Striatal-Limbic Grey Matter Volume in Boys with Early-Onset Conduct Problems: Examining Linkages with Callous-Unemotional Traits

• In Event: 2-014 - Charting the Biological Underpinnings of the Development of Maladaptive Aggression

Integrative Statement

Meta-analytic findings indicate that individuals exhibiting antisocial behavior exhibit reduced GMV across regions in the striatum, amygdala, and hippocampus relative to controls (Aoki et al., 2014). However, most of these studies have focused on adult offenders, making it unclear whether these abnormalities are present in children exhibiting early-onset conduct problems. Moreover, relatively few studies have examined whether these brain volume differences are most pronounced among children exhibiting callous-unemotional (CU) traits. This area of research is important given that CU traits have been linked to brain function abnormalities in the fronto-striatal-limbic neural network subserving emotion processing and reinforcement learning (Blair, 2013).

Participants were 51 predominately Black (76%) boys with severe conduct problems (CP; mean age=10.4, range 8-11) and 17 healthy developing boys of similar age (mean age=10.4, range 8-11,). High resolution structural images were acquired using a 3T Siemens scanner. GMV for targeted limbic structures (i.e., amygdala, hippocampus, nucleus accumbens) were obtained via automated segmentation using FreeSurfer. Parent-report measures were used to assess boys’ conduct disorder symptoms, internalizing problems and callous-unemotional traits.

Initial group comparisons indicated that CP boys exhibited significantly lower grey matter volume in the left and right hippocampus related to controls, but these differences were eliminated after controlling for total intracranial volume. No significant group differences were found for the amygdala or nucleus accumbens. Regression models were then used to examine the association between CU traits and GMV for each brain region, controlling for intracranial volume, age, race, and co-occurring internalizing problems. Results from these models indicated that CU were significantly associated with reduced left (β=-.29, p=.02) and right (β=-.30, p=.02) hippocampal volume. A marginally significant negative association was also found between CU traits and right amygdala volume (β=-.22, p=.09).

These findings are consistent with functional studies linking CU traits to brain function abnormalities in limbic structures associated with emotion processing and reinforcement learning. However, it will be important for future studies to further elucidate the potential mechanisms through which brain structure may influence the development of CU traits.

Authors

• Amy Byrd, University of Pittsburgh
  Presenting Author

• Dustin Pardini, Arizona State University
  Non-Presenting Author

• Jamie Hanson, University of Pittsburgh
  Non-Presenting Author