The 8500-8 also requires reporting "any other nontraffic convictions" in block 18w, and note that "public intoxication" is one of the examples in the instructions, MIP being pretty similar to that. If Anon was "convicted" (and the post says "MIP alcohol convictions") I belive that conviction should have been reported with his first medical application. If the FAA finds out about it later, they will likely act by suspending the medical certificate for up to 180 days, just like they did the pilot who was out of flying without a current medical when the 61.15 DUI 60-day reporting rule was imposed, and who reported it on renewing his medical several years after the event.
For those reasons, my suggestion is to contact an aviation attorney in your state for legal advice, as this is a legal, not medical issue. There may be a way to work this out if you tell them before they find you, but you'll need a good lawyer to negotiate it for you. In addition, as you were a minor when it happened, those records may be sealed or expunged, and the FAA may not be able to get them, which could make the problem go away, but that would depend on state laws as well as federal, so your advice would have to come from someone who knows both. Bottom line is you need good legal advice on this, and the only place to get that is a good lawyer -- and I am not a lawyer in your state or any other.
If you're a member of the AOPA Legal Services Plan, start there. If not, you can still get them to recommend someone you can pay for out of pocket.
