Introduction

By the end of the nineteenth century, paranoia was well established as a psychiatric illness and was regarded as being not uncommon. Yet, as has been described in Chapter 1, it all but vanished as a diagnosis during the middle of the twentieth century. That process, and the subsequent rehabilitation of the concept, has already been discussed in some detail.

Renamed ‘delusional disorder’, paranoia was firmly reinstated in 1987 by DSMIIIR and it is fully accepted under this title in DSMIV (1994) and ICD10 (1992–93). It is increasingly being diagnosed, but because of its long absence from the canon, it is not necessarily familiar to all psychiatrists.

What is meant by paranoia?

This chapter will describe an illness characterized by a stable and persistent delusional system which is relatively encapsulated and which, in many cases, leaves much of the personality surprisingly intact, allowing a considerable degree of social functioning to persist. The individual clings to the delusion with fanatical intensity and nearly always spurns any suggestion that he or she is ill. Hallucinations may occur but are usually less prominent than in schizophrenia: when they are present their themes tend to be congruent with the delusional belief. The illness is chronic, often infact lifelong, but it does not have the principal characteristics of schizophrenia as stipulated by criterion A for schizophrenia in DSMIV.

Paranoia was renamed ‘delusional disorder’ in DSMIIIR because of the considerable confusion of terminology in English-speaking psychiatry.