Lamotrigine previously was found to attenuate ketamine-induced behavioral changes and, in 2 placebo-controlled trials, to improve psychosis when added to antipsychotic medication. We sought to evaluate the potential role of lamotrigine augmentation in schizophrenia patients resistant to atypical antipsychotic medication.

Goff DC, Keefe RSE, Citrome L, Davy K, Krystal J, Large C, Volayka J, Webster EL. Lamotrigine as add-on therapy in schizophrenia:  Results of two placebo-controlled trials. Journal of Clinical Psychopharmacology, 2007; 27(6): 582-589.