It is extremely difficult at the present time to say whether insanity is increasing. Statistics in all lands giving the numbers committed to insane hospitals show on their face a great increase, but so many factors enter into these statistics that their value is uncertain. There is now an ever-increasing provision for the care of the insane. Owing to the recognition of insanity as a part of nervous disease and its separation from criminality there is no longer the same attempt to conceal it as was formerly the case, and hospitals for the insane are no longer associated with ideas of Bedlam. It is generally believed that modern conditions in the hurry and excitement of life, and the extreme social differences, the greater urban life, the greater extension of factory life, all tend to an increase in insanity, but there is no absolute proof that this is true. We know very little about insanity in the Middle Ages, but the conditions then were not conducive to a quiet life. There prevailed then as now excess and want, luxury and poverty, enjoyment and deprivations, balls and dinner parties and other features of the social game. There were factions in the cities, public executions, not infrequent sieges, scenes of horror, epidemics, famines, and all these combined with religious superstition and the often unjust and cruel laws should have been factors for insanity. There were actual epidemics of insanity affecting masses of the population, as shown in the children's crusade, the Jewish massacres and the dancing mania in the Rhine provinces. Where civilization seems to be the highest, statistics show the most insane, but this most probably depends upon better recognition of the condition and better provision for asylum care.
The so-called functional diseases have a close relation with diseases of the nervous system, for they chiefly concern the reactions of nerve tissue. Disease expressing itself in disturbance of function only, does not seem to fit in with the conceptions of disease which have been expressed, nor can we imagine a disturbance of function which does not depend upon a change of material. Living matter does not differ intrinsically from any other sort of matter; like other matter its reactions depend upon its composition structure[11] and the character of the action exerted upon it. By functional disease there is expressed merely that no anatomical or chemical change is discoverable in the material which gives the unusual reaction. The further our researches into the nature of disease extend, particularly the researches into the physiology and chemistry of disease, the smaller is the area of functional disease. In functional disease there may be either vague discomfort or actual pain under conditions when usually such would not be experienced, and on examination no condition is found which in the vast majority of cases would alone give rise to that impression on the nervous system which is interpreted as pain. In the production of the sensations of disease there can be change at any place along the line, in the sense organs, in the conducting paths or in the central organ. Thus there may be false visual impressions which may be due to changes in the retina or in the optic nerve or in the brain matter to which the nerve is distributed. It is perfectly possible that substances of an unusual character or an excess or deficiency of usual substances in the fluids around brain cells may so change them that such unusual reactions appear. There may be, of course, very marked individual susceptibility, which may be congenital or acquired. The perception of every stimulus involves activity of the nerve cells, and it is possible that the constant repetition of stimuli of an ordinary character may produce sufficient change to give rise to unusual reactions, and this particularly when there is lack of the restoration which repose and sleep bring. We know into what a condition one's nervous system may be thrown by the incessant noise attending the erection of a building in the vicinity of one's house or the pounding of a plumber working within the house, this being accentuated in the latter case by the thought of impending financial disaster. Even the confused and disagreeable sound due to the clatter of high-pitched women's voices at teas and receptions may, when frequently repeated, be productive of changes in the nerve cells sufficiently marked to give rise to the unusual reactions which are evidence of disease.
In the condition known as neurasthenia, which is often taken as a type of a functional disease, the basal and intrinsic cause is activity of the nervous system with the using up of material which is not compensated for by the renewal which comes in repose and sleep. Neurasthenia is one of the common conditions of our civilization, found among children and adults, the poor and rich, the idle and the factory worker; it is rife in the scholastic professions and among those who earn their living by brain work. It seems to be more common in the upper classes and particularly in the women, but this is because these are more subject to medical care and the condition is more in evidence. There are all sorts of symptoms attached to the condition, for the unusual mental action can be variously expressed. The cerebral form has been thus described by a well-known medical writer: "One of the most characteristic features of cerebral neurasthenia is a weary brain. The sensation is familiar enough to any fagged man, especially if he fall short of sleep. Impressions seem to go half into one's head and there sink into a woolly bed and die. Voices sound far off, the lines of a book run into one another and the meaning of them passes unperceived. Doors bang and windows rattle as they never did before; if a shoestring breaks, an imprecation is upon the lips. Business matters are in a conspiracy to go wrong. Letters are left unopened partly from want of will, partly from a senseless dread lest they contain bad news. At night the patient tosses on his bed possessed by all the cares which blacken with darkness. Headache is common, loss of memory is distressing, and in severe cases it is wider and deeper than mere inattention can explain. There is often the torture of acute hearing, or an inability to suppress attention; the hater of clocks and crowing cocks is a neurasthenic." The disease is especially common in the women players of the social game, and its unhappy victims too often seek relief from the nervous irritability which is a common early symptom in still greater nervous excitement. It is a sad commentary on our civilization that one of the means of treatment for these persons which has been found efficacious is to supply them with some restful household occupation such as knitting or plain sewing, and there are institutions which combine refuge from social activities, often called duties, with simple occupation.
Chapter XII
The Rapid Development Of Medicine In The Last Fifty Years.—The Influence Of Darwin.—Preventive Medicine.—The Dissemination Of Medical Knowledge.—The Development Of Conditions In Recent Years Which Act As Factors Of Disease.—Factory Life.—Urban Life.—The Increase Of Communication Between Peoples.—The Introduction Of Plant Parasites.—The Increase In Asylum Life.—Infant Mortality.—Wealth And Poverty As Factors In Disease.
Certain conditions have arisen in the past fifty years which have profoundly affected the thoughts, the beliefs and the activities of man. Within this period what is generally known as Darwinism, including under this evolution, has developed. Unlike theories which came from philosophical speculation only, the theory of evolution was one which could be subjected to observation and experiment. It freed man's mind from dogmas, it stimulated the imagination, it enlarged the territory in which it seemed possible to extend knowledge by the methods of science, and has resulted in an enormous increase of knowledge. This has been more striking in medical science than elsewhere, and in this of more far-reaching influence. Evolution coincided with another important development. History shows that all great periods of civilization have at their back sources of energy. In the civilizations of the past such sources of energy have come from the enslavement of conquered peoples or from commerce, or more direct forms of robbery, which have enabled a favored class to appropriate for its purposes the results of the work of others. While these sources have not been absent in the development of our civilization, the great source of energy has come from the rapid, and usually wasteful and reckless, utilization of the stored energy of the earth. The almost incredible advance in medical and other forms of scientific knowledge and the utilization of this knowledge is largely due to the greater forces which we have become possessed of.
Disease plays such a large part in the life of man and is so closely related to all of his activities that the changes in this period must have exerted an influence on disease. We have already seen that within the period we have obtained knowledge of the causes of disease and the conditions under which these causes became operative. The mystery which formerly enveloped disease is gone; disease is recognized as due to conditions which for the most part are within the control of man, and like gravity and chemical attraction it follows the operation of definite laws. There has been developed within the period what is known as preventive medicine, which aims rather at prevention than cure, and the resources of prevention are capable of much greater extension.