The special feature of active depression is psychic pain, which is distinct and sufficiently intense to render the subject subjectively conscious of it. The appearance of this new phenomenon modifies to a certain extent the fundamental symptoms which have been described in connection with passive depression.
Like physical pain, psychic pain tends to limit the field of consciousness, to exclude other mental manifestations, and to become what Schule has designated by the term pain-idea. In certain cases the disturbance of consciousness which it causes results in marked disorientation and confusion. These phenomena, caused by the pain, become less marked as the pain becomes abated in intensity and disappear as the paroxysm passes off.
When psychic pain attains a certain intensity it results in anxiety. This phenomenon consists chiefly in a feeling of oppression or constriction, most frequently localized in the precordial region, occasionally in the epigastrium or in the throat, and more rarely in the head. This peculiar feeling is always accompanied by certain somatic phenomena, the most important of which are pallor of the skin, sometimes cyanosis, panting respiration, general tremor, irregular and accelerated pulse, and dilatation of the pupils.
Anxiety is frequently seen in the melancholias. It also occurs in cases of obsession. It may appear without cause in constitutional psychopaths (the paroxysmal anxiety of Brissaud).
From the standpoint of the reactions, psychic pain, like physical pain, may manifest itself either by a sort of psychomotor paralysis - so that the patient remains immovable, with a haggard expression, silenced, so to speak, by the anxiety - or by various phenomena of agitation.
In the latter case, the more frequent, the pain, an active phenomenon, brings about a reaction which to a certain extent overcomes the fundamental psychic inhibition and manifests itself by two symptoms which are. frequently seen together, motor agitation and delusions.
Acting as a stimulus, psychic pain overcomes the motor inertia of melancholia and gives rise to melancholy agitation, which is characterized by movements that are, in the normal state, the expression of violent despair. The patient wrings his hands, strikes his head against the wall, etc. The agitation of anxiety is essentially an expression of opposition, of resistance. The reactions are either automatic or governed by delusions: movements of flight, refusal of food, attempts of suicide, etc.
Suicide is one of the most formidable consequences of psychic pain. Though most melancholiacs have a desire to die, the aboulia which characterizes the state of depression very seldom permits them to carry out their desire. On recovering part of their energy they are apt to make suicidal attempts.
Delusions are a frequent but not constant manifestation of psychic pain. They are absent in certain cases of melancholia in spite of the existence of even very painful depression.
What is the mechanism of the production of delusions in melancholia? The most widely accepted opinion is that of Griesinger:1 "The patient feels that he is a prey to sadness; but he is usually not sad except under the influence of depressing causes: moreover, according to the general law of cause and effect, this sadness must have a ground, a cause - and before he asks himself this question, he already has an answer: all kinds of mournful thoughts occur to him as explanations; dark presentiments, apprehensions, over which he broods and ponders until some of these ideas become so dominating and so persistent as to fix themselves in his mind, at least for some time. For this reason these delusions have the character of attempts on the part of the patient to explain to himself his own state."
1 Griesinger. Pathologie und Therapie der psychischen Krankheiten.
Though of great interest, this ingenious theory is perhaps somewhat too exclusive. Kraepelin has noted, in fact, that the delusions occurring in states of depression do not always present the character of explanations sought by the patient. Many melancholiacs instead of accepting the delusions, on the contrary reject them, at least in the beginning. Again, the appearance of a delusion does not bring with it the relative calm which would be expected if it really constituted the explanations sought by the patient. It seems, then, that this interpretation, ingenious though it is, is rather superficial. The view of Dumas appears to be nearer the truth. Psychic pain provokes delusions because it acts as a stimulus, struggling against the lassitude, and finally conquering it. Thus there is no logical relationship between psychic pain and delusions, but rather a dynamic one.