Relating changes in cortical GM across time to clinical measures or behavioral outcomes remains challenging, as there are obvious potential confounds, such as medication history and the effects of chronic illness. Animal studies have begun to assess the effects of medications on brain development. Another important area of future research would be to explore the relationships between genotype and imaging phenotypes, in both healthy and diseased populations, to understand the role of genotype on regionally specific brain development. New datasets are being collected that contain large-scale genomic data (e.g., genome wide association scans using million-SNP arrays) and GM and WM maps with increasingly finer spatial resolution, as well as multiple imaging measures at each voxel (Lee et al., 2009; Pausova et al., 2007). These imaging genetics studies pose huge computational and statistical challenges (Chiang et al., In Press; Glahn, Thompson, & Blangero, 2007), but will likely yield remarkable new sources of information on the genetic influences on normal and abnormal brain development. Data from our studies and other similar studies suggest the need to focus on individual differences/factors that may either predispose to psychopathology or are protective. Such studies are currently underway at the NIMH, UCLA, and other centers.
