The “Dictionary of Psychological Medicine” (1892), giving the terms used in medical psychology with the symptoms, treatment, and pathology of insanity. Two vols. Edited by D. Hack Tuke, M.D., LL.D., Examiner in Mental Psychology in the University of London; lecturer on Psychological Medicine, etc., says:

Loss of Sleep as a Cause and Consequence of Insanity: Insomnia is the indication of a morbid condition. It is also, when prolonged, something more. Loss of sleep may frequently be a cause, or one of several causes, of mental disorder. To remove it is therefore of the greatest consequence in the early treatment of the insane. In a large number of instances it is doubtless the consequence and not the cause of mental trouble. The agony of mind associated with melancholia, or the rapid flow of ideas in acute mania, may render sleep an almost unattainable boon, and in these cases it requires great discrimination to decide when, if at all, to administer hypnotics. (P. 1173.)

Remedies Known as Somnifacients, Soporifics, Hypnotics, and Narcotics: At the outset we must put the question, Is there a distinction between hypnotics and narcotics? Dujardin-Beaumetz answers in the affirmative. He holds that for the drug to be hypnotic it must imitate the natural condition of sleep by effecting a lowered intra-cranial pressure, and that drugs which, though bringing about unconsciousness, do not lower cerebral pressure, or which increase it, cannot claim to be hypnotics. On this line he separates chloral as a hypnotic from opium as a narcotic ... in the different forms of artificial or drugged sleep it is probable that these two factors—quantity of blood, including blood pressure, and quality of blood, do each play a part. (P. 1129.)

Medical science has been able so far to do little for sleeplessness, except to call it “Insomnia.” Insomnia: Loss of sleep has been classified under various heads by writers on wakefulness. Thus German-SÉe has made no less than nine divisions:

a—dolorous insomnia.

b—digestive.

c—cardiac and dyspnoeal insomnia.

d—cerebros-spinal, neurotic insomnia comprising lesions of encephalon, general paralysis, acute and chronic mania, hysteria, hypochondriasis.

e—psychic insomnia (emotional and sensational).

f—insomnia of cerebral and physical fatigue.

g—genito-urinary insomnia.

h—febrile, infectious, autotoxic insomnia.

i—toxic insomnia (coffee, tea, alcohol).[10]

Among the causes of insomnia those of a predisposing character are the female sex, old age, nervous temperament, intellectual pursuits.

Of exciting causes may be enumerated organic or functional diseases of the brain, worry, anxiety, grief, and bodily pain; noise, if not monotonous, fever, coffee, tea, etc.

Among the insane, insomnia is one of the most frequent symptoms, except in chronic dementia. In melancholia it is the most distressing accompaniment of the disorder, and is especially marked in the early morning.

A careful analysis of the conditions or causes of insomnia has been made by Dr. Folsom (U. S.). The principal ones may be briefly enumerated as follows: Habit, reflex causes, as indigestion, genito-urinary disorders; autotoxic causes, as gout, lithÆmia, syphilis, habitual constipation; anÆmia, vaso-motor changes, neurasthenia, hallucinations of sight or hearing, astigmatism—the strain of the eye which in health may be unnoticed, producing “in states of debility, headache, dizziness, spasmodic muscular action or wakefulness” and the neurotic temperament.[11]