Nonsteroidal Anti-Inflammatory Drugs in Schizophrenia

OBJECTIVE: Mounting evidence suggests that inflammation is involved in the pathogenesis of schizophrenia. This evidence implies that anti-inflammatory agents are potentially useful therapeutic strategies in schizophrenia. This article quantitatively summarizes the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) to augment antipsychotic treatment to reduce schizophrenia symptom severity. DATA SOURCES: An electronic search was performed using MEDLINE, Embase, the National Institutes of Health Web site clinicaltrials.gov, Cochrane Schizophrenia Group entries in PsiTri, and the Cochrane Database of Systematic Reviews. The following basic search terms were used: schizophrenia, nonsteroidal anti-inflammatory drug, and NSAID together with the name of each specific NSAID (ibuprofen, diclofenac, naproxen sodium, and acetylsalicylic acid). We applied no year or language restrictions. STUDY SELECTION: Studies were selected if they met the following inclusion criteria: (1) randomized, double-blind, placebo-controlled trials regarding augmentation of antipsychotic medication with an NSAID, (2) patients included had a diagnosis of a schizophrenia spectrum disorder according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, and (3) studies reported sufficient information to compute common effect size statistics, or corresponding authors could supply these data upon request. DATA EXTRACTION: The primary outcome measure was the mean change in total score on the Positive and Negative Syndrome Scale (PANSS). Secondary outcome measures included positive and negative symptom subscores of the PANSS. RESULTS: We could include 5 double-blind, randomized, placebo-controlled trials, reporting on 264 patients. Four studies applied celecoxib, and 1 used acetylsalicylic acid. We found a mean effect size of 0.43, which was significant at P = .02 in favor of NSAIDs on total symptom severity. For positive symptom severity, the mean standardized difference was 0.34 (P = .02). For severity of negative symptoms the mean standardized difference was 0.26 (P = .03). CONCLUSIONS: These results suggest that NSAID augmentation could be a potentially useful strategy to reduce symptom severity in schizophrenia. As these are the first studies on a relatively new strategy and the included sample size is modest, these results should be interpreted with caution. However, augmentation with acetylsalicylic acid may have the additional benefit of reducing cardiac and cancer mortality in schizophrenia. We therefore believe that application of NSAIDs in schizophrenia deserves further investigation as augmentation of antipsychotic treatment and reducing comorbid somatic diseases.