A unique neuroimaging biomarker has been identified for major depressive disorder (MDD), one of the most disabling and wide-spread mental health conditions, by researchers at Korea University Medicine. Led by Professors Byung-Joo Ham and Kyu-Man Han, this study published 8 May 2023 in Psychological Medicine found that the local gyrification index (LGI), a metric derived from brain scans measuring cortical folding, was substantially higher in those with MDD than in the healthy population. This indicates a clear link between abnormal gyrification and MDD, supporting the importance of the brain’s outermost cortex in its proper functioning and validates the LGI as a reliable indicator for diagnosing the illness.
For the first time, researchers have assessed the link between major depressive disorder (MDD) and a unique biomarker of brain development known as lissencephaly gyrification index (LGI). Using detailed brain MRI scans to observe the LGI values, the researchers discovered significant hypogyrification, or decreased cortical folding, in seven cortical regions across both hemispheres of the brain of MDD patients.
They also noted a surprising association between recurrent and duration of illness and increased gyrification in several occipital and temporal cortical regions. This breakthrough in MDD research sheds light on the potential of LGI as a trustworthy biomarker, transparent of spontaneous state fluctuations, for assessing MDD risk.
Dr. Han’s research results have far-reaching implications, offering potentially groundbreaking insights into the pathophysiology of Major Depressive Disorder (MDD). By highlighting the regions of hypogyrification that play a critical role in neural circuits pertaining to emotional regulation, these findings could provide a key starting point for targeting treatments to improve MDD symptoms, including non-invasive brain stimulation with electricity, specifically the stimulation of the prefrontal cortex.