Statistics show that dementia praecox is a disease chiefly of young life. According to Kraepelin, in 60% of the cases it begins before the twenty-fifth year. It is rare after the age of thirty. It seems, however, difficult to state at what age it entirely ceases to occur. Certain psychoses identical with it in symptoms and evolution are met with at advanced ages.
1E. Rudin. Einige Wege und Ziele der Familienforschung, mit Rucksicht aufdie Psychiatric Zeitsch. f. d. gesamte Neurol, u. Psychia trie, Nov., 1911. - A. J. Rosanoff and F. I. Orr. A Study of Heredity Severe infections, overwork, grief, and traumatisms are occasionally found in the history of dementia praecox. (For a discussion of contributing causes see pp. 9-12.)
The nature of the disease has so far escaped us, and we must be content for the present with hypotheses.
According to some authors dementia praecox results from an arrest of mental development; the brain ceases to acquire new impressions, being exhausted by previous efforts which were too great for the energy which it originally possessed. This explanation, assuming it to be correct, can account for but a small number of cases. In reality, in most of the patients we observe not a stationary condition, but a true retrogression. Facts that have been acquired partly disappear, or at least cease to be coordinated so as to give rise to generalized ideas. Moreover, the disorders of affectivity and of the will cannot be accounted for by simple arrest of development.
According to Kraepelin's hypothesis dementia praecox is a disease of autointoxication. Many of the physical symptoms described above resemble the phenomena by which intoxications of exogenous or of endogenous origin are usually manifested: epileptiform attacks, disorders of the circulation and of the secretions, and alterations of the general nutrition.
Possibly the poison is the consequence of a disorder of secretion of the genital organs. The frequent appearance of the first symptoms at the age of puberty, or in the female at the time of her first childbirth, and the occasional development of the disease in interrupted stages, each corresponding to a period of pregnancy, are arguments in favor of this hypothesis.
A suggestive and far-reaching hypothesis bearing on the pathogenesis of dementia praecox has been advanced by Adolf Meyer.
in Insanity in the Light of the Mendelian Theory. Amer. Journ. of Insanity, Oct., 1911. - Ph. Jolly. Die Hereditat der Psychosen. Arch, f. Psychiatrie u. Nervenkrank., Vol. 52, 1913.
It is quite true that in some cases of dementia praecox we find a history of some infection or traumatism which is perhaps to some extent responsible for the mental disorder. But it is equally true that in the great majority of cases, as far as we know, the disorder develops without any such cause.
From Meyer's point of view such a clinical picture as that of dementia praecox may be the result of an acquisition and unchecked development of vicious mental habits or of abnormal "types of reaction" which ultimately replace by substitution healthy and efficient mental reactions such as are necessary in our constant acts of adjustment to our usual environment as well as to newly arising situations.
The importance of this view lies in its bearing on therapeutics and, even to a greater extent, on prophylaxis.
To quote from the original paper:1
"Every individual is capable of reacting to a very great variety of situations by a limited number of reaction types."
"The full, wholesome, and complete reaction in any emergency or problem of activity is the final adjustment, complete or incomplete, but at any rate clearly planned so as to give a feeling of satisfaction and completion. At other times there results merely an act of perplexity or an evasive substitution. Some of the reactions to emergencies or difficult situations are mere temporizing attempts to tide over the difficulty, based on the hope that new interests crowd out what would be fruitless worry or disappointment; complete or incomplete forgetting is the most usual remedy of the results of failure, and just as inattention and distraction correct a tendency to overwork, so faultfinding with others, or imaginative thoughts, or praying, or other expedients, are relied upon to help over a disappointment, and, as a rule, successfully. Other responses are much more apt to become harmful, dangerous, uncontrollable - a rattled fumbling, or a tantrum, or a hysterical fit, or a merely partial suppression, an undercurrent, an uncorrected false lingering attitude, or whatever the reaction type of the individual may be.
What is first a remedy of difficult situations can become a miscarriage of the remedial work of life, just as fever, from being an agent of self-defence, may become a danger and more destructive than its source. In the cases that tend to go to deterioration certain types of reactions occur in such frequency as to constitute almost pathognomonic empirical units. I would mention hypochondriacal trends, ideas of reference, fault-finding or suspicions, or attempts to get over things with empty harping, unaccountable dream-like, frequently nocturnal episodes, often with fear and hallucinations, and leading to strange conduct, such as the running out into the street in nightdress, etc., or ideas of strange possessions with hallucinatory dissociations, or the occurrence of fantastic notions. All these appear either on the ground of a neurasthenoid development, or at times suddenly, on more or less insufficient provocation, with insufficient excuse, but often enough with evidence that the patient was habitually dreamy, dependent in his adjustment to the situations of the world rather on shirking than on an active aggressive management, scattered and distracted either in all the spheres of habits or at least in some of the essential domains of adjustment which must depend more or less on instinct or habit.
