Specific Contributions of Age of Onset, Callous-Unemotional Traits and Impulsivity to Reactive and Proactive Aggression in Youths with Conduct Disorders

The longitudinal relationship between executive dysfunction and reactive and proactive aggression in adolescents: impulsivity as a mediator and sex differences

Background

Adolescent aggression poses a significant threat to mental health and social functioning. This study investigated the underlying mechanisms of reactive and proactive aggression in Chinese adolescents, focusing on the roles of executive dysfunction, impulsivity, and sex. We hypothesized that executive dysfunction would predict both reactive and proactive aggression, with impulsivity mediating these relationships. Furthermore, we explored the moderating role of sex in the association between impulsivity and both types of aggression.

Method

A longitudinal design with a 1-year follow-up was employed. The sample comprised 617 middle school students (mean age = 15.26 years at Time 2; 59% male). Participants completed self-report questionnaires at two time points (T1: April 2023; T2: April 2024): the Reactive-Proactive Aggression Questionnaire (RPQ), the Teenage Executive Functioning Inventory (TEXI), and the Barratt Impulsiveness Scale (BIS).

Results

Executive dysfunction at T1 significantly predicted both proactive and reactive aggression at T2. Impulsivity at T2 partially mediated the relationship between executive dysfunction at T1 and both proactive and reactive aggression at T2. Sex moderated the relationship between impulsivity and aggression. Specifically, impulsivity at T2 significantly predicted proactive aggression at T2 only in male adolescents. Impulsivity at T2 significantly predicted reactive aggression at T2 in both male and female adolescents, with a stronger effect observed in males.

Conclusion

Our findings suggest that executive dysfunction contributes to adolescent aggression both directly and indirectly through increased impulsivity. Sex plays a moderating role, with male adolescents demonstrating greater vulnerability to the influence of impulsivity on aggression. These results underscore the importance of considering executive function, impulsivity, and sex in the development of interventions to prevent and reduce adolescent aggression.

Assessing Callous-Unemotional Traits Across Early Adolescence: Further Evaluation of Short Versions

Literature on the Inventory of Callous-Unemotional (ICU) traits has suggested different versions of the instrument for assessing these traits during development. However, consensus on the instrument version and the best factorial solution remains a matter of debate, with only a few studies having validated ICU versions from a longitudinal perspective. The current study aims to contribute to the literature by comparing ICU models in a longitudinal sample of early adolescents (N = 739; 70.6% of eligible subjects, 371 females and 368 males, in the 6th grade at baseline assessment and in the 8th grade at the second assessment). We tested the validity of various versions of the ICU scales and their respective dimensions by conducting a series of confirmatory factor analyses to verify the factor structure, alongside assessments of internal consistency. For the best-fitting structure, we then analyzed gender and longitudinal invariance in addition to construct and predictive validity, using internalizing and externalizing criteria as well as prosocial behavior. From the comparative analysis, it emerged that the abbreviated 11-item ICU scale version displayed overall better data fit than the full 24-item version. Moreover, its confirmed gender invariance underscores its applicability across genders within the studied age group. With regard to longitudinal invariance, our findings advise caution when comparing ICU scores across early adolescence. Practical implications are discussed.

The neurofunctional basis of human aggression varies by levels of femininity

Aggression can be categorized into reactive aggression (RA) and proactive aggression (PA) based on their underlying motivations. However, previous research has rarely identified the relationship between femininity and RA/PA, and there is a lack of understanding regarding the femininity-related neurofunctional basis of these aggressive behaviors. Thus, this study first examined the relationships between femininity and aggression, then explored the aggression-by-femininity interactions on the fractional amplitude of low-frequency fluctuations using resting-state fMRI among 705 university participants (mean age = 19.14 ± 0.99). The behavioral data indicated that femininity was more negatively associated with RA and PA when masculinity was controlled for. Additionally, the neural data revealed that femininity-specific relationships of RA in the left middle occipital gyrus (i.e. individuals with low femininity had positive relationships between RA and the left middle occipital gyrus, whereas those with high femininity had negative relationships) as well as of PA in the left middle frontal gyrus (i.e. individuals with high femininity showed significant negative relationships, whereas those with low femininity did not exhibit significant relationships). These findings reflect that individuals with varying levels of femininity exhibit distinct neural bases when expressing different subtypes of aggression, which are associated with societal expectations of gender.

