Brain network properties in treatment-resistant schizophrenia patients and their healthy siblings

To explore brain network topological properties in treatment-resistant schizophrenia patients and their healthy siblings, identify genetic susceptibility markers and protective factors of the disease, and assist clinical diagnosis and treatment.

28 treatment-resistant schizophrenia patients (after excluding two for head motion), 25 healthy siblings, and 38 healthy controls were enrolled. Resting-state functional brain networks were constructed using functional magnetic resonance imaging (fMRI) data. Topological properties were analyzed via graph theory, followed by statistical and correlation analyses with clinical symptom scales.

1. No significant difference in small-world properties among the three groups. 2. No difference in global efficiency. 3. No difference in local efficiency. 4. In the sibling group, nodal efficiency and degree centrality of the bilateral amygdala and right hippocampus were lower than those in healthy controls, while those of the right thalamus were lower than in patients. 5. Right thalamus properties in patients negatively correlated with PANSS scores and positively correlated with WAIS digit symbol scores.

Healthy siblings show brain network abnormalities, while patients have higher right thalamic metrics than siblings but do not differ from controls. The right thalamus correlates negatively with negative symptoms; this is observational, not a prognostic indicator. Whether this reflects compensation (e.g., thalamic compensation) remains speculative. Brain network abnormalities might tentatively suggest genetic susceptibility, and siblings could have protective factors. All findings are preliminary and require validation.