Descriptive Psychopathology: The Signs and Symptoms of ...

278 Section 3: Examination domainshad disappeared and that he had been castrated by the Pope, so that he would beput into the choir at St Peter’s Basilica. 24Delusional perceptionDelusional perception is one of Kurt Schneider’s first rank symptoms. It is adelusion derived from a presumed accurate perception that is then given personalsignificance, without an understandable connection between the delusional ideaand the perception. For example, a patient sees two new flower pots on aneighbor’s window sill and concludes that he will be killed in his sleep that night.Recent multivariate studies of delusions separate Schneider’s passivity delusions(control, thought withdrawal, and insertion) from other forms and links then to apoor long-term prognosis. 25Some primary delusions differ from delusional perceptions in that the evidencethe patient offers to account for the delusional idea is understandable. Forexample, the patient concludes that he will be killed in his sleep because he hasnoticed the same new automobile parked on his street for the past several days,then he sees a man on the street who looked like a person who shouted at himon the highway, and then he hears noises in the house suggestive of personssneaking about.Dereistic thinking is thinking based on “feelings” rather than logic. 26 It is thethinking that permits myths or folktales to be accepted, e.g. the idea that themammalian Easter Bunny lays colored eggs. It underlies delusional perceptions,such as the patient seeing an empty coffee cup on the conference room table as the“proof” that the plot to kill him continues. He “knows” it without understandinghow he knows.Passivity delusionsExperience of control and alienation are defined as passivity delusions becausethe sufferer feels helpless during the experience, either being controlled by anoutside force or inhabited by another person’s thoughts.Experience of control entails some outside force or agency experienced ascontrolling the sufferer’s emotions, thinking or movements, forcing compliance.One patient was forced to say and do things by “people watching” him throughthe walls of the hospital as if they were “one-way” mirrors. Another insisted ateacher was giving her hidden signals forcing her to assume certain postures.Patients rarely can describe the consequences of resisting.Experience of alienation is the experience that someone else’s thoughts are inone’s mind, or that a body part is not one’s own but belongs to another person oranimal, or is made of other than human tissue. One patient insisted others coulderase his mind (thought withdrawal) and then fill his head with their thoughts.