If you have rage problems, new research indicates that it could be caused by your furry, feline friend. No, not because he knocks things off the shelf and attacks your feet while you’re sleeping -- although I'm sure those things don't help. Rather, a study, published on March 23 in the Journal of Clinical Psychiatry, suggests that the common cat parasite Toxoplasma gondii (t. gondii) might be linked to uncontrollable, extreme bouts of anger -- such as road rage.
The study of 358 adult subjects found that those with a psychiatric disorder called Intermittent Explosive Disorder (IED) were twice as likely to have been infected by the parasite than healthy individuals with no psychiatric diagnosis. This study coincides with others that have linked toxoplasmosis to schizophrenia, bipolar disorder and impulsivity. This research suggests that the parasite may somehow alter people's brain chemistry to cause long-term behavior problems.
Study author Dr. Royce Lee stressed, “correlation is not causation, and this is definitely not a sign that people should get rid of their cats.” There is an association between toxoplasmosis and rage, but we should not conclude that the infection causes rage.
According to the Centers for Disease Control and prevention, more than 20% of the US population has been infected by the Toxoplasma parasite, though most remain asymptomatic. “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. However, we do not know if this relationship is causal, and not everyone who tests positive for toxoplasmosis will have aggression issues,” said Dr. Emil Coccaro. .
Nine percent of control subjects tested positive for the parasite; however, 22 percent of participants with IED were found to be infected. This is a clear indication that most infected people do not suffer from aggression issues.
The researchers say they aren't certain why the link exists between the common parasite conditions such as IED. "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,” said Dr. Lee. “Our study signals the need for more research and more evidence in humans."