Monothematic delusion: a delusional state that extends to only one domain.
Multi-thematic or polythematic delusion: extends to many.

Delusions and related conditions

• Capgras - a close person is replaced by an identical-looking impostor.
• Fregoli - different looking people are the same person in disguise.
• Cotard - the subject is dead or does not exist.
• Mirrored self-misidentification - reflection in a mirror is someone else.
• Reduplicative paramnesia - place (eg. hospital) / person / object looks the same but has been duplicated.
• Unilateral neglect - ignores one side of the body / sensory field; denies ownership of body parts on one side.
• Alien control - someone else contolling one's actions.
• Thought insertion - thoughts & words in the mind have been put in by someone else.
• Anosognosia - patient unaware of or denies the existence of their handicap, e.g. blindness, paralysis.

Mind