Interesting. Cats can give humans toxoplasmosis. ...which studies are starting to link to greater depression and suicidality.
This is just one study....
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5810447/
That is interesting, but note it was done in Korea. Toxoplasmosis is much, much less common in first-world countries (that's probably not politically correct and I'm sorry). The CDC says: In the United States it is estimated that 11% of the population 6 years and older have been infected with
Toxoplasma. In various places throughout the world, it has been shown that more than 60% of some populations have been infected with
Toxoplasma.
To get it from a cat, the cat has to ingest something infected with it, ie, a rodent, bird, lizard, etc. Then, the person cleaning the litter box has to come into direct contact with the infected cat's stool, then practice poor hygiene (no handwashing) and ingest the parasite themselves.
Source: I have been pregnant while owning cats, so I researched this. It's not very easy to get toxoplasmosis.