I can speak perfectly coherently when HIGHLY psychotic. Not always but more often than not. While a person might be able to tell "something" is going on, they would have no idea the extents unless I openly started discussing my internal workings. Sometimes my delusions force me to be silent and "play their game by their rules so they can't lock me up". Usually I'm highly agitated and that is noticeable but neurotypicals get highly agitated at times too. People would be surprised by the amount of highly delusional people who are successful at hiding it. And being able to hide it well isn't a good sign, it's often one that results in death with people saying "I didn't know how bad it was, why didn't they tell me". We all have different abilities and seeing hallucinations which terrify you, self harming and being SI doesn't automatically make a person incoherent. Lots of people see tons of hallucinations and remain coherent. ((((Hugs)))

Not saying anyone was insinuating otherwise but in case someone is reading this and thinking "wouldn't you be incoherent if delusional". I want to make the answer clear that not necessarily. (((Hugs)))