Using street drugs when you're on medication for a mental illness is a really bad idea. It's probably what triggered his episode in the first place.

You said that he had been honest with you from the start, about his diagnosis and his meds. Did he tell you about rehab, or what he went there for? Did you know he was using marijuana? Had you ever been with him when he was high before?

This has bad written all over it. Not because of the mental illness; that can be dealt with. But because he's also an addict, out of rehab and back to using street drugs. He's sabotaging his own recovery.

Just be careful, and make sure you protect your heart.