Cannabis can precipitate or exacerbate latent or existing mental disorders, so you sooner or later would have succomb to schizophrenia, jus weed CAN be a catalyst, not 100% iron clad, and BBC News 24 is a terrible source man. This is the same broadcasting company that made out ecstasy killed Leah Betts, when really it was the paranoia caused by the media at the time that was the real cause, she worried she would dehydrate so drank copious amounts of water and died of brain swelling from water intoxication.

www.erowid.com is a reliable source