72 THE PEEBI^Y INHIBITED. 



which helps to maintain, if it does not cause, the mental state." And 

 the blood-pressure, we know, is in turn influenced by fluctuations in the 

 amount of certain internal secretions in the body, especially "suprare- 

 nin" or "adrenin" from the suprarenal glands.^ 



Rosenfeld (1913), who has gone rather thoroughly into the matter 

 of the relation of somatic disturbances to manic depressive insanity, 

 finds disturbances of emotions "due to arteriosclerosis, Buedon's dis- 

 ease, vaso-motor neuroses, blood-gland disease, disturbances due to 

 vagotonia, heart trouble, and the circulation psychoses." Evidently 

 the normal mood must be conditioned within very narrow limits, so 

 that the remarkable thing is that so many have the normal mood, not 

 that so few have. However, the important point is that all of these 

 conditions — small thalamus, reduced blood-pressure, and the rest — 

 acting in an hereditarily predisposed organism, produce, as a more or less 

 periodic end result, an absence of the normal inhibitions ; so that the 

 individual reacts with unwonted or extraordinary violence to a given 

 stimulus. 



Such a hyperkinetic tendency is frequently associated in the same 

 individual with depression; and hence arises the so-called manic- 

 depressive psychosis, of which more anon; but the important point 

 for us now is that this association is by no means universal or even 

 the usual thing. Repeatedly, do we find in ordinary life persons who 

 show constant elated traits; they are very busy, restless, ambitious, 

 scheming, original, sociable, talkative, "always jolly," enthusiastic. 

 In more extreme cases they are erratic, "changeable." For example, 

 the father in No. 2 "never stuck to an)rthing very long and was con- 

 stantly sinking money in one line of business or another, never making 

 anything of it." They are often braggarts, conceited, profane, hyper- 

 erotic, brutal, and have fits of violent temper. In a word, they show in 

 some degree the characteristics of the feebly inhibited. 



Such persons are not always in the elated state ; they may for longer 

 or shorter periods be quite average in their reactions, at times they 

 may even show a depression ; but the prevailing mood is a hyperkinetic 

 one and their ordinary depressed state is typically that of calm, quiet, 

 and tractableness which is usually regarded as more desirable from a 

 social standpoint. 



'Upon the subject of adrenin and blood-pressure Cannon and his pupils have recently made a 

 series of most important studies, admirably summarized by Cannon, 1915. It is shown that 

 under emotional stress impulses are discharged along sympathetic pathways, of which the effect 

 must be to stimulate the heart to more rapid action; and the discharge of adrenin tends to heighten 

 these effects. Every physician is aware of the danger of excitement to persons with degenerated 

 and weakened arteries, doubtless due to their walls giving way under increased pressure. There 

 seems, at first, to be a conflict between the suggestion of Dawson that low arterial tension may 

 cause mania and the findings that high arterial tension follows excitement. It is to be kept in 

 mind, however, that the excitement of mania seems to be mainly of endogenous origin as con- 

 trasted with induced excitement in ' ' normal ' ' persons. It is conceivable that low arterial pressure 

 is the endogenous cause of a state (excitement) which has this end result that it tends to restore 

 the normal blood-pressure, though it actually often causes an excessive pressure. The subject 

 of blood-pressures before, during, and after maniacal attacks seems to require further study. 



