Does it work for food craving?
Maybe.
Overeating and overdrinking are both behavior disorders.
If the behavior disorder is compelled by a certain genetic disorder, the Naltrexone would remove that part of the compulsion.
Yeah, how about for computer games?
I had the good fortune of being raised in a teetotaling religion, with several alcoholic in-laws of a different faith to provide frequent object lessons in the dangers of alcohol. But being of Irish descent, the addiction gene is still there, and I have to be "in recovery" from a number of bad habits like eating or marathon web surfing — even compulsions like overbuying the same items every time I'm at the grocery "just in case" and then having to throw half of them out. It's a daily process. Al-Anon and ACOA (Adult Children of Alcoholics — only for me it was "grandchild of alcoholics") helped me get a handle on it; and AA has helped one of my alcoholic friends transformatively.
Point being, that even the children of dry parents can still have the genetic make-up and must understand and monitor their behaviors accordingly. I read an article once that said that the children of Methodist and/or Baptist teetotalers are very vulnerable to becoming alcoholics if when they leave home and start experimenting with drinking, because they have little experience with it. So I guess my alcoholic granddads and uncles were a blessing in disguise. It was no fun watching the distress and destruction their behaviors caused.