The latest case involves a man named Diego Costa Silva in Ireland. He decapitated his wife, claiming he believed she was possessed by a serpent due to “cannabis-induced psychosis” – and that he had to remove her head to kill the snake entity. Two psychiatrists backed up his insanity plea, testifying that Silva genuinely suffered delusions and hallucinations from heavy cannabis use, rendering him legally not guilty by reason of insanity for the grisly murder.