I've nearly been a murder-suicide victim due to esketamine, so yes, it definitely exists. In fact, they screen out people out of the trials with psychosis due to this known potential side-effect. They also remove people from the trials for things like that.
It's too bad, because other than that side-effect, it was doing a lot of good.
Not much to tell, my partner took esketamine for a few months for treatment-resistant depression. I woke up one day to someone holding a knife and sobbing uncontrollably, calmed them down and took the knife away.
The treatment stopped after that, of course, and sharp things got put away quickly. Thankfully there are no guns in the house. There may have been latent psychosis prior.
It's too bad, because other than that side-effect, it was doing a lot of good.