The Danish study found that women infected with the parasite, found in cat waste, are one and a half times more likely to commit suicide, WebProNews reported.
The Toxoplasma gondii bacteria is correlated not only with suicide, but with violent means like cutting or stabbing themselves or jumping from a ledge or a bridge, as opposed to drug overdoses.
Researchers studied 45,000 women in Denmark to find an association between T. gondii infection and suicide, according to Gawker, in the largest study on the subject so far.
The Centers for Disease Control and Prevention said toxoplasmosis is considered to be a leading cause of death attributed to foodborne illness in the United States. More than 60 million men, women, and children in the U.S. carry the toxoplasma parasite, but very few have symptoms because the immune system usually keeps the parasite from causing illness. Toxoplasmosis is considered one of the Neglected Parasitic Infections, a group of five parasitic diseases that have been targeted by CDC for public health action.
However, women newly infected with toxoplasma during pregnancy and anyone with a compromised immune system should be aware that toxoplasmosis can have severe effects.
The parasite has been linked to mental illness and schizophrenia in the past, WebProNews stated.
Teodor Postolache, the senior author in this study, from the University of Maryland School of Medicine, said the connection between the parasite and suicide is still nebulous.
We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that warrants additional studies. We plan to continue our research into this possible connection.
He added that the study did not explain how T. gondii actually induces suicide.
Is the suicide attempt a direct effect of the parasite on the function of the brain or an exaggerated immune response induced by the parasite affecting the brain? We do not know. In fact, we have not excluded reverse causality as there might be risk factors for suicidal behavior that also make people more susceptible to infection with T. gondii. If we can identify a causal relationship, we may be able to predict those at increased risk for attempting suicide and find ways to intervene and offer treatment.
But you don't need to be a cat lady to contract the parasite. It infects one third of the world's population, and though it's commonly found in cat feces, one can also get it from eating undercooked meat or unwashed vegetables, Gawker said.
A similar study done on rats with T. gondii showed that they lost their fear of cats and became attracted to cat urine. This change in behavior increased the rat's chance of being eaten by a cat- - which would allow for the parasite to then get into the cat's intestine where it could sexually reproduce, NPR reported.
The absolute risk of suicide is minimal, NPR explained. Fewer than 1,000 of the 45,000 women attempted any kind of self-injurous behavior in the 30-year study span, and just seven actually took their own lives.
People should not give their cats away because of this study, Postolache says.
For a little bit of fun, we added a Simpson's video that protrays a crazy cat lady.