Table 2.

Clusters of significant (p<0.01) association between structural measures and substance use (N=200).

	Cluster Size	Cigarettes per Smoking Day			Grams per Cannabis Day			Drinks per Drinking Day			Sex			Age
Region^a	(voxels)	t	p	$η_{p}^{2}$	t	p	$η_{p}^{2}$	t	p	$η_{p}^{2}$	t	p	$η_{p}^{2}$	t	p	$η_{p}^{2}$
Mean Diffusivity
Superior longitudinal fasciculus L	6683	6.10	<0.01	0.16	−1.46	0.15	0.01	0.50	0.62	0.00	−1.66	0.10	0.01	−1.77	0.08	0.02
Superior longitudinal fasciculus R	4181	5.84	<0.01	0.15	−0.56	0.58	0.00	−0.70	0.48	0.00	1.55	0.12	0.01	−1.82	0.07	0.02
Superior longitudinal fasciculus R	70	3.82	<0.01	0.07	0.75	0.46	0.00	−0.30	0.77	0.00	2.15	0.03	0.02	−1.58	0.12	0.01
Radial Diffusivity
Superior longitudinal fasciculus L	11392	6.34	<0.01	0.17	−0.82	0.41	0.00	0.49	0.62	0.00	−2.21	0.03	0.03	−1.59	0.11	0.01
Superior longitudinal fasciculus R	7529	5.75	<0.01	0.15	0.32	0.75	0.00	−0.68	0.50	0.00	−0.07	0.95	0.00	−1.48	0.14	0.01
Inferior longitudinal fasciculus L	1070	5.44	<0.01	0.13	0.05	0.96	0.00	−0.43	0.67	0.00	0.10	0.92	0.00	−0.00	0.99	0.00
Superior longitudinal fasciculus R	396	4.31	<0.01	0.09	−1.44	0.15	0.01	1.46	0.15	0.01	−1.18	0.24	0.01	−1.56	0.12	0.01
Corticospinal tract R	360	5.09	<0.01	0.12	−1.06	0.29	0.01	1.07	0.29	0.01	−0.58	0.56	0.00	−1.83	0.07	0.02
Body of corpus callosum R	143	2.78	<0.01	0.04	0.38	0.71	0.00	−0.27	0.79	0.00	−1.58	0.12	0.01	−1.67	0.10	0.01
Anterior thalamic radiation R	92	3.28	<0.01	0.05	−1.41	0.16	0.01	1.07	0.28	0.01	−1.95	0.05	0.02	0.21	0.83	0.00
Superior longitudinal fasciculus L	29	2.69	<0.01	0.04	−2.37	0.02	0.03	0.48	0.64	0.00	−2.89	<0.01	0.04	−1.54	0.12	0.01
Genu of corpus callosum R	28	2.60	0.01	0.03	1.85	0.07	0.02	−2.05	0.04	0.02	0.06	0.95	0.00	1.11	0.27	0.01
Inferior longitudinal fasciculus R	21	3.10	<0.01	0.05	−0.92	0.36	0.00	0.53	0.60	0.00	3.10	<0.01	0.05	0.06	0.95	0.00
Axial Diffusivity
Superior longitudinal fasciculus L	34	1.69	0.09	0.02	−6.59	<0.01	0.18	3.20	<0.01	0.05	0.70	0.49	0.00	−1.68	0.10	0.01

Peak association

L=Left, R=Right