Table 2.

Interaction term (group * change in mean diffusivity) statistics and robustness of findings when utilizing clinician-administered (MADRS) vs. self-report (QIDS) outcomes and when including covariates in models.

Region	No covariate	Covarying TRD severity	Covarying medication burden	Covarying pre-MD
MADRS
L BA10	∆R2 = 0.029; β = 0.308; t96 = 1.760; p = 0.082	∆R2 = 0.022; β = 0.267; t96 = 1.534; p = 0.128	∆R2 = 0.028; β = 0.302; t96 = 1.716; p = 0.089	∆R2 = 0.035; β = 0.290; t96 = 1.641; p = 0.104
R BA10	∆R2 = 0.000; β = 0.019; t96 = 0.109; p = 0.913	∆R2 = 0.002; β = −0.083; t96 = −0.474; p = 0.637	∆R2 = 0.000; β = 0.013; t96 = 0.078; p = 0.938	∆R2 = 0.001; β = −0.043; t96 = −0.250; p = 0.803
L Amygdala	∆R2 = 0.045; β = 0.414; t96 = 2.238; p = 0.028	∆R2 = 0.055; β = 0.459; t96 = 2.518; p = 0.014	∆R2 = 0.043; β = 0.410; t96 = 2.188; p = 0.031	∆R2 = 0.044; β = 0.414; t96 = 2.13; p = 0.029
R Amygdala	∆R2 = 0.001; β = −0.046; t96 = −0.255; p = 0.799	∆R2 = 0.000; β = −0.028; t96 = −0.158; p = 0.874	∆R2 = 0.001; β = −0.049; t96 = −0.270; p = 0.788	∆R2 = 0.001; β = −0.048; t96 = −0.266; p = 0.791
L Hippocampus	∆R2 = 0.044; β = −0.337; t96 = −2.178; p = 0.032	∆R2 = 0.048; β = −0.351; t96 = −2.315; p = 0.023	∆R2 = 0.044; β = −0.338; t96 = −2.175; p = 0.032	∆R2 = 0.045; β = −0.343; t96 = −2.202; p = 0.030
R Hippocampus	∆R2 = 0.033; β = −0.303; t96 = −1.902; p = 0.060	∆R2 = 0.035; β = −0.310; t96 = −1.986; p = 0.050	∆R2 = 0.034; β = −0.308; t96 = −1.923; p = 0.058	∆R2 = 0.033; β = −0.304; t96 = −1.897; p = 0.061
vACC	∆R2 = 0.001; β = −0.043; t96 = −0.254; p = 0.800	∆R2 = 0.000; β = −0.032; t96 = −0.193; p = 0.847	∆R2 = 0.001; β = −0.042; t96 = −0.246; p = 0.806	∆R2 = 0.001; β = −0.055; t96 = −0.322; p = 0.748
QIDS
L BA10	∆R2 = 0.045; β = 0.386; t96 = 2.143; p = 0.035	∆R2 = 0.037; β = 0.352; t96 = 1.952; p = 0.054	∆R2 = 0.043; β = 0.377; t96 = 2.084; p = 0.040	∆R2 = 0.046; β = 0.382; t96 = 2.094; p = 0.039
R BA10	∆R2 = 0.016; β = 0.238; t96 = 1.305; p = 0.195	∆R2 = 0.007; β = 0.160; t96 = 0.855; p = 0.395	∆R2 = 0.016; β = 0.233; t96 = 1.276; p = 0.205	∆R2 = 0.010; β = 0.212; t96 = 1.144; p = 0.256
L Amygdala	∆R2 = 0.059; β = 0.477; t96 = 2.446; p = 0.016	∆R2 = 0.070; β = 0.521; t96 = 2.711; p = 0.008	∆R2 = 0.056; β = 0.465; t96 = 2.359; p = 0.020	∆R2 = 0.050; β = 0.440; t96 = 2.261; p = 0.026
R Amygdala	∆R2 = 0.001; β = −0.063; t96 = −0.333; p = 0.740	∆R2 = 0.001; β = −0.047 t96 = −0.254; p = 0.800	∆R2 = 0.001; β = −0.068; t96 = −0.360; p = 0.719	∆R2 = 0.002; β = −0.072; t96 = −0.392; p = 0.696
L Hippocampus	∆R2 = 0.001; β = −0.061; t96 = −0.353; p = 0.725	∆R2 = 0.002; β = −0.065; t96 = −0.383; p = 0.702	∆R2 = 0.001; β = −0.060; t96 = −0.351; p = 0.727	∆R2 = 0.002; β = −0.070; t96 = −0.410; p = 0.683
R Hippocampus	∆R2 = 0.000; β = −0.011; t96 = −0.063; p = 0.950	∆R2 = 0.000; β = −0.010; t96 = −0.059; p = 0.953	∆R2 = 0.000; β = −0.017; t96 = −0.096; p = 0.924	∆R2 = 0.000; β = −0.007; t96 = 0.042; p = 0.967
vACC	∆R2 = 0.005; β = 0.124; t96 = 0.695; p = 0.489	∆R2 = 0.006; β = 0.140; t96 = 0.793; p = 0.430	∆R2 = 0.005; β = 0.128; t96 = 0.713; p = 0.478	∆R2 = 0.005; β = 0.118; t96 = 0.654; p = 0.515

The values provided for ∆R², β, t, and p in each column above all uniformly correspond to the addition of the group * ∆MD interaction term (for the specified region) into regression models which also contain main effects of group and ∆MD in predicting % improvement in the MADRS (top half of table) and QIDS (bottom half of table). The “No Covariate” column reflects the statistics for primary models, as reported in “Results” section text; the additional 3 columns to the right reflect the impact on the interaction term statistics when also including each specified variable as a covariate in models.