Kraepelin has thrown light upon the true nature of these cases, which are more frequent than is generally supposed and in which the symptoms of excitement and of depression appear in the same patient at the same time.
In one group of cases the usual signs of depression are associated with extreme mobility of attention and veritable flight of ideas. The patients complain that the direction of their thoughts escapes them. "My head always wanders," said one such patient: "I cannot fix my attention upon anything." Occasionally there is melancholic logorrhoea. Many depressed patients show a surprising prolixity and harass those about them by unceasing incoherent lamentations about their unhappy lives.1
In a second group of cases the disease presents itself with the characteristics of manic stupor (Kraepelin). The psychic paralysis is associated with more or less pronounced excitement: the patient is constantly moving, disarranges his bed, tears his clothes, soils the walls of his room, and at the same time shows such dulling of the mind that even the simplest questions put to him remain unanswered.
1 Kraepelin. hoc cit., p. 545.
Finally, in a third group, inhibition is less pronounced, and the elated mood of mania is replaced by an uneasy, gloomy, irritable one, the basis of which is sadness, like in the depressed type.
The mixed type sometimes persists through the entire duration of the attack. More frequently it is met with in the transition periods of circular psychoses, where the patient wavers, so to speak, between excitement and depression.
Each attack here consists of two periods: a period of depression and one of excitement. It usually begins with the depression.
The transition from depression to excitement occurs either suddenly - a patient goes to bed a melancholiac and rises the next morning a maniac - or gradually, with an intervening period of a mixed condition, as mentioned above. The psychomotor inhibition gradually becomes less prominent and is replaced by excitement; flight of ideas and logorrhcea appear. Finally the sadness disappears and elation replaces it.
When a maniac falls into depression the same transition occurs inversely.
The treatment of each phase comprises the same indications as for attacks of simple depression and of mania respectively.