Ryan's post plus President Obama's announcement today essentially means that doctors, psychiatrists, and counselors all are on notice that they had better ask every client or patient if he or she owns guns. If they answer "yes," then look for a visit from the local police.
I have no doubt that we will see an escalation of state gun violence out of all this. Bureaucrats are risk-averse, which means that the new default position will be the confiscation of guns from anyone who might be taking any medication for depression, sleeplessness, or something like Ritalin. This is not so much because all of them will be threats to kill others, but rather it presents a new opportunity to government agents to further control, harass, bully, and even kill others.