In this cross-sectional volumetric MRI study, one-month-abstinent alcohol dependent individuals without current psychostimulant dependence (ALC), ALC individuals with current dependence on at least one psychostimulant (PSU), and drug-free LD differed significantly on regional GM and WM volumes normalized to ICV: PSU had significantly larger lobar WM volumes than LD and ALC, whereas ALC showed no regional WM volume differences compared to LD. GM volumes in PSU were lower only in the temporal lobe, thalami and lenticular nuclei compared to LD. In ALC however, most lobar cortical GM volumes, thalamic GM, and total cerebellar volume were significantly smaller than in LD. Consistent with these tissue volume differences, sulcal CSF volumes of the frontal and temporal lobes in PSU were smaller than in both ALC and LD. All effect sizes for the significant WM differences between PSU and LD or ALC were greater than 0.50, indicating moderate-to-large magnitude group differences. Parietal WM volume in PSU correlated positively with prior year cocaine use, suggesting a substance-related parietal WM volume expansion. Frontal, parietal, and total cortical GM volumes were associated with some critical neurocognitive
