Early deviations from normative brain morphology and cortical microstructure in schizophrenia spectrum disorders

Area of Science:

• Neuroimaging
• Psychiatry
• Brain Structure

Background:

• Schizophrenia spectrum disorders (SSD) involve gray matter (GM) and white matter (WM) alterations.
• Identifying early biomarkers is challenging due to disease progression and brain maturation.
• Understanding early structural changes is crucial for timely intervention.

Purpose of the Study:

• Investigate structural brain abnormalities in drug-naïve/minimally medicated SSD patients.
• Examine associations between structural markers and symptom severity.
• Evaluate the potential of normative modeling and diffusion imaging for early SSD detection.

Main Methods:

• Structural MRI for cortical thickness (CT) and subcortical volumes.
• Diffusion Tensor Imaging (DTI) for fractional anisotropy (FA) and cortical mean diffusivity (cMD).
• Normative modeling to derive centile scores for structural metrics.

Main Results:

• SSD patients exhibited reduced CT centiles, ventricular enlargement, and subcortical reductions (hippocampus, thalamus, amygdala, nucleus accumbens).
• Widespread increases in cMD were observed in SSD.
• Positive symptoms correlated with reduced CT/FA and increased cMD; negative symptoms showed no significant associations.

Conclusions:

• Early, multimodal brain abnormalities are present in SSD.
• Normative modeling and diffusion imaging markers show promise for identifying individualized early brain changes.
• Cortical mean diffusivity (cMD) may serve as a potential marker for SSD-related microstructural alterations.