Yes, long-term isolation is a recognized torture tactic and is known to provoke severe psychosis and hallucinations when strictly enforced. The current lockdowns may not involve total isolation, but they'll certainly be having a powerful negative effect after a whole year.

This is an interesting article about it: https://www.sciencealert.com/isolation-has-profound-effects-on-the-human-body-and-brain-here-s-what-happens

There's a reason they put prisoners in isolation as a punishment. Because it works.