Altered White-Matter Microstructure in Conduct Disorder Is Specifically Associated with Elevated Callous-Unemotional Traits

Chris Clark,Edmund J. S. Sonuga-Barke,Kiran Seunarine,Graeme Fairchild,Kate Sully,Ignazio Puzzo,Angela Darekar

doi:10.1007/s10802-017-0375-5

Abstract

Adolescents with conduct disorder (CD) and elevated callous-unemotional (CU) traits have been reported to present with a more severe and persistent pattern of antisocial behaviour than those with low levels of CU traits. However, relatively few studies have investigated whether there are differences in brain structure between these subgroups.We acquired diffusion tensor imaging data and used tract-based spatial statistics (TBSS) to compare adolescents with CD and high levels of CU traits (CD/CU+; n = 18, CD and low levels of CU traits (CD/CU-; n = 17) and healthy controls (HC; n = 32) on measures of fractional anisotropy (FA), axial (AD), radial (RD) and mean (MD) diffusivity. Compared to CD/CU- adolescents, those with CD/CU+ presented increased FA and reduced RD and MD (lower diffusivity) in several tracts including: body and splenium of the corpus callosum, right inferior longitudinal fasciculus, ILF; right inferior fronto-occipital fasciculus, IFOF; left superior longitudinal fasciculus, SLF; left cerebral peduncle, bilateral internal capsule, left superior and posterior corona radiata, bilateral thalamic radiation and left external capsule. In addition, relative to CD/CU- individuals, adolescents with CD/CU+ showed lower diffusivity (indexed by reduced RD and MD) in left uncinate fasciculus and bilateral fornix. Finally, relative to healthy controls, CD/CU+ individuals showed lower diffusivity (reduced RD) in the genu and body of the corpus callosum and left anterior corona radiata. These results suggest that CD/CU+ individuals present with white-matter microstructural abnormalities compared to both CD/CU- individuals and age-matched healthy controls. This finding is consistent with emerging evidence suggesting that CD/CU+ represents a distinct subtype of CD, and illustrates the importance of accounting for heterogeneity within CD populations.

Highlights

Conduct Disorder (CD) is characterized by pervasive and persistent antisocial behavior that violates other people’s rights or ageappropriate societal norms (APA 2013)
The present study investigated the impact of CU traits on white-matter microstructural properties in CD adolescents, by explicitly comparing individuals with CD and elevated callous-unemotional traits (CD/CU+), individuals with CD and lower levels of callous-unemotional traits (CD/CU-) and healthy control groups using a similar design to that adopted in earlier Functional magnetic resonance imaging (fMRI) and sMRI studies (e.g., Viding et al 2012; Sebastian et al 2016)
The present study shows that white-matter microstructural alterations in key white-matter tracts previously implicated in socioemotional development were observed in adolescents with CD and elevated callousunemotional traits, rather than in those with CD and lower levels of callous-unemotional traits

Summary

Introduction

Conduct Disorder (CD) is characterized by pervasive and persistent antisocial behavior that violates other people’s rights or ageappropriate societal norms (APA 2013). It affects around 5% of Forensic Research & Development Domain, Broadmoor High Secure Hospital, West London Mental Health Trust, Southall, UK. London, UK the adolescent population (NICE 2006), and is associated with a range of negative educational, social and mental health outcomes. Most importantly, it is a precursor of adult antisocial personality disorder (Teplin et al 2005; Fazel et al 2008). These characteristics, often considered under the umbrella term of callous-unemotional (CU) traits (Kimonis et al 2006) have been shown to distinguish between subgroups of CD individuals that differ in terms of etiology and neurocognitive processing (Frick and Viding 2009)

Methods

Results

Conclusion