The issue with mental health isn't that the kids/adults aren't getting help or that some of the meds actually work, the problem is that those that are a serious risk are being hidden and that info isn't being sent to NICS. Those that are a serious threat, regardless of service or not, should be prevented from owning a gun until they are good. And I think you'll find soldiers agree.
The problem is that the last few bills in congress have wanted to permanently ban anyone that's ever been on certain meds and one of those certain meds is weed. They're not worried about helping anyone, they just want excused to take away guns. If people see that the law is written with actual care involved and that it is never a permanent solution unless its a permanent problem for them, it will be accepted. The biggest problem with the system right now is doctors and police stations simply not passing the information up the chain. Fixing that alone will make a big difference.