Depression and Paranoid Schizophrenia

Abstract

This paper deals with the relationship between psychotic depression and paranoid schizophrenia as one of the paranoid spectrum disorders. Although paranoid schizophrenia is still officially recognized as a subtype of schizophrenia, there is considerable evidence to suggest that paranoid schizophrenia differs from other forms of schizophrenia (1). Thus, paranoid schizophrenics tend to be older on first admission to hospital and their prognosis is generally better. They also differ markedly from nonparanoid schizophrenics on a variety of cognitive tasks where their performance is characterized by rigidity and by a hypersensitivity to stimuli. For instance, they resist shifting from one concept to another and demonstrate perceptual overconstancy. It is noteworthy that the performance of normal subjects on these tasks falls between that of paranoids and nonparanoids, thereby highlighting the paranoid-nonparanoid dichotomy. Numerous authorities (2,3) have maintained that the paranoid syndrome should be made independent of schizophrenia. The evidence from familial studies provides further support for this distinction. Kendler and Davis (4) concluded that there is an indication that schizophrenia is rarer amongst the relatives of paranoid schizophrenics compared with nonparanoid schizophrenics and that paranoid schizophrenia breeds true to type, i.e., the close relatives of paranoid schizophrenics are more likely to be paranoid than nonparanoid, though this latter finding is debatable (5).