This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
The excitant emotions may often be usefully brought into play, in depressed or disordered states of the nervous functions. Hope, confidence, joy, love, ambition, and other analogous states of mind, exercise, within due bounds, a most happy influence, overflowing, as it were from their own special centres, over the whole cerebral and spinal regions, and throughout the sensitive system, diffusing a sort of physical exhilaration, which is admirably adapted to equalize excitement, and raise up the morbidly depressed nervous functions to their healthy level. Their effects are, indeed, closely analogous, in several respects, to that of the purer nervous stimulants. They not only excite the nervous centres, but, through them, increase the frequency of the pulse, diffuse a glow over the frame, and not unfrequently increase the various secretions, including even the menstrual. These are ordinary effects of the class of medicines we are now considering. Another coincidence is the wakefulness which they often occasion in a state of health, while they sometimes produce sleep by quieting the nervous disorder, which prevents it in disease. Like these medicines, also, in excess, they may give rise to vertigo, headache, mental confusion, tremors, etc.; but very seldom, like the narcotics, cause positive intoxication, delirium, or stupor, by their own immediate action.
The methods of bringing their influence to bear upon a patient in any particular case, and the precise circumstances under which they should be resorted to, must be left to the sagacity and judgment of the practitioner. But every one should bear in mind their great efficiency, and be prepared to avail himself of it when the occasion may offer. He should also bear in mind one important rule; to proportion, namely, the degree of the influence wanted to the requisitions of the case, and take care that injury is not done by excess. He must be as cautious not to overdose his patient, in the use of these remedial means, as in that of medicines. Hysteria, hypochondriasis, and insanity, are affections upon which the medicina mentis may often be brought usefully to bear. The influence of hope and confidence in favouring the action of other remedies is well known. How often do neuralgic pain and even spasm seem to yield to paeans wholly inert, as to the metallic tractors, or the globules of the homoeopathist, when the hopes of the patient are strongly excited, or his full confidence gained in the efficacy of the measures used! How often do we see epileptic convulsions postponed for months in pure functional cases, or perhaps set aside completely, under the use of remedies from which the patient confidently expected relief, though long experience may have satisfactorily proved their utter worthlessness! Intermittent fever, and other periodical diseases, are often interrupted by a conviction inspired into the patient, by whatever means, that he will miss the approaching, or any particular paroxysm. It is well known that successful love has often arrested approaching insanity, if it has not proved remedial even after the disease has been established. But it is unnecessary to multiply instances. I have no doubt that the various excitements of travel, its anticipations, novelties, surprises, diversified incidents, varieties of scene, and multiplied enjoyment of social pleasures and the beauties of nature and art, contribute, in many cases of nervous disorder, more powerfully to the cure, than any medicine or combination of medicines which could be applied.
Under the same head may also be placed the effects of surprise, or other startling impression upon the mind, in overcoming neuralgic pains, and morbid mental or physico-nervous associations. One of the most efficient methods of checking mild singultus is to startle the patient by a sudden exclamation, or by a declaration calculated to produce quick and strong emotion. The hysterical female, or hypochondriac male, will be roused out of apparent stupor in the case of the former, or some morbid conceit in that of the latter, by skilfully contrived plans of powerfully impressing their feelings or imagination. Nervous headache is often relieved by a sudden and strong diversion of the attention, however effected.