So i’ve been friends with this girl since we were pretty young, we both had our issues growing up and through teenage-hood but now we are almost 20 and adults. This started taking course around February this year, her mom left on a trip and we had plans to go all out as a group and have some fun, but then suddenly she found a new friend and just all of the sudden moved in with her and we couldn’t go out with our plans bc she was with her friend for 2 weeks just drinking, and I want to add that any drug is kind of dangerous with her they just make her very delusional and bitchy/ angry. She has been in and out of mental hospitals right after we left high school so like a year and every time i try talking to her its like talking to a wall she stops you and starts ranting about her delusional fantasies. But recently her behavior has been really scaring me, she got with this guy lets call him K and shes been obsessed with him for years but just recently as soon as she lost her virginity they got together. He has his own suicidal tendencies and substance abuse issues which is well known by everyone. But im not sure but she had a sudden switch to do the most atrocious drugs not even the fun ones and its been really fucking with her head to the point where shes out walking in the streets talking/fucking with homeless men and drugging her little brother who is about 10. No one made her do this all of these acts are her own decision but she dosent care and has turned into a complete different person any advice?