First, you don't say what it is he's been diagnosed with. You don't say where he lives and if he's tried to get into Medicaid. You don't say if he's asked your state health dept what help is available for those who can't afford their meds. As to withdrawal, usually, 21 days isn't going to be enough time on them to cause a bad withdrawal, though some people are very sensitive to meds. The longer you're on them the harder it is to stop, but if they didn't work, for example, the body might not have even been absorbing them in which case no withdrawal. Withdrawals therefore might not be the problem here, though it is possible. It's more likely the problem he got on the drugs for in the first place is the problem. If it is withdrawal, know that sleep aids might not work. When one gets a bad withdrawal and being unable to sleep is a side effect of that, often the best thing to do is go back on them and taper off more slowly. As to whether pot will work or not, I guess it depends on whether it did that before. Back in the day when I used it I never wanted to go to sleep because I wanted to keep enjoying it. But if there's an anxiety problem, it can make that worse. I don't think the smoking has to do with not sleeping. I would say again that the most likely problem is the problem that got him hospitalized in the first place.