Table 2.

The relationship between major depressive disorder and glutamic acid decarboxylase expression or function

Brain region	Target	Technique	Comparison groups	Direction	Reference
DLPFC	GAD67	WB	13 medication-free depressed patients versus 13 controls	Down	30
DLPFC	GAD67	WB	8 medicated depressed patients versus 13 controls	NC	30
PFC	GAD67	WB	15 depressed patients (mostly treated) versus 15 controls	NC	32
DLPFC	GAD67	IHC	15 depressed patients versus 15 controls	NC	33
DLPFC	GAD67	qPCR	19 depressed patients (mix of treated and untreated) versus 19 controls	NC	34
DLPFC	GAD65	WB	13 medication-free depressed patients versus 13 controls	NC	30
DLPFC	GAD65	WB	8 medicated depressed patients versus 13 controls	NC	30
PFC	GAD65	WB	15 depressed patients (mostly treated) versus 15 controls	NC	32
DLPFC	GAD65	qPCR	19 depressed patients (mix of treated and untreated) versus 19 controls	NC	34
DLPFC	GAD	IHC	9 depressed patients versus 19 controls	Up	35
DLPFC	GAD	IHC	7 nonsuicide depressed patients (of a total of 21 depressed patients) versus 18 controls	Down	36
FC	GAD	Enzyme function	21 suicide victims (13 untreated, 6 on antidepressants, 2 on another drug) versus 21 controls	NC	38
DLPFC	GAD	IHC	9 depressed patients versus 18 controls	NC	37
OFC	GAD	IHC	9 depressed patients versus 19 controls	Up	35
OFC	GAD	IHC	9 depressed patients versus 18 controls	NC	37
ACC	GAD	IHC	9 depressed patients versus 19 controls	NC	35
ACC	GAD	IHC	9 depressed patients versus 18 controls	NC	37
STC	GAD	IHC	9 depressed patients versus 19 controls	Up	35
TC	GAD	Enzyme function	21 suicide victims (13 untreated, 6 on antidepressants, 2 on another drug) versus 21 controls	NC	38
EC (layer III)	GAD	IHC	21 depressed patients (including 14 suicide victims) versus 18 controls	Up	36
EC	GAD	IHC	9 depressed patients versus 18 controls	Up	37
HC	GAD	IHC	14 depressed suicide victims (of 21 total depressed patients) versus 18 controls	Up	36
HC	GAD	IHC	9 depressed patients versus 18 controls	Up	37
HC	GAD	IHC	9 depressed patients versus 19 controls	Up	35
MDT	GAD	IHC	9 depressed patients versus 19 controls	NC	35
MDT	GAD	IHC	9 depressed patients versus 18 controls	NC	37
LDT	GAD	IHC	9 depressed patients versus 18 controls	Up	37
CB	GAD67	WB	15 depressed patients versus 15 controls	Down	31
CB	GAD65	WB	15 depressed patients versus 15 controls	Down	31

Abbreviations: ACC, anterior cingulate cortex; CB, cerebellum; DLPFC, dorsolateral prefrontal cortex; EC, entorhinal cortex; FC, frontal cortex; GAD, glutamic acid decarboxylase; HC, hippocampus; IHC, immunohistochemistry; LDT, lateral dorsal thalamus; MDT, mediodorsal thalamus; NC, no change; OFC, orbitofrontal cortex; PFC, prefrontal cortex; qPCR, quantitative polymerase chain reaction; STC, superior temporal cortex; TC, temporal cortex; WB, Western blot.