While most people are aware of the physical effects of food poisoning such as stomach cramps and vomiting, a recent research reveals that certain food poisonings could trigger emotional and mental problems as well.

In particular, researchers were able to confirm the previously theorized link between Toxoplasma gondii (T gondii) and psychiatric disorders and self-directed aggression according to a Food Safety News article. The findings, published in The Journal of Clinical Psychiatry, were obtained by analyzing data from 1991 to 2008.

The scientists, using data from patients during the 17-year period, found people who were infected with T gondii are more likely to show impulsive behaviors and aggression, which could include suicide. The recent study finally confirms the complex effect of T gondii on human behavior.

The same effects on rats and mice have been shown in previous studies.  For example, mice with T gondii lost their natural fear of cats and even tried to interact with the predators. Such dramatic behavioral change meant that the affected rodents exhibited increased impulsive risk-taking behaviors, which is also commonly associated with suicidal tendencies.

According to the research, the parasite attacks the brain hiding within neurons and glial cells and forming cystic intracellular structures to protect itself from the immune system. These modifications of the brain's neural networks could account for the behavioral change in its host.

According to Centers for Disease Control and Prevention (CDC), Toxoplasma gondii is a single-celled parasite that causes the disease toxoplasmosis. CDC estimates that more than 60 million Americans are infected with the parasite but only very few have symptoms because the parasite is normally handled by a healthy immune system. However, people with compromised immune systems and pregnant women may be susceptible to the infection.

People could get the parasite by eating undercooked and contaminated meat or drinking contaminated water. In addition, transmission could occur when there is contact with cat feces with an infected feline.