Scientists have discovered a cat parasite that is commonly spread from cats to humans, and may be the reason for impulsive aggression. Humans who contract the parasite may experience changes in the brain that increase the risk of aggressive behavior.
The study, published Wednesday in the Journal of Clinical Psychiatry, drew a link between toxoplasmosis, and intermittent explosive disorder (IED) and increased aggression. Toxoplasmosis is transmitted through the feces of infected cats, undercooked meat or contaminated water. An estimated 30 percent of all humans carry the parasitic infection.
"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, Ellen. C. Manning professor and chair of psychiatry and behavioral neuroscience at the University of Chicago, said in a news release.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, defines IED as recurrent, impulsive, problematic outbursts of verbal or physical aggression that are disproportionate to the situations that trigger them. According to the release, IED affects an estimated 16 million Americans— more than bipolar disorder and schizophrenia combined.