Cat Litter Parasite Linked To Outbursts Of Rage

There is one parasite that lurks in the litter boxes of your cat. It might be pointing the way to a rare disorder that leads to sporadic and excessive outbursts of rage, says a new study.

Experts looked at intermittent explosive disorder (IED) that characterise only some people. The people tend to respond "aggressively, impulsively or violently" even when such reactions are not called for.

Studying the behaviour of 358 adults for psychiatric disorders such as IED and depression, the scientists graded them on certain characteristics, such as aggression, impulsivity and anger. About one-third of them showed IED.

The IED group participants seemed to be twice as likely to show a positive test for the parasite, toxoplasma gondii, found commonly in feces of infected cats, compared to others who did not show signs of IED or related psychiatric conditions.

People who had positive blood tests were 22 percent in the IED group, 9 percent in the healthy control group and 16 percent in the group of those who had psychiatric disorders but did not include IED.

Those with IED had the highest scores for aggression and impulsivity as per the report.

"Our work suggests that latent infection with the toxoplasma gondii parasite may change brain chemistry in a fashion that increases the risk of aggressive behavior," said Ellen C. Manning Professor and Chair of Psychiatry and Behavioral Neuroscience at the University of Chicago Emil Coccaro. "However, we do not know if this relationship is causal, and not everyone that tests positive for toxoplasmosis will have aggression issues."

"Correlation is not causation, and this is definitely not a sign that people should get rid of their cats," added Royce Lee, an associate professor of psychiatry and behavioral neuroscience at the University of Chicago and a co-author of the study, which was published in the Journal of Clinical Psychiatry. "We don't yet understand the mechanisms involved - 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. Our study signals the need for more research and more evidence in humans."