Now, hear me out before you reflexively get angry.
I approve of this based on decades of mental health practice--not the current practice, but the DSM-IV definitions of mental health.
But the APA is a small group of people. 37,800 members. I'd bet they'd be happy to take on foreign members. A LOT of foreign doctors would hold with every bit of those prior posts.
How would that work out?
And you don't always JUST lose your guns if this cartel decides you're mentally ill. You may lose all your freedoms.