Linear regressions were used to test whether cannabis exposure (in the full sample, N=483) and age of onset or frequency of use (among exposed individuals, N=262) predicted WBV, subcortical (left and right amygdala, hippocampus, and VS), or OFC volumes, controlling for the primary covariates and WBV (when predicting regional volumes). Bootstrapped 95% confidence intervals were calculated to account for familial clustering (R boot package22). False-discovery rate (FDR) was used to control for the nine regression analyses with each cannabis measure. Only brain regions with q<0.05 were examined in the sibling analysis.
