Many states have regulations prohibiting the mentally ill from owning firearms. Unfortunately, this is frequently just a self-certification, or a tardy cross check of court records IF a judge has ordered release to law enforcement. And at best, this doesn't help prevent firearms from being in the home of someone not adjudged mentally ill, but registered to another family member. So it's kind of a toothless regulation.
What if a cross check against the prescription database for psychiatric medication prescriptions was run using the address? A match would mandate further inquiry--either that the applicant should not be allowed a firearm; or if the address matches and it's another family member, extra security measures need to be taken to keep the weapons secure?
And while I'm at it, what if pharmaceutical warnings specifically stated that various medications should not be used by patients with access to firearms? (I mean they warn about driving and using heavy machinery, why not guns?)