TABLE 2.

Results of mixed models predicting post-ketamine change from baseline in the KYN pathway

Dependent Variable		230 minutes	Day 1	Day 3
IDO (ln)	Change from baseline (95% CI)	−0.16 (−0.27 – −0.06)	−0.24 (−0.35 – −0.12)	−0.2 (−0.31 – −0.1)
	Statistical Test	t(34) = −3.05, p = .004	t(34) = −4.12, p = .0002	t(34) = −3.91, p = .0004
KYN (ln)	Change from baseline (95% CI)	0.07 (−0.11 – 0.26)	0.5 (0.23 – 0.76)	0.39 (0.08 – 0.7)
	Statistical Test	t(34) = 0.77, p = .45	t(34) = 3.69, p = .0008	t(34) = 2.44, p = .02
KynA (ln)	Change from baseline (95% CI)	0.03 (−0.04 – 0.1)	0.12 (0.04 – 0.2)	0.15 (0.06 – 0.23)
	Statistical Test	t(34) = 0.82, p = .42	t(34) = 2.85, p = .007	t(34) = 3.36, p = .002
QA (ln)	Change from baseline (95% CI)	0.01 (−0.01 – 0.04)	0.01 (−0.01 – 0.04)	0.03 (−0.02 – 0.08)
	Statistical Test	t(34) = 1.28, p = .21	t(34) = 0.94, p = .35	t(34) = 1.26, p = .22
KYN/KynA	Change from baseline (95% CI)	0.01 (−0.03 – 0.06)	0.09 (0.03 – 0.15)	0.07 (−0.01 – 0.14)
	Statistical Test	t(34) = 0.59, p = .56	t(34) = 2.91, p = .006	t(34) = 1.76, p = .087
QA/KYN	Change from baseline (95% CI)	0 (−0.01 – 0.01)	−0.02 (−0.03 – −0.01)	−0.01 (−0.02 – 0.01)
	Statistical Test	t(34) = 0.24, p = .81	t(34) = −3.31, p = .002	t(34) = −0.91, p = .37
KynA/QA	Change from baseline (95% CI)	−0.09 (−0.32 – 0.13)	0.03 (−0.18 – 0.25)	−0.12 (−0.42 – 0.19)
	Statistical Test	t(34) = −0.82, p = .42	t(34) = 0.29, p = .78	t(34) = −0.75, p = .46

IDO: indoleamine 2,3-dioxygenase; KYN: kynurenine; KynA: kynurenic acid; QA: quinolinic acid; ln: natural logarithm

Note: Results of a mixed model with empirical sandwich variance estimator and repeated effect of time. Type 3 tests are shown in Supplementary Table S2. Table shows specific contrast between estimated values at baseline and follow-up (illustrated in Figure 2). Age, body mass index (BMI), and type of mood stabilizer were included as covariates in all analyses.