Statins as an adjuvant therapy for patients with schizophrenia: An up-to-date systematic review and meta-analysis

Background Evidence suggests that inflammatory processes play a role in the pathophysiology of schizophrenia. Statins exert anti-inflammatory and antioxidant effects and may be effective in improving the symptoms of schizophrenia. This study explored whether statins, as an adjunctive therapy, can alleviate the symptoms of schizophrenia. Methods PubMed, EMBASE, and the Cochrane Library were searched for articles published up to March 2023. The risk-of-bias tool for randomized trials was used to assess study quality. Two researchers independently assessed the risks of bias and extracted data. Pooled data on Positive and Negative Syndrome Scale (PANSS) scores were analyzed. A random-effects model was employed to calculate pooled effect sizes. Statistical heterogeneity across studies was assessed using the I2 statistic. All analyses were performed using RevMan5 and Comprehensive Meta-Analysis software. Results Nine trials enrolling 533 patients in total were included. Add-on statin therapy was found to be associated with a significantly better total PANSS score [standardized mean difference (SMD) = −0.42, 95% confidence interval (CI) −0.75 to −0.09, I2 = 72%; P = 0.01] and PANSS negative subscale score (SMD = −0.26, 95% CI −0.45 to −0.07, I2 = 0%; P = 0.009) in comparison with placebo. However, add-on statin therapy did not appear to improve scores for the PANSS positive and general subscales at the study-defined endpoint (6–24 weeks). Conclusions Our meta-analysis indicates that adjunctive statin therapy may confer benefits in ameliorating PANSS negative and total scores. It needs more solid data to confirm the results are related to clinical improvement and functioning.