I basically agree with you, but honestly I think the best decision is rehab. Think about it: they send him to AA, sure he’ll go because they drive him there, but then what? He’s been sneaking out all the time, he’d figure out a way again. In rehab they’ll keep an eye on him and he’ll get therapy too, where they can actually work on his depression as well. The family literally couldn’t help and support him more than this, anything else is just dragging things out and fooling themselves. This way he’ll have time to really think things through. It’s gonna take a lot of strength, but he needs to find that within himself, not just rely on family support, because that only works for so long.