UPDATE ON SCHIZOPHRENIA – Recent studies have suggested that dysfunctional nitric oxide (NO) signalling in the prefrontal cortex is involved in schizophrenia (Fejgin et al. Neuropsychopharmacology  2008; 33: 1874-1883; free full text at www.nature.com/npp/journal/v33/n8/full/1301587a.html).  For example, in the phenylcyclidine model of schizophrenia, PCP-induced behavioural effects appear to be due in part to an increase in NO activity (Klamer et al. Eur Neuropsychopharmacol 2005; 15: 587-590; Johansson et al. Psychopharmacology (Berl); 1997; 131: 167-173).