Neurobiological correlates of aggression and emotion regulation in children and adolescents

Aggressive and antisocial behaviour is associated with impaired emotion regulation and neurobiological alterations that are reflected on the level of autonomic as well as central nervous system functioning. Recent research on central autonomic control – as posited in the neurovisceral integration model – indicates associations between autonomic nervous system (ANS) activity and functional and structural brain correlates. An overlap of the central autonomic network (CAN) with brain regions involved in emotion regulation highlights the relevance of ANS measures in research on emotion regulation and aggression. The main aim of this thesis was to investigate and gain more insight into neurobiological correlates of aggression and emotion regulation in children and adolescents. First, we examined the relationship between resting ANS activity and aggression in more detail than has been done before. We therefore included a comprehensive assessment of ANS activity with two measures of general ANS activity (heart and respiration rate) and two measures capturing parasympathetic nervous system (heart rate variability) and sympathetic nervous system (pre-ejection period) activity separately, while considering relevant covariates such as smoking. A further sub aim was to gain more clarity on the best approach for linking psychopathology and neurobiology. Recent findings on a general psychopathology factor suggest that a dimensional approach captures psychopathology better than a categorical approach. Thus, we chose to compare two analysis approaches: a categorical (chapter 2) – based on DSM-5 – and a dimensional approach (chapter 3). The second aim of the thesis was to investigate functional brain correlates of implicit-controlled emotion regulation in individuals with and without conduct disorder (CD) (chapter 4). The third aim of the thesis was to investigate the relationship between resting heart rate variability and brain structure in female CD patients compared to typically developing adolescents (chapter 5). The findings presented in this dissertation advance the knowledge on the neurobiology of aggression and emotion regulation in children and adolescents. In line with recent evidence, the presented studies suggest that resting ANS activity, especially heart rate, might not be as strongly correlated with antisocial behaviour as previously assumed. In addition, the novel finding of higher respiration rate in female CD suggests that this measure should be further considered in future research – with a particular focus on its potential to impact heart rate variability and emotion regulation. More research on respiration in aggressive individuals could improve current treatment modalities. Further, the result indicating that comorbid internalising disorders in female CD patients are associated with lower heart rate variability warrants additional investigation and consideration of specific treatment needs. This CD group might represent a more severe psychopathological subgroup with more pronounced emotion regulation problems. Our findings of the neural correlates of implicit emotion regulation additionally support the notion of CD being characterised by deficient emotion regulation. Moreover, we reported negative correlations between resting heart rate variability and brain structure in CAN regions, which are implicated in emotion regulation. We highlighted the relevance of smoking for emotion regulation – which has been neglected so far in the context of neurobiological research on aggression and might be an important confounding factor to consider in future studies

Atypical dorsolateral prefrontal activity in females with conduct disorder during effortful emotion regulation

BACKGROUND: Conduct disorder (CD), which is characterized by severe aggressive and antisocial behavior, is linked to emotion processing and regulation deficits. However, the neural correlates of emotion regulation are yet to be investigated in adolescents with CD. Furthermore, it remains unclear whether CD is associated with deficits in emotional reactivity, emotion regulation, or both. METHODS: We used functional magnetic resonance imaging to study effortful emotion regulation by cognitive reappraisal in 59 female adolescents 15 to 18 years of age (30 with a CD diagnosis and 29 typically developing (TD) control adolescents). RESULTS: Behaviorally, in-scanner self-report ratings confirmed successful emotion regulation within each group individually but significant group differences in emotional reactivity and reappraisal success when comparing the groups (CD < TD). Functional magnetic resonance imaging results revealed significantly lower activation in left dorsolateral prefrontal cortex and angular gyrus in CD compared with TD adolescents during emotion regulation, but no group differences for emotional reactivity. Furthermore, connectivity between left dorsolateral prefrontal cortex and the bilateral putamen, right prefrontal cortex, and amygdala was reduced in CD compared with TD adolescents during reappraisal. Callous-unemotional traits were unrelated to neural activation, but these traits correlated negatively with behavioral reports of emotional reactivity. CONCLUSIONS: Our results demonstrate reduced prefrontal brain activity and functional connectivity during effortful emotion regulation in female adolescents with CD. This sheds light on the neural basis of the behavioral deficits that have been reported previously. Future studies should investigate whether cognitive interventions are effective in enhancing emotion-regulation abilities and/or normalizing prefrontal and temporoparietal activity in female adolescents with CD

