The diagnostic distinction most predictive of response to pharmacological treatment, according to available controlled studies, is between mood disorders with psychotic features and disorders in which psychosis persists in the absence of mood syndromes The treatment of acute mania and schizophrenia overlap considerably in terms of the typical and atypical neuroleptics, but begin to diverge with the recognized mood stabilizers for bipolar affective illness lithium, carbamazepine, and valproate which are substantially less effective in schizophrenia than in affective illness. Polypharmacy is a critical issue in the treatment of schizophrenia. Citrome et al.  reported that 43.4% of the inpatients diagnosed as having schizophrenia received a mood stabilizer. There are few controlled studies of the newer thymoleptic agents such as sodium valproate or of the newer antidepressants such as selective serotonin reuptake inhibitors in schizophrenic and schizoaffective patients. The aim of this article is to provide a debate regarding the usefulness of sodium valproate as an adjunct to schizophrenia spectrum disorders.