INSANITY.
Definition.—Insanity means disordered mental function.
All disordered mental function is, however, not insanity; for example, the delirium of fever, of alcoholic or drug intoxication, although disordered mental function, is not, strictly speaking, in sanity; still, the physical disorder upon which the febrile or toxic delirium de pends does not differ so much from the underlying physical condition of insanity as may at first thought appear. The dis order of function in all cases is primarily due to a derangement of nutrition in the brain. This brings us to the funda mental fact that in order to have dis ordered function of the brain we must have either disordered nutrition or structural alteration of this organ.
At the present day this apparently ma terialistic conception must be accepted. As no mental or psychical manifestations can occur except through the medium of the brain, we may say outright that the brain is the organ of the mind, and any alteration in the structure or nutrition of the brain will affect favorably or un favorably the functions of that organ. Upon this basis we may assume that without brain there can be no thought; and without healthy brain there can be no healthy thought.
The morbid physical basis of insanity is disordered nutrition of the brain in differing stages. It may he: 1. Anminia.
2. Hyperemia.
3. Inflammation of the brain or me ninges.
4. Toxic substances circulating in the blood (drug or bacterial poisons).
5. Gross lesions of brain-structure, such as tumors, apoplexies, abscesses, embolism with consecutive softening. These may be results of nutritive dis turbances.
6. Interstitial hyperplasia of connect ive tissue, which is probably primarily in flammatory.
7. Primary structural alteration, he reditary or acquired.
Insanity must be conceived as a phys ical disease,—a disease of the brain. While it is customary to speak of mental disease, or of a psychosis, it is well under stood that a disorder of the mind—or psyche—having no relation to a physical substratum, the brain, is impossible.
Classification. — Basing mental dis ease upon these physical substrata, the usual symptomatic classification of in sanity into mania, melancholia, and de mentia appears about as rational as a division of kidney diseases into polyuria, anuria, and incontinence.
The first requisite for a logical study of insanity is, therefore, a rational classi fication,—one based upon the known pathology or pathogeny of the disease. The time for a perfect classification of this sort has not yet arrived; our knowl edge is still too vague or incomplete; but in the following an attempt has been made which may have some merits as a working scheme.
In this classification there are seven classes or groups of mental disturbance, most of them clearly differentiated clin ically, but all based upon pathology or pathogeny.
The groups are as follow:— I. Psychoses due to imperfect develop ment of the brain, which may be heredi tary, congenital, or acquired. To this group belong idiocy and imbecility.
II. Psychoses due to vicious or abnor mal brain-organization. These are al ways hereditary. To this group belong paranoia, circular and recurrent insanity.
Some cases of hysteria and epilepsy may also be included.
Causes of insanity investigated in the last 1014 patients admitted to the Bris tol Lunatic Asylum, 507 being males and a like number females.
From the statistics obtained it would appear that all forms of insanity are strongly hereditary, the percentage being for all cases with a definite history of hereditary predisposition 28,7 per cent., and with a strongly neurotic history 4.1 per cent.: total, 32.8 per cent.
That of all forms the congenital hold the first place with 44.4 per cent. Puerperal insanity seems to be the next most hereditary form, with 33.3 per cent. hereditary predisposition, and 7 per cent. with neurotic history, these percentages having regard to female cases only. Then follow the ordinary eases, with 29.7 hereditarily predisposed and 4.9 with a history of neurosis; 23 per cent. in general paralysis, 21.5 per cent, in epilepsy. J. R. Blachford (Jour. of Men tal Science, July, '98).