Morphometric measures were adjusted for the fixed effects of age and site using linear regression. Further, structural measures were adjusted for global size. Volume measures were adjusted for estimated total intracranial volume, neocortical surface area measures for total surface area, and neocortical thickness measures for total average cortical thickness. The residual estimates were then used in full information maximum likelihood analyses of individual observations in Mx 1.66 (Neale et al. 2006).
