Given the left-wing bias of the APA, it won't be long until everybody is diagnosed with some type of unprovable impairment that would exclude them for lawfully possessing a firearm.
Hippa(crit) has allowed for years that a doctor has to inform the authority of certain things. In MI and PA (that I know of) doctor can tell DMV if their patient admits to heavy alcohol drinking.. And DMV can revoke license.