Ol' Blood and Guts would have had something to say about it.
Consider something around 15% of troops actually engage in combat, 54% seems high. Not saying that (for whatever reason) the diagnoses are not on the rise, but does that reflect an increase in the condition, or an increase in diagnosing it, and if the latter, has it always been that bad (and went undiagnosed/treated) or is this something new?