Thanks for your reply. Interesting to know the writers regret that. Yeah, I know they were both in the same cult and thus had both been exposed to that thought, but it's a bit unbelievable to me that they'd both manifest nearly the same hallucination.
If we take that scene as being true, then it suggests to me that…

Can someone explain to me how it is that Ryan's mother saw her cat as a
person. That wasn't from Ryan's perspective, and he didn't even know
about it. Neither of them knew the other was seeing things like that.
Even if their mental illness was hereditary, I've never heard of the
exact same type of hallucination…