There were two weak phenotypic correlations between measures of cortical thickness and cigarette pack-years for two regions in the temporal lobe, specifically, the right transverse temporal gyrus (rP = -0.09, p = 0.001) and the right middle temporal gyrus (rP = 0.05, p = 0.01). These correlations were due to significant unique environmental covariances (right transverse temporal gyrus [covE = -0.12, 95% CI = -0.21; -0.04, p = 0.002] and right middle temporal gyrus [covE = 0.11, 95% CI =0.03; 0.19, p = 0.01]). The unique environmental correlations were moderate in magnitude, indicating some overlap between the unique environmental factors shared between cigarette pack-years and these neocortical ROIs (rE = -0.26 and 0.23).
