This is contradictory to what I posted but I will be the first to admit this area of gun law is not my forte. I will say that there are plenty of cases out there where States have challenged the feds and won. It depends on whether it was a law passed by Congress and signed off on by the Prez (in which case you would be correct IF it has gone through the appeals process and been refused to be heard, or heard and upheld by USSC) or it was a "promulgation" by the fucking ATF (in which a state can and has sued and won against the "administrative rule").
And I realize the government can find out anything they want to about you but minors fall under different safeguards than the rest of us commoners.
Under federal law, a person can be tallied in a database and barred from purchasing or possessing a firearm due to a mental illness under two conditions: if he is involuntarily committed to a mental hospital, or if a court or government body declares him mentally incompetent.
In many states, including Florida, law enforcement can take an individual to a mental hospital against his or her will for an initial evaluation. If after 72 hours the doctors observing the individual want to continue that treatment, then they can petition a court for permission, even against the patient's wishes.
That – a court order allowing a person's continued involuntary institutionalization – is one thing that should stop an individual from purchasing a firearm.
If the person was taken in for mental treatment involuntarily but was not requested to be held past 72 hours, he is not blocked from buying a gun.
In Florida, if the court chose to commit even an underage individual, he would fail a background check on that basis.
I'd imagine it would work pretty much the same way in Texas, but don't know for sure.
Source:
I just found this regarding Texas law pertaining to guns and mental illness:
Involuntary Commitment
Individuals who have been involuntarily committed to a mental health institution are prohibited from owning firearms for a period of five years from the date of release.
Mental Health Adjudication
Individuals who have been declared mentally incompetent or have been involuntarily committed to a mental health institution are prohibited from owning firearms.
Source:
Discover mental health considerations for Texas gun owners, restrictions on gun ownership, and how to get help for mental health issues in this article.
carry-texas.com
I would still bet it works the same way in Texas, as it does in Florida, regarding juveniles who have been committed.