It seems like he was at the very least close to that. Since we only get his first-person account it's hard to say, but:

> They discussed philosophy, psychology, science and the universe...

> When they went to their daughter’s birthday party, she asked him not to talk about AI. While there, Biesma felt strangely disconnected. He couldn’t hold a conversation. “For some reason, I didn’t fit in any more,” he says.

> It’s hard for Biesma to describe what happened in the weeks after, as his recollections are so different from those of his family...

> he was hospitalised three times for what he describes as “full manic psychosis”.

You don't get hospitalized three times for mania without being pretty severely detached from reality.

> They discussed philosophy, psychology, science and the universe...

I mean, I've discussed all those things with an LLM, mostly because I'm able to interactively narrow in on the specific bits I don't understand, and I've found it to be great for that.

The rest ... yes, definitely psychosis.