I don't know...I just researched this case and I think it's pretty clear he was schizophrenic. Not all schizophrenics have auditory hallucinations, but the crazy somatic delusions he had are pretty conclusive that if he wasn't schizophrenic, he was definitely some kind of delusional. And I don't think he was faking it, either. He was engaging in this kind of delusional behavior from an early age. Certainly the drug use could have exacerbated it.

Personally, I think the legal standard for being considered insane is too hard to be much help. If someone is gripped with insane delusions like they need to drink blood or else their own blood will turn to dust - or like Andrea Yates, their children are going to hell if she doesn't send them to heaven now - that should qualify as insane. They are divorced from reality, to a dangerous degree. Not that that would mean letting them go free; far from it, they would need to be committed to an insane asylum to get whatever treatment they need, and to keep the community safe.

Just my 2c.