Well, State Sen. Daniel Thatcher (R) has a plan to deal with this situation which he calls "unconscionable". Thatcher has introduced SB80 (text here) into the Utah state Senate, a bill which would set up a system by which people who'd pled guilty by reason of insanity or were committed to a mental institution could petition to get their gun rights back.
As Thatcher explained: "In the state of Utah, there is absolutely no method, no matter how diligent you've been or no matter what treatment process you've gone through, and I don't think that's OK. It is my belief people can get better."
The bill passed through committee Monday afternoon on a 3-1 vote. The sole dissenter was Sen. Pat Jones (D).