Table 1. ¹H-MRS GABA data sets: clinical characteristics of the samples.

Region	First author (reference)	Year	Patient group	g	Sample size		SCZ %M	SCZ age mean	%AP	%BZ	PANSS	DOI
					C	SCZ
mFC	Goto55, 56	2009	FEP	−0.2	18	18	50	29	100	NR	68	0.5
	Öngür57	2010	SCZ	0.5	19	21	67	39	95	76	51	21
	Tayoshi58	2010	SCZ	−0.3	29	38	53	34	100	42	51	21
	Kegeles40	2012	SCZ unmed	0.7	11	16	69	32	0	19	71	7
	Kegeles40	2012	SCZ med	0.2	11	16	69	32	100	19	57	9
	Rowland42	2013	SCZ young	0.0	10	11	82	30	100	0	63	7.7
	Rowland42	2013	SCZ old	−1.0	10	10	70	51	100	0	57	25.5
	Marsman59	2014	SCZ	−0.8	19	13	76	28	100	35	53	6.5
	De la Fuente Sandoval41	2015	CHR	0.7	24	23	65	21	0	0	NR	—
	Brandt60	2016	SCZ	0.3	24	24	79	38	100	17	NR	NR
	Marenco38	2016	Siblings	−0.7	61.3	31	55	30	0	0	NR	—
	Marenco38	2016	SCZ unmed	−0.4	61.3	25	72	28	0	0	NR	6.0
	Marenco38	2016	SCZ med	−0.3	61.3	70	71	31	100	36	NR	9.5
	Menschikov61	2016	CHR	−4.1	26	21	100	NR	NR	NR	NR	—
	Rowland43	2016	SCZ young	0.0	40	29	69	26	93	0	NR	5.6
	Rowland43	2016	SCZ old	−0.7	37	31	61	48	90	0	NR	24
	Yang62	2016	FEP	0.8	23	22	41	26	0	NR	69	1.6
POC	Goto55, 56	2009	FEP	0.2	18	18	50	29	100	NR	68	0.5
	Öngür57	2010	SCZ	0.4	19	21	67	39	95	76	51	21
	Yoon63	2010	FEP/SCZ	−2.6	13	13	85	28	62	NR	73	NR
	Kelemen64	2013	FEP	−0.7	20	28	64	25	0	0	88	0.8
	Marsman59	2014	SCZ	0.3	19	15	76	28	100	35	53	6.5
	Thakkar39	2016	Sibling	0.0	12	23	53	31	0	0	NR	—
	Thakkar39	2016	SCZ	−0.5	12	21	71	36	100	24	49	14
Striatum	Goto55, 56	2009	FEP	−0.8	18	18	50	29	100	NR	68	0.5
	Tayoshi58	2010	SCZ	−0.2	29	38	53	34	100	42	51	21
	De la Fuente Sandoval41	2015	CHR	1.3	24	23	65	21	0	0	NR	—
	Thakkar39	2016	Sibling	−0.3	12	23	53	31	0	0	NR	—
	Thakkar39	2016	SCZ	−0.1	12	21	71	36	100	24	49	14
dlPFC	Kegeles40	2012	SCZ unmed	−0.1	11	16	69	32	0	19	71	7
dlPFC	Kegeles40	2012	SCZ med	−0.4	11	16	69	32	100	19	57	9
Hippocampus	Stan65	2015	SCZ	−0.2	16	18	78	42	61	28	NR	NR
CSO	Rowland42	2013	SCZ younger	0.2	10	11	82	30	100	0	63	7.7
CSO	Rowland42	2013	SCZ older	−0.7	10	10	70	51	1000	0	57	25.5

Abbreviations: %AP, percentage of SCZ group currently taking antipsychotic medication; %BZ, percentage of SCZ group currently taking benzodiazepine or anticonvulsant medication; C, control; CHR, clinical high risk; CSO, centrum semiovale; dlPFC, dorsolateral prefrontal cortex; DOI, mean duration of illness in years; FEP, first episode psychosis; g, Hedge’s g effect size; %M, percentage of male in the SCZ sample; mFC, medial frontal cortex area; NR, not reported; PANSS, Positive and Negative Syndrome Scale mean total symptom score; POC, parietal/occipital cortex; SCZ, schizophrenia or schizophreniform disorder; sibling, healthy siblings of patients with SCZ. Age is expressed in years (mean).