Wernicke's theories regarding the elaboration of mental mechanisms have already been referred to. He saw in dementia praecox and other deteriorative processes the possibility of a dissociation of psychical reflexes due to an interruption or disturbance located in the psychomotor projection field, preventing its proper coordination with the intrapsychic elaboration mechanisms.
The psychological processes involved in schizophrenia as outlined by Bleuler[295] (1911) have a very important bearing on the interpretation of the symptoms of dementia praecox. The group which he described under this designation is a very broad one, including "many atypical melancholias and manias of other schools (as well as hysterical melancholias and manias), the most of the hallucinatory confusions, many of the amentias described by others (our conception of amentia is much narrower), some of the forms belonging to acute delirium, Wernicke's motility psychoses, primary and secondary dementias without special designations, the most of the paranoias of other schools, especially the hysterical paranoias and almost all of the incurable hypochondrias, nervousness, compulsions and impulsions." To these he adds the various "juvenile and masturbation forms," a large part of the degenerative psychoses of Magnan, many prison psychoses and the Ganser symptom complex. In view of the fact, as Bleuler[296] expresses it, that "The name dementia praecox, which neither leads to dementia nor is precocious in its origin, necessarily, gave rise to many misunderstandings," he suggested the designation schizophrenia as more appropriate. "Even if we cannot make a natural grouping, it would appear that schizophrenia is not a disease in the narrower sense but a group of diseases somewhat analogous to the organic group, which includes paralysis, the senile forms, etc. Schizophrenia should therefore be spoken of really in the plural. The disease pursues a chronic course or progresses in attacks and may come to a standstill at any stage or may even regress but never to a complete restitutio ad integrum. It is characterized by a specific type of alteration in thinking, feeling and relation to the outer world encountered nowhere else. Accessory symptoms of a characteristic type are particularly common.... Dementia praecox in any stage may come to a stop, and many of its symptoms partially or entirely disappear but when it progresses further it leads to dementia and dementia of a definite type." A fundamental symptom, according to Bleuler, is the disturbance of association of ideas. "The normal association of ideas loses its stability; others enter at will and take their place. Thus the ideas lose their relation to each other and thought becomes incoherent." As Hoch[297] says of this disturbance, "Bleuler described it very extensively, and yet somehow it is not so very easy to grasp the nature of this disorder; it is evidently not so very different from Wernicke's sejunction, though free from all localizing anatomical bywork. It is conceived of as a more or less widespread primary interruption of the associative connection of ideas. Actual or latent associations, which, in the normal, determine the train of thought or combinations of such ideas may remain without influence upon it in an apparently aimless fashion, whereas other ideas which have no connection may intrude themselves. Hence the train of thought is scattered, bizarre, illogical, abrupt. This may be so slight that it is difficult to discover, and in his description of mild conditions he says it may not be found, or only after a thorough search; it accounts for much of the scattering of ideas in chronic states, and, as we have said, it is supposed to be the explanatory principle in acute incoherence. On the other hand, similar phenomena may be due to the action of complexes, and have to be explained psychogenically. But the psychogenic explanation does not appear to him sufficient. It is somewhat difficult to see, especially when we consider the extensive symbolization and substitution, the indifference, the negativism, etc., why something beyond these psychogenically explicable disorders is required." An essential feature of Bleuler's[298] concept is "autismus." "The schizophrenics lose their contact with reality, the mild cases inconspicuously here and there, the severe cases, completely".... "When we allow our fancies free reign in mythology, in dreams and in many of the morbid states, thought will not or cannot concern itself with realities; it follows the dictates of instincts and emotions. This disregarding of the inconsistency with reality is characteristic of autistic thinking."
In his excellent review of Bleuler's schizophrenia already referred to, Hoch[299] makes the following comments on this subject:—"A difficult subject is autism. By autism Bleuler means that which we have called the shut in tendency, the more or less complete shutting out of the environment, or at any rate, all that which does not correspond to the wishes. It may be so marked that the patients even shut out all sensory impressions, close their eyes and ears, make their body as small as possible by crouching. Bleuler regards this autism as a secondary phenomenon, and looks upon it as one of the results of his association disorder, whereas the autistic thinking is the day-dreaming, the thinking without reference to reality. This autistic thinking flourishes in schizophrenia—Bleuler thinks that the schizophrenic defect in logic makes the exclusion of a great many external and internal facts possible, and thus gives sway to a tendency which we all have, namely, to live in fancies which suit us, something which we indulge in but do not allow to influence our conduct, but which in the schizophrenic assumes the value of reality." An outline of Bleuler's views would not be complete without his definition of blocking,[300] an important symptom. "Blocking is a sudden emotional inhibition of the psychic processes and in itself not pathological." He found it in normal individuals in nervousness and in hysteria. "Where it is not based on adequate psychological grounds, is generalized or of long duration, its presence warrants the diagnosis of schizophrenia."
