The present volume is a significant update on an earlier volume by the same editors (Functional Neuroimaging in Child Psychiatry, Cambridge University Press, 2000). Several interesting points arise in the comparison of the 2009 and 2000 editions. First, the breadth of topics around which sufficient numbers of neuroimaging studies have been conducted has increased dramatically, as has the depth of coverage within each topic. Areas such as normal brain development, affective disorders, attention deficit/hyperactivity disorder, and autism spectrum disorders, to name just a few, have seen an explosion of interest and investigation over the past decade. In fact, a quick PubMed search for any relevant term reveals at minimum a 3- to 4-fold increase in yearly citations since 2000, and that pace is only accelerating. This is due to many factors, including greater recognition of psychiatric disorders in pediatric populations, greater awareness of the importance of studying prodromal or risk periods for disorders typically in the domain of the adult neuroimaging literature (e.g., schizophrenia), a proliferation of access to noninvasive imaging methods (e.g., functional and structural magnetic resonance imaging instead of positron emission tomography), and, overall, a greater interest in the interplay between normal and abnormal development. As one illustration of how rapidly pediatric neuroimaging has progressed, the 2000 edition had six chapters in the Future Directions section, while the present one contains only one such chapter. Though this is not to be taken as an indication that the field has sufficiently matured and that few open questions remain—quite the contrary, many more new and important questions are being opened up. Rather, this is an indication that future directions can now be incorporated into a substantive discussion of progress made and, therefore, is a natural extension of a well-grounded literature base.