THE capacity to sleep can be acquired by effort in the same way as the capacity to think concretely or to run without getting out of breath. We know that many men whom we now class among the immortals possessed this capacity to sleep to a most unusual degree-Shelley, Napoleon, Brougham.
It is related of the poet that no matter how harassing the family relationship became he could go to sleep at will. It seems incredible that a man of the energy, enthusiasm, activity, vigour and variety of intellect and ambition of Brougham could also switch on sleep as one turns on electric light. It is not unlikely that it was to this ability that he owed his remarkable longevity, or rather the retention of his faculties until four score years and ten. When one recalls the physical and mental activities of this extraordinary man one wonders how the workings of such a brain could be shut ,off and turned on at will.
Circumstances and things apparently trivial may cause insomnia. A celebrated German physician, Strumpell, has published a story of a patient afflicted with a disease which made him insensitive to touch and temperature and who went to sleep immediately when his eyes and ears, the two remaining sense organs, were closed.
Convenience directed us to work in the light and sleep in the dark, and custom has confirmed these directions, adding to darkness perfect quiet and bodily comfort. But man can learn to sleep without these easy introductions. Boiler-makers grow accustomed to taking their rest beneath the clang of their comrades’ rivet-hammers, and the overworked, busy practitioner of medicine has often to get his sleep by taking naps of a few minutes duration as he is driven from the home of one patient to another. Everyone knows how astonished the countryman is on coming to the metropolis to find that his city cousin sleeps peacefully through the clang and thunder of cable cars, elevated railway trains, and the countless noises of the street which to his bucolic soul make night hideous. On the other hand, the city cousin who visits the old farm finds the crowing of cocks, the barking of dogs, the interminable conflict of “Katy did” and “Katy didn’t,” and the early twittering of birds infinitely worse than the roar and clang of the city. The question is merely one of habit as admirably set forth in the ancient ditty:-
An old lady who lived by the shore,
At length got so used to the roar
That she never could sleep
Unless someone would keep
A-pounding away at the door!
Three Classes of Insomniacs.The causes of insomnia are countless, varying from an unkind word to a serious mental or bodily illness. It facilitates recognition of the causes of insomnia to classify the conditions to which it bears relationship. For instance, one class of patients have great difficulty in getting to sleep. If they are allowed to prolong their slumbers into morning, there are usually no ill consequences, but as duty compels them to rise at a stated time, many of them suffer from the effects of curtailed sleep and it is this class particularly in whom fear of not getting to sleep and distressing impotent efforts to secure sleep combine to exhaust the victim’s strength and energy. This variety of sleeplessness has a fairly uniform causation. It is dependent upon mental conditions, excitement, fear, dread, anxiety, overwork and use of intoxicants or stimulants, particularly tea. Not infrequently such insomnia has its beginning in intentional and deliberate curtailment of sleep, in order to give more time to work.
It is the commonest form of sleeplessness in those who carry their troubles and their labours to bed with them. It is the sleeplessness which afflicts the individual who has engaged in an argument or altercation where perhaps his vanity has been wounded or his feelings hurt. It is the form of insomnia experienced by the anxious mother, the possessor of a weak heart, or by the individual who has recently been listening to the plaudits attending his efforts.
Another class of insomniacs is made up of those who experience a profound drowsiness terminating, often against the patient’s will, in refreshing slumber of variable duration which comes on early in the evening, followed either by repeated and apparently causeless awakenings, or by abrupt and complete awakening with mental alertness, but often with depression of spirits. Here again the ego which dominates the individual takes great delight in unwinding a scroll upon which is written in glittering letters a record of the infirmities of the spirit, or upon which is painted by the unforgetting brush of memory certain bitter or miserable incidents in the past, the contemplation of which revives the old emotions, awakens the old suffering and banishes all possibility of sleep. Insomnia of this kind is most commonly associated with some variety of self-poisoning, usually arising from indigestion and constipation and what is technically called “auto-intoxication.” Occurring in persons after middle life, it is not infrequently an expression of impaired elasticity of the blood vessels, the beginning of that disease which is now having what might be called a conventional popularity, viz.–arteriosclerosis. This form of disturbed sleep is of course much more common in so-called nervous persons, especially in those who take alcoholic stimulants, than in phlegmatic individuals. Physicans have found out that the early manifestations of disorder of the circulation of the blood may be recognised more unmistakably by certain methods of instrumental examination than by any other means. They have learned also that this condition can be cured.
