The state takes away our responsibility but cannot ease our grief, we have to carry it alone and it reaches deep within our dreams.
Ernst Jünger, Storm of Steel
[I ran across this article at least a decade ago. It's actually a highly informed piece from a medical journal, but it starts with a description of how the phenomenon of shell shock, today known as PTSD, was long recognized by early authors.]
Mankind's earliest literature tells us that a significant proportion of military casualties are psychological, and that witnessing death can leave chronic psychological symptoms. As we are reminded in Deuteronomy 20:1-9, military leaders have long been aware that many soldiers must be removed from the front line because of nervous breakdown, which is often contagious:
When thou goest out to battle against thine enemies, and seest horses, and chariots, and a people more than thou... the officers shall say, What man is there that is fearful and fainthearted? Let him go and return unto his house, lest his brethren's heart faint as well as his heart. (King James Version )
Mankind's first major epic, the tale of Gilgamesh, gives us explicit descriptions of both love and post-traumatic symptoms, suggesting that the latter are also part of human fundamental experience. After Gilgamesh loses his friend Enkidu, he experiences symptoms of grief, as one may expect. But after this phase of mourning, he races from place to place in panic, realizing that he too must die. This confrontation with death changed his personality. The first case of chronic mental symptoms caused by sudden fright in the battlefield is reported in the account of the battle of Marathon by Herodotus, written in 440 BC (History, Book VI, trans. George Rawlinson):
A strange prodigy likewise happened at this fight. Epizelus, the son of Cuphagoras, an Athenian, was in the thick of the fray and behaving himself as a brave man should, when suddenly he was stricken with blindness, without blow of sword or dart; and this blindness continued thenceforth during the whole of his afterlife. The following is the account which he himself, as I have heard, gave of the matter: he said that a gigantic warrior, with a huge beard, which shaded all his shield, stood over against him; but the ghostly semblance passed him by, and slew the man at his side. Such, as I understand, was the tale which Epizelus told.
It is noteworthy that the symptoms are caused not by a physical wound but by fright and the vision of a killed comrade, and that they persist ewer the years. The loss of sight has the primary benefit of blotting out the vision of danger, and the secondary benefit of procuring support and care. Frightening battle dreams are mentioned by Hippocrates (4607-377 bc), and in Lucretius's poem, De Rerum Natura, written in 50 BC (Book IV, trans. William Ellery Leonard):
The minds of mortals... often in sleep will do and dare the same... Kings take the towns by storm, succumb to capture, battle on the field, raise a wild cry as if their throats were cut even then and there. And many wrestle on and groan with pains, and fill all regions round with mighty cries and wild, as if then gnawed by fangs of panther or of lion fierce.
This text shows very vividly the emotional and behavioral re-experiencing of a battle in sleep. Besides Greco-Latin classics, old Icelandic literature gives us an example of recurring nightmares after battle. The Gisli Súrsson Saga tells us that the hero dreams so frequently of battle scenes that he dreads obscurity and cannot stay alone at night.
Jean Froissart (1337?–1400/01) was the most representative chronicler of the Hundred Years War between England and France. He sojourned in 1388 at the court of Gaston Phoebus, Comte de Foix, and narrated the case of the Comte's brother, Pierre de Beam, who could not sleep near his wife and children, because of his habit of getting up at night and seizing a sword to fight oneiric enemies. The fact that soldiers are awakened by frightening dreams in which they re-experience past battles is a common theme in classical literature, as, for instance, Mercutio's account of Queen Mab in Shakespeare's Romeo and Juliet (I, iv):
Sometime she driveth o'er a soldier's neck.
And then dreams he of cutting foreign throats.
Of breaches, ambuscadoes, Spanish blades,
Of healths five fathom deep; and then anon
Drums in his ear, at which he starts and wakes,
And being thus frighted, swears a prayer or two,
And sleeps again.
Etiologic hypotheses were put forward by army physicians during the French Revolutionary wars (1792–1800) and the Napoleonic wars (1800–1815). They had observed that soldiers collapsed into protracted stupor after shells brushed past them, although they emerged physically unscathed. This led to the description of the “vent du boulet” syndrome, where subjects were frightened by the wind of passage of a cannonball. The eerie sound of incoming shells was vividly described by Goethe, in his memoirs of the cannonade at the battle of Valmy in 1792 — “The sound is quite strange, as if it were made up of the spinning of a top, the boiling of water, and the whistling of a bird.” In the same text, Goethe gives an account of the feelings of derealization and depersonalization induced by this frightening environment:
I could soon realize that something unusual was happening in me...as if you were in a very hot place, and at the same time impregnated with that heat until you blended completely with the element surrounding you. Your eyes can still see with the same acuity and sharpness, but it is as if the world had put on a reddish-brown hue that makes the objects and the situation still more scary...I had the impression that everything was being consumed by this fire...this situation is one of the most unpleasant that you can experience.
"From shell shock and war neurosis to posttraumatic stress disorder: a history of psychotraumatology" by Marc-Antoine Crocq, MD, and Louis Crocq, MD, in Dialogues in Clinical Neuroscience, March 2000