Belief is generally delusional across the board! We know very little and just think we know stuff. Part of Buddhist teaching and something most serious meditators in general come to at some point is practicing not being attached to their own beliefs. This is certainly something I practice in general. If we understand belief to be like this — something one must be wary about at best, then we can start to understand that “delusional” beliefs of those labeled with psychiatric illness is simply not particularly different from many ordinary beliefs. Just like Lisa Bortolotti, in the video, discusses.
Book by Lisa Bortolotti: