Cortical abnormalities and association with symptom dimensions across the depressive spectrum

- Few studies have investigated the relationship between structural brain abnormalities and dimensions of depressive symptomatology.
- Widespread brain morphometric abnormalities were associated with major depressive disorder (MDD), particularly within specific frontal and medial temporal regions of the brain.
- Across the entire cohort of subjects (MDD and healthy volunteers), cortical volume reductions in the right ventrolateral prefrontal cortex robustly correlated with negative affect (sadness and worry) as well as mental fatigue.
- Overall, we found that cortical morphometric reductions are associated with specific depressive symptoms across the illness spectrum.
- If replicated, structural MRI abnormalities linked with specific symptoms of depression may help to identify patients at high risk for depression and enable earlier treatment interventions.

BackgroundFew studies have investigated the relationship between structural brain abnormalities and dimensions of depressive symptomatology.MethodsIn the current study, we examined the relationship between cortical structural abnormalities and specific behavioral dimensions relevant to depression in a sample of unmedicated patients with major depressive disorder (MDD, n=57) and demographically similar healthy control volunteers (HC, n=29). All subjects underwent diagnostic assessment with the SCID, MRI at 3T, and dimensional assessments using the visual analog scales (VAS). Cortical regions were extracted for each subject, and group comparisons of cortical volume (CV), surface area (SA), and cortical thickness (CT) were performed controlling for multiple comparisons using a bootstrapping technique. Regions demonstrating group differences were analyzed for correlation with specific dimensions assessments.ResultsAs compared with HC, MDD subjects exhibited reduced CV within the left supramarginal gyrus, right ventrolateral prefrontal cortex (VLPFC), entorhinal cortex, parahippocampal gyrus, fusiform gyrus and pericalcarine; reduced SA in the right VLPFC, cuneus, and left temporal pole; and reduced CT in the right rostral anterior cingulate cortex (rACC) (all p's<0.05, corrected). The largest effect occurred within the right VLPFC for CV and SA (MDD