Is he up for days because he can't sleep due to obsessions/thoughts or because he doesn't want to or can't because of too much energy?

I don't know whether it's helpful to have two threads about this: people on here might together come to the best advice and don't feel like repeating themselves.

Edit:
I would let him feel the consequences of his actions. Depression is much about guilt and he can relieve some of that by turning himself in. If he is angry at the world, causing the depression, he must understand that the world won't change by isolation but by taking responsibility.

Another edit:
3 years isn't that long when having BP: many of us have probably "wasted" a lot more time. If it helps him to realise he has real psychiatric problems then it might be preferable.