The world loves cats. Why not when cats sailed with the Vikings, can understand physics, and mimic their owner's accent.

One study published in 2016, however, claims that cats are not perfect and that cats can be possibly blamed for certain psychiatric disorders. A new study disputes such claims.

While the older study points fingers at cats and their natural parasite Toxoplasma gondii, which has been linked to mental issues such as psychosis and schizophrenia, the new study by researchers from the University College London finds no links between your feline buddy and psychotic symptoms.

"The message for cat owners is clear: there is no evidence that cats pose a risk to children's mental health," says lead author Francesca Solmi of UCL.

"In our study, initial unadjusted analyses suggested a small link between cat ownership and psychotic symptoms at age 13, but this turned out to be due to other factors," she added.

The experts found out that once they have controlled factors such as household overcrowding and socioeconomic status, the data did not point to the cat. Previous studies that linked cat ownership to psychosis were not able to account for other possible explanations and missing data.

Cat Ownership Does Not Cause Psychotic Symptoms

The new study, published in the journal Psychological Medicine, cast a cloud of doubt on previous studies that claim a link between cat ownership and mental illness. So, people who grew up with cats do not have to worry that their pets might someday make them hear voices or cause uncontrollable road rage.

"Our study suggests that cat ownership during pregnancy or in early childhood does not pose a direct risk for later psychotic symptoms," says James Kirkbride, one of the authors of the study.

"However, there is good evidence that T. gondii exposure during pregnancy can lead to serious birth defects and other health problems in children. As such, we recommend that pregnant women should continue to follow advice not to handle soiled cat litter in case it contains T. gondii," he added.

The latest study used a more reliable methodology that allowed the researchers to follow up with the subjects for almost 20 years. Older studies only relied on interviews and used smaller sample population.

Why Experts Thought Cats Make Humans Go Nuts

The cat itself is not to be blamed actually. The parasite T. gondii is the real culprit.

The feline parasite demonstrated that it can control the mind of its host. When a rodent, for example, is infected by T. gondii, the parasite goes to the host's brain and finds a way to switch off the rat's natural fear of cat urine. When that happens, one can only imagine a gory version of Tom and Jerry.

The single-celled parasite is known to cause toxoplasmosis in humans. In the United States, about 60 million people might be infected with T. gondii. In case one might be wondering where these people are, you might actually not see symptoms of toxoplasmosis in most of them as the immune system has a way to keep the effects of the parasite at bay.

If one is infected with T. gondii, one must be aware of the signs and symptoms of toxoplasmosis that may include muscle aches and swollen lymph glands just like when one catches the flu. An infected individual may also experience blurred vision and redness of the eye. Severe cases may cause damage to one's brain.

Experts advise pregnant women and those with a compromised immune system to take extra caution. Most infants infected with the parasite while in the womb might not have symptoms at birth but symptoms might surface later in life.

Toxoplasmosis can also be caused by ingesting contaminated meat, infected water, or accidentally swallowing T. gondii through contact with cat feces infected with it.

Photo: Martie Swart | Flickr