It’s a condition that people often think means Multiple Personality Syndrome, I’m not really sure but I think it somehow detaches the person from reality, hallucinations things like that.
Indeed, often wrongly considered to mean Multiple personalities.
People with Schizophrenia however, have periods where they have delusions and lose contact with reality. This can involve visual and/or auditory hallucinations (hearing voices, seeing beings that are not there), paranoia, and a warped perception of elements in their surroundings. Hence, a peacock can be perceived as a “vampire”.