Table 3.

Linear regression of total intracranial volumes, attention-deficit/hyperactivity disorder (ADHD) symptoms, and major depressive disorder (MDD) symptoms on gray matter volumes in areas of group difference centered within the left insula and right interior frontal gyrus

Variable	Insula (mL)				Inferior Frontal Gyrus (mL)
	R2	B	SE	β	R2	B	SE	β
TIV	0.60	2.118	0.314	0.737***	0.40	0.654	0.145	0.602***
ADHD symptoms		−0.012	0.005	−0.299**		−0.004	0.002	−0.238Ŧ
TIV	0.61	2.054	0.308	0.715***	0.44	0.636	0.139	0.585***
MDD symptoms		−0.010	0.003	−0.318**		−0.004	0.002	−0.318*
TIV	0.62	2.085	0.311	0.726***	0.44	0.637	0.142	0.586***
ADHD symptoms		−0.006	0.007	−0.142		0.000	0.003	−0.015
MDD symptoms		−0.007	0.005	−0.215		−0.004	0.002	−0.307

Notes. TIV = total volume in liters; ADHD and MDD symptom scores defined as the sum score of DSM-IV symptoms. Gray matter volumes are reported for the left insula and right interior frontal gyrus. Similar results were found for the right insula, and are not reported.

^*p<.05;

^**p<.05;

^***p<.001;

^Ŧp = 0.084.