Valproate as an adjunct to antipsychotics for schizophrenia: a systematic review of randomized trials

Randomized controlled trials comparing valproate (as a sole, or as an adjunctive compound) to placebo for patients with schizophrenia or schizophrenia-like disorders were summarized in a metaanalysis. It was possible to include only five trials (n = 379) examining valproate as add-on to antipsychotics in this review. Some of the single studies showed inconsistent beneficial effects on some aspects of response, but no overall superiority of valproate augmentation at study endpoints was shown.