Mesolimbic dopamine reward system hypersensitivity in individuals with psychopathic traits

Abstract

Psychopathy is a personality disorder that is strongly linked to criminal behavior. Using [(18)F]fallypride positron emission tomography and blood oxygen level-dependent functional magnetic resonance imaging, we found that impulsive-antisocial psychopathic traits selectively predicted nucleus accumbens dopamine release and reward anticipation-related neural activity in response to pharmacological and monetary reinforcers, respectively. These findings suggest that neurochemical and neurophysiological hyper-reactivity of the dopaminergic reward system may comprise a neural substrate for impulsive-antisocial behavior and substance abuse in psychopathy.

Figure 1

Impulsive-Antisocial traits predict nucleus accumbens DA release. A. Statistical Parametric Map (SPM) demonstrating that PPI-IA factor scores selectively predict increased amphetamine-induced DA release in bilateral NAcc (A; left NAcc: −16, 10, −10, p_FDR = 0.003, Z = 3.74, k = 56; right NAcc: 16, 18, −6; p_FDR = 0.002, Z = 4.21, k = 44). All coordinates reference MNI space. SPM thresholded at p < 0.05 uncorrected for visualization purposes. B–C. Scatter plot depicts the relationship between PPI-IA factor scores and amphetamine-induced DA release in left (B) and right (C) NAcc. DA release values extracted from clusters defined by a p_FDR < 0.05 threshold. C. Left = Left, Right = Right. Color bar indicates t-statistic value.

Figure 2

Impulsive-Antisocial factor scores are selectively associated with NAcc BOLD signal during monetary reward anticipation. A. Image depicts the Harvard-Oxford Nucleus Accumbens anatomical region of interest from which BOLD signal estimates were obtained. B. Scatter plot depicts the relationships between PPI-IA and PPI-FD factor scores and reward anticipation-related BOLD signal in the right NAcc. Left = Left, Right = Right.