Neural Mechanisms of MBCT in Late-Life Depression

To further explore possible mechanisms of MBCT, fMRI was performed to measure changes in brain function during the resting state (33 (link), 34 (link)) in LLD patients before and after treatment at baseline (pre-test) and 8 weeks (post-test). fMRI data for all participants were acquired using a research-dedicated 3.0 T GE EXCITE HD scanner (GE Medical Systems, Milwaukee, WI, USA) at Peking University Sixth Hospital with an 8-channel head coil. For each participant, high-resolution T1-weighted structural images were acquired using the following parameters: field of view (FOV) = 25.6 cm³, flip angle = 12°. Eight-min resting-state fMRI scans were performed using a gradient-echo echo-planar imaging (EPI) sequence (FOV = 22.0 cm³, TR = 2,000 ms, TE = 30 ms, flip angle = 90°, number of slices = 43, total scans = 240). We then performed diffusion tensor imaging (DTI) scans by a gradient-echo EPI sequence (FOV = 22.0 cm³, TR = 2,000 ms, TE = 30 ms, flip angle = 90°, number of slices = 43, total scans = 240). To reduce motion artifacts, the participant's head was fixed with foam pads on the scanner bed. Each participant was instructed to stay still and awake during data acquisition.