Diagnosis

HC (n = 38)

MDD (n = 38)

significant

differences

sample name

young men (n = 25)

young women (n = 10)

old men (n = 20)

old women (n = 20)

young men (n = 7)

young women (n = 18)

old men (n = 3)

old women (n = 10)

Tryptophan (μM)

63.92 ± 10.84

67.79 ± 9.30

68.89 ± 13.32

47.68 ± 7.19

64.09 ± 13.77

58.48 ± 10.40

59.11 ± 2.026

51.24 ± 11.01

*1

Serotonin (nM)

1.29 ± 1.97

42.90 ± 35.49

68.61 ± 90.31

4.49 ± 6.03

325.6 ± 351.4

267.6 ± 204.4

120.3 ± 96.01

160.2 ± 145.2

*2

Kynurenine (nM)

713.18 ± 136.02

1588.09 ± 313.52

1696.82 ± 1074.65

719.94 ± 173.87

2506.5 ± 1042.9

1653.0 ± 510.16

1014.2 ± 418.25

1666.4 ± 534.60

*3

5-Hydroxyindoleacetic acid (nM)

9.00 ± 1.92

30.87 ± 9.55

33.15 ± 12.57

13.17 ± 3.30

28.04 ± 22.07

35.00 ± 28.99

22.82 ± 28.11

48.68 ± 58.22

*4