Boys with conduct problems and callous-unemotional traits: Neural response to reward and punishment and associations with treatment response

Abstract

Abnormalities in reward and punishment processing are implicated in the development of conduct problems (CP), particularly among youth with callous-unemotional (CU) traits. However, no studies have examined whether CP children with high versus low CU traits exhibit differences in the neural response to reward and punishment. A clinic-referred sample of CP boys with high versus low CU traits (ages 8-11; n = 37) and healthy controls (HC; n = 27) completed a fMRI task assessing reward and punishment processing. CP boys also completed a randomized control trial examining the effectiveness of an empirically-supported intervention (i.e., Stop-Now-And-Plan; SNAP). Primary analyses examined pre-treatment differences in neural activation to reward and punishment, and exploratory analyses assessed whether these differences predicted treatment outcome. Results demonstrated associations between CP and reduced amygdala activation to punishment independent of age, race, IQ and co-occurring ADHD and internalizing symptoms. CU traits were not associated with reward or punishment processing after accounting for covariates and no differences were found between CP boys with high versus low CU traits. While boys assigned to SNAP showed a greater reduction in CP, differences in neural activation were not associated with treatment response. Findings suggest that reduced sensitivity to punishment is associated with early-onset CP in boys regardless of the level of CU traits.

Keywords: Callous-unemotional (CU) traits; Conduct problems; Punishment; Reward; fMRI.

Fig. 1

Schematic of events within each trial of the fMRI reward/punishment task.

Fig. 2

Interaction between group and task condition in the left amygdala. a. Region in the amygdala significant at p < .05, corrected using 3DclusterSim threshold for contiguous voxels (F(6,244) = 9.41, 22 voxels). Coronal slice shown at y = −6 (MNI peak voxel). Color bar reflects t-values; b. Bar graphs depict extracted mean BOLD signal change (%) across all voxels within the cluster along with standard errors. * = p < .05; ** = p < .01. P-values are based on Games-Howell pairwise comparisons for extracted mean BOLD response. Note. BOLD = blood oxygen level dependent; CP = conduct problems; CU = callous-unemotional traits; HC = healthy control; NS = non-significant.

Fig. 3

Activation in the bilateral amygdala is negatively associated with conduct problems, even after controlling for variance associated with callous-unemotional traits. a. Region in the bilateral amygdala significant at p < .05, corrected using 3DclusterSim threshold for contiguous voxels (Right amygdala: 33 voxels, t = 3.20; Left amygdala: 29 voxels, t = 2.87). Coronal slice shown at y = 0. Color bar reflects t-values; b. Scatter plot depicts association between baseline levels of conduct problems (x-axis) and mean BOLD signal change (%) in the amygdala (y-axis) after controlling for co-occurring callous-unemotional traits (r = −0.42). Note. BOLD = blood oxygen level dependent

Fig. 4

Significant reduction in conduct problems for youth participating in the SNAP intervention. Post-hoc paired sample t-tests revealed a significant reduction in conduct problems between baseline levels and 3-month follow-up for those youth participating in SNAP (t(33) = 5.14; p < .001). No differences were seen between conduct problems at baseline and 3-month follow-up for those youth in Standard Services (t(33) = 1.13; p > .25). Note. SS = Standard Services; SNAP = Stop-Now-and-Plan Intervention.