Associations presented below were FDR significant without evidence of Q trait heterogeneity. For regional cortical volume, genetic correlation estimates yielded a single FDR‐significant association between AUD and the left pars orbitalis (r g = 0.19; Table S27). For subcortical structure volume, there were no FDR‐significant associations with any of the traits (Table S28). For cortical surface area, nine regions were significantly positively correlated with sensation seeking (r g = 0.08–0.10) and 21 regions were significantly positively correlated with alcohol consumption (r g = 0.08–0.18; Table S29). Seven overlapping cortical surface area associations, primarily localised to temporal and parietal areas in addition to the superior frontal gyrus, did not significantly differ in their magnitude between sensation seeking and alcohol consumption (Figure 1D). For cortical thickness, considerable overlap across regions was observed between alcohol consumption (26 regions: r g = −0.07 to −0.17) and AUD (18 regions: r g = −0.11 to −0.20; Table S30), and overlapping associations that did not significantly differ in magnitude were localised to four frontal (lateral/medial orbitofrontal, pars orbitalis, and superior frontal) and the middle temporal regions (Figure 1D).
