I can't say for sure what goes on in the civilian medical sector because my interface with civilian docs has (thankfully) been very limited.
I am unfortunately quite familiar with the VA medical system and I can echo what Santahog says.
If you talk about PTSD to a VA doc, you get essentially the equivalent of a Section 8 noted in your file. This translates into losing your right to ever legally own any firearm. And, irrespective of your earlier answers, every time you go through the most routine procedure--like an annual check-up--you will be asked about your state of mind, are you ever depressed, do you have feelings of isolation, do you ever think about suicide, etc. Any "yes" answer at any time gets you permanently flagged. Permanently! And it could be for something as simple as your dog just died or you lost a parent--anything that might make you temporarily depressed.
Thankfully, I had the benefit of another vet's counsel prior to my initial intake and knew what not to talk about.
Still, I made the mistake of admitting once that I smoked tobacco but quit some 30 years ago. To this day, I get the quitting tobacco now will prolong your life propaganda every time I have a visit.
VA records are like a "roach motel." Things go in, but they never get out.
I have an erroneous entry noting that I am allergic to Vicodin. I'm not. But that notice showed up during my first hip replacement and a year later during my second. Now, if any of you have experienced a hip replacement, you know you want more than an aspirin for the pain. Both times I managed to eventually get the drug, but both times I had to have my primary care doc override the erroneous statement in my record. But, it's still in there!
Younger vets, even those who know they may have a mental hygiene issue, are very reluctant to mention anything because they don't want to be permanently assigned to the "nut bag" classification and relinquish many of their Constitutional rights.
It is definitely something that needs to be addressed. Feeling anxious or depressed shouldn't strip you of your rights. It should just result in getting whatever level of help you may need to get back to being healthy.
FWIW
Crusader