The Relationship Between Frontal Cortical Thickness and Externalizing Psychopathology is Associated with Treatment Outcomes in Children with Externalizing Problems: A Preliminary Pilot Study: La relation entre l’épaisseur du cortex frontal et les tro

ObjectivesChildren with externalizing disorders commonly show emotion dysregulation and callous-unemotional (CU) traits. However, it is unclear whether emotion dysregulation and CU traits share underlying neurobiology that can be predictive of psychosocial treatment outcomes. In this preliminary study, we examined neural correlates of externalizing psychopathology dimensions and their prediction of treatment outcomes.MethodsWe analyzed a pilot sample of 17 children with an externalizing disorder (9-12 years; 10.45 ± 1.02) who underwent structural magnetic resonance imaging (MRI) before participating in a 15-week psychosocial group intervention targeting conduct problems. We examined cross-sectional associations between emotion dysregulation or CU traits and cortical thickness (anterior cingulate cortex [ACC] and insula) and amygdala volume at baseline. We then examined whether the pre-treatment brain-behaviour relationships were linked to reduction in conduct problems post-treatment.ResultsLower ACC and insula thickness as well as amygdala volume was associated with greater levels of emotion dysregulation and CU traits at baseline (pre-treatment, <i>r</i> = |0.36-0.61|). There was a significant three-way interaction between emotion dysregulation/CU traits, left insula/right rostral ACC, and treatment (pre/post; β = -1.01 to 3.6). Overall, greater baseline insular and rostral ACC thickness was related to reductions in conduct problems following group-based psychosocial intervention regardless of baseline emotion dysregulation and CU trait levels.ConclusionsThe results provide preliminary evidence of shared neural signatures underlying both emotion dysregulation and CU traits. Additionally, alterations in frontolimbic brain structure may be useful predictors of pre-treatment associations with externalizing psychopathology dimensions and post-treatment behavioural outcomes.Plain Language Summary TitleFrontal cortical thickness and externalizing psychopathology are associated with treatment outcomes in children with externalizing problems.