Table 1.
Demographic and clinical characteristics of MDD patients and healthy controls.
Abbreviation: HDRS-17, Hamilton Depression Rating Scale 17 Items; PHQ-9, Patient Health Questionnaire 9 Items; QIDS, Quick Inventory of Depressive Symptomatology; T-AI, Trait Anxiety Inventory.
Fig 1.
Regions showing group differences in task-induced activation and resting-based ALFF.
(A) Compared with the HC group, the MDD group showed only decreased activation in the frontal-parietal, subcortical, and midbrain areas, especially in the dorsal part of the anterior cingulate cortex (dACC) and anterior parts of the bilateral insulae (AI) which constitute the salience network. (B) Comparison between the two groups demonstrated significant differences in the standardized ALFF (zALFF) values based on resting-state data. The bilateral AI showed significantly increased zALFF values in the MDD group. The color bars indicate t-values for each analysis.
Table 2.
Regions with decreased activation elicited by contrasts of MDD versus HC in positive, neutral, and negative tasks.
Thresholds were set at a voxel-level p < 0.005, cluster size > 1242 mm3 voxels, corresponding to a corrected p < 0.05 as determined by AlphaSim correction. Abbreviation: IFGorb, orbital portion of inferior frontal gyrus; dACC, dorsal part of anterior cingulate cortex; DLPFC, dorsolateral prefrontal cortex; AG, angular gyrus; L, left; R, right; BA, Brodmann area.
Table 3.
Regions showing group differences in zALFF values.
Thresholds were set at a voxel-level p < 0.005, cluster size > 351 mm3 voxels, corresponding to a corrected p < 0.05 as determined by AlphaSim correction. Abbreviation: sgACC, subgenual part of anterior cingulate cortex; MTG, middle temporal gyrus; DLPFC, dorsolateral prefrontal cortex; AG, angular gyrus; Parahip, parahippocampal gyrus; Amyg, amygdala; PreCG, precentral gyrus; PostCG, postcentral gyrus; LG, lingual gyrus.
Fig 2.
Brain regions showing synchronized abnormalities across task and resting states in MDD group.
Regions with synchronized abnormalities in the MDD group are shown by overlapping alterations revealed in task-activated brain maps and resting-based zALFF map, respectively. Among the regions, the bilateral anterior insulae (AI) were determined as seeds for further analyses.
Table 4.
Common brain regions showing abnormalities in both task and resting states in MDD group.
The bilateral anterior insulae (AI) were determined as seeds for further analyses.
Fig 3.
Results of resting-state functional connectivity analysis (rs-FC).
Voxel-wise analyses were performed for each subject, followed by group-level t-tests. One-sample t-tests were only used for the HC data to show the intact rs-FC in the healthy state (left parts of A and B). Two-sample t-tests were used to show the altered rs-FC caused by MDD (right parts of A and B). (A) Results of L. AI-centered rs-FC analysis. (B) Results of R. AI-centered rs-FC analysis. The color bars indicate t-values for each analysis. Abbreviation: mPFC, medial prefrontal cortex; sgACC, subgenual part of anterior cingulate cortex; dACC, dorsal part of anterior cingulate cortex; SMA, supplementary motor area; PCC, posterior cingulate cortex; NAcc, nucleus accumbens; LG, lingual gyrus; DLPFC, dorsolateral prefrontal cortex; CN, caudate nucleus; AI, anterior insula; THA, thalamus; Puta, putamen; AG, angular gyrus; L, left; R, right.
Table 5.
Regions showing group differences in voxel-wise functional connectivity based on resting-state data.
Thresholds were set at a voxel-level p < 0.005, cluster size > 351 mm3 voxels, corresponding to a corrected p < 0.05 as determined by AlphaSim correction. Abbreviation: sgACC, subgenual part of anterior cingulate cortex; mPFC, medial prefrontal cortex; LG, lingual gyrus; NaCC, nucleus accumbens; dACC, dorsal part of anterior cingulate cortex; DLPFC, dorsolateral prefrontal cortex; MCG, middle cingulate gyrus; SMA, supplementary motor area; SPL, superior parietal lobule; STG, superior temporal gyrus; MOG, middle occipital gyrus; PCC, posterior cingulate cortex; AG, angular gyrus.
Fig 4.
Correlations between fMRI results and clinical data in MDD group.
(A) The rs-FC between the left AI and ipsilateral putamen positively correlated to the mean percentage BOLD signal change of the left AI during the PT; (B) mean percentage BOLD signal change of the right AI during the PT exhibited negative correlations with the total score of HDRS-17; (C) the rs-FC between the left AI and left sgACC positively correlated to the subscore for “little interest or pleasure in doing things” of PHQ-9; (D) mean percentage BOLD signal change of the right AI during the PT presented negative correlations with the subscore for “feeling down, depressed or hopeless” of PHQ-9. The HC group did not show any significant correlation between brain functional data and clinical scores. Abbreviation: rs-FC, resting-state functional connectivity; PT, positive task; AI, anterior insula; sgACC, subgenual part of anterior cingulate cortex; HDRS-17, Hamilton Depression Rating Scale 17 Items; PHQ-9, Patient Health Questionnaire 9 Items.