postmortem prefrontal cortex revealed that gene network structure was significantly correlated with lifetime alcohol consumption in addition to an overall loss in network structure (Farris et al., 2015a; Farris and Mayfield, 2014). Intermodular correlations were found to be significantly higher among modules associated with alcohol drinking compared to modules with low connectivity, implying integrated biological function for a set of gene modules directly related to lifetime alcohol consumption in humans. The differences in intermodular connectivity suggest that the neurobiology of alcohol dependence may be due to altered covariation of gene modules, rather than discrete changes in differentially expressed genes across the transcriptome (Farris and Mayfield, 2014).