On this ground reaction types which also occur in milder forms of inadequacy, in psychasthenia and hysteria or in religious ecstasy, etc., turn up on more inadequate foundation and with destructive rather than helpful results. We thus obtain the negativism no longer as healthy indifference and more or less self-sparing dodging, but distinctly as an uncontrollable, unreasoning, blocking factor. We obtain stereotypies not merely as substitutive reactions and automatisms on sufficient cause such as everybody will have, but, as it were, as a reaction of dead principle in a rut of least resistance. We see paranoic developments with the same inadequacy of starting point and failure in systematization, and in holding together the shattered personality, etc."
1 Adolf Meyer. Fundamental Conceptions of Dementia Precox. British Med. Jour., Sept. 29, 1906.
"Therapeutically, this way of going at the cases will furnish the best possible perspectives for action. We stand here at the beginning of a change which will make psychiatry interesting to the family physician and practitioner. As long as consumption was the leading concept of the dreaded condition of tuberculosis, its recognition very often came too late to make therapeutics tell. If dementia is the leading concept of a disorder, its recognition is the declaration of bankruptcy. To-day the physician thinks in terms of tuberculous infection, in terms of what favours its development or suppression; and long before ' consumption' comes to one's mind, the right principle of action is at hand - the change of habits of breathing poor air, of physical and mental ventilation, etc. In the same way, a knowledge of the working factors in dementia praecox will put us into a position of action, of habit-training, and of regulation of mental and physical hygiene, as long as the possible ' mental consumption ' is merely a perspective and not an accomplished fact. To be sure, the conditions are not as simple as with an infectious process. The balancing of mental metabolism and its influence on the vegetative mechanisms can miscarry in many ways.
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."
Meyer's views gain additional significance in the light of the more recent contribution of August Hoch,1 who finds in a large percentage of his cases of dementia praecox (51-66%) evidences of a peculiar mental make-up which he has termed "shut-in personality." This make-up he defines as follows: "Persons who do not have a natural tendency to be open and to get into contact with the environment, who are reticent, seclusive, who cannot adapt themselves to situations, who are hard to influence, often sensitive and stubborn, but the latter more in a passive than an active way. They show little interest in what goes on, often do not participate in the pleasures, cares, and pursuits of those about them; although often sensitive they do not let others know what their conflicts are; they do not unburden their minds, are shy, and have a tendency to live in a world of fancies. This is the shut-in personality." And he adds further: "What is, after all, the deterioration in dementia praecox if not the expression of the constitutional tendencies in their extreme form, a shutting out of the outside world, a deterioration of interests in the environment, a living in a world apart?" For purposes of control Hoch examined the histories of his cases of manic-depressive psychoses and failed to find plain evidences of a marked shut-in personality.2
From a biological viewpoint dementia praecox, or at least its underlying constitution, may be regarded as a trait or a complex of traits somewhat analogous in its origin and mode of transmission by heredity to such traits as color of iyes, color of hair, stature, etc., and possessing medical and sociological interest only by reason of the disability by which it manifests itself.
1 Constitutional Factors in the Dementia Praecox Group. Rev. of Neurol, and Psychiatry, Aug., 1910.
2 Journ. of Nerv. and Ment. Dis., Apr., 1909.
No discussion of the nature of dementia praecox would be complete without a reference to the existence of various transition forms, firstly, between it and the normal mental condition, and, secondly, between it and other constitutional disorders, particularly arrests of development, epilepsy, paranoia, and manic-depressive psychoses.1 Perhaps of similar significance are the familial relationships between dementia praecox and these disorders.2
The recognition of these facts led Adolf Meyer over fifteen years ago to provide in the official classification of the New York state hospitals such groups as "allied to dementia praecox" and "allied to manic-depressive psychoses." 3 Similar considerations led Bleuler later to widen the original Kraepelinian conception of dementia praecox by including, under the new name schizophrenia, various paranoic conditions, most psychoses arising on a basis of constitutional psychopathic inferiority, many somewhat impure psychoses usually assigned by others to the manic-depressive group, alcoholic delusional states, and other conditions which are for the most part so mild as to be rarely seen in institutions.4