Table 1.

CSF Cytokine and Tryptophan Catabolite Alterations in Patients With Schizophrenia, Bipolar Disorder, and MDD vs Controls

Marker	N			Mean ES	95% CI		P Value	Heterogeneity		I 2	References
	Studies	Pt	Control					χ2	P Value
Schizophrenia
IL-1α	2	70	31	−0.33	−0.77	0.11	.143	3.44	.06	70.9	43,44
IL-1β	3	57	45	0.75	0.29	1.21	.001	40.30	<.01	95.0	33,38,54
IL-2	4	114	52	−0.01	−0.35	0.33	.954	6.14	.11	51.2	33,35,43,44
sIL-2R	2	19	20	−0.84	−1.50	−0.18	.013	0.66	.42	0.0	33,46
IL-6	7	244	180	0.40	0.20	0.60	<.001	6.12	.53	0.0	27,33,37,38,53,54,56
IL-8	3	112	101	0.35	0.07	0.63	.013	1.01	.60	0.0	27,37,54
TNF-α
sTNF-R2	2	56	45	−0.09	−0.49	0.30	.646	2.56	.11	61.0	37,46
KYN	3	60	92	1.22	0.86	1.58	<.001	14.66	<.01	86.4	25,27,44
KYNA	4	148	141	0.59	0.34	0.83	<.001	2.87	.41	0.0	25–27,44
Bipolar disorder
IL-1α
IL-1β	2	151	101	0.31	0.05	0.58	.020	27.51	<.01	96.4	39,54
IL-2
sIL-2R
IL-6	2	151	101	−0.13	−0.39	0.12	.310	12.94	<.01	92.3	39,54
IL-8	2	151	101	0.22	−0.03	0.48	.087	6.97	<.01	85.7	39,54
TNF-α
sTNF-R2
KYN
KYNA	2	74	35	0.79	0.36	1.21	<.001	0.36	.408	0.0	48,49
MDD
IL-1α
IL-1β	2	30	57	0.27	−0.21	0.75	.266	12.28	<.01	91.9	41,45
IL-2
sIL-2R
IL-6	7	127	222	0.40	0.17	0.63	.001	21.49	<.01	67.4	34,41,45,47,50,53,57
IL-8	2	38	114	0.57	0.20	0.95	.003	2.12	.15	52.9	45,57
TNF-α	3	48	82	0.26	−0.10	0.63	.161	1.18	.55	0.0	41,45,47
sTNF-R2
KYN
KYNA

Note: CSF, cerebrospinal fluid; MDD, major depressive disorder; KYN, kynurenine; KYNA, kynurenic acid. Bolded P values were significant at the P < .05 level.