Just because you never heard of it doesn't mean it doesn't happen.
My wife's son dabbled with Yaa Baa when he was 16. By the time he was 20 he was diagnosed as being Paranoid Schizophrenic,as a direct consequence of drug use. He's now 26 and can look forward to a life of daily, strong medication. He's unable to function as a normal human being, even with his meds.
Taking Yaa Baa was devastating for both him, and his mother.