I know of a uk Drink driver who continued to fly professionally. The CAA had/may still have a special clinic for such alcohol related problems, with referrals from courts, ame, companies, self referrals etc to supervise any rehab needs or perhaps make a call on licence suspension. I would expect other countries run similar schemes.
Again a conviction in UK doesn't automatically stop an airside pass. Certain types of offence might do, others are looked at on a case by case basis by the DOT I believe.