Systematic reviews to support evidence-based psychiatry: what about schizophrenia?

Objective: To assess whether systematic reviews (SRs), the gold standard for scientific research, can offer valuable support in evidence-based psychiatry in the treatment of schizophrenia.
Methods: We used three database services (Ovid, PubMed and Cochrane) to identify SRs related to schizophrenia, found 163 reviews and grouped them by topic. We then evaluated each study's conclusions and divided them into three groups based on results (ranging from certain to null conclusions).
Results: SRs of pharmacological treatments represented 59% of the studies sampled, only 23% of which had reached certain conclusions. Other clinical topics were less frequently represented and had achieved lower degrees of certainty.
Conclusions: Only 40 SRs (22 studies investigating pharmacological treatment) provided clear-cut answers to clinical questions examined. Results therefore showed that SRs provide a certain but rather limited contribution to scientific evidence in the field of schizophrenia.