I would say it would be unusual for a military veteran to not either be connected.... Either they were diagnosed while they were still in the military, and they were put into care in their specialized clinics, which have a different acronym from ours but do the same thing, the same function....
Is it possible there's a veteran who's not one of our clients and shows up to their family doctor who refers them to a psychiatrist? PTSD is not unknown to psychiatrists. If it's with respect to their military service, I think they would know that Veterans Affairs pays attention to this and I would hope they would refer them back to their case manager who would say that they should be going to an OSI clinic.
I haven't encountered cases where people have been prevented from accessing care because their psychiatrist was uncomfortable with treating it.