Large-scale networks underlie cognitive insight differs between untreated adolescents ongoing their first schizophrenic episode and their reference non-schizophrenic mates.

Objectives: Cognitive insight (CI), the ability to perceive erroneous beliefs and correcting them based on safe experiences, is a common cognitive manifestation among schizophrenic individuals. Even though the functional morphology of the default mode network (DMN), the central executive network (CEN) and the salience network (SN) differs between non-schizophrenic and schizophrenic individuals, it is unclear whether such differences are already in place by the first schizophrenic episode. Methods: Forty-two adolescents, including twenty-one AOS subjects was recruited, and performed independent component analysis (ICA) on resting-state fMRI data to explore alterations in the three networks in schizophrenia and the association of network changes with Beck Cognitive Insight Scale (BCIS) scores. Results: Compared to the non-schizophrenic group, the AOS group showed hyper-connectivity in the left middle temporal gyrus (MTG) and hypo-connectivity in the right parahippocampal gyrus within the DMN; hypo-connectivity in the dorsal anterior cingulate (dACC) and supplementary motor area (SMA) within the SN were also detected in AOS individuals. CI subscores were positively correlated with functional connectivity (FC) in the right parahippocampal gyrus. Conclusions: The correlations reported here suggest that increased DMN connectivity in the right parahippocampal gyrus might be an early neural correlate of reduced cognitive insight in a number, but not all, adolescent untreated individuals ongoing their first schizophrenic episode.

Alterations in functional network centrality in first-episode drug-naïve adolescent-onset schizophrenia.

Schizophrenia is a disorder resulting from aberrant brain networks and circuits. In the current study, we aimed to investigate specific network alterations in adolescent-onset schizophrenia (AOS) and to help identify the neurophysiological mechanisms of this adolescent disorder. We recruited forty-one subjects, including 20 AOS patients and 21 matched healthy controls (HCs), and we acquired brain images to examine the specific changes in functional network patterns using degree centrality (DC), which quantifies the strength of the local functional connectivity hubs. Whole-brain correlation analysis was applied to assess the relationships between clinical characteristics and DC measurements. The AOS group exhibited increased DC in the right inferior frontal lobe, right fusiform gyrus and right thalamus (p < 0.05, AlphaSim correction). Whole-brain correlation analysis found that the DC value in the right parahippocampus was positively correlated with PANSS-positive symptom scores (r = 0.80); DC in the right superior parietal lobe (SPL) was positively correlated with PANSS-negative symptom scores (r = 0.79); DC in the left precuneus was positively correlated with self-certainty (SC) scores (r = 0.70); and DC in the left medial frontal gyrus (MFG) was negatively correlated with self-reflectiveness (SR) scores (r = 0.69). We conclude that frontoparietal network and cortico-thalamo-cortical pathway disruptions could play key roles in the neurophysiological mechanisms underlying AOS. In AOS patients, the right parahippocampus and SPL are important structures associated with positive and negative symptoms, respectively, and the left precuneus and MFG contribute to deficits in cognitive insights.