Electroconvulsive therapy, ketamine infusion, and total sleep deprivation all reduced depressive symptoms in 127 patients with treatment-resistant depression, but they affected other clinical measurements and brain structures differently. All three treatments increased gray matter volume in the left caudate. Only electroconvulsive therapy increased gray matter volume in the hippocampus, parahippocampus, amygdala, insula, fusiform gyrus, and several occipital and temporal areas. Neither baseline gray matter volume nor its change correlated with depressive symptom improvement for any treatment. The findings suggest that different rapid interventions for treatment-resistant depression have distinct effects on brain structure, which may help personalize treatment.
Alpha oscillations (8–13 Hz) are the dominant electrophysiological rhythms during resting state and correlate more strongly than other frequency bands with blood oxygen-level dependent (BOLD) signals in default mode network (DMN) regions. Using simultaneously collected high-density EEG and fMRI data from 20 healthy volunteers at rest, the authors detected the DMN from source-reconstructed EEG data across multiple frequency bands and mapped correlations between EEG-derived DMN activity and fMRI-BOLD signals voxel by voxel. The correlation map for alpha oscillations overlapped with DMN regions more than maps for other bands did, supporting a primary role of alpha oscillations in DMN functioning. Simultaneous EEG-fMRI is suggested as a tool for investigating human brain networks.