Saturated Fatty Acids and White Matter Microstructure in Individuals With At-risk Mental State.

BACKGROUND AND HYPOTHESIS

Excessive saturated or deficient unsaturated fatty acids and white matter microstructural abnormalities are observed before the psychosis onset. Whereas fatty acids variations are implicated in white matter pathology, conventional Diffusion Tensor Imaging has limitations in disentangling their biological relevance. Free-water imaging provides improved biological specificity to white matter microstructure, such as fractional volume of free-water (FW) and tissue-specific fractional anisotropy (FAt). This study aims to investigate the associations between altered proportion of saturated or unsaturated fatty acids and free-water imaging parameters in prodromal psychosis.

STUDY DESIGN

We applied free-water imaging and Tract-Based Spatial Statistics to compare FAt and FW between 78 individuals with at-risk mental state (ARMS) and 129 healthy controls. In a subsample with available blood samples (n = 53 and n = 42, respectively), relationships between fatty acid composition of erythrocyte membrane and FAt or FW were examined alongside clinical and cognitive variables.

STUDY RESULTS

Compared to the controls, individuals with ARMS exhibited higher relative concentrations of saturated fatty acids as well as lower FAt and higher FW in multiple association and projection fibers. In the ARMS group, elevated proportion of saturated fatty acids was associated with lower FAt and with positive symptoms and impaired verbal fluency.

CONCLUSIONS

The association of saturated fatty acids with FAt in ARMS suggests that fatty acids may influence disrupted white matter microstructure, such as impaired myelin maintenance prior to psychosis onset. Future studies should explore early interventions to mitigate white matter cellular deterioration by optimizing saturated fatty acid levels.