Abnormal default-mode network homogeneity and its correlations with neurocognitive deficits in drug-naive first-episode adolescent-onset schizophrenia

The default mode network (DMN), is one of the most popularly employed resting-state networks applied in schizophrenia (SCZ) research. However, the homogeneity of this network in adolescent-onset SCZ (AOS) remains unknown. This study aims to use network homogeneity (NH) to explore the functional connectivity in the DMN of AOS patients. Resting-state functional magnetic resonance imaging scans were used to study 48 drug-naïve, first-episode AOS patients and 31 healthy age, gender, and education matched control. An automatic NH approach was employed to analyze the imaging dataset. Our results revealed that the patients had significantly higher NH values in the left medial prefrontal cortex (MPFC), and significantly lower values in the bilateral posterior cingulate cortex/precuneus (PCC/PCu) than those in healthy controls. We performed the receiver operating characteristic curve analysis to show that NH values of the left superior MPFC might be regarded as a potential marker in helping to identify patients. In addition, negative associations were found regarding abnormal values of NH in the left PCC/PCu as well as in the Maze and Stroop color-word tests in patients. The outcomes showed abnormal NH values in the DMN of drug-naïve, first-episode AOS suggesting specific functions of the DMN in the pathophysiology of SCZ.