Is Donald Trump's frontostriatal connectivity weakened?

Chester et al. find an interesting correlation between grandiose narcissism and the strength of connections between brain areas that process self-relevant stimuli (the medial prefrontal cortex) and reward (the ventral striatum):

Narcissism is characterized by the search for affirmation and admiration from others. Might this motivation to find external sources of acclaim exist to compensate for neurostructural deficits that link the self with reward? Greater structural connectivity between brain areas that process self-relevant stimuli (i.e. the medial prefrontal cortex) and reward (i.e. the ventral striatum) is associated with fundamentally positive self-views. We predicted that narcissism would be associated with less integrity of this frontostriatal pathway. We used diffusion tensor imaging to assess the frontostriatal structural connectivity among 50 healthy undergraduates (32 females, 18 males) who also completed a measure of grandiose narcissism. White matter integrity in the frontostriatal pathway was negatively associated with narcissism. Our findings, while purely correlational, suggest that narcissism arises, in part, from a neural disconnect between the self and reward. The exhibitionism and immodesty of narcissists may then be a regulatory strategy to compensate for this neural deficit.