The results of this study suggest that a reduction in the volume of the orbitofrontal cortex, which plays a role in the automatic regulation of emotions and is a part of the medial prefrontal network, is associated with the heritability of bipolar disorder. Conversely, increased dorsolateral prefrontal cortex volume may be a neural marker of a resistance factor as it is part of a network of voluntary emotion regulation and balances the effects of the disrupted automatic emotion regulation system.