Table 4.

Table 4a: Relationship between PMRG, Putamen and parahippocampal gyrus GMV and diagnostic group, gender, scan (acquisition parameters) and trait anxiety
	PMRG				Left
	Left		Right		Putamen		Parahippocampal Gyrus
	F	P	F	P	F	P	F	P
Main effect of group	(1,36)2.14	0.15	(1,36)2.00	0.17	(1,36)18.13	<0.001	(1,36)7.5	0.009
Main effect of gender	(1,36)0.08	0.77	(1,36)0.18	0.67	(1,36)0.001	0.97	(1,36)0.01	0.91
Main effect of scan	(1,36)0.00	0.97	(1,36)0.01	0.92	(1,36)0.03	0.85	(1,36)<0.001	0.99
Main effect of trait anxiety	(1,36)3.79	0.06	(1,36)2.57	0.12	(1,36)0.91	0.34	(1,36)0.64	0.43
Interaction group by gender	(1,36)0.52	0.47	(1,36)0.40	0.53	(1,36)0.52	0.48	(1,36)0.003	0.95
Interaction group by scan	(1,36)0.54	0.47	(1,36)0.52	0.47	(1,36)1.62	0.21	(1,36)0.04	0.84
Interaction group by trait anxiety	(1,36)2.00	0.17	(1,36)3.08	0.09	(1,36)0.85	0.36	(1,36)0.04	0.85
Interaction group by gender by scan	(2,36)2.56	0.09	(2,36)1.24	0.30	(2,36)0.17	0.84	(2,36)0.62	0.54
Interaction group by gender by trait anxiety	(2,36)3.97	0.03	(2,36)1.73	0.19	(2,36)2.58	0.09	(2,36)1.1	0.34
Interaction group by scan by trait anxiety	(2,36)0.78	0.46	(2,36)0.19	0.83	(2,36)0.99	0.38	(2,36)0.21	0.81
interaction group by gender by scan by trait anxiety	(1,36)0.00	0.97	(1,36)0.02	0.88	(1,36)0.58	0.45	(1,36)0.66	0.42

Table 4b. Post hoc tests to examine significant findings regarding the relationship between left PMRG GMV and diagnostic group, gender, and trait anxiety
Post hoc tests to examine the significant interaction group by gender by anxiety in left PMRG (P<0.01 to control for multiple tests)
	F	P	F	P	F	P
	Min effect of group		Min effect of anxiety		Iteraction group by anxiety
Gender male	(1,16)0.63	0.44	(1,16)5.87	0.03	(1,16)7.59	0.01
Gender female	(1,25)5.18	0.03	(1,25)0.03	0.87	(1,25)0.61	0.44
	Main effect of group		Main effect of gender		Interaction group by gender
Anxiety low	(1,22)15.39	<0.001^a	(1,22)0.38	0.54	(1,22)0.79	0.38
Anxiety high	(1,19)0.48	0.50	(1,19)1.97	0.18	(1,19)1.60	0.22
	Main effect of gender		Main effect of anxiety		Interaction gender by anxiety
Group BPI	(1,21)1.54	0.23	(1,21)2.44	0.13	(1,21)4.12	0.06
Group HC	(1,20)0.00	1.00	(1,20)0.06	0.81	(1,20)0.16	0.69
Post hoc tests to examine the significant group x anxiety interaction in males in left PMRG (P<0.005 to control for multiple tests)
	F	P

	Main effect of group
Anxiety low	(1,10)43.63	<0.001^b
Anxiety high	(1,4)0.34	0.59
	Main effect of anxiety
Group BPI	(1,6)37.20	<0.001^c
Group HC	(1,8)0.04	0.84

PMRG: posteromedial rectal gyrus. The statistical threshold used was: P<0.05. The trend for main effect of trait anxiety resulted form all high trait anxiety individuals having slower left PMRG GMV than all high trait anxiety individuals

BPI: bipolar disorder, type I; HC: healthy controls

: All low trait anxiety BPI had significantly smaller left PMRG GMV than all low trait anxiety HC

: All male low trait anxiety BPI had significantly smaller left PMRG GMV than all male low trait anxiety HC

: All male high trait anxiety BPI had significantly smaller left PMRG GMV than all male low trait anxiety BPI