Cognitive impairment and pain in depression: The mediating role of the kynurenine pathway

Table 3 Differences in tryptophan-kynurenine pathway metabolites between the with and without painful physical symptoms groups

Variable	With PPS group (n = 33)	Without PPS group (n = 37)	F value	P value
TRP	11.18 ± 2.17	11.51 ± 1.82	1.657	0.202
KYN	396.58 ± 92.55	333.62 ± 92.46	6.508	0.013
KA	2.52 ± 0.92	2.70 ± 2.12	1.063	0.306
QA	29.61 ± 13.12	27.25 ± 15.70	0.153	0.697
3-hydroxykynurenine	4.35 ± 1.75	4.13 ± 2.14	0.494	0.485
5-hydroxytryptamine	33.39 ± 40.01	22.71 ± 27.91	1.560	0.216
TRP-KYN	35.99 ± 7.82	29.00 ± 7.15	14.076	< 0.001
KA/QA	0.09 ± 0.04	0.10 ± 0.05	1.132	0.291

KA: Kynurenic acid; KYN: Kynurenine; PPS: Painful physical symptoms; QA: Quinolinic acid; TRP: Tryptophan.