Table 1.

Brain glutamate homeostasis in depression.

S. No.	Diagnosis/model	Brain region	Species	Technique	Quality index	Glu	Glx	NAA	References
1.	MDD	dACC	Human (H 25, D 51)	MEGAPRESS, 4T	CRI < 19%	↓	–	–	Benson et al. (106)
2.	MDD	vmPFC	Human (H 63, D 31)	PRESS, 3T	CRLB < 30%	↓	↓	–	Draganov et al. 2020 (107)
3.	MDD	RFL	Human (H 32, D 32)	EPSI, 3T	CRLB < 25%	NS	–	↓	Kahl et al. (108)
4.	Depression (CRS)	SSC	Rat (H 8, D 33)	PRESS, 9.4T	CRLB < 15%, NR > 9.5	↓	↓	–	Seewo et al. (109)
5.	Depression (CRS)	NAc	Mice (H 14, D 14)	SPECIAL, 14.1T	CRLB < 20%	↓	–	↓	Cherix et al. (110)
6	BID EU	ACC	Humans (H 80, D 128)	PRESS, 3T	CRLB < 20%, SNR > 10	↑	↑	NS	Soeiro-de-SouZa et al. (111)
7.	Depression (CSDS)	PFC	Mice (H 24, D 25)	Ex vivo, 1H-[13C]-NMR, 14T	–	↓	–	↓	Mishra et al. (112)
8.	MDD	rdPFC	Human (H 33, D 25)	SPECIAL	CRLB < 20%	NS	↓	↓	Jollant et al. (113)
9.	MDD	PFC	Human (H 27, D 22)	PRESS, 3T	CRLB < 10%	↓	↓	–	Shirayama et al. (114)
10.	MDD	HPC	Human (H 38, D 63)	PRESS, 3T	CRLB < 20%	↑	–	–	Hermens et al. (115)
11.	Depression (CSDS)	PFC	Mice (H 15, D 30)	Ex vivo, 1H-[13C]-NMR, 14T	–	↓	–	↓	Veeraiah et al. (116)
12.	PPD	mPFC	Humans (H 12, D 12)	STEAM, 3T	CRLB < 20%	↑	NS	NS	McEwen et al. (117)
13.	Depression (CMS)	PFC & HPC	Rat (H 10, D 10)	PRESS, 7T	CRLB < 20%	↓	↓	↓	Hemanth Kumar et al. (118)
14.	MDD	vmPFC	Humans (H 15, D 45)	PRESS, 3T	CRLB < 30%	↓	–	↓	Portella et al. (119)
15.	MDD	ACC	Humans (H 26, D 23)	PRESS, 3T	CRLB < 20%, SNR > 15	↓	NS	↓	Järnum et al. (120)
16.	MDD	HPC	Humans (H 10, D 18)	PRESS, 3T	–	–	↓	–	Block et al. (121)
17.	Depression (CFSS)	PFC	Mice (H 12, D 12)	Ex vivo, 1H NMR, 11.7T	–	↓	↓	NS	Li et al. (122)
		HPC				↓	NS	↓
18.	MDD	dm/da PFC	Humans (H 20, D 20)	PRESS based J editing, 3T	–	–	↓	NS	Hasler et al. (71)
19.	MDD	Subcortical nuclei	Humans (H 21, D 20)	PRESS, 1.5T	–	↓	↓	–	Ajilore et al. (123)
20.	MDD	OCC	Humans (H 38, D 33)	ISIS, J-editing, 2.1T	–	↑	–	–	Sanacora et al. (72)
21.	MDD	ACC	Humans (H 18, D 19)	PRESS, 1.5T	–	↓	↓	NS	Auer et al. (124)

ACC, anterior cingulate cortex; BID EU, euthymic bipolar I disorder; CFS, chronic forced swim stress; CRS, chronic restraint stress; CUMS, chronic unpredictable mild stress; CSDS, chronic social defeat stress; CRI, Cramer–Rao index; CRLB, Cramer–Rao lower bound; dACC, dorsal anterior cingulate cortex; dm/daPFC, dorsomedial/dorsal anterolateral PFC; EPSI, echo planar spectroscopic imaging; EAP, experimental autoimmune prostitis; HPC, hippocampus; ISIS, image selected in vivo spectroscopy; LD, light deprivation; MDD, major depressive disorder; mPFC, medial prefrontal cortex; MEGA-PRESS, Meshcher–Garwood point-resolved spectroscopy; NAc, nucleus accumbens; NS, no significant change; OCC, occipital cortex; PFC, prefrontal cortex; PPD, postpartum depression; PRESS, point-resolved spectroscopy; rdPFC, right dorsal PFC; RFL, right frontal lobe; SNR, signal-to-noise ratio; SPECIAL, spin echo full intensity acquired localized sequence; SSC, sensorimotor cortex; STEAM, stimulated echo acquisition mode; TRD, treatment resistant depression; UDR, unipolar depression; vmPFC, ventromedial prefrontal region; ↓ depicts decrease, ↑ represents increase. The numbers in the parenthesis under species represent the number of healthy (H) and depressed (D) subject.