In COGA, individuals with increased parietal-occipital theta EEG coherence had an increased number of maxdrinks. There was evidence of association between several variants meeting genome-wide criteria for low theta (3-5 Hz) parietal-occipital theta EEG coherence with maxdrinks and AUD severity (p<0.05 in EAs and p<0.01 in AAs), suggesting a potential role for low theta EEG coherence variants in alcohol use behavior in the COGA sample, particularly among participants of African ancestry. Further, all six SNPs meeting genome-wide criteria for low parietal-occipital theta EEG coherence in COGA were also associated with alcohol use and intake frequency in the UK Biobank, a population of European ancestry. Taken together, these data suggest a role of 18q23 in alcohol use behavior, however whether this also extends to alcohol use disorder (DSM-IV or DSM-5) is less clear. We also note that previous work from our group implicated high theta coherence as most significant for alcohol dependence in a sample of non-COGA participants as well as for significant genetic association in a COGA sample of linkage families, densely affected with alcohol dependence9, whereas the current study’s
