Memory, Knowledge and Delusions

In schizophrenia, where they find their fullest expression, delusions are an extraordinary phenomenon. They can take a bewildering variety of forms, persecutory, grandiose, hypochondriacal, referential, and so on. They can be fixed and immutable, or alternatively may shift and change to the point of what Bleuler termed a delusional chaos. Finally, their degree of implausibility starts from the inherently unlikely, ranges through the patently absurd and bizarre, and not infrequently comes to violate common sense at its most elementary in fantastic delusions.