Morphometric Brain Alterations in Patients with Depression after COVID-19: A Comparative Study with Non-COVID-19 Depression and Healthy Controls

The aim of this study was to compare structural brain differences in individuals who experienced a depressive episode after COVID-19 with those who developed a first episode of depression without prior COVID-19 and healthy controls to uncover neural alterations associated with COVID-19-related depression. From 2020 to 2021, 32 patients with a first major depressive episode (MDD) after COVID-19 were recruited. MDD was diagnosed by psychiatrists, and depression severity was assessed using the Beck Depression Inventory-II. All patients underwent brain MRI on a 1.5 T scanner with morphometric analysis using FreeSurfer 7.2.0. These data were compared with data from 32 age- and sex-matched patients with first-episode MDD treated at the same center in the preCOVID period, and 32 healthy controls recruited between 2017 and 2019. Statistical analysis was performed using ANCOVA with Holm–Bonferroni correction for multiple comparisons. The study revealed significant morphometric differences between the groups. Patients with depression after COVID-19 showed decreased volumes in the left supramarginal gyrus and right inferior parietal gyrus, and increased volumes in the right supramarginal gyrus compared to patients with non-COVID-19 depression. Compared to healthy controls, the COVID-19 exposed group had decreased volumes in the left paracentral gyrus and right entorhinal cortex. In contrast, the COVID-19 unexposed depression group had enlarged third and left lateral ventricles and left choroid plexus. These findings highlight distinct neural alterations in COVID-19-related depression, emphasizing the relevance of morphometric studies for understanding the neural substrates of depression. Further research is needed to explore the clinical implications and potential for targeted interventions.