# The Increase of Insanity, 1907/Lecture 2

LECTURE II
This lecture will be devoted to the causes of insanity. I shall only take a few of these, such as will indicate sufficiently my views as to the probable increase among the insane. The three principal causes to which I shall refer are hereditary predisposition, alcoholic excess, and the influenzal poisoning.
The whole question of heredity is being studied with so much care that enormous numbers of facts have been added to our knowledge, but as yet no great and directing guide has been discovered, for though one has to accept it as established that no mutilation or established acquisition is transmitted to the offspring, yet I have to maintain that many nervous peculiarities are passed on more or less modified from one generation to another. A considerable part of my lecture will be devoted to my views founded on my experience as to the amount and forms of neurosis which may be transmitted, and probably this is one of the most important questions that I have to consider. It is a very widely spread belief that every case of insanity depends in some way upon nervous inheritance, and that all forms of insanity are equally dangerous, as far as their ​Page:The increase of insanity.djvu/32 ​Page:The increase of insanity.djvu/33 ​Page:The increase of insanity.djvu/34 ​Page:The increase of insanity.djvu/35 ​Page:The increase of insanity.djvu/36 ​Page:The increase of insanity.djvu/37 ​Page:The increase of insanity.djvu/38 ​children and a very small amount of money to live upon. She has to change her residence and lives in a poor and meagre way. Avoiding the expense of entertaining friends she and her children live absolutely alone. She gets morbidly suspicious about them and about everybody in the neighbourhood, begins to suspect people of talking about her, of interfering with her, and, perhaps, tampering with her food. This is slowly borne in upon the young children, who in due course develop similar delusions. That, of course, is an extreme case, but it bears out what one wishes to impress upon you, that the association of the insane parent with the child may have a dangerous effect upon the mental stability of the child.
Again, it is not an uncommon experience for me to be consulted about the daughter of some elderly widow who has died after a prolonged mental illness. The daughter has devoted herself body and soul to this mother who has been a chronic or paralytic dement. In due course, after the death of the mother, the daughter begins to wonder whether her mother’s symptoms are not reappearing in herself, and it has been not an uncommon experience for me to see such a daughter mimicking to a great extent the symptoms of her mother. Expectancy and association have a great deal to do with heredity.
It has been thought that there is a great danger of transmission of the suicidal tendency, and I would put it in this way : that I have histories of families many members ​of which have committed suicide, and in many cases the suicides have occurred in different parts of the world and under different conditions, and apparently without any knowledge of the occurrence of suicide in any other mem- bers of the family. This, of course, may or may not be quite accurate. At all events, I have known families in which suicides have been common. Such families undoubtedly belong to the unstable, to the neurotic — that is, to those who are unduly sensitive and unduly emotional. I say that probably there is a tendency to transmit not necessarily melancholia, but emotional states which readily lead to melancholia ; and so people who are unusually sensitive and unusually emotional react too readily to painful surroundings and the tendency is to suicide. That definite concrete ideas or delusions should reappear apart from collusion seems to me at least improbable, yet I have had several instances like the following. I was consulted about a girl, aged 20 years, who, being sleepless and depressed, accused herself of the unpardonable sin. After some weeks she improved and finally recovered. Then her father, a bright and prominent business man, called on me and said that for years he had been convinced that he was “the man of sin,” that he had committed “the unpardonable sin,” and there was no hope for him. He, being convinced of his doom, had borne it without a word to his family and he was horrified to find its reappearance in his daughter. It is difficult to explain this case, though I ​Page:The increase of insanity.djvu/41 ​Page:The increase of insanity.djvu/42 ​Page:The increase of insanity.djvu/43 ​Page:The increase of insanity.djvu/44 ​Page:The increase of insanity.djvu/45 ​Page:The increase of insanity.djvu/46 ​Page:The increase of insanity.djvu/47 ​to moral defect as well as to imbecility and idocy; that consanguinity alone is not to be looked upon as very dangerous. I take it for granted that there is no such thing as inheritance of any function as such, but only the transmission of the physical capacity or predisposition to react in certain definite ways under certain definite stimulation. Thus, the power to learn to speak exists, but not the special tendency to speak in one language. Again, manual aptitudes may be transmitted, but there is no special transmission of power to perform definite acts in definite ways. The power of rapidly varying in relationship to a rapidly changing surrounding is represented by still more and more mobile organic compounds. The possession of such mobile combinations tends to instability; and, after all, we have to consider neurosis as nothing but a special form of instability. Such instability may be represented by brilliant genius or feeble inconsequence. As already pointed out, various neuroses are allied and may in some cases be interchangeable. Neurotic instability and tendency to insanity may depend on causes of physical weakness in a parent, yet unstable parents may have normal children. Atavism is not so marked in insanity as in some forms of physical peculiarity. It is not true that all forms of insanity are easily transmitted to the offspring. Healthy mating, too, may get rid of the tendency, or may reduce it to a slight tendency to tricks, habits, or manners as representing the neurosis in the parent. Strong neurotic inheritance will ​often show itself in special forms of nervous disorder in childhood and adolescence, and, again, in anti-social or criminal tendencies.
TABLE XII. (Irish Commissioners’ Report) Causation
NUMBER OF CASES.
Heredity.
Drink.
M.
F.
T.
M.
F.
T.
1884—1893
148
137
285
104
17
121
1894—1903
235
200
435
183
30
213
Increase
87
63
150
79
13
92
Increase per cent.
58-7
46-0
52-6
76-0
76-4
76-0
Senility.
Anxiety, Worry, &c.
1884—1893
8
14
22
52
68
120
1894—1903
18
28
46
30
62
92
Increase
10
14
24
22*
6*
28*
Increase per cent.
1250
100-0
109-0
42-3*
9-6*
31-0*
D