Systematic meta-review and quality assessment of the structural brain alterations in schizophrenia

BackgroundThe large quantity of systematic reviews of magnetic resonance imaging studies in schizophrenia challenges their meaningful interpretation. This meta-review synthesises the available information from systematic reviews of structural alteration in both chronic and first-episode schizophrenia.MethodsSystematic reviews were identified using electronic databases. Review methodological quality was assessed according to the Assessment of Multiple Systematic Reviews checklist. Data were extracted in duplicate and quality assessed for consistency and precision, guided by Grading of Recommendations Assessment, Development and Evaluation recommendations.ResultsIntegration of volumetric and voxel-based estimates allowed critical assessment of the magnitude and location of anatomical differences. There is evidence for grey matter reductions of anterior cingulate, frontal (particularly medial and inferior) and temporal lobes, hippocampus/amygdala, thalamus, and insula that may be magnified over time. Other regional alterations appear specific to illness stage or medication status.ConclusionsThere is limited high quality evidence supporting grey or white matter changes in schizophrenia, which has previously been obscured by a large volume of conflicting lower quality evidence.

► We collate and assess available systematic reviews on MRI and DTI in schizophrenia.
► Limited high quality evidence has been obscured by conflicting lower quality evidence.
► Consistent reduction in cingulate and frontal cortex, insula, thalamic grey matter.
► Other regional alterations appear specific to illness stage or medication status.