"Our results provide evidence that the non-cannabimimetic constituent of marijuana, cannabidiol, exerts clinically relevant antipsychotic effects that are associated with marked tolerability and safety, when compared with current medications."

Source

Leweke, FM; Piomelli, D; Pahlisch, F; Muhl, D; Gerth, CW; Hoyer, C; Klosterkotter, J; Hellmich, M; and Koethe, D, "Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia," Translational Psychiatry (New York, NY: Nature Publishing Company, March 2012), p. 6.
http://www.nature.com/tp/jour…