In the early months of the war medical writers mentioned physical and psychic factors in the etiology of hysteria more or less indiscriminately. Gradually, as the distinction became clear between true cerebral concussion and hysteria, the view gained ground that physical factors, as such, played no part in the etiology of the latter.

1 A. J. Rosanoff. A Study of Hysteria Based Mainly on Materiel Observed in the U. S. Army Hospital for War Neuroses at Plattsburg Barracks, N. Y. Arch, of Neurol, and Psychiatry, Oct., 1919.

In studying the etiology of war neuroses it would seem important to distinguish the acute emotional disorders observed at the front from hysteria. This distinction has been perhaps most clearly drawn by Leri, whose experience extends over the entire duration of the war and who, in that time, had opportunities of seeing cases at the front, in field hospitals, and in neuro-psychiatric centers in the interior.1

Many writers have shown a tendency to confound emotional with hysterical disorders. But according to Leri it is a mistake to think that hysterical manifestations are an integral and necessary part of the emotional syndrome. They can appear independently of all emotion; and the emotional syndrome has nothing in common with hysteria.

It seems that the psychic factors to which war neuroses in general have been attributed - fright caused by danger from projectiles, horrifying sights, etc., play a part only in the acute emotional syndrome; hysterical phenomena are not directly produced by them.

I come now to the consideration of a factor which, though seldom frankly avowed by patients and seldom definitely established by clinical investigation in individual cases of hysteria, yet has made itself clearly apparent to many observers in all armies. Speaking for myself and with special reference to my war experience, I would say that this factor has obtruded itself on my attention until I have come to regard it as the mainspring of hysterical conduct.

This factor consists in a concealed, illicit, morally untenable motive.

The motive is not always the same, but it is always characterized by the above mentioned qualities. Its most frequent variations are: (1) To evade the law of conscription. (2) To procure, upon reporting for physical examination at a training camp, rejection for physical unfitness. (3) To evade dangerous, disagreeable, or difficult duty, or to evade all duty. (4) To procure the ease and privileges of hospital care. (5) To procure discharge on certificate of disability. (6) To procure compensation for disability.

1 A. Leri. Commotions et Emotions de Guerre. Paris, 1918.

That illicit motive and it alone, and not shell concussion, war strain, emotional shock, etc., is the factor which actuates hysterical conduct is further shown by three groups of facts of the highest significance.

In the first place are to be mentioned the cases of hysteria arising in the domestic training camps, i.e., thousands of miles from the seat of war. In every National Army cantonment cases came to light often on the day of reporting for military duty, more often early in the course of training - at any rate before any "war strain" could possibly have made itself felt. These cases presented all the manifestations of hysteria which, when seen in overseas cases, have so often been attributed to "shell shock."

In the second place is the striking fact that among prisoners of war who have been, like other soldiers, exposed to shell fire, strain, etc., scarcely any cases of hysteria or other psychoneuroses have been observed.1

In the third place is the very common experience of quick and complete recovery from hysterical symptoms upon evacuation to a base hospital, followed by a return of the symptoms in the same or even a greater degree of intensity or by development of new symptoms upon any prospect arising of being sent again to duty. Many of the overseas cases have furnished such a history. The relapse has generally occurred either on the way from the hospital to a re-classification camp or shortly upon arrival at such a camp. Sometimes no cause is given for the relapse, at other times a trivial cause.

1F. Lust. Kriegsneurosen und Kriegsgefangene. Munch, med. Woch., Dec. 26, 1916. Abstracted in Journ. Am. Med. Assn., Feb. 24, 1917. - R. Gaupp. Discussion of War Neuroses, cited in Berlin Letter. Journ. Am. Med. Assn., Feb. 24, 1917.