Most will tell you that insanity is not a disease, but the Black Lunacy is. For those few who catch it, the results are quite disastrous. An outbreak of black lunacy about six years ago occurred in a faction-less district of Cabal. That area is still toxic and avoided by all life. Dark stains cover the walls, floors and ceilings of the buildings there and the shattered bones of the long deceased lay strewn about haphazardly. They say that the screams echoed for weeks before everyone finally killed one another.
Arcanists and others with knowledge of magic suspect that Lunacy is much more than it appears. There are records of mass hallucinations of an insane, cackling voice talking to those who catch the disease. Many mages suspect that the disease is actually sentient. So far, no one is truly sure how it is contracted or spread. There are cases where only a single individual in a densely populated area is afflicted. Rumors say that it is not spread the same as any other disease, but rather is spread by a corrupted idea.