Fig. 2.

The functional connectivity between the stimulated left DLPFC and left NAcc (MNI coordinates: −9, 9, −8). The subjects are marked with different colors according to stimulated DLPFC–NAcc FC strength a The inset box-and-whisker plot indicates the statistical differences of FC between groups. The upper and lower whiskers denote the largest and smallest values, respectively. The early improvers exhibited increased negative FC with respect to early non-improvers (Mann–Whitney U-test, U = 19.0, P = 0.03). The scatter-plot indicates a significant negative correlation between the left DLPFC–NAcc FC strength and the HAMD-17 improvement ratio b and the HAMA-14 improvement ratio c Filled circles denote data points included in the correlation; open circles denote outliers. Solid lines and dashed lines represent the best-fit line and the 95% confidence interval of Pearson’s correlation coefficient, respectively