Table 3.

Least squares mean volumes (in cm³) of regions of interest

Regions	sAL (n=7)	nsAL (n=7)	sNA (n=6)	nsNA (n=7)	Significant outcomes where P<0.05 (effect size %)
Cortical
L caudal middle frontal	5.82 ± 1.48	5.65 ± 1.49	6.18 ± 1.63	6.18 ± 1.47	nsAL < sNA (9%)
R caudal anterior cingulate	1.97 ± 0.75	1.74 ± 0.76	2.31 ± 0.83	1.79 ± 0.75	nsNA < sNA (26%)
R caudal middle frontal	5.63 ± 1.53	4.65 ± 1.53	5.68 ± 1.68	5.43 ± 1.52	nsAL < sNA (19%)
R pars orbitalis*	2.49 ± 0.51	2.45 ± 0.51	2.25 ± 0.56	2.64 ± 0.50	sNA < nsNA (16%)
R precentral	11.50 ± 1.48	11.89 ± 1.49	12.31 ± 1.63	12.39 ± 1.47
R rostral middle frontal	13.81 ± 2.39	14.82 ± 2.40	13.64 ± 2.64	13.37 ± 2.38	nsNA < nsAL (10%)
Subcortical
L accumbens area	0.44 ± 0.18	0.52 ± 0.18	0.44 ± 0.20	0.44 ± 0.18	nsNA < nsAL (19%)
R thalamus proper	6.85 ± 0.93	6.89 ± 0.93	6.65 ± 1.02	7.09 ± 0.92	sNA < nsNA (6%)
Cortical
L fusiform	9.07 ± 1.93	9.59 ± 1.94	8.62 ± 2.12	9.30 ± 1.92	sNA < nsAL (10%)
L paracentral	2.88 ± 0.54	2.89 ± 0.54	3.06 ± 0.59	3.46 ± 0.53
L parahippocampal	1.86 ± 0.48	2.05 ± 0.49	2.19 ± 0.53	2.21 ± 0.48
L supramarginal	9.78 ± 2.02	10.42 ± 2.03	8.56 ± 2.23	10.29 ± 2.01
L temporal pole	2.23 ± 0.38	2.36 ± 0.39	2.35 ± 0.42	2.54 ± 0.38	sAL < nsNA (13%)
R entorhinal	1.78 ± 0.58	1.83 ± 0.58	1.51 ± 0.63	1.87 ± 0.57
R superior parietal	11.48 ± 3.01	10.92 ± 3.02	11.28 ± 3.32	12.97 ± 2.99	nsAL < nsNA (19%)
R temporal pole	2.28 ± 0.45	1.95 ± 0.45	2.22 ± 0.50	2.22 ± 0.45
L total cortex	207.85 ± 18.61	210.00 ± 18.72	205.19 ± 20.53	212.67 ± 18.51	sNA < nsNA (4%)
Subcortical
L pallidum*	1.37 ± 0.39	1.30 ± 0.39	1.34 ± 0.43	1.68 ± 0.39
L ventral diencephalon	3.28 ± 0.59	3.46 ± 0.59	3.6 ± 0.65	3.72 ± 0.58	sAL < nsNA (13%)
R amygdala	1.42 ± 0.22	1.46 ± 0.23	1.41 ± 0.25	1.58 ± 0.22
R pallidum	1.44 ± 0.37	1.24 ± 0.37	1.37 ± 0.41	1.46 ± 0.37	nsAL < nsNA (16%)
White matter
L inferior parietal WM*	9.03 ± 1.71	10.04 ± 1.72	9.73 ± 1.88	9.17 ± 1.7
L middle temporal WM*	5.05 ± 1.22	5.33 ± 1.23	5.64 ± 1.35	4.87 ± 1.22	nsNA < sNA (15%)
L superior frontal WM*	17.14 ± 3.39	18.23 ± 3.41	18.84 ± 3.74	16.99 ± 3.37
R banks of the superior temporal sulcus WM*	2.63 ± 0.91	3.25 ± 0.91	3.16 ± 1.00	3.04 ± 0.9
R caudal anterior cingulate WM	2.77 ± 0.54	2.86 ± 0.55	3.08 ± 0.60	2.75 ± 0.54	nsNA < sNA (12%)
R caudal middle frontal WM	5.85 ± 1.36	5.24 ± 1.37	6.26 ± 1.50	6.1 ± 1.35
R fusiform WM	6.45 ± 1.49	6.47 ± 1.50	6.85 ± 1.64	6.92 ± 1.48	nsAL < sNA (6%)
R inferior temporal WM	5.93 ± 1.21	6.29 ± 1.22	6.02 ± 1.34	5.57 ± 1.2	nsNA < nsAL (12%)
R rostral middle frontal WM	12.72 ± 2.61	13.44 ± 2.63	12.66 ± 2.88	11.64 ± 2.6
Ventricles
Fourth ventricle	1.71 ± 1.26	1.72 ± 1.27	2.64 ± 1.39	1.84 ± 1.26	sAL < sNA (47%)
R inferior lateral ventricle	0.44 ± 0.31	0.24 ± 0.31	0.35 ± 0.34	0.22 ± 0.31

Notes: Group effects were identified with age and total brain volume covariates. All values are listed as mean ± SD. Significant findings for a priori regions are listed above the dashed line, and additional significant findings follow.

^*Significant interactions between smoking and alcoholism, where P<0.05. In purple: comorbid effects (sAL versus nsNA). In red: smoking effects (sAL versus nsAL or sNA versus nsNA). In blue: alcholism effects (sAL versus sNA or nsAL versus nsNA). In green: cross effects of smoking and alcoholism (sNA versus nsAL).

Abbreviations: L, left hemisphere; R, right hemisphere; nsAL, alcoholic participants – currently not smoking; nsNA, nonalcoholic participants – currently not smoking; sAL, alcoholic participants (the comorbid group); sNA, nonalcoholic participants – current smokers; WM, white matter; SD, standard deviation.