Significance of adolescent neurodevelopment for the neural circuitry of bipolar disorder.

The deficits of executive control of emotions and impulses of adult BD implicate involvement of a ventral prefrontal cortex (VPFC) neural system that subserves these functions that include the VPFC, as well as its subcortical connection sites of amygdala, striatum, and thalamus. Differences in the timing of major developmental changes in the structures within this neural system suggest that abnormalities in particular components of this neural system may emerge during critical developmental epochs during the course of the illness. Our recent neuroimaging data suggest that abnormalities in the subcortical components of VPFC neural systems may be evident by early adolescence in BD, whereas VPFC deficits progress over the course of adolescence and may be difficult to detect prior to late adolescence or early adulthood. This potential neurodevelopmental model for BD could have important implications for the recognition of early signs of the disorder and for age-specific treatment strategies.