In some states of india up to a few years ago you had registered opium addicts they could go to goverment stores to get their raw opium or poppy pods . These people were productive members of society they raised families and worked so like you said when cheaked it works , I did not mean go get prescription drugs with no checks then you get the problem I saw in punjab it was bad i was bad because it was like a kid in a candy store .No that's just shoddy work.
Especially opiate (ab)use would have to be checked very strictly.
The process would have to be guided by professionals..(you know, professionals that actually work I mean)