Notwithstanding all of these advances, the generally recognized mental diseases, as late as 1895, included the following types:—mania, melancholia, dementia, imbecility, idiocy, general paresis, chronic delusional insanity or paranoia and senile insanity. This was in substance the psychiatry of Savage, Maudsley, Clouston, Blandfield, Régis, Chapin, Kellogg, Spitzka, Kirchoff, Berkley and many other well-known writers of a comparatively recent date. A new era in the history of mental medicine was ushered in by Kraepelin when the sixth edition of his "Psychiatrie" appeared in 1899. This established manic-depressive insanity and dementia praecox as clinical entities. Kraepelin called attention to the fact that excitements and depressions frequently recur in the same individual, often with frequent attacks but with no marked tendency towards mental enfeeblement. This class of cases he grouped together as manic-depressive psychoses and pointed out certain characteristics common to the excitements and depressions included. He showed that certain other forms of depression marked by anxiety, fear, restlessness, self-accusation, marked suicidal tendencies, etc., were common to the involutional period of life. To this anxious depression the name involution melancholia has been applied, although Kraepelin is now somewhat in doubt as to its differentiation from the manic-depressive group. To certain other cases characterized by emotional dulness, apathy, hallucinations with phantastic delusions, and in some types, mannerisms, negativism, stereotypy, verbigeration, etc., tending sooner or later towards deterioration, he attached the name dementia praecox. This included the hebephrenia of Hecker and the katatonia of Kahlbaum.
Wernicke in 1906 advanced the hypothesis that psychical symptoms may be attributed to disturbances of various association mechanisms. These interruptions were to be found in various parts of the psychical reflex arcs. This included the psychosensory tracts or receptive mechanisms, the intrapsychical tracts or elaboration mechanisms and the psychomotor mechanisms. Manic-depressive psychoses were looked upon as representing a disorder of the intrapsychic mechanism, while dementia praecox was considered to be an illustration of a disturbance of the psychomotor mechanisms. This was an exceedingly interesting but purely theoretical scheme for putting psychiatry on a definite anatomical and pathological basis.
The progress made by Kraepelin, Stransky, Wernicke, Bleuler, Ziehen and other modern psychiaters led to renewed interest in pathological research. This was to a considerable extent due to the suggestion of Kraepelin that dementia praecox was autotoxic and endogenous in origin. The neurons were exhaustively studied by Alzheimer and changes in metabolism thoroughly investigated by Folin and many others. To the researches of Nissl and Alzheimer in 1904 we are largely indebted for an accurate knowledge of general paresis. Studies of the cortex in dementia praecox by Alzheimer and many others have been extremely interesting if not conclusive. The introduction of lumbar puncture by Quincke and the studies of the cerebrospinal fluid made by Widal, Plaut, Nonne, Mott and others were of great aid in diagnostic procedure. These have been supplemented by the Wassermann reaction, the colloidal gold test, etc. The isolation of the treponema pallidum in the cortex settled the question of the identity of general paresis and cerebral syphilis for all time.
Another line of research responsible in no small measure for the remarkable progress of psychiatry during the last few decades was that instituted by Freud, Jung and others in their studies of psychological mechanisms. It is a rather remarkable fact that it is only in comparatively recent years that a study of the psychological processes of the normal mind has been looked upon as essential to an understanding of the mental reactions involved in the development of a psychoneurosis or psychosis. This is really the basis of Freud's work.
Psychiatry may be said to be practically the only branch of medical science in which a study of pathological processes has not been based largely upon physiological and anatomical foundations. Our textbooks for many years have insisted that "insanity" was a disease of the brain but have not given much consideration to a correlation of the physiology with the pathology of that organ. The application of psychological methods to psychiatric research was largely a result of the studies of hysteria by Janet. This was supplemented by the important contribution of Breuer and Freud in 1895 calling attention to their theories in regard to the production of the psychoneuroses by psychic traumas, usually of a sexual nature. Freud's views were outlined more fully in his "Selected Papers on Hysteria," "Three Contributions to the Sexual Theory," and his studies of the "Psychopathology of Everyday Life," etc. The psychological processes of dementia praecox and paranoia were subjected to elaborate studies by Freud, Jung and various other authors.
The relation existing between psychology and psychiatry has been placed on a very practical basis by the studies of shell shock and other hysterical conditions so important during the recent war. Probably nothing will contribute more towards a recognition of the importance of psychiatry than the discovery made early in the war that mental diseases and defects were responsible for more disabilities than were attributable to almost any other single cause. Certainly the inactivity of many years has been followed by an awakening which has placed modern psychiatry on a dignified plane and its progress will now compare favorably with the accomplishments of any other branch of medicine. The statement is, I think, justified, that psychiatry has been established on a thoroughly scientific basis as the result of the work of comparatively few years. We have, however, reached a stage where careful analyses should be made of the clinical data upon which future progress entirely depends.
A brief consideration of existing conditions should be sufficient to show this conclusively. Psychiatric literature is, and for many years has been, characterized largely by an unfortunate absence of accurate scientific information which would warrant the conclusions reached in many instances by the authors of our textbooks. We have been subjected to an avalanche of theories and a remarkable paucity of facts. In the discussion of abstract propositions where concrete evidence is not obtainable this is of course unavoidable. There has, however, been a very noticeable oversight of many facts which the wealth of clinical material in our hospitals has placed at our disposal. Our literature has been filled with too many unsubstantiated statements. There is no reason why many of the views entertained by various authorities should be matters of personal opinion or based entirely on individual observation. The fact that there are over two hundred thousand cases of mental disease in the state hospitals of this country, with an admission rate of sixty thousand annually, is sufficient evidence to justify the statement that there is no lack of material for accurate studies.
A brief reference to some of the discrepancies shown in a consideration of the various psychoses will serve to illustrate the need of more accurate information on many of these subjects. In discussing the predisposing causes of mental diseases, for instance, White[123] made the following statement, which is perfectly correct: "An inherited predisposition to mental disorder is found in from 30 to 90 per cent of cases according to different authorities, while the average for all conditions has been estimated at from 60 to 70 per cent." Information on this subject is certainly far from being complete or satisfactory. The Thirty-first annual report of the State Hospital Commission shows that of 4,492 first admissions to the New York hospitals during the year ending June 30, 1919, 2,003, or 44.6 per cent, were reported as having a family history of insanity, nervous diseases, alcoholism or other neuropathic taint. As far as could be determined 55.4 per cent showed no evidence of heredity in their family history. The necessity of further information on this important subject would appear to be obvious. The question as to the relation between syphilis and general paresis may be said to have been definitely settled for all time. The origin of this disease has, however, been the subject of controversy since 1857. Paton[124] in a review of this discussion in 1905 states that Gudden found a history of syphilis in 35.7 per cent of his cases, Hirsch, in fifty-six per cent, Jolly, in sixty-nine, Mendel, in seventy-five, and Alzheimer, in ninety per cent. In the light of our present knowledge this difference of opinion and experience is quite interesting and illuminating.
The most extravagant and misleading statements made about etiological factors, perhaps, are those which relate to the alcoholic psychoses. This was due largely to the statements of enthusiastic propagandists who were advocating prohibitory legislation. The facts of the matter are that when the use of liquor was unrestricted, the admission rate of alcoholic psychoses, as shown by the New York state hospital reports, had averaged ten per cent for a number of years (1908 to 1913).