The Interplay between Fear Reactivity and Callous-Unemotional Traits Predicting Reactive and Proactive Aggression

Research has indicated that youths with CU traits are fearless, and this fearlessness plays a bidirectional role in both the development of CU traits and engagement in aggressive behavior. However, research specifically testing the role of fear in the association between CU traits and aggression is scarce. The goal of the current study was to test if fear reactivity, both conscious (self-report) and automatic (skin conductance reactivity; SCR), moderated the association between CU traits and aggression subtypes (reactive and proactive aggression). Participants included 161 adolescents (Mage = 15 years) diagnosed with conduct disorder. CU traits were assessed using the self-report Inventory of Callous-Unemotional Traits. Conscious and automatic fear reactivity were measured during a virtual reality rollercoaster using the Self-Assessment Manikin and skin conductance reactivity (SCR), respectively. Hierarchical regressions found that high fear reactivity on SCR moderated the link between CU traits and reactive aggression, while feeling more excited during fear induction moderated the link between CU traits and proactive aggression. Overall, a possible explanation of our divergent findings between conscious and automatic fear may be the difference between the instinctual biological response to threat versus the cognitive and emotional appraisal and experience of threat. Implications for intervention strategies targeting emotional recognition and regulation in reducing aggression in CD populations are discussed.

Different whole-brain functional connectivity correlates of reactive-proactive aggression and callous-unemotional traits in children and adolescents with disruptive behaviors

BACKGROUND

Disruptive behavior in children and adolescents can manifest as reactive aggression and proactive aggression and is modulated by callous-unemotional traits and other comorbidities. Neural correlates of these aggression dimensions or subtypes and comorbid symptoms remain largely unknown. This multi-center study investigated the relationship between resting state functional connectivity (rsFC) and aggression subtypes considering comorbidities.

METHODS

The large sample of children and adolescents aged 8-18 years (n = 207; mean age = 13.30±2.60 years, 150 males) included 118 cases with disruptive behavior (80 with Oppositional Defiant Disorder and/or Conduct Disorder) and 89 controls. Attention-deficit/hyperactivity disorder (ADHD) and anxiety symptom scores were analyzed as covariates when assessing group differences and dimensional aggression effects on hypothesis-free global and local voxel-to-voxel whole-brain rsFC based on functional magnetic resonance imaging at 3 Tesla.

RESULTS

Compared to controls, the cases demonstrated altered rsFC in frontal areas, when anxiety but not ADHD symptoms were controlled for. For cases, reactive and proactive aggression scores were related to global and local rsFC in the central gyrus and precuneus, regions linked to aggression-related impairments. Callous-unemotional trait severity was correlated with ICC in the inferior and middle temporal regions implicated in empathy, emotion, and reward processing. Most observed aggression subtype-specific patterns could only be identified when ADHD and anxiety were controlled for.

CONCLUSIONS

This study clarifies that hypothesis-free brain connectivity measures can disentangle distinct though overlapping dimensions of aggression in youths. Moreover, our results highlight the importance of considering comorbid symptoms to detect aggression-related rsFC alterations in youths.

Association between lower-level of environmental lead exposure and reactive and proactive aggression in youth: Sex differences

Lead exposure during childhood has been associated with a variety of negative outcomes, including antisocial/aggressive behavior. However, different subtypes of antisocial behavior have been found to have different neurobiological correlates, and it is unclear whether lead exposure is related to specific subtypes of aggressive behavior. The objective of the study was to examine relationships between childhood blood lead levels (BLL) and proactive and reactive aggression. Further, given prior findings of sex differences in the effects of lead exposure, we examine whether there are sex differences in these relationships. In a sample of 818 youth (47.2% girls) ages 10-13 in China, we assessed BLL and administered the Reactive Proactive Aggression Questionnaire. Results show that BLLs were associated with reactive, but not proactive aggression. There was a significant interaction between BLL and sex in predicting aggression; boys with higher BLL scored higher in both proactive and reactive aggression than boys with lower BLL, but these differences were not present for girls. These findings suggest that lead exposure may have broad effects on antisocial behavior, but that boys may be more susceptible than girls. These findings may provide insights to identifying protective factors that could be potential targets for intervention.

Creating profiles of juvenile offenders using functions of aggression and callous-unemotional traits: relations to crime type

A rich line of criminological theories and research has suggested that individual characteristics may be important to predicting criminal activity. However, there is limited research examining how individual characteristics may be related to the type of crime committed (e.g. violent, sex, drug). To provide guidance to these questions, the current set of two studies used latent profile analysis to identify groups of offenders based on individual factors (i.e. proactive and reactive aggression, and callous-unemotional traits), chosen for their interrelatedness and their established associations with crime, and examined whether these groups relate to type, severity or the number of crimes committed across two studies. In both studies, four groups of offenders were identified, but these groups were not associated with offending behaviors or patterns. Findings and implications are discussed.