The third variety of sleeplessness, classifying sleeplessness now according to the time of its occurrence, is technically spoken of as dysomnia in contradistinction to insomnia. Here the adequate number of hours is apparently obtained but there is lacking that feeling of refreshment and invigoration which should come after normal sleep. The tired body and the exhausted mind craves sleep so keenly that at first it comes on very profoundly and then abruptly, the victim awakens to find that his mind is carrying on its particular problems at exactly the same point, and in quite the same way, as before he went to sleep.
Insomnia in Health and in Disease.-Insomnia in one form or another accompanies nearly every disorder of the health, but it occurs also in individuals who are entirely well. In the majority of instances it is a state of mind founded in fear and apprehension. But frequently it can be ascribed to a direct and immediate physical cause, indigestion for instance, or tooth-ache.
Of all the physical causes of insomnia, as dis tint from the mental, none is so positive or prevalent as indigestion. We take so many liberties with the functions of our body that we easily forget that the digestive tract is the main road to health and efficiency. Very few have the good fortune to reach middle age without having experienced some disorder of digestion. The effects of such disorder may be revealed in many ways, but the commonest way, especially in persons with what is popularly called the nervous temperament is through disorder of sleep.
Sleep disturbances from indigestion are apt to occur in brain-workers, in persons of a sedentary occupation and in those who are exposed to harassing, anxious and depressing emtional experiences. Anxiety, worry, consternation, terror and grief, emotions which most of us experience at one time or another, have their effect first upon the digestion and then in turn upon the various other functions of the body.
Although I purposely refrain from enumerating the various diseases which cause insomnia, special mention must be made of the sleeplessness resulting from influenza. In my experience it is most obstinate and taxes the resources of the patient and of the physician.
Insomnia may be, and often is, an accompaniment of certain specific diseases both acute and chronic, but this sort of insomnia is almost invariably self-limited and ceases when the disease terminates. In other cases insomnia is due to intoxication from poisons arising within the system, such as those accompanying disorders of digestion, gout, rheumatism, diabetes and excessive bodily fatigue. It is much more often, however, the result of poisons taken into the system, such as tobacco, tea, coffee and drugs, such as strychnine and so-called nerve tonics of one kind or another all of which contain circulatory excitants. That certain stimulants, particularly tea and coffee, are powerful agencies in the prevention of sleep is undisputed. There are many persons, however, who can drink a cup of strong black coffee and immediately proceed to bed and to sleep as though they had quaffed the cup of Lethe. Probably coffee is a more potent agency in causing wakefulness than tea because it is a more fundamental stimulant and its effect upon the heart and blood-vessels is more pronounced. Tea, however, has a unique capacity for causing wakefulness in a certain type of nervous individuals, the intermediate cause being generally flatulent dyspepsia. It may be remarked, by the way, that much of the sleeplessness attributed to the after-dinner coffee may legitimately be laid to the dinner which preceded the coffee.
Cases of insomnia that are caused by drug addiction, such as opium or cocaine, are particularly obstinate and require the most rigorous kind of treatment. They are as difficult to conquer as the insomnia presaging and accompanying mental diseases.
The occurrence of insomnia signifies that the mental, emotional or somatic machinery is out of order. Before it will run well again the cause of the disorder must be found and overcome.
Sleep is an endowment, like charm or a good disposition. It can be added to by cultivation and effort or it can be shattered. Originally it may have been meted out alike to the rich and the poor, but in the present stage of evolution there would seem to be much discrimination. It is a fact that insomnia is much rarer amongst the poor than amongst the wealthy and it is remarkable how seldom complaint of insomnia is heard from the lower class of hospital patients. The explanation possibly is that insomnia frequently flows out of overfeeding, idleness, self-absorption and ennui, and the labouring poor are not beset by any of these ills. It may be that they regard sleeplessness as a minor ailment and do not mention it, but it is more likely that they are less subject to many causes of sleeplessness than their envied brothers.