A couple off the top of my head would be two Bergman films - "Through a Glass Darkly" and possibly "Winter Light" - although the latter is part of the existential angst theme of his "faith trilogy", so maybe not exactly what you're looking for.  There is also a very good British picture from the mid-sixties called "Morgan" about a man who goes somewhat insane as a result of personal conflicts.  There is also Truffaut's "The Story of Adele H." about delusional sexual obsession.  "Repulsion" was mentioned.