Objective Negative urgency, or the tendency to act rashly when experiencing negative affect, is a transdiagnostic risk factor for vulnerability to a number of psychopathologies. When combined with high levels of neuroticism, the two factors predict high rates of externalising behaviours. In this study we examined whether there are overlapping neurobiological markers of both urgency and neuroticism in the healthy population. Method: One hundred and fifty-two participants underwent T1-weighted MRI (1×1×1 mm) at 3T. Voxel-based morphometry using diffeomorphic anatomical registration through exponentiated lie algebra in SPM8 was used to examine grey matter volumes. Self-report measures of urgency were acquired using the UPPS impulsivity scale. General linear models were used to examine associations between urgency and grey matter volumes in brain regions previously linked to neuroticism (the dorsomedial prefrontal cortex, medial temporal lobe and precentral gyrus). Age, gender and intracranial volumes were included as covariates of no interest.
Results Individual variability in urgency was negatively associated with individual variability in grey matter volumes within the dorsomedial prefrontal cortex (P).
Conclusion Grey matter volumes within the dorsomedial prefrontal cortex, a region strongly implicated in emotion regulation, are linked to individual variability in both negative urgency and neuroticism. Normal inter-individual variation in grey matter volumes within this region may impact upon the risk and resilience of developing psychiatric disorders, particularly those associated with externalising disorders.