I side with Alex; even tho’ he is the kind of Dude that goes to parties and gets pussy thrown at him just for sitting around. . .
Either the friend/fool will get totally sucked in by the trim and give you the boot, or he will eventually get over it, probably be stronger for it, and will appreciate that you were there for him.
In either event, having once gone to bat for him, you are bound by the great Cosmic Compact of Righteous Dudes to do the right thing by your Bro, unless/until he voids said compact by turning on you in his pussy-madness.
Regarding the weed smoking aspect of it and the comments attached to that.
That cannabis causes psychosis is a misconception. A major study at Cologne University and King’s College in London showed a much more complex picture with different chemical constituents of cannabis having different effects. The researchers found that although tetrahydrocannabinol(THC) (the bit that produces a high giggly feeling) can trigger psychosis in a very small number of users, another chemical component to cannabis, cannabidinol (CBD) actually inhibits and suppresses psychotic symptoms in people suffering from them.
CBC is so good at suppressing psychotic symptoms that it proved to be more effective than any of the major anti-psychotics currently prescribed by doctors.
That said - there is a lot to be said for sitting around, getting high and fucking all day.
Recent studies show that over 80% of old people when asked what they regret about their life or wish they’d done more of answered that they wished they’d had more sex.
On a similiar note - sitting around and fucking all day. To many, your friend is living the dream. Granted a slightly off kilter version of the dream, but hey, it’s pretty close.
If he was actually your friend you’d make a proper effort, whether that was finding some way of trying to gain access to their lives. Even if say you called over and sat and had a beer outside their front door and chatted to her like that a few times, a gradually introduction of you. Or more helpful, tried to find some other options of help for her and them, if she does indeed mean that much to your friend. Be that some form of counsellor or alternative therapy - going down the psychiatrist who medicates the shit out of every problem often does not work for the majority.
Gradual introduction of you, in different ways seems a good option.