I've googled and wiki'd for both PTSD and shellshock, and haven't found anything before WWI (which I believe is when it was first properly recognised). Searching for either term + Napoleonic era has given me surprisingly little of any use. So...
Following a traumatic event involving someone nearby being disembowelled by a cannonball, it's obvious that there is something wrong with my character (he shakes uncontrollably, starts screaming whenever he hears a banging noise, usually won't sleep or eat, and suffers from nightmares when he does sleep), but what would his surgeon decide was wrong with him? Was there any equivalent diagnosis to PTSD?
Also, how would he be treated, if at all?
Thanks in advance!
ETA: Thanks folks, you're fantastic as always! (And I've definitely discounted hysteria now!)