The onset of mental affections rarely occurs suddenly and without warning, as often depicted in novels and on the stage. As a rule they are preceded by a premonitory stage, and it is important to bear this in mind. The patient gradually becomes " different " from what he had been before Changes in demeanour, etc., may, of course, occur also in persons who are mentally sound, but in these cases the change is based upon extraneous, pleasant or unpleasant, events. In the insane individual, on the other hand, the change usually occurs without any such reasons. The individual gradually, at first imperceptibly, develops various peculiarities 'of character. He may become taciturn, reserved, brooding, and anxious ; he may develop a markedly cheerful disposition ; he may become fickle, restless, and quarrel some ; he may grow distrustful, irritable, and whimsical ; he may become tactless, careless, and indecent ; or he may grow indifferent, dull, and stupid.
In many cases the true cause of this change of character is not suspected during the first period ; not even in court, where these patients are often summoned, owing to their mental transformation, which is very liable to make them commit criminal acts. Numerous insane individuals reach the asylum every year by the roundabout road of the prison, although they were already mentally sick at the time sentence was pronounced. At that time, however, nobody thought of consulting an alienist. The patient talked quite rationally, and the natural inference of common-sense was that his mind was sound. In this manner sentence is often pronounced upon innocent persons. If, on the other hand, such a patient be spared by the penal code, it often happens that he ruins himself and his family by rash deeds, senseless extravagance, or inconceivable actions. At length his peculiarities become too conspicuous to be misjudged as to their nature ; or the scene is unexpectedly changed by acts of violence to others, or by suicide. Only then (too late, unfortunately) " common-sense " comprehends that the excesses of a mentally diseased person were at the bottom of the previous actions. Further developments usually go on in the insane asylum or sanatorium. While they are less apparent to the laity, the progress of these diseases is important.
Laymen usually distinguish between real mental diseases and psychical affections, taking the former to be those in which the " reason has suffered," which would not apply to the latter. Although the entire mind is affected in every mental disturbance, it is possible for practical reasons to separate two groups of insanity. The patient's mind may be morbidly depressed,
so that he becomes morose and anxious, often tormenting himself with his morbid apprehensions. This condition is known as melancholia. An opposite condition is characterised by exuberance of spirits, by restlessness and irritability, and sometimes by excitement bordering almost on frenzy. Both states sometimes alternate in periods lasting weeks or months (manic depressive insanity), the transition often occurring Nvith surprising suddenness. Slighter disturbances of this character are frequently misjudged by the public. A third form of emotional state is sometimes observed. It is characterised by dulness, indifference, and mental inertia ; and the patient becomes rapidly demented. Mental diseases are usually associated with various bodily disturbances, such as headache, sleeplessness, congestions, palpitation of the heart, oppressions, ctc.
False sense perceptions, or hallucinations, are frequent accompani ments of many diseases of the mind. The patient sees hideous forms or persons who are long since dead ; or he hears abusive language or threats, which in reality Nvere not uttered by anyone ; or he feels electric strokes, tastes poison in his food, or smells loathsome odours. These perceptions are by no means imaginary, inasmuch as the patient observes them as keenly and distinctly as normal individuals perceive their sense impressions. Therefore, he depends on them just as a healthy' person believes in what he hears, sees, or feels. Hallucinations of hearing are most frequent. If they recur persistently, they give rise to delusions. When he hears threat ening the patient imagines that he is persecuted, or feels himself subjected to bodily torture ; if the words heard are acclamatory, he imagines himself to be chosen for a high mission and to be especially favoured by Providence. According to the character and frequency of these hallucina tions, the patient gradually becomes helpless, timid, confused, or excited.
Hallucinations also occur in healthy individuals, especially in those who are subject to mental emotions. A frightened person, for instance, may imagine that he sees a ghost ; and a person \V110 is anxiously waiting for some one may have hallucinations of hearing voices. Religiously exalted persons sometimes have visions in which they see the gate of heaven open before them, and the Mother of God descending ; or they may hear the voice of the Saviour. Dreams are likewise accompanied by hallucinations.