In addition to subcortical neurogenetic findings, sensation seeking and alcohol consumption exhibited overlapping genetic associations with cortical surface area in frontal, temporal, and parietal regions. These findings support prior studies emphasising associations between sensation seeking and increased frontotemporal surface area in adolescents, 13 , 66 and shared genetic influences between alcohol consumption and greater total cortical surface area. 67 Interestingly, H‐MAGMA dopaminergic midbrain‐specific gene associations for sensation seeking (BRSK2) and both sensation seeking and alcohol consumption (RUNX1T1) highlight genes previously implicated in surface area and sulcal depth. 68 , 69 Thus, these shared associations between sensation seeking and alcohol consumption point to genes that may have pleiotropic influences on both midbrain dopaminergic neurons and cortical surface area, providing a potential explanation for observed associations between sensation seeking and cortical neuroimaging phenotypes that would be hypothesised as more relevant to ‘top‐down’ cognitive control processes. 8 , 18
