Aberrant levels of cortical myelin distinguish individuals with unipolar depression from healthy controls

Abstract

The association of unipolar depression (UD), relative to healthy controls (HC), with cortical myelin is underexplored, despite growing evidence of associations with white matter tract integrity. We characterized cortical myelin in the 360 Glasser atlas regions using the T1w/T2w ratio in 39 UD and 47 HC participants (ages=19-44, 75% female). A logistic elastic net regularized regression with nested cross-validation and a subsequent linear discriminant analysis conducted on held-out samples were used to classify UD vs. HC. True-label model performance was compared against permuted-label model performance. Cortical myelin distinguished UD from HC with 68% accuracy (p<0.001; sensitivity=63.8%, specificity=71.5%). Consistently selected regions were located in the orbitofrontal cortex, anterior cingulate, extended visual, and auditory cortices, and showed statistically significant both decreases and increases in myelin levels in UD vs. HC. The patterns of cortical myelin in these regions may be a biomarker of UD.

Neurofilament light protein as a biomarker in depression and cognitive function

“…Disruptions of axon-myelin adhesion seen in participants diagnosed with depression can initiate axonal damage by altering the axonal cytoskeleton. In depression, there are decreases in myelin cross-sectional areas across specific regions and at a whole brain level [2,22].…”