Atypical Dorsolateral Prefrontal Activity in Female Adolescents With Conduct Disorder During Effortful Emotion Regulation

BACKGROUND: Conduct disorder (CD), which is characterized by severe aggressive and antisocial behavior, is linked to emotion processing and regulation deficits. However, the neural correlates of emotion regulation are yet to be investigated in adolescents with CD. Furthermore, it remains unclear whether CD is associated with deficits in emotional reactivity, emotion regulation, or both. METHODS: We used functional magnetic resonance imaging to study effortful emotion regulation by cognitive reappraisal in 59 female adolescents 15 to 18 years of age (30 with a CD diagnosis and 29 typically developing (TD) control adolescents). RESULTS: Behaviorally, in-scanner self-report ratings confirmed successful emotion regulation within each group individually but significant group differences in emotional reactivity and reappraisal success when comparing the groups (CD < TD). Functional magnetic resonance imaging results revealed significantly lower activation in left dorsolateral prefrontal cortex and angular gyrus in CD compared with TD adolescents during emotion regulation, but no group differences for emotional reactivity. Furthermore, connectivity between left dorsolateral prefrontal cortex and the bilateral putamen, right prefrontal cortex, and amygdala was reduced in CD compared with TD adolescents during reappraisal. Callous-unemotional traits were unrelated to neural activation, but these traits correlated negatively with behavioral reports of emotional reactivity. CONCLUSIONS: Our results demonstrate reduced prefrontal brain activity and functional connectivity during effortful emotion regulation in female adolescents with CD. This sheds light on the neural basis of the behavioral deficits that have been reported previously. Future studies should investigate whether cognitive interventions are effective in enhancing emotion-regulation abilities and/or normalizing prefrontal and temporoparietal activity in female adolescents with CD

Resting autonomic nervous system activity is unrelated to antisocial behaviour dimensions in adolescents: Cross-sectional findings from a European multi-centre study

Purpose: Autonomic nervous system (ANS) functioning has long been studied in relation to antisocial behaviour, but relevant measures (heart rate, heart rate variability, pre-ejection period, respiration rate) have rarely been considered together. This study investigated the relationship between these measures and antisocial behaviour. Methods: Using a sample of 1010 youths with (47.8%) and without conduct disorder (52.2%) aged between 9 and 18. years (659 females, 351 males, mean age = 14.2. years, SD = 2.4), principal component analysis (PCA) was applied to various measures of psychopathology and antisocial behavior. Structural equation modelling was performed in order to test whether the ANS measures predicted PCA-dimensions. Cluster analysis was used in order to classify patterns of ANS activity. Analyses were performed separately for males/females and controlled for body-mass-index, age, caffeine use, cigarette smoking, sports, socioeconomic status, medication, cardiac problems. Results: The PCA yielded three components: antisocial behaviour/comorbid psychopathology, narcissistic traits, and callous-unemotional traits. ANS measures were only weakly correlated with these components. Cluster analysis yielded high and low arousal clusters in both sexes. When controlling for covariates, all associations disappeared. Conclusion: Our findings suggest that resting ANS measures are only weakly related to antisocial behaviour and indicate that smoking should be considered as an important covariate in future psychophysiological studies

