The term paranoid (para = beside, nous = mind) literally means a mind beside itself. It designates patients who show “fixed suspicions, persecutory delusions, dominant ideas or grandiose trends logically elaborated and with due regard for reality once the false interpretation or premise has been accepted. Further characteristics that differentiate pure paranoia from typical schizophrenia are formally correct conduct, adequate emotional reactions, and coherence of the train of thought” (Rosanoff). In other words, in pure paranoia (delusional disorder in DSM-IV), there is supposed to be no mental defect other than the delusional system—no dementia, hallucinations, or emotional disturbance. In past years, a large group of the mentally ill was classified as paranoid. But with advancing knowledge of mental illness, a decreasing number have been left in this category.
The trouble that psychiatrists have taken to couch this definition in negatives implies that paranoia is frequently a feature of other forms of mental illnesses, notably schizophrenia, bipolar disease, Alzheimer disease, Lewy-body disease, toxic or alcoholic psychosis, and general paresis. This fact about paranoia was known from the beginning, when Heinroth originally described it in 1818 and classified it as a limited disorder of the intellect. Kraepelin, in agreement with the ideas of Kahlbaum, distinguished between paranoia and dementia praecox, but remarked that approximately 40 percent of patients who developed paranoia early in life went on to become schizophrenic. In DSM-IV, this disorder is classified as “delusional (paranoid) disorder” and defined it as a persistent delusion that is not part of any other mental disorder. Furthermore, the delusions are nonbizarre, that is, while improbable, they involve situations that could occur in real life, such as being followed, poisoned, infected, loved at a distance, deceived by a spouse, or having a disease.
Figures on the frequency of isolated paranoia are probably not reliable because they are of necessity based on hospital records. Doubtless there are many individuals with mild forms of the disorder who have never crossed the threshold of a mental hospital. These individuals are relatively harmless and in their communities are judged to be “off,” eccentric, or simply odd. Males and females are equally affected. Among psychiatric hospital patients, true isolated paranoia is rare (0.1 percent of admissions, according to Winokur).
It would be difficult to give an account of all the many ways in which patients with paranoia behave. A simple amalgam will suffice—that of a middle-aged man of uneasy, brooding, asocial, eccentric nature who gradually develops a dominating idea or belief of his own importance, of having in his possession special powers that make him the envy of others who become bent on persecuting him. As the delusion grows, he becomes more preoccupied, less efficient, and increasingly suspicious of others, with a tendency to interpret every one of their words, gestures, or actions as having some reference to himself. On examining such a person, one is impressed with his capacity for careful reasoning, even betraying good intelligence. Whatever the delusional theme—erotomanic (a delusion that another person, usually of higher status, is in love with the patient), grandiose, jealous, persecutory, or somatic, the last being the most common—the patient’s arguments are logical and buttressed cogently by evidence. The patients express their false beliefs with certainty and conviction and are totally unaccepting of all arguments that impugn their rationality. Also, the views of such patients about matters other than their delusions can be quite sensible.
The querulous patients with paranoia are the most problematic. They remain in the community, flooding the mails with copies of documents accusing people falsely of various misdeeds, incessantly writing to newspapers, and expressing their opinions about anything and everything. As the years pass, the patient changes little, although a few such patients may later break down and begin to hallucinate and finally end in a deteriorated state much like that of schizophrenia. This trend supports Bleuler’s opinion that the illness is a variant of schizophrenia.