In all the forms of primary delusional insanity the whole history of the case is difficult to get at, and there may be, and usually is, so strong a tinge of possibility at least, if not of actual probability, in the delusions, in the early stage of the disease, that a correct diagnosis cannot be arrived at until the time and opportunity for a cure have passed.
DOUBTING INSANITY (Folie du doute, Maladie du doute, Grübelsucht) is classed by Régis22 as a form of melancholia (mélancolie délirante), on the ground that it has the three elements of melancholia—namely, fixed ideas (délire) of a sad nature, general mental depression, and tendency to suicide. The melancholia is secondary, however, rather than primary, and doubting insanity belongs more properly under the head of a psycho-convulsive mental disease closely allied to delusional insanity, like which it is more commonly a manifestation of psychoneurotic heredity, appearing for the most part among the cultivated classes. It consists in an uncontrollable doubt and indecision, unanswerable by any degree of rational explanation, regarding the occupations, duties, or events of the day, religion, a future life, the commonest acts, or the most abstruse problems of life. Doubting insanity essentially depends upon an anomalous action of the will, with imperative conceptions and impulses. It is classed by some writers as a monomania of the degenerative type. Schüle calls it Verrücktheit sensu strictiori, using the term Verrücktheit also for the three forms of primary delusional insanity just described.
22 Manuel pratique de Médecine mentale.
Délire du toucher, an insane dread of touching certain objects, and the morbid fear of defilement, called by Hammond mysophobia (similar names may be multiplied indefinitely), belong in the same category.
There are mild cases of all these forms of disease, which seem like simple weakness of character, others requiring for treatment the conveniences of the retreat for nervous and mental diseases, with a fair prospect of recovery, and still others tending to chronicity in which hallucinations, delusions, and dementia appear only as a further development into another form of insanity. They may, in mild degrees, be symptoms in the course of other mental diseases, especially melancholia, like many other manifestations of morbid mental energy, such as Doctor Johnson's inability to enter a room with his left foot first or to pass a lamp-post without striking it with his cane, etc.
PRIMARY MENTAL DETERIORATION or PRIMARY BRAIN ATROPHY is a term suggested for a curable impairment of the mind arising from brain-exhaustion in persons, usually men, between the ages of from fifty-five to sixty-five. I have found it in some cases associated with interstitial nephritis and with degenerative disease of the walls of the heart, and have suspected atheroma of the cerebral arteries or possibly endo-arteritis of specific or other origin. It occurs at a time when atrophy of the brain is naturally taking place. There are the usual indications of physical wear and such marked deterioration of the mental powers as to seriously interfere with the capacity to attend to customary business and every-day duties, and to closely simulate the early stage of paralytic dementia. There occur also, in a certain proportion of cases, epileptiform convulsions, slight attacks of dizziness, petit mal, and always disappearance of sexual power and desire. There may or may not be headache. The patient recognizes his condition, his mental depression does not far exceed the physiological limit, and there is no reasonable risk of suicide, except from reasons which would impel a sane man to it.
Under the influence of rest, if begun early, tonics, and a strict regard to the laws of health the symptoms commonly disappear if there is no organic disease. I have never seen the brain recover its tone to the extent of making it safe or even possible to resume the previous kind and amount of work. In a certain proportion of cases there is striking mental impairment, even dementia, and the primary atrophy of the brain sometimes makes rapid progress to unconsciousness and death.
It is not possible to say, by the degree of atrophy found post-mortem, whether there was or was not primary mental deterioration during life.
The TREATMENT consists in entire freedom from care, rest from work, travel, tonics, etc.
As mental disease is more than a brain disease, and is a disease of the intellect, each age from infancy up (and each individuality) impresses its peculiar mark upon it, and there are certain terms in common use to express insanity associated with certain physiological processes whose meaning should be explained.