Isolated by Magnan from the poorly defined group of paranoic conditions, delire chronique presents a striking analogy to certain forms of dementia praecox, which fact led Krae-pelin to include it under the heading of paranoid dementia. Conforming to French usage, we shall describe it as a separate clinical entity, which appears to us to be justifiable, at least provisionally, in view of the following considerations:

(1) This condition appears at an age when dementia praecox is already rare - after thirty years in the majority of cases;

(2) The delusions present perfect systematization and a regular evolution, which is unusual in dementia praecox;

(3) The dementia does not appear for many years. Sometimes it does not appear at all, even when the patient has reached an advanced age (Falret).

The name "dementia praecox" would scarcely be applicable to an affection usually appearing at an adult age, and in which mental deterioration does not supervene until long after the onset - twenty years or more. Though we may consider this disorder as being very closely related to dementia praecox, it would seem that more facts are necessary to establish the identity of the two conditions.

The evolution of delire chronique occurs in four periods, which we shall consider hastily, for the symptoms encountered in each of these periods have already been described, and it is but the special grouping of these symptoms that imparts to this disease its characteristic aspect.

First Period: Incubation

This period is always a prolonged one. The personality of the patient undergoes a slow and insensible, though profound, transformation. The symptoms observed at the beginning present no definite character. They consist of an irritability and a singular pessimism, with which are often associated hypochondriacal ideas.

Little by little these pathological phenomena become more and more marked and develop into ideas of persecution. Suspiciousness and uneasiness appear first, followed later by delusional interpretations: the patient imagines he is watched as he walks in the street, he discovers a hidden meaning in a conversation. Illusions of all the senses, but especially those of hearing and of smell, gradually appear as the affection reaches the second period.

Second Period: Systematization of the Delusions; Appearance of Hallucinations. - Hallucinations are constant and affect all the senses except vision. They are always of a painful character. The first to appear are phonemes (verbal auditory hallucinations), which, vague at the beginning, assume after a certain time remarkable distinctness. They are followed by the appearance of hallucinations of taste, smell, general sensibility, including the genital sense, and, later on, motor hallucinations also.

Visual hallucinations are extremely rare, if ever present at all. On the other hand, illusions of sight are as frequent as those of the other senses, often taking the form of mistakes of identity.

By degrees the delusions group themselves and become systematized. The hallucinations are interpreted and explained. The patient recognizes the voices, discovers his persecutors, the methods they make use of, and the aims they pursue. As he is perfectly convinced of the reality of his delusions, he reacts, seeking to protect himself against his imaginary enemies and to find justice. The means to which he may resort are infinitely varied: protests before authorities and before the public, frequent changing of residence, and but too often assaults and murder.

As the disease advances, more and more evident signs of psychic disaggregation appear: echo of the thoughts, autochthonous ideas, motor hallucinations, etc.

Third Period: Ideas Of Grandeur

Some authors regard the ideas of grandeur as a logical sequence of those of persecution, resulting from the following line of reasoning, which the patient is assumed to pursue more or less consciously: "They persecute me so unmercifully and with such stubbornness because they are afraid of me or jealous of me." This explanation is perhaps applicable to a small number of cases, but not to all.

The real cause of the ideas of grandeur is the mental deterioration which makes its appearance at this period.

These ideas are of all possible forms: ideas of wealth, of power, or of transformation of the personality. One patient was God and his persecutor was the devil. Another reigned over the planet Mars, and once decided to destroy the earth by means of aeroliths.

Fourth Period: Dementia

Mental deterioration here becomes clearly apparent. Its character is very similar to, if not identical with, that of dementia praecox, and this is undoubtedly strong evidence of a close relationship between the two conditions.

Almost always some stereotyped delusions persist as a last remnant of the former system of delusions.

The evolution of the disease is very slow, often requiring twenty or thirty years for its completion.

The prognosis is fatal from the psychic standpoint. But the morbid process does not affect the organic functions, and the patients may live to an old age.