I don't think drinking less and doing less drugs makes you more depressed, stressed, sexless and lonely. I think the reverse is true with possible exception of loneliness, but you are better off without the type of company booze and drugs provide.
More social isolation could lead to both less drugs and sex. Less drugs is probably good but if it is only because people are becoming depressed shut-ins, that's bad
Booze and drugs are often social activities. If everyone's busy there's less time to go get high with your friends.
If company sans booze and drugs exist. Online gaming doesn't count as company.