Gray Matter Correlates of Impulsivity in Psychopathy and in the General Population Differ by Kind, Not by Degree: A Comparison of Systematic Reviews

Abstract

A fundamental question in neuropsychiatry is whether a neurobiological continuum accompanies the behavioral continuum between subclinical and clinical traits. Impulsivity is a trait that varies in the general population and manifests severely in disorders like psychopathy. Is the neural profile of severe impulsivity in psychopathy an extreme but continuous manifestation of that associated with impulsivity in the general population (different by degree)? Or is it discontinuous and unique (different by kind)? Here, we compare systematic reviews of the relationship between impulsivity and gray matter in psychopathy and in the general population. The findings suggest that the neural profile associated with extreme impulsivity in psychopathy (increased gray matter in rostral and ventral striatum and prefrontal cortex) is distinct from that associated with impulsivity in the general population (decreased gray matter in rostral and ventral prefrontal cortex). Severe impulsivity in psychopathy may therefore arise from a pathophysiological mechanism that is unique to the disorder. The results caution against the use of community samples to examine impulsive psychopathic traits in relation to neurobiology.

Brain gray matter structures associated with trait impulsivity: A systematic review and voxel‐based meta‐analysis

“…In addition, psychopathic individuals who behave impulsively also exhibited decreased GMV in the right OFC (de Oliveira‐Souza et al, 2008; Ly et al, 2012). On the other hand, the impulsive‐antisocial dimension of psychopathy was positively correlated with GMV in the OFC in psychopathic patients, which may indicate a unique neural mechanism of the general population (Korponay & Koenigs, 2020). Functional MRI studies have indicated that OFC activation is associated with hypo‐impulsivity (Whelan et al, 2012), and stronger resting‐state functional connectivity of OFC with striatum is linked with greater impulsivity (Korponay, Dentico, et al, 2017).…”

“…However, the CTh of bilaterial MFG was negatively associated with trait impulsivity in studies using adults (Holmes et al, 2016; Schilling et al, 2012), which might be explained by the distinct property between GMV and CTh. Intriguingly, the neural correlates of OFC underlying impulsivity in adult individuals remain controversial (Korponay & Koenigs, 2020), given the findings of inverse correlation of right OFC (Korponay, Pujara, et al, 2017; Matsuo et al, 2009). In this regard, the left‐lateralized neural activity associated with impulsivity may partially induce the unique developmental trajectory of left OFC (Hecht, 2011).…”

A neurocognitive model of early onset persistent and desistant antisocial behavior in early adulthood

“…Hence, future studies should disentangle to what extent difficulties in emotion regulation and response inhibition are driven by general psychopathic traits, or (interactions between) specific sub-dimensions (not only focusing on Impulsive-Irresponsible and Callous-Unemotional, but also Grandiose-Manipulative traits) (Lilienfield, 2018), to further unravel the etiology and maintenance of antisocial behavior (Gillespie et al, 2022). In this regard, it is important to consider different components of response inhibition and emotion regulation, and to combine self-report measures with experimental fMRI tasks to uncover the neural underpinnings of cognitive control that are specific for psychopathic traits and persistent antisocial behavior ( (Korponay and Koenigs, 2021).…”