This group comprises the essentially benign affective psychoses: mental disorders which fundamentally are marked by emotional oscillations and a tendency to recurrence. Various psychotic trends, delusions, illusions and hallucinations, clouded states, stupor, etc., may be added. To be distinguished are:

The manic reaction with its feeling of well-being (or irascibility), flight of ideas and over-activity.

The depressive reaction with its feeling of mental and physical insufficiency, a despondent, sad or hopeless mood and in severe depressions, retardation and inhibition; in some cases the mood is one of uneasiness and anxiety, accompanied by restlessness.

The mixed reaction, a combination of manic and depressive symptoms.

The stupor reaction with its marked reduction in activity, depression, ideas of death, and often dream-like hallucinations; sometimes mutism, drooling and muscular symptoms suggestive of the catatonic manifestations of dementia praecox, from which, however, these manic-depressive stupors are to be differentiated.

An attack is called circular when, as is often the case, one phase is followed immediately by another phase, e.g., a manic reaction passes over into a depressive reaction or vice versa.

Cases formerly classed as "Allied to Manic-depressive" should be placed here rather than in the "Undiagnosed" group.

In the statistical reports the following should be specified:

(a) Manic attack.

(6) Depressive attack.

(c) Stuporous attack.

(d) Mixed attack.

(e) Circular attack.