Abstract
The study is based upon 103 cases, which have been observed at either the Phipps Psychiatric Clinic or the Maudsley Hospital; twenty-seven different ætiological agents are represented. The following questions are raised:—
(1) Whether there is evidence that different ætiological agents produce specific or even characteristic delirious states. (2) In what ways are the ætiological agents directly related to the states they produce. (3) What other factors help to determine the clinical picture. (4) What are the characteristics which these states appear to possess in common. (5) What light may this shed upon the rôles of exogenous as opposed to endogenous factors in the production of mental disease.
The symptomatology, as recorded, is briefly sketched and some cases to illustrate particular points are given.
It is advanced, on the observations made—with a clear realization that different and more detailed study might come to quite other conclusions—that:—
(1) Nothing was found to suggest that any ætiological agent bore a truly specific relationship to the delirious state it produced.
(2) The delirious states produced appeared to be directly related to the ætiological agent, and could be considered characteristic of them, in so far as the ætiological agent tended to affect the intensity and duration and “stability” of the functional disturbance in a fairly uniform manner.
(3) The final clinical picture was also strikingly dependent upon the previous personality of the subject, and upon environmental stimuli sustained during the period of illness.
(4) The nature of the functional disturbance which all these cases had in common had two aspects: (a) a decrease in the ability to discriminate and differentiate, “confusion,” a deficiency in just those qualities for whose proper exhibition the integrity of the cerebral cortex is generally considered to be necessary, and (b) an increased activity of a type bearing close resemblance to the dreaming state.
(5) Finally, it is argued that it is highly improbable that in psychoses which do not show “confusion,” exogenous factors are likely to play more than a subsidiary, though in certain instances none the less an exceedingly important, rôle. Thus a study of exogenous reaction types might help to a better perspective in such debated issues as the importance of “focal sepsis” and the speculative toxæmias in the production of mental disease.