Yeah. That isn't the law, though.
So? Citing the law does not suddenly make your argument a sound one.
Unless you believe that adults should be forced to undergo treatment when they refuse it for scientifically unsound reasons, then we both agree that people should be allowed to make bad decisions about their health care. I am saying that that right should not be categorically denied to someone simply because they're not 18 yet. And I'm not seeing any rational arguments being presented as to why it should.