New biomarker for major depressive disorder identified

Researchers led by Professor Byung-Joo Ham and Associate Professor Kyu-Man Han from Korea University Medicine have reported the successful identification of a neuroimaging-based biomarker for MDD in a recent study.

Prof. Ham explains, “Our first-of-its-kind study investigated the association of MDD with the local gyrification index or LGI of multiple cortical regions at the whole-brain level and the association of local gyrification index( LGI )with the clinical characteristics of MDD.”

But what indeed is the local gyrification index (LGI)?

LGI is a measurement of cortical folding that is derived from brain scans as a ratio of the curved and smoothed surfaces of the cortex in a region of interest. In this study, the researchers compared the LGI values from multiple cortical regions in the brain of patients with MDD with those of healthy individuals. The neuroimaging data used to compare and analyze both groups were obtained from magnetic resonance imaging scans.

Prof. Ham and his team showed that LGI values from multiple cortical regions in the brain of patients with MDD showed hypo gyrification—a condition characterized by decreased cortical folding—when compared with healthy individuals. They found that patients with MDD showed significantly lower LGI values in 7 out of the 66 cortical regions assessed (in both hemispheres of the brain), which included the prefrontal cortex, anterior cingulate cortex, insula, and several temporal and parietal regions. Notably, the most significant hypo gyrification was observed in the left pars triangularis of patients with MDD.

Reference: Decreased Cortical Gyrification in Major Depressive Disorder, Psychological Medicine, DOI: https://doi.org/10.1017/s0033291723001216