorder called Intermittent Explosive Disorder, or IED, were twice as likely to have been infected by the toxoplasmosis parasite compared with healthy individuals with no psychiatric diagnosis.”
While the study has not forged a direct cause-and-effect link (no need to kick your cat to the curb just yet), researchers did discover an association between Toxoplasmosis and rage.
The study looked at 358 adults – one third suffered from IED, defined as “recurrent, impulsive, problematic outbursts of verbal or physical aggression disproportionate to the situations that trigger them.” Another third suffered from a similar psychiatric disorder that manifests itself in fits of anger. The remaining third were healthy adults and served as a control group.
Researchers found that 22 percent of the people with IED tested positive as carrying toxoplasmosis, and 16 percent of the other group with psychiatric disorders also tested postivive. This compared to only nine percent of the control group.
“Not everyone that tests positive for toxoplasmosis will have aggression issues,” commented Dr. Emil Coccaro, chairman of psychiatry and behavioral neuroscience at the University of Chicago and study leader. “But exposure to the parasite does appear to raise the risk for aggressive behavior.”
Researchers however have not been able to pinpoint how the infection is tied into the loss of self-control, though antibody-initiated inflammation of the brain is one theory.
“We don’t yet understand the mechanisms involved,” said Dr. Royce Lee from the University of Chicago, a co-author on the report. “It could be an increased inflammatory response, direct brain modulation by the parasite, or even reverse causation where aggressive individuals tend to have more cats or eat more undercooked meat.”
Approximately one quarter to one fifth of the world’s population carries the tiny parasite, though most human infections are asymptomatic, reports Live Science. It can be picked up by humans after handling infected cat litter. The Centers for Disease Control and Prevention estimates more than 60 million people in the US may be carriers of the parasite.
This latest study, published in the Journal of Clinical Psychiatry, adds to a growing body of research that links psychiatric disorders with the cat parasite.