In these cases occupation plays a great role.

The excitement and privations of war especially in the tropics and the ennui of camps leads to insanity in soldiers; occupations such as that of the baker in which there is loss of sleep and the mental strain of students can all act in the same way.

A woman who gives no sign of nervous defect may become insane under the strain of pregnancy.
Although insanity is determined by the social relations of man, that part of the social organization which is termed _Society_, and which has been developed by the idle as a diverting game, is a fertile source of nervous disease and even of insanity, affecting particularly females.

The strenuosity of the life, the nervous excitement alternating with ennui, the lack and improper times of sleep, the lack of rest and particularly of restful occupation, the not infrequent use of alcohol in injurious amounts, are all factors calculated to make a defect operative.

The so-called "coming out" of young girls is an important element in the game, and their headlong plunge into such a life at a period under any conditions full of danger to the nervous system is especially to be reprobated.