> Interesting aside, the "mental" addiction can be harder to kick than the physical. Some former opiate and gabapentin users I know have mentioned this - psychological cravings for even years after stopping. Anyone who has ever tried quit nicotine will also know this.

Oh yes for sure, didn't mean to make it seem like it wasn't. I was(/am) a poly drug addict from Finland. Buprenorphine and amphetamine were my jam for a couple years. One year of using intravenously daily. It's been years since my last time but I still think about shooting up every now and then. It's a deviously strong urge. But the mental battle doesn't only start after the physical stuff is over: at the beginning they both compound on each other and it's absolutely devastating when you've been awake for two weeks because of the restless legs...