A new study has suggested that the common "cat parasite" is linked to road rage.
The researchers involved in the study said that IED is more common than bipolar disorder and schizophrenia combined. This symptom affects as much as 16 million Americans.
The findings of the study were published on March 23 in the Journal of Clinical Psychiatry. For the study, the researchers involved 358 adults and evaluated them for IED, personality disorders, depression and other psychiatric disorders. The participants were later categorized into one of three groups. Roughly one third had IED.
One third were healthy controls with no psychiatric history. The remaining third were individuals diagnosed with some psychiatric disorder, but not IED. The last group was used by the researchers to serve as a control to distinguish IED from other psychiatric conditions.
According to the researchers, the people with IED were more than twice as likely to test positive for t. gondii exposure (22 percent) compared with the healthy group (9 percent). The study also showed that t. gondii-positive group scored higher on all assessments of anger, impulsiveness and aggression.
"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," senior study author Dr. Emil Coccaro, a chair of psychiatry and behavioral neuroscience at the University of Chicago, said in a statement.
"However, we do not know if this relationship is causal, and not everyone who tests positive for toxoplasmosis will have aggression issues," Coccaro said, adding that additional studies are needed.