1) Ignes fatui 
Misconceptions and their resultant afflicted states of MIND. Syn.
Is a false belief as a result of an illness process and occurs often with AD patients. This is very difficult for family members to deal with; families often argue with or try to reason with the patient or are hurt because they feel the patient is intentionally lying to them. The person with AD has lost their ability to reason and therefore, careg...
A false belief regarding the self or persons or objects outside the self that persists despite the facts, and is not considered tenable by one's associates. ... (12 Dec 1998) ... 
If someone is suffering from delusions, they have lost touch with reality and may experience hallucinations.
Delusions are bizarre thoughts that have no basis in reality.
Irrational beliefs or convictions that a person with psychosis (often schizophrenia) holds on to, despite all evidence to the contrary. They are one of the positive symptoms of schizophrenia.
A condition wherein the patient loses his/her ability to discern reality, experiencing mis-perceptions and hallucinations.
False or irrational beliefs maintained despite clear evidence to the contrary.
False beliefs that are held strongly despite contradictory evidence.
a perception that is thought to be true by the person experiencing it, although the perception is wrong.