Manic-depressive attacks present a very marked tendency to recur. According to the particular forms assumed by the successive attacks, several types of manic-depressive psychoses are distinguished.

(A) Periodic psychoses: (a) Recurrent mania;

(6) Recurrent depression.

(B) Alternating psychoses.

(C) Psychoses of double form.

(D) Circular psychoses.

(E) Irregular forms. .

(A) Periodic Psychoses. (A) Recurrent Mania

The attacks are always of the manic type and are separated from each other by normal periods. The number of attacks and the duration of the normal periods vary greatly. Some patients have but two or three attacks during their lifetime; it is altogether exceptional for an individual to have but one attack, at least if his life is a long one. In all likelihood nonrecurring mania does not exist.

In other cases the attacks follow each other at brief intervals and with a certain regularity.

Recurrent Mania

Scheme 1. - Recurrent Mania.

(B) Recurrent Depression

Less frequent than the preceding, this form is, so to speak, its counterpart. What has been said about recurrent mania is applicable to recurrent depression.

Recurrent Depression

Scheme 2. - Recurrent Depression.

(B) Alternating Psychoses

Attacks of mania and those of depression alternate and are separated from each other by normal intervals.

Alternating Psychosis

Scheme 3. - Alternating Psychosis.

(C) Psychoses Of Double Form

Each attack consists of a period of depression and one of excitement; the attacks are separated from each other by normal intervals.

Psychosis of Double Form.

Scheme 4. - Psychosis of Double Form.

(D) Circular Psychoses

Attacks of double form follow each other without interruption.

Circular Psychosis

Scheme 5. - Circular Psychosis.

(E) Irregular Forms

These are most frequent. The attacks follow each other without order or regularity, assuming at random the depressed, manic, or mixed form.

Finally, one may observe the periodic, circular, and irregular forms combine in a complex manner, so that, for instance, a patient with a circular psychosis becomes a periodic maniac for a time, or a patient whose previous attacks have all been of the manic type presents an attack of depression.

It is quite frequent, though not constant, to see attacks of the same type present each time the same aspect: a manic attack resembles previous ones in the same patient, and it is very probable that the future manic attacks will present the same features.

The general prognosis of the disease is not favorable. The attacks have in some cases a tendency to come closer together, so that the normal intervals became gradually shorter and shorter until they are either totally wanting or almost so.

Etiology

Manic-depressive psychoses are common.

According to Kraepelin they represent about 15% of all admissions to psychopathic hospitals.

The causes are not fully known; the essential feature in the etiology seems to be a constitutional predisposition which is believed to be inherited. The heredity is often similar.1

The predisposition to have manic-depressive attacks seems to be observed with particular frequency in persons of certain fairly well defined mental make-up; such make-up is characterized either by a constitutional pessimism, gloomy or worrisome disposition, or, on the contrary, by a happy, exuberant, demonstrative temperament, or, finally, by emotional instability consisting of exaggerated reactions to situations by despair, discouragement, or by premature and unwarranted display of triumph and hopefulness, as the case may be. This was pointed out by Hoch,2 who has emphasized particularly the contrast which such personalities present to that type of personality - the "shut-in personality" - which he has defined as being particularly prone to develop dementia praecox.3 In a more recent study Reiss has arrived at similar conclusions:4 "Upon a survey of the whole material which has been at my disposal, I find as a general fact that in cases of happy disposition manic states, while in those of pronounced depressive disposition the sad melancholy states predominate."

The age at which the first attack occurs is not constant. In most cases it is before the twenty-fifth year, in some before the tenth, and in others after the fiftieth. Quite frequently in women the disease appears with the onset of menstruation or with the first pregnancy.

Diagnosis

The principal elements of diagnosis are:

1C. B. Davenport. Inheritance of Temperament. Washington, 1915.

2 Journ. of Nerv. and Ment. Dis., Apr., 1909.

3 See p. 259.

4 Eduard Reiss. Konstitutionelle Verstimmung und manisch-depres-sives Irresein. Zeitschr. f. die gesamte Neurol, u. Psychiatrie, Vol. II, p. 600, 1910.

psychic paralysis associated with the special symptoms of exaggerated mental automatism, which have already been described; absence of mental deterioration; recurrency of the attacks with restitutio ad integrum after each.

We differentiate:

General paralysis by the mental deterioration, a certain degree of which persists even during the remissions; the physical signs; and lumbar puncture findings;

Involutional melancholia by the intense and persistent psychic pain, which is much more marked than in the depressed form of manic-depressive psychoses;

Acute confusion by its special etiology, and by the much more marked disorientation;

Delirium tremens by its specific hallucinations;

Dementia pr&cox by the rapid and pronounced diminution of affectivity, by catatonic phenomena, and by the absence of flight of ideas even in those cases which closely resemble mania.