Neuroimaging twin studies of SUD have begun to connect knowledge regarding the role of neural networks invovled in SUD with genetic and environmental influences on the disorder. For example, small, widespread negative associations were recently reported between cigarette pack-years and the volume and/or surface area of several cortical as well as subcortical brain structures (Prom-Wormley et al., 2015). Importantly, correlations were the result of shared genetic and unique environmental factors in brain structures involved in the processing of environmental influences related to smoking.
