Acording to: http://en.wikipedia.org/wiki/SLUDGE_syndrome
Sludge is a mnemonic for the pathological effects indicative of massive discharge of the parasympathetic nervous system. Unlikely to occur naturally, SLUDGE is usually encountered only in cases of drug overdose, ingestion of certain poisonous mushrooms (particularly the muscarine-containing members of the genera Inocybe and Clitocybe), or exposure to nerve gases.