So even if the mental-health criteria for rejecting gun buyers (or for commitment) were expanded, there is little reason to think they could distinguish between future Lanzas and people who pose no threat. Survey data from the National Institute of Mental Health indicate that nearly half of all Americans qualify for a psychiatric diagnosis at some point in their lives. That's a pretty wide dragnet.
Should half of us lose our Second Amendment rights, at least for the duration of whatever mental disorder (depression, anxiety, addiction, inattentiveness, etc.) afflicts us? Assuming a prescription for Prozac, Xanax or Adderall is not enough to disqualify someone from owning a gun, what should the standard be?
Even under current law, mental illness can become a label for unconventional political beliefs. Remember Brandon Raub, the Marine Corps veteran who was forced to undergo a psychiatric evaluation in Virginia last summer based on his conspiracy-minded, anti-government Facebook posts?
The malleability of mental illness was also apparent at a 2007 debate among the candidates for the Democratic presidential nomination. After seeing a YouTube video in which Jered Townsend of Clio, Mich., asked about gun control and referred to his rifle as "my baby," Joseph Biden said: "If that's his baby, he needs help. ... I don't know that he is mentally qualified to own that gun. I'm being serious."
So perhaps excessive attachment to your guns should be grounds for taking them away. Biden, by the way, is in charge of formulating the policies the Obama administration will pursue in response to Lanza's horrifying crimes.