Table 1.

Study Characteristics.

Study	Sample Size	Age^a	% female	Structure measure^b	Method	Regions^c	Cognitive Test^d
Baare, 1999	14	26.9 (5.9)	0	lobe volume	ROI	PFC, LPFC, OFC, MPFC	verbal & semantic fluency
Bender, 2012	72	49.96 (14.26) [19–77]	69.4%	GM volume	ROI	LPFC	Composite WM score
Burzynska, 2012	56	64.8 (2.6) [60–71]	48.2%	GM thickness	VBM	LPFC	WCST
	73	25.6 (3.1) [20–32]	43.8%
Choi, 2004	34	26.24 (6.28)	17.7%	GM volume	ROI	OFC	TMT; WCST; verbal fluency
Dickerson, 2008	15	69.5 (4.8) [66–81]	46.7%	GM thickness	VBM	PFC	TMT
Garlinghouse, 2010	26	30.5 (11.3)	50.0%	lobe volume	ROI	frontal lobe	DBS (WM)
Gautam, 2011	397	66.5 (1.40) [64–68]	44.6%	GM volume GM thickness	ROI	LPFC	TMT; DBS (WM)
	400	46.7 (1.40) [44–48]	55.5%
Gianaros, 2006	58	59.86 (5.10) [52–70]	100%	GM volume	ROI	LPFC	TMT; Fourword Short-term Memory Test (WM)
	76	61.33 (4.95) [50–70]	0				TMT; Fourword Short-term Memory Test (WM)
Goldstein, 2011	16	30.63 (8.11)	43.8%	GM volume	ROI	LPFC	CANTAB (WM)
Grambaite, 2011	23	63.2 (8.0)	52.2%	GM thickness	ROI	LPFC, OFC	TMT; verbal fluency; Interference
Gunning-Dixon, 2003	139	63.71 (7.97) [50–81]	59.7%	GM volume	ROI	DLPFC + OFC	WCST; computation span and listening span (WM)
Gur, 2000	47	25.72 (6.36)	100%	GM volume	ROI	LPFC & MPFC	WCST
	34	27.26 (7.07)	0
Haldane, 2008	44	43.1 (11.2)	54.5%	GM volume	VBM	LPFC	Interference: Stroop
Hanninen, 1997	47	71.1 (4.0)	51.1%	lobe volume	ROI	frontal lobe	verbal fluency; Interference: Stroop; WCST; TMT
Hartberg, 2011	192	36.1 (9.6)	49.0%	GM thickness	ROI	LPFC	digit span (WM), color-word interference, set shifting
Head, 2009	117	42.4 (21.2) [18–80]	70.94%	GM volume	ROI	DLPFC	WCST; WM; Interference
Kochunov, 2009	38	[30–90]	60.5%	GM thickness	ROI	LPFC	Executive Interview
	33	[19–29]	63.6%
Koutsouleris, 2010	30	26.0 (2.7)	40.0%	GM volume	VBM	MPFC	TMT
Kozicky, 2013	30	22.9 (4.7)	60%	GM volume	ROI	DLPFC	CANTAB (WM)
MacLullich, 2002	97	67.8 (1.3) [65–70]	--	lobe volume	ROI	frontal lobe	verbal fluency
Morgen, 2006	19	31.7 (7.5) [22–44]	--	GM volume	VBM	PFC	DBS (WM)
Nakamura^e, 2008	21	41.1 (9.1) [22–55]	23.8%	GM volume	ROI	OFC	TMT; WCST
Paul, 2009	251	36.8 [18–79]	58.2%	GM volume	ROI	LPFC	TMT; Interference; Fluency; DBS (WM)
Raz, 1998	95	44.02 (16.35) [18–77]	56.80%	GM volume	ROI	DLPFC+OFC	WCST; composite WM
Rusch, 2008	26	28.2 (5.9)	32.3%	GM volume	ROI	DLPFC	WCST
Salat, 2002	30	84.2 [71.6–93.5]	53.3%	GM volume	ROI	LPFC, OFC	self-ordered pointing and n-back (WM)
Schretlen, 2000	112	54 (19)	57.1%	lobe volume	ROI	frontal lobe	modified WCST
Takeuchi, 2013	168	21.12 (1.79)	0.00%	GM volume	VBM	OFC	Dysexecutive Questionnaire
	135	21.39 (1.67)	100.00%
Tu, 2012	36	41.81 (10.70)	61.1%	GM thickness	VBM	LPFC	Color Trail Test (substitute TMT)
Tullberg, 2004	52	77.5	--	GM volume	ROI	PFC	Composite executive function: Perseveration, DBS, visual span backwards, fluency test.
Van Petten, 2004	48	73.2 (5.3) [65.5–85.8]	68.8%	GM volume	ROI	LPFC	F-factor, including WCST, verbal fluency, mental arithmetic, DBS and mental control tests
Zimmerman, 2006	148	40.05 (14.88)	49%	GM volume	ROI	LPFC, MPFC, OFC	TMT-B; Stroop interference; DBS (WM); maze
Zuffante, 2001	23	43.3 (9.6)	0	lobe volume	ROI	LPFC	spatial delayed response task, self-ordered pointing (WM)

Note:

Mean ages are shown, with standard deviation of age in parentheses and age range in brackets.

GM = gray matter; lobe volume = volume of gray matter + white matter;

LPFC = lateral prefrontal cortex; OFC = orbito-frontal cortex; MPFC = medial prefrontal cortex.

WCST = Wisconsin Card Sorting Test; WM = working memory; TMT = Trail Making Test; DBS = Digit backwards span; CANTAB: Cambridge Neuropsychological Test Automated Battery.

In Nakamura’s (2008) study, age was averaged from 25 subjects, whereas the cognition-volume relationship was assessed from a subset of 21 subjects.