New studies suggest that impulsive behavior is linked to a harmless parasite - the Toxoplasma gondii (T. gondii)
An earlier study published in Schizophrenia Bulletin, stated that the parasite, commonly found in undercooked meat and cat feces, is found to be highly associated with bipolar disorder and schizophrenia.
The University of Chicago study was carried out in an attempt to pioneer in the diagnosis and management of Intermittent Explosive Disorder (IED) and impulsive anger as the disease is believed to affect about 16 million people in the United States.
The researchers studied 358 adults that were tested for personality disorder, depression, IED, and other psychiatric disorders. The individuals were also evaluated on their behavioral traits, such as aggression, anger, and impulsivity. Study participants were grouped into three - healthy controls with no psychiatric history, patients with IED, and the control group.
It was found that those exposed to the parasite show impulsive anger (22 percent) twice as much than the unexposed individuals (9 percent).
"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 Dr. Emil Coccaro, senior study author.
Although a correlation is found between Intermittent Explosive Disorder (IED) and T. gondii exposure, study authors are still uncertain whether the relationship is causal. Coccaro suggests further studies to see whether there is a direct link.
If toxoplasmosis, aggression, and IED are highly related, experts can establish diagnostic and treatment strategies in the future.
"If we can learn more, it could provide rational to treat IED in toxoplasmosis-positive patients by first treating the latent infection," he added.
The study was published in the Journal of Clinical Psychiatry and was supported by the National Institute of Mental Health.
The Centers for Disease Control and Prevention (CDC) estimates that about 22.5 percent of the population have the parasite in the body but would not show symptoms — making detection quite a challenge.
Cats are the hosts of these protozoans but can also be found in contaminated water and soil, and undercooked meat. T. gondii are less likely to cause any serious medical illness but immunocompromised individuals may develop toxoplasmosis. The infection may cause blindness, flu-like illness, mental disorders, and even death.
Healthy individuals who are carriers of the parasite oftentimes do not need any treatment but for those who show signs and symptoms are advised to take a combination of medications, such as sulfadiazine and pyrimethamine with folinic acid.
Pregnant women, newborns, and infants can also take medications but the protozoans can still remain in their tissue cells in a latent phase.
Immunocompromised individuals require longer treatment process. Individuals with AIDS may need lifetime medication.
Photo: Steve Jurvetson | Flickr
