Makes sense. Maybe it's a question of severity. In WW1 British doctors thought it was a physical neurological condition caused by the concussion of artillery shells. They noticed that soldiers had trembling “rather like a jelly shaking”; headache; tinnitus, or ringing in the ear; dizziness; poor concentration; confusion; loss of memory; and disorders of sleep.

While there are many things that can cause a person to suffer from this (life and limb type scenarios) I'm questioning the validity of wide spread self diagnosed "PTSD".