Cortical Thinning in Network-Associated Regions inCognitively Normal and Below-Normal Range Schizophrenia

This study assessed whether cortical thickness across the brain and regionally in terms of the default mode, salience, and centralexecutive networks differentiates schizophrenia patients and healthy controls with normal range or below-normal range cognitiveperformance. Cognitive normality was defined using the MATRICS Consensus Cognitive Battery (MCCB) composite score (𝑇=50±10) and structural magnetic resonance imaging was used to generate cortical thickness data. Whole brain analysis revealed thatcognitively normal range controls (𝑛=39)hadgreatercorticalthicknessthanbothcognitivelynormal(𝑛=17) and below-normalrange (𝑛=49) patients. Cognitively normal controls also demonstrated greater thickness than patients in regions associated withthe default mode and salience, but not central executive networks. No differences on any thickness measure were found betweencognitively normal range and below-normal range controls (𝑛=24) or between cognitively normal and below-normal rangepatients. In addition, structural covariance between network regions was high and similar across subgroups. Positive and negativesymptom severity did not correlate with thickness values. Cortical thinning across the brain and regionally in relation to the defaultand salience networks may index shared aspects of the psychotic psychopathology that defines schizophrenia with no relation tocognitive impairment