Every state does have some form of civil / involuntary commitment, though nothing like before the 80's.
Many drugs also come with unpleasant side effects, especially if someone steals them from you and you're stuck with withdrawals. I'm reminded of one person my friend was helping who hated taking his medicine, but if he didn't, he would inevitably become increasingly paranoid that vampires were out to get him. Helping the poor guy live anything close to a "normal" life was a constant challenge.