Structural and functional neuroimaging of pediatric depression

Pediatric major depressive disorder (MDD) is a common disease associated with significant morbidity and mortality. Newly available noninvasive neuroimaging techniques provide unique opportunities to illuminate the underlying neurobiological factors of MDD. This article reviews structural and functional neuroimaging data in pediatric MDD. In general, neuroimaging studies in pediatric MDD tend to confirm findings in adult depression implicating the prefrontal cortex, amygdala, and hippocampus. These brain regions are linked and believed to be critical in modulating emotional responses. However, neuroimaging research in pediatric MDD is still in its infancy, and inconsistencies are rife. These inconsistencies are largely due to the small samples and lack of agreement regarding methodology in ascertainment as well as in imaging. Greater focus on careful delineation of clinically and neurobiologically defined subgroups will likely lead to improved understanding of the pathophysiology of MDD.