He's an addict, addicts/alcoholics don't think beyond their next fix. He'll come out of jail an addict, he'll be clean, but his brain will still be that of an addict, it's more than drugs or alcohol, people use prescription pain killers and alcohol all the time and don't get hooked. But there are others who do, there are underlying psychological issues that and instead of seeking treatment for those, they end up self medicating.
This is the part that makes me have no sympathy for addicts. If they quietly did their drug of choice and didn't bother anyone than I say go for it and have fun but we all know that isn't reality. They cheat, lie, and steal to get their next fix and they don't care who they run over in the process. The people killed by junkies driving while high, the little girl in DC that almost got her eyes gouged out because the guy was on PCP, the countless number of people that are robbed everyday so someone can get his next fix, and it goes on and on. I will not lose any sleep over either one of them and anyone like them. No one gets physically addicted the first time they try a drug so this is something they chose to do and now they want people to feel sorry for them now that it isn't fun anymore. It would be like me saying "pity me because I got lung cancer due to smoking" and I say if it happens I deserve no pity because I am the dumb @$$ that started in the first place and if I quit, I don't deserve a medal and I am no hero, I am just like everyone else that quit before me or who was smart enough to never pick it up in the first place. These are just my opinions but like I said earlier I have no sympathy for either of them.