A predisposing influence of more importance than would at first sight appear is found in sensational popular writings upon the subject. As Kane has well said, “At the time in which De Quincey, Coleridge, and Southey lived the people and the profession knew little of the opium habit save among foreign nations. The habitués were few in number, and consequently when De Quincey's article appeared it created a most decided impression upon the popular mind—an impression not yet effaced, and one which bore with it an incalculable amount of harm. Men and women who had never heard of such a thing, stimulated by curiosity, their minds filled with the vivid pictures of a state of dreamy bliss and feeling of full content with the world and all about, tried the experiment, and gradually wound themselves in the silken meshes of the fascinating net, which only too soon proved too strong to admit of breaking.” There can be no question that a percentage of cases of the opium habit, small though it be, is even in our day to be attributed to this cause.
Somewhat analogous in its etiological importance is the influence of example upon persons of idle and luxurious habits. Nowhere in Western countries, with the exception of the opium-smoking dens of the Chinese and their depraved associates, are there public places of resort devoted to the practice of the opium and morphine habits, as there are in Turkey and the East. According to Jouet—whose statements are corroborated by occasional statements in French newspapers—the habitual injection of morphine is to-day, in France at least, almost a matter of fashion. Landowski states that friendship is occasionally pushed to the extent of the exchange of pretty syringes in silver cases as presents, and that a patient received upon his birthday a hypodermic syringe as a present from his sister. Zambaco, whose observations were made at Constantinople, states that among the Moslems the opium habitués prefer the crude drug, either alone or associated with certain aromatic substances, such as ambergris, canella, or saffron, which are used for their aphrodisiac effect. These mixtures are prepared openly in the family, and carried upon the person in the form of pills in rich boxes of gold and enamel among the better classes. This observer further says that the ladies of the better classes carry jewelled cases containing hypodermic syringes and artistic flaçons for the seductive solution, and that they avail themselves of favorable opportunities to take an injection of morphine even when together.
In addition to the predisposing influences already mentioned, it has been customary to regard insanity as a cause of the opium habit. Laehr6 and Fidler7 have gone so far as to class the morphine habit among the psychoses. This view appears to be no longer tenable. The opium habit must be classed with the taste for alcohol, gambling, avarice, and lust as among human passions. That nervous subjects, invalids, and individuals wanting in moral and physical tone are specially prone to it is obvious. It constitutes in these cases, however, an expression of the morbid constitution rather than a substantive affection in itself. In the same manner, the opium habit in insane persons must be looked upon as an epiphenomenon of the morbid mental condition.
6 Allgemeine Zeitschrift für Psychiatrie, 1872.
7 Jahresb. der Gesellschaft für Natur und Heilkunde, Dresden, 1876.
Levinstein has with reason insisted upon the essential difference between the disturbances resulting from chronic poisoning by alcohol, lead, arsenic, etc., and that produced by morphine. In the former group the mental conditions are expressions of physical and chemical alterations of the central nervous system, which, once established, persist for an indefinite period, whereas in morphinomania the troubles of the nervous system are chiefly functional and of a transitory character. He regards the nervous disorders developed from the prolonged use of morphine as the result simply of depression of the nervous system, and the extreme suffering experienced on the withdrawal of the regular dose to which the subject has been accustomed as a trouble of innervation rather than as a psychical derangement. This physical suffering and the mental depression which accompanies it have their analogues in the angina occasionally seen in paroxysmal affections of the heart, the blood-vessels, and the respiratory organs. Certain it is that individuals addicted to opium and morphine excesses in a high degree not only frequently retain full possession of their intellect, but occasionally achieve and maintain great distinction in professional and scientific life. Furthermore, subjects of the opium habit, notwithstanding the gravest mental disturbance manifested during the continuance or upon the cessation of the habit, usually exhibit when cured no further indication of mental disorder.