The effects of callous-unemotional traits and aggression subtypes on amygdala activity in response to negative faces

BACKGROUND

Brain imaging studies have shown altered amygdala activity during emotion processing in children and adolescents with oppositional defiant disorder (ODD) and conduct disorder (CD) compared to typically developing children and adolescents (TD). Here we aimed to assess whether aggression-related subtypes (reactive and proactive aggression) and callous-unemotional (CU) traits predicted variation in amygdala activity and skin conductance (SC) response during emotion processing.

METHODS

We included 177 participants (n = 108 cases with disruptive behaviour and/or ODD/CD and n = 69 TD), aged 8-18 years, across nine sites in Europe, as part of the EU Aggressotype and MATRICS projects. All participants performed an emotional face-matching functional magnetic resonance imaging task.

RESULTS

Differences between cases and TD in affective processing, as well as specificity of activation patterns for aggression subtypes and CU traits, were assessed. Simultaneous SC recordings were acquired in a subsample (n = 63). Cases compared to TDs showed higher amygdala activity in response to negative faces (fearful and angry) v. shapes. Subtyping cases according to aggression-related subtypes did not significantly influence on amygdala activity; while stratification based on CU traits was more sensitive and revealed decreased amygdala activity in the high CU group. SC responses were significantly lower in cases and negatively correlated with CU traits, reactive and proactive aggression.

CONCLUSIONS

Our results showed differences in amygdala activity and SC responses to emotional faces between cases with ODD/CD and TD, while CU traits moderate both central (amygdala) and peripheral (SC) responses. Our insights regarding subtypes and trait-specific aggression could be used for improved diagnostics and personalized treatment.

Cold-Blooded and on Purpose: A Review of the Biology of Proactive Aggression

Proactive aggression (PA) is a planned and unprovoked form of aggression that is most often enacted for personal gain or in anticipation of a reward. Frequently described as "cold-blooded" or goal oriented, PA is thought to be associated with low autonomic arousal. With this view in mind, we performed a scoping review of the biological correlates of PA and identified 74 relevant articles. Physiological findings indicated a robust association between PA and reduced resting heart rate, and to a lesser extent a relationship between PA and decreased heart rate and skin conductance reactivity, perhaps indicating dampened sympathetic function. The twin literature identified PA as a heritable trait, but little evidence implicates specific genes in the pathogenesis of PA. Neuroimaging studies of PA pinpoint impaired amygdala function in the assessment and conditioning of aversive stimuli, which may influence the establishment of behavioral patterns. Nodes of the default mode network were identified as possible neural correlates of PA, suggesting that altered function of this network may be involved in the genesis of PA. Given the overlap of PA with reactive aggression and the overall behavioral complexity of PA, it is clear that multiple endophenotypes of PA exist. This comprehensive review surveys the most salient neurobiologically informed research on PA.

Heterogeneity Within Youth With Childhood-Onset Conduct Disorder in the ABCD Study

The purpose of this study was to examine if personality traits can be used to characterize subgroups of youth diagnosed with childhood-onset conduct disorder (CD). Participants were 11,552 youth from the Adolescent Brain Cognitive Development study. Data used in this report came from doi: 10.15154/1504041 (M age 9.92; 45.3% female, 49.6% white, 19.0% Hispanic). A subset of this sample (n = 365) met criteria for CD. Latent profile analyses (LPA) were performed on this subgroup (n = 365) to define profiles of individuals with CD based on self-report measures of impulsivity, punishment sensitivity, reward response, and callous-unemotional traits. Follow up analyses determined if these groups differed on clinically relevant variables including psychopathology, environmental risk factors, social risk factors, and neurocognitive functioning. Participants with a CD diagnosis scored significantly higher on psychological, environmental, social, and neurocognitive risk factors. The LPA revealed three unique profiles, which differed significantly on liability for broad psychopathology and domain-specific liability for externalizing psychopathology but were largely matched on environmental and social risk factors. These unique configurations provide a useful way to further parse clinically relevant subgroups within youth who meet criteria for childhood-onset CD, setting the stage for prospective longitudinal research using these latent profiles to better understand the development of youth with childhood-onset CD.

Correlations of impulsivity and aggressive behaviours among adolescents in Shanghai, China using bioecological model: cross-sectional data from Global Early Adolescent Study

OBJECTIVE

To examine the correlations between impulsivity and aggressive behaviours among Chinese adolescents.

DESIGN

A school-based cross-sectional study.