Impact of short-term meditation and expectation on executive brain functions

Meditation improves executive functions such as attention and working memory processes. However, it remains unclear to what extent contextual effects contribute to these improvements, since the role of meditation-associated expectations has not been investigated so far. In a randomized, single-blind, deceptive, between-subject design we compared the impact of short-term meditation (MG) on executive functioning with an expectation (ECG) and a passive control group (CG) as well as the effect of positive and negative outcome expectations. Fifty-nine healthy meditation-naïve volunteers participated on three consecutive days (20 min/session). Five groups were examined: 2 MGs, 2 ECGs and 1 CG. While one MG and one ECG were given positive suggestions concerning the effect of meditation on attention, the other two groups were given negative suggestions. MGs practised a focused attention meditation technique; ECGs were told that they were practising meditation but were given instructions for a sham meditation. CG participants sat in silence with their eyes closed. Interference control (Stroop task), selective sustained attention (d2 task), figural and verbal fluency measures of executive functions were assessed. Results indicate that suggestions have a substantial impact on interference control and verbal fluency, with positive suggestions leading to an increase in performance, whereas negative suggestions impeded improvement. This proof of concept study demonstrates the importance of the implementation of a credible ECG to elucidate context effects in meditation processes. It also indicates that suggestions can modulate the small effect of meditation on verbal fluency

Altered neuronal responses during an affective Stroop task in adolescents with conduct disorder

Contains fulltext : 197103.pdf (publisher's version ) (Open Access)Conduct disorder (CD) is a psychiatric disorder of childhood and adolescence which has been linked to deficient emotion processing and regulation. The behavioral and neuronal correlates targeting the interaction of emotion processing and response inhibition are still under investigation. Whole-brain event-related fMRI was applied during an affective Stroop task in 39 adolescents with CD and 39 typically developing adolescents (TD). Participants were presented with an emotional stimulus (negative/neutral) followed by a Stroop task with varying cognitive load (congruent/incongruent/blank trials). fMRI analysis included standard preprocessing, region of interest analyses (amygdala, insula, ventromedial prefrontal cortex) and whole-brain analyses based on a 2(group) x 2(emotion) x 3(task) full-factorial ANOVA. Adolescents with CD made significantly more errors, while reaction times did not significantly differ compared to TD. Additionally, we observed a lack of downregulation of left amygdala activity in response to incongruent trials and increased anterior insula activity for CD relative to TD during affective Stroop task processing [cluster-level family-wise error-corrected (p < 0.05)]. Even though no three-way interaction (group x emotion x task) interaction was detected, the findings presented still provide evidence for altered neuronal underpinnings of the interaction of emotion processing and response inhibition in CD. Moreover, our results may corroborate previous evidence of emotion dysregulation as a core dysfunction in CD. Future studies shall focus on investigating the interaction of emotion processing and response inhibition in CD subgroups (e.g., variations in callous-unemotional traits, impulsivity, or anxiety).12 p

Erratum to : START NOW - a comprehensive skills training programme for female adolescents with oppositional defiant and conduct disorders: study protocol for a clusterrandomised controlled trial

The original publication [doi:10.1186/s13063-016-1705-6] contains a typographical typo in the Author’s contributions section..

Baseline autonomic nervous system activity in female children and adolescents with conduct disorder:Psychophysiological findings from the FemNAT-CD study

Purpose: Autonomic nervous system (ANS) functioning has been widely studied in relation to antisocial behavior, such as Conduct Disorder (CD). However, research in females is scarce and findings are inconsistent. This study investigated baseline ANS activity in CD children and adolescents and tested for sex differences. Furthermore, subgroups of CD were investigated: +/‐ Limited Prosocial Emotions (LPE), +/‐ comorbid internalizing disorders (INT). Methods: Baseline ANS activity was measured by Heart Rate (HR), Heart Rate Variability (HRV; parasympathetic activity), Pre-Ejection Period (PEP; sympathetic activity), and Respiration Rate (RR). 659 females (296 CD, 363 controls) and 351 males (187 CD, 164 controls), aged 9–18 years participated. Results: Baseline HR, HRV and PEP did not differ between CD subjects and controls in both sexes. RR was higher in CD participants than controls amongst females, but not males. LPE was unrelated to ANS activity, whereas females with CD + INT presented lower HRV. Conclusions: These results suggest that baseline ANS activity is not a robust indicator for CD. However, deviant ANS activity – especially parasympathetic activity - was observed in CD females with internalizing comorbidity. The psychophysiological abnormalities observed in this subgroup are indicative of emotion regulation problems. Accordingly, this subgroup may require specific interventions