Functional stability predicts depressive and cognitive improvement in major depressive disorder: A longitudinal functional MRI study

Functional stability is a newly developed dynamic functional connectivity approach. The objective of this study was to adopt functional stability to investigate diagnosis-associated abnormalities (patients vs. controls) and status-related changes (acute vs. remitted status) in brain function in major depressive disorder (MDD). 132 MDD patients and 102 healthy controls underwent resting-state functional MRI as well as clinical and cognitive assessment at baseline, with 48 patients completing follow-up examinations at an average of 7 months. Results showed no group differences in baseline functional stability and no longitudinal functional stability changes from acute to remitted status in patients. However, we found that baseline functional stability in the dorsal and ventral anterior cingulate cortex, calcarine sulcus, and middle occipital gyrus could predict improvement in depressive symptoms from acute to remitted status in MDD patients, with longitudinal functional stability changes in these regions related to the degree of symptom improvement. In addition, lower baseline functional stability in the inferior temporal gyrus could predict a greater improvement in sustained attention, which was associated with a greater functional stability increase in this region. Our findings highlight functional stability as a potential prognostic biomarker to predict and track disease progression or stratify MDD patients for optimizing disease management and treatment strategies.