Why would cats be involved in suicides at all? Is it really safe to have cats for pets?

This is according to Dr. Keith Ablow of FoxNews:
“A recent study in Denmark implicates an infection spread by cats in causing humans to feel suicidal.
”The infection is called toxoplasmosis. It is caused by a parasite found, among other places, in the GI tracts of cats. Therefore, contact with cat feces when emptying a cat’s litter box is one way humans can get it. Other ways include eating undercooked meat.
“We have known for some time that toxoplasma antibodies (proof of exposure to the parasite) seem to be elevated in patients with schizophrenia.
“Among that 27 percent (as opposed to the other 73 percent of women), self-destructive violence was more common by about 50 percent. And the higher the antibodies to toxoplasm (presumably showing a more significant exposure), the greater the risk. Those with the highest level of antibodies were at almost 100 percent higher risk for self-harm.”