At worst you'll have to release him and hope for the best. I guess that is often what happens with the addicts in our lives too.
You can probably get some advice from the vet about his chances of adjusting to domestication. The shelter that I work with has a trap-neuter-release program because the adult cats don't make good pets. Feral kittens can adapt though. When they are caught, they go to nurturing foster homes until they are old enough to be neutered and socialized enough for adoption. If you don't keep your kitty maybe you could consider becoming an animal foster parent. It's very rewarding.