Advances in neuroimaging methodology, combined with the availability of longitudinal data, now provide unique opportunities to gain insights into the disease onset, time-course and etiopathologic mechanisms of major neuropsychiatric illnesses. They may also be used to compare how different medications affect disease progression (P. M. Thompson et al., 2008). As population statistics are compiled from subjects with detailed genetic data, statistical mapping can be used to discover genes that protect brain structure or make it more vulnerable to disease (Cannon et al., 2003). Longitudinal imaging studies of pediatric populations have provided a unique developmental perspective on the neuropathology of these illnesses and highlight the power of longitudinal data for research and clinical applications. However, research in this field still remains limited by relatively small samples and relatively few longitudinal and population based studies, stressing the need for continued future work in this area. Some key areas for future work include the discovery of specific genes involved in GM maturation, and the correlation of functional MRI signals with structural changes in the brain (L. H. Lu et al., In Press). There
