The conception of manic-depressive psychoses is due to Kraepelin and constitutes one of the most important advances in psychiatry. Although the grouping of such apparently different and even opposite pathological states as depression and mania may appear unreasonable on superficial consideration, its legitimacy is nevertheless incontestable and is based on two principal considerations:

(1) The existence of certain fundamental symptoms common to all forms, manic, depressed, and mixed.

(2) The alternation, regular or not, as the case might be, of the phenomena of excitement and depression in the same subject.

(1) Fundamental Symptoms

The symptoms of manic-depressive psychoses can be readily divided into two groups.

The first group comprises all the morbid phenomena dependent on psychic paralysis, namely: (a) weakening of attention; (6) sluggish formation of associations of ideas; (c) insufficiency of perception; (d) pathological indifference.

These symptoms of psychic paralysis are especially prominent in the depressed type. But in mania, though usually masked by phenomena of exaggeration of mental automatism (flight of ideas, motor excitement), they are, nevertheless, also present, as can be readily shown by a careful examination.

Let us consider these symptoms individually.

(A) Weakening Of Attention

Abnormal mobility of attention is one of the fundamental symptoms of mania. Yet, as shown in the first part of the book, this is but a manifestation of weakening of attention.

(B) Sluggish Formation Of Associations Of Ideas

Kraepelin 1 and his pupils have shown by means of psy-chometry that the acceleration of mental processes in mania affects only automatic processes, voluntary associations of ideas being actually retarded, just as they are in the depressed states.

(C) Insufficiency Of Perception

Perception of the external world is inaccurate in depression as well as in mania; but while in the former case the perceptions are often incomplete and are manifested clinically by uncertainty, in the latter case automatic associations occur in the place of missing normal ones and give rise to false perceptions or illusions. Neither the melancholiac nor the maniac perceives the phenomena of the external world in their true aspect, but the one remains in doubt while the other affirms errors.

(d) Pathological indifference also clearly exists in mania as well as in depression. To be convinced of this, it suffices but to recall the perfect serenity with which the maniac receives news of a misfortune in his family which, in the normal state, would profoundly distress him.

Psychic inhibition expressed by the above four symptoms is, therefore, the fundamental and constant disorder constituting the common basis of the diverse clinical types of attacks of manic-depressive psychoses.

1 Psychiatrie, 7th edition, Vol II. p. 504. On the subject of measurement of the rapidity of the associations in the insane, particularly in circular insanity, see also Ziehen's contribution in Neurol. Centralbl., 1896.

The symptoms of the second group are dependent, not upon psychic inhibition, but upon exaggerated mental automatism, which so often accompanies it. The principal symptoms of this group are: (a) Flight of ideas; (6) irritability; (c) impulsive reactions; (d) delusions and psychosensory disorders; (e) fixed ideas and, occasionally, imperative ideas.

All these morbid phenomena are incidental. Their presence or absence modifies the aspect but not the nature of the attack. Some appear with equal frequency in mania and in depression, namely, delusions and hallucinations. Others are, on the contrary, peculiar either to the one or to the other of these states: flight of ideas, irritability, impulsiveness to mania, fixed ideas to depression. But there is no absolute rule in this respect; we meet with depressed cases with flight of ideas, and with cases of mania in which the delusions are more or less fixed.

(2) Alternation Of Excitement And Depression In The Same Patient

The close relationship existing between states of depression and manic states becomes still more evident when, instead of considering a single attack, we make a study of all the attacks of one patient. First of all, it is extremely rare for a patient to have only one attack of mania or of depression in his life. Thus isolated and nonrecurring mania or depression is almost eliminated. In some cases, it is true, the attacks are always manic, while in some others they are always depressed. These two groups apparently separated by an unfathomable abyss, are in reality connected by a much larger group of double, alternating, circular, and irregular forms, which establish an insensible transition from the one to the other. Moreover, a close study of cases shows that the majority of attacks presenting the manic type or the depressed type are in reality attacks of double form. In fact, on careful inquiry we find that almost constantly manic symptoms are preceded by a prodromal period characterized by more or less marked depression; again, we often find an attack of depression to be followed by a state of excitement which cannot be attributed to any known cause, not even to the patient's prospect of returning to his usual mode of life in the near future.

Thus all attacks of mania and of depression contain in a rudimentary form the elements of excitement and of depression. Circular psychoses thus become the prototype from which the other types are derived.

The above considerations show us that, in spite of the apparent diversity of the symptoms, mania, depression, and their various combinations are not to be considered, as heretofore, as different morbid entities, and that the following conclusion arrived at by Kraepelin is perfectly justifiable:

"The diverse forms which have been described are but different manifestations of one and the same fundamental pathological process, equivalents, like the many forms assumed by epileptic paroxysms." 1

Treatment

For the treatment of the symptoms which may arise in the different phases of manic-depressive psychoses the reader is referred to Chapter VIII (The Practice Of Psychiatry. General Therapeutic Indications), Part I, of this Manual.

As to the problem of prevention of recurrency it is important to insist on abstinence from all alcoholic beverages. A single drink of whiskey has been known to act as the undoubted cause of an attack in a manic-depressive individual, and there are some cases in which most of the attacks are attributable to over-indulgence in alcohol.

An attempt has been made by Kohn to prevent the recurrency of attacks in cases in which the outbreaks are brief and frequent and occur with such regularity that the date of their onset can be predicted with more or less accuracy. In such cases, beginning several days before the expected attack, the patient is given from 12 to 15 grams of sodium bromide daily until the "danger period" is over, when the dose is gradually diminished and the drug finally discontinued. It seems in some cases possible to prevent the outbreaks of excitement by this method of treatment.

1 Kraepelin. Psychiatrie, 7th edition, Vol. II, p. 558.