Macro- and Micro-Structural Alterations in the Midbrain in Early Psychosis

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Early psychosis (EP) is characterized by rapid brain changes, with growing evidence pointing to altered functional connectivity and structure.
• The midbrain plays a critical role in psychotic disorders, especially during the EP phase.
• The Human Connectome Project - Early Psychosis (HCP-EP) dataset provides a valuable resource for studying brain alterations in EP.

Approach:

• A multimodal MRI approach was used, combining Deformation Based Morphometry (DBM) and Diffusion Tensor Imaging (DTI).
• Macro- and micro-structural brain alterations were examined in 179 participants (123 EP, 56 controls).
• Tract-Based Spatial Statistics (TBSS) and correlation analyses were employed to assess white matter integrity and its association with clinical outcomes (PANSS).

Key Points:

• DBM revealed structural alterations in the hippocampus, midbrain, and caudate/putamen.
• DTI analysis indicated midbrain reductions in Fractional Anisotropy (FA) and Axial Diffusivity (AD), with increased Mean Diffusivity (MD).
• Midbrain volume correlated with cognitive scores and all DTI metrics; FA correlated with PANSS dimensions.

Conclusions:

• Findings highlight midbrain circuitry involvement and complementary alterations in the early stages of psychosis.
• The study provides insights into potential brain-based biomarkers for EP.
• This research paves the way for future investigations into the relationship between neuroimaging findings and clinical manifestations in psychosis.