It is perhaps, however, more especially on the medical side that the question of the utilisation of psychological knowledge for practical purposes has been brought into prominence by the war. The very large number of soldiers and civilians suffering from war-shock in its various forms has emphasised the need for psychological treatment of the functional nervous disorders; and has drawn further attention to the various methods of treatment by suggestion, re-education, psycho-analysis and other psycho-therapeutic measures, which even before the war were beginning to attract widespread interest. The work that had been done by these methods before the war had indicated that there existed a very considerable prevalence of nervous troubles even among those who were apparently subjected to no abnormally high degree of mental strain. The examination of many cases of war neuroses has shown that there is little if any qualitative difference between the case of those who break down under the abnormal pressure of war conditions and the case of those who are unable to stand even the relatively mild stresses and difficulties incidental to a time of peace. All persons are, it would appear, liable to suffer nervous breakdown if subjected to emotional strain beyond a certain limit; this limit varying, however, very considerably from one individual to another. Modern war increases to some degree the strain to be borne by almost everyone, the increase being very great in the case of those actually engaged in fighting; as a consequence the limit is passed, and some form of nervous disability or breakdown occurs in a large number of persons who would have remained unaffected during peace. [Sidenote: Psychic integration] [Sidenote: Importance of correct mental development]