PREDISPOSING CAUSES OF INSANITY.
effects on disease in general of the influence of parents have been already discussed at some length at page 30 and the two following pages. Much of what is written there is directly applicable to the special dis ease now being discussed, and reference should be made to these pages. Insanity in the parents is one of the most frequent causes of insanity in the offspring. Dr. Maudsley says that at least one-fourth of all the people who so suffer have inherited the disease ; and it is said to be more frequently inherited from the mother than from the father, and by the daughters than by the sons. Further, it is not uncommon for insanity in the children to bo due to other ner vous diseases in the parents. Epilepsy, for instance, in the father may produce insanity in the child. As already observed (p. 31), drunkenness in the parents may be a predis.
posing cause of madness in the children, pro bably because constant alcoholic excess seriously deteriorates the brain tissue generally. Frequent intermarriage of close relations, it is well known, has a bad effect upon the offspring. Breeders of animals know full well that they must intro duce fresh blood every now and again to main thin the quality of their stock. The same is equally true of the human species. The brain shares in the general bad influence of frequent intermarriage, which thus tends to produce a liability to insanity. The popular prejudice against marriage between full cousins is not without ground.
Education is second in importance only to heredity, if indeed second to it, in the consider ation of mental disease.
First of all, a mind that is not naturally strong may be marvellously improved by ju dicious training. It is a physiological rule applicable to the whole body that regular exer cise, followed by equally and regular stated periods of repose, promotes the activity and health of the tissues, and, if regular and not excessive,increases their strength and efficiency. It is the regular and yet not excessive exercise that the blacksmith's arm receives that pro duces such brawny well-developed muscles. It
is a second rule, equally applicable to all the tissues, that want of use is shortly accompanied by degeneration, and perhaps finally complete decay. The arm that is kept tied up for weeks without exercise because of fracture, when taken down has lost much flesh, is thin, and weak. Finally, youth is the time when such regular exercise is capable of stimulating to greatest strength and development. Now all these rules applied to brain mean that a faculty, whether it be of observation or of memory, of self-re straint or of will, of imagination or of reason, which receives this early, regular, and careful exercise, is stimulated to growth, and increased in strength. Hence, careful training may do much to ward off degeneration from a naturally weak nervous organization. The reverse is equally true, that want of training may not only leave the weak brain an easy prey to dis ease, but may actually cause it to grow weaker, and so become a more easy victim.
Secondly, the kind of training may directly excite the disease to the attack. Repression, harshness, and cruelty, excessive mental exer cise, compelling children to cram too many lessons, or, on the other hand, want of control over children, yielding to their every desire, and letting them yield to their angry fits or tempers, all these are injurious. Deep impres sions made on children's minds, by terrifying stories or sudden frights, will have similar bad effects.
Sex does not seem to have any important influence on the disease.
regard to this it is only necessary to remark that, while no age is exempt, in sanity is commonest between the ages of twenty five and fifty, probably because it is between these years that labours, worries, and anxieties are greatest in number and intensity.
Social seems that the married relationship tends to preserve health and sanity. Among the insane there are more single than married people.