The research on ptsd began with US veterans afaik. It’s probably the group that is most studied for it and also receives trials.
The US also spends a large amount of money on each veteran. If they can find a cure for trauma they would benefit hugely from it. The side effect of this is that others would benefit as well.
That's damning in another way -- it suggests we aren't spending money on the other, larger groups of PTSD survivors.
Shame it has to be a side effect.