Fig. 2. Associations between change in depression and change in hippocampal mean diffusivity as a function of treatment.

Within-group correlations between change in MADRS score and the change in mean diffusivity for left (A) and right (B) hippocampus. Post hoc Pearson r and p values shown separately for the vehicle (n = 31) and ketamine (n = 67) groups; see main text and Table 2 for full omnibus regression statistics. A positive change in depression score indicates an improvement in depression on the MADRS, and a positive change in MD indicates decreased diffusion in that region (interpreted as increased plasticity).