A study of the psychogenic factors concerned in dementia praecox led Meyer[301] to the conclusion that the psychological processes of the disease were due to abnormal mental mechanisms developing in individuals unable to adjust themselves to their surroundings. "The general principle is that many individuals cannot afford to count on unlimited elasticity in the habitual use of certain habits of adjustment, that instincts will be undermined by persistent misapplication, and the delicate balance of mental adjustment and of its material substratum must largely depend on a maintenance of sound instinct and reaction type." This theory is supported somewhat by the "shut in personality" found by Hoch[302] in his studies of the history of a large number of cases developing dementia praecox.
Elaborate analyses of the psychological mechanisms involved in dementia praecox have been made by Jung and others. Freud believed hysteria to be the result of a psychic trauma. The unpleasant idea associated with this trauma is repressed into the subconscious because the individual is unable to react to it in a normal way and it is forgotten, but not until it is compensated for by a hysterical symbol or symptom which takes its place. By means of psychoanalysis, the association test and the study of dreams the nature of the psychic trauma can often be determined. Jung[303] adapted these methods of study to a consideration of dementia praecox. His investigations showed that many of the seemingly meaningless manifestations of that disease are symbols or substitutes for buried complexes. In some instances these remain in their original form without transformation. Complexes associated with a feeling of deficiency and injured pride may lead to suspicion and delusions of persecution. Unfulfilled longings may be actualized in a delirium or delusion of grandeur. Symbols and substitutes generally are said to represent complexes which are antagonistic to the ego and are therefore transformed and become unrecognizable. The peculiar symptoms of dementia praecox as a rule are a result of the individual's inability to make compensatory readjustments. In the paranoid forms the patient entirely reconstructs his psychical life. White[304] attempts to explain the meaning of some of these delusional formations in his "Outlines of Psychiatry":—"The relation of the delusion to the complex is often obvious if one is familiar with the more important of the infantile material. A man believes himself pregnant, that a child is in his stomach. This is obviously a regression to the period when as an infant he had not understood that gestation was a particular function of the female. Another patient enucleated his eye (castration symbol); a colored man of about forty years of age invented a perpetual motion machine (compensation for impotence); a man tries to invent the greatest cannon on earth (compensation for small penis complex); a homosexual man of the "sissy" type made wild claims of physical prowess, fighting ability, and incessantly swore and used vulgar language to demonstrate his toughness (over-compensation of homosexuality); a woman complains that her sister's husband follows her through underground passageways and shoots electricity into her genitalia and anus (anal erotism); an oral erotic woman starves herself in order to be tube fed; oral erotic patients often cut their throats while under the erotic pressure; patients frequently say that God talks with them or go to Washington to see the President (father complex); in severe grades of introversion they sit in a dark corner, head on breast, arms folded and legs and thighs flexed (intra-uterine position); a young woman says her real parents are the King and Queen of Norway (Œdipus phantasy); etc. Of course much of the delusional material is not so obviously related to infantile material and must be worked out at length with the individual to determine its meaning. It must not be forgotten that a praecox may have, however, complex reactions exactly like that of hysteria and the psychoneuroses. To that extent such a patient is hysterical or psychoneurotic."
The appearance of the last edition of his textbook showed that Kraepelin has somewhat revised his views on the subject of dementia praecox. He now speaks of a series of morbid pictures "brought together under the designation endogenous dementias for the purpose of a preliminary understanding." This embraces not only dementia praecox but a new entity described as "paraphrenia."[305] This includes forms "which, contrary to the usual manifestations of dementia praecox, are characterized throughout their entire course by the marked prominence of a characteristic intellectual disturbance while an independent impairment of volition and particularly an emotional alteration are lacking or only present in a mild form. For this differentiation it seems to me that no more suitable expression than "paraphrenia" could be employed for the designation of the disease processes experimentally brought together here." He speaks of the following types:—systematica, expansiva, confabulans and phantastica.
The clinical forms of dementia praecox shown in his last edition are as follows:—dementia simplex, hebephrenia, simple depressive or stuporous dementia, depressive delusional dementia, circular, agitated and periodic forms, katatonia, paranoid types (dementia paranoides gravis and mitis, hallucinatory and paranoid feeblemindedness) and confusional speech or schizophasia.
His views as to the delimitation of these different types should be expressed perhaps in his own words:[306]
"Simple progressive deterioration as described by Diem under the designation of 'Dementia Simplex,' consists in an imperceptible and complete impoverishment and breaking down of the entire mental life."
Of hebephrenia or silly dementia he says, "In this disease picture there stands out particularly with the progressive deterioration of the mental life, an incoherence of thought, feeling, and conduct."