Finally something I may be able to answer. I'm a doctoral candidate in clinical psychology specializing in PTSD with combat veterans. I'm currently finishing my dissertation on the sequela of combat trauma in male and female veterans, and I open my dissertation with a quote from Shakespeare's Henry IV, believed to have been written in 1597 (mods, I apologize if that's not the right time period for this question).
Why dost thou bend thine eyes upon the earth, And start so often when thou sit'st alone? Why hast thou lost the fresh blood in thy cheeks; And given my treasures and my rights of thee To thick-eyed musing and cursed melancholy?
In thy faint slumbers I by thee have watch'd, And heard thee murmur tales of iron wars; Speak terms of manage to thy bounding steed; Cry 'Courage! to the field!' And thou hast talk'd Of sallies and retires, of trenches, tents,
Of palisadoes, frontiers, parapets, Of basilisks, of cannon, culverin, Of prisoners' ransom and of soldiers slain, And all the currents of a heady fight. Thy spirit within thee hath been so at war
And thus hath so bestirr'd thee in thy sleep, That beads of sweat have stood upon thy brow Like bubbles in a late-disturbed stream; And in thy face strange motions have appear'd, Such as we see when men restrain their breath
Now, PTSD is currently defined as 4 constellations of symptoms that revolve around an index trauma. That is, these symptoms are all caused by that event. The symptom clusters are broken up into: Intrusion/reexperiencing, Arousal, Negative mood/cognition and Avoidance. These clusters are believed to represent changes that occur not only in terms of our psychology and cognition, but underlying biological mechanisms as well; so, we would expect these changes to exist in humans from the past as well as present when exposed to trauma.
The quote I opened with touches on many of these clusters, and is said by Lady Percy about her husband Henry Percy, a famed soldier and knight with numerous battles in his past (suggests an index trauma)
Why dost thou bend thine eyes upon the earth,
Suggests avoidance; specifically emotional numbing.
And start so often when thou sit'st alone?
Suggests arousal; specifically exaggerated startle response
And given my treasures and my rights of thee To thick-eyed musing and cursed melancholy?
Suggests negative alterations in mood and cognition; specifically peristent negative beliefs about self, others and world
In thy faint slumbers I by thee have watch'd, And heard thee murmur tales of iron wars;
Suggests Intrusion/reexperiencing; specifically nightmares
Based on this quote, it appears that Henry experiences many symptoms of PTSD. In fact, it's likely that he would meet criteria for PTSD as indicated by the DSM5 today. I would also say that the specific criteria Lady Percy has noted would probably make him a good candidate for evidence based psychotherapy to ameliorate those symptoms (I personally would recommend Prolonged Exposure).
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC: Author.
Cahil, S. P. & Foa, E.B. (2007). Psychological Theories of PTSD. In Friedman, M. J., Keane, T. M., & Resick, P. A. (Eds.), Handbook of PTSD, Science and Practice (55-77). New York, NY: The Guilford Press
Crowther, John, (Ed.). (2005). No Fear Henry IV Part 1. Retrieved April 30, 2015, from http://nfs.sparknotes.com/henry4pt1/
EDIT: Please disregard this, the comments below indicate I misread this passage in terms of context. Apologies!
Hi there, this question has asked a few times before, and has a spot in the r/askhistorians FAQ, so you may want to also check that out.
A similar question with some excellent answers can be seen here: www.reddit.com/r/AskHistorians/comments/1les1j/how_did_the_soldiers_of_antiquitymedieval_times/