Second-generation antipsychotic effect on cognition in patients with schizophrenia-a meta-analysis of randomized clinical trials

Objective To investigate the effect of second‐generation antipsychotics on cognitive function in patients diagnosed with schizophrenia or schizoaffective disorder. Method Multiple‐treatments meta‐analysis model. Results On cognitive composite score, sertindole was superior to clozapine, effect size (ES) 0.87; 95% CI: 0.12–1.63, quetiapine, ES 0.75; 95% CI: 0.00–1.49, and first‐generation antipsychotics (FGAs), ES 0.89; 95% CI: 0.14–1.64. Analyses on each cognitive domain showed clozapine, ES 0.37; 95% CI: 0.00–0.74, olanzapine, ES 0.31; 95%CI: 0.02–0.59, quetiapine, ES 0.34; 95% CI: 0.03–0.64, and FGAs, ES 0.51; 95% CI: 0.18–0.83 performing poorer on verbal working memory than ziprasidone, as well as FGAs performing poorer than risperidone, ES 0.31; 95% CI: 0.04–0.58. On executive function, sertindole performed better than clozapine, ES 0.82; 95% CI: 0.06–1.58, olanzapine, ES 0.81; 95% CI: 0.07–1.55, quetiapine, ES 0.76; 95% CI: 0.02–1.51, ziprasidone, ES 0.90; 95% CI: 0.14–1.67, and FGAs, ES 0.83; 95% CI: 0.08–1.58. On processing speed, FGAs performed poorer than sertindole, ES 0.97; 95% CI: 0.02–1.91, and quetiapine, ES 0.36; 95% CI: 0.01–0.72. On long‐term verbal working memory, clozapine performed poorer than olanzapine, ES 0.41; 95% CI: 0.06–0.76. On verbal fluency, FGAs performed poorer than olanzapine, ES 0.26; 95% CI: 0.01–0.50, and clozapine, ES 0.44; 95% CI: 0.06–0.81. Lastly, FGAs, ES 0.41; 95% CI: 0.04–0.78, and clozapine, ES 0.44; 95% CI: 0.05–0.83, performed poorer on visuospatial skill compared to olanzapine. Conclusion The meta‐analysis was able to detect some trends in the data analyzed, but did not show any drug having a uniform positive cognitive profile.