My friend (M30) is Bipolar is in the midst of a manic episdode and I have no idea what to do. I want to reach out to him, mainly to urge him to seek help and come off any triggering substances etc but I don't know how to do so without upsetting him. This has been happening with him roughly once a year for the last 3 years and happens the same way each time.

Basically he goes through a depressive stage, levels out into a medicated but healthy mental stage, then tries to taper off meds, tries to replace his mood stabilisers with weed, but then it triggers him into a manic stage, which happens over the course of a few months. 

Currently as far as I know he is not going out much, not sleeping much, and has gone into a hyper-religious stage, posting prolificly on his socials that he 'is a messenger of god' and large religious rambling walls of text on his feed. He is a vaguely spiritual and religious person when stable but not like this. I've been with him in person when he is like this and its extremely unsettling and uncomfortable to be around him or try talking to him, he goes off on these rants and when he is in a particularly paranoid state he becomes convinced hes being watched or that 'the man' is onto him etc. 

Any advice on what to do here would be much appreciated, in the past I've just broke contact with him for a while until he's rode it out but I always feel guilty about this, as if I'm contributing to his isolation. He does have a girlfriend and also lives with his parents however..