B. The Exciting Cause.—In addition to the usual constituents of vegetable substances, mucilage, albumen, proteids, fat, volatile substances, and salts of ammonium, calcium, and magnesium, opium contains a number of alkaloids, two neutral substances, and meconic acid. Some of the alkaloids are probably derivatives from morphia. The three most important alkaloids are morphine, codeine, and thebaine. The neutral substances are meconin and meconiasin. Morphinæ hydrochloras, acetas, and sulphas, codeina, and apomorphinæ hydrochloras are officinal in the United States Pharmacopœia. Opium and its alkaloids act principally on the central nervous system, and in mammals on the brain. The functions of the nervous system, as Brunton has pointed out, are abolished in the order of their development, the highest centres being the first affected. In man the action of opium is chiefly manifested upon the brain. With small doses a stage of excitement, attended by increased activity of the circulation, augmented nervous energy, and under favorable circumstances an agreeable languor, followed by quiet sleep, constitute the effects of the drug; with larger doses, of from one to two grains, the transient stage of excitement is followed by deep sleep, the awakening from which is marked by headache, nausea, and evidences of gastro-intestinal catarrh; with still larger doses, of three grains or more, deep sleep is produced, which speedily passes into coma. The drug has an especial action on the vaso-motor system, which is manifested in its power to diminish congestion and relieve inflammation. With the exception of the urine and the sweat, the secretions of the body are diminished by opium. The action of the drug upon the intestines varies with the dose. In moderate doses it diminishes peristalsis and causes constipation; in very small doses it increases peristalsis; in large doses peristaltic action ceases. Morphine is eliminated unchanged by the kidneys. It is eliminated also by the gastro-intestinal mucous membrane, having been found in the stomach after hypodermic injection. The action of opium and its derivatives, as that of other narcotics, is much influenced by habit. In those accustomed to the drug large (and sometimes enormous) quantities are required to induce the characteristic manifestations. Not rarely these manifestations are much retarded. The enormous amount of two pints of tincture of opium has been taken in the course of a day; a female patient afterward successfully treated by the writer took habitually for a long period of time from ten to twelve grains of morphine per diem, hypodermically. Diedriech8 assumes that a portion of the morphine introduced into the organism is converted into oxydimorphine or other analogous substances which have the property of counteracting to some extent the toxic effects of the morphine.
8 Ueber oxydimorphine, Inaug. Diss., Göttingen, 1883.
Levinstein concludes as a result of experiments upon animals that morphine, besides its influence upon the nervous system, exerts an especial action upon two sets of organs: first, upon the digestive tube; and second, upon the sudoriferous glands. Taken by the mouth, it irritated the gastric mucous membrane. Whether taken by the mouth or hypodermically, it diminishes the secretion of gastric juice and the peristaltic movements of the intestine. These disturbances serve to explain not only certain of the phenomena of the opium habit itself, but even more fully some of the symptoms manifested upon its discontinuance. The nausea, vomiting, and constipation occurring during the continuance of the habit must be looked upon as a result of the derangement of function of the gastro-intestinal glandular apparatus and the chronic catarrh which accompanies it. The abrupt discontinuance of the drug is followed by the sudden return of functional activity, hence salivation, persistent vomiting, anorexia, and diarrhœa.
The effects of habitual excesses in opium and morphine upon the nervous system are in essential particulars the same. Upon the functions of the digestive system and upon nutrition they differ to a considerable extent. Opium, as a rule, soon produces gastro-intestinal derangements of a marked kind. These derangements consist in loss of appetite, enfeebled digestion, nausea, vomiting, and constipation alternating with occasional diarrhœa. The anorexia is usually persistent and of a high degree, and has much to do with the development of the wasting which is so common and so marked. The occasional excessive appetite for food manifested by opium-eaters is of brief duration. Its gratification aggravates the functional disturbances, provokes gastro-intestinal catarrh, and thus tends to increase the general malnutrition. On the other hand, morphine is much better borne. At the present time almost all morphine habitués use the hypodermic syringe, and, notwithstanding the elimination of the drug in part by the gastric mucous membrane, thus escape in part its evil effects upon the organs of digestion, and remain for a long time, often despite enormous excesses, free from the nutritive disturbances which are almost characteristic of the habitual abuse of crude opium.