SETTING

Three primary middle schools located in less developed communities of Shanghai.

PARTICIPANTS

1524 adolescents aged 11-16 years.

MEASURES

The impulsivity was measured by Barratt Impulsivity Scale, and the aggressive behaviours were determined by self-reports. Data were collected through computer-assisted self-interview using tablets. Multivariate Firth logistic regression model was conducted to examine correlations between total, attentional, motor, and non-planning impulsivity and aggressive behaviours, respectively.

RESULTS

Totally, 7.48% of participants reported aggressive behaviours toward others during the past 6 months. The proportion of aggressors among boys and girls was 10.60% and 4.18%, respectively. Results of the multivariate regression suggested the risk of aggressive behaviours was significantly increased among those with the highest tertile of total impulsivity (adjusted OR (aOR)_boys=3.14, 95% CI: 1.48 to 6.65; aOR_girls=3.74, 95% CI: 1.10 to 12.76) and motor impulsivity (aOR_boys=2.91, 95% CI: 1.46 to 5.82; aOR_girls=3.57, 95% CI: 1.25 to 10.20.), comparing with those with the lowest tertile, for boys and girls, respectively. Besides, younger age, lower social cohesion and being bullied within 6 months were associated with a higher risk of aggressive behaviours among girls. Less family caring and being bullied within 6 months were associated with the risk among boys.

CONCLUSIONS

The present study indicates a positive association between impulsivity and aggressive behaviours, with a more salient correlation between motor impulsivity subtrait and aggressive behaviour among both boys and girls. Furthermore, adolescents' aggressive behaviours were affected by multiple factors from individuals, family, peers and community. Comprehensive intervention strategies such as controlling the aggressor's impulsivity, helping them better channel their anger, creating a better family, school and neighbourhood environment, and providing support and services for victims of violence are needed.

Neural Correlates of Empathy in Boys With Early Onset Conduct Disorder

Background: A deficit in empathy has repeatedly been described in individuals with conduct disorder (CD), and in particular in those with callous unemotional traits. Until now, little is known about the neural basis of empathy in children and adolescents with early onset conduct disorder. The aim of this study was to examine neural responses during empathizing in children and adolescents with CD with a task that allowed to differentiate between the judgment of the emotional states of other people and the own emotional response to other people's emotional state. Moreover, we investigated associations of callous-unemotional traits and neural activations during empathizing. Methods: Using functional magnetic resonance imaging (fMRI) we investigated 14 boys with early onset CD and 15 typically developing (TDC) age matched controls between 8 and 16 years of age. Happy and sad faces were presented, and participants were asked to either infer the emotional state from the face (other-task) or to judge their own emotional response (self-task). A perceptual decision on faces was used as a control task. Individual empathic abilities and callous unemotional traits were assessed. Results: During the other task, TDC boys showed significantly larger right amygdala responses than CD boys. Higher empathic abilities (as assessed with the Bryant Index of Empathy) were associated with higher responses in the right amygdala within the CD boys and across the entire sample. Moreover, across the entire sample, callous-unemotional traits were negatively related to the BOLD-response in the right amygdala. CD boys showed larger responses in the dorsal and ventral medial prefrontal cortex across tasks and increased activation in dorsal medial prefrontal cortex specifically during the self-conditions, which were also related to empathic abilities within the CD boys. Conclusions: The data emphasize the important role of the amygdala in empathy related emotional processing. Diminished amygdala responses and their association with low empathy suggest a pivotal influence of impaired amygdala processing in early-onset CD, in particular for deficits in empathic behavior and related callous-unemotional-traits. Elevated response in the medial prefrontal cortex in boys with CD point toward increased involvement of brain areas related to self-referential processing and cognitive empathy during empathizing.

Understanding Chronic Aggression and Its Treatment in Children and Adolescents

PURPOSE OF REVIEW

Youth aggression is common and has a significant burden on individuals, families, and society. However, its treatment is often a challenge for clinicians. Thus, this review will examine the current understanding of youth aggression, conceptualize aggression as a symptom rather than its own disorder, and provide an overview of treatment strategies.

RECENT FINDINGS

Youth aggression is associated with complex genetic, neurobiological, and environmental risks. Prevention strategies are of the utmost importance for at-risk families and youth. Psychosocial interventions are the first line treatment. But if not fully effective, then pharmacologic interventions-including psychostimulants, alpha-2 agonists, atomoxetine, and risperidone-have shown benefits. Other medications, such as SSRIs, can be useful in certain scenarios. It is important to conceptualize youth aggression as being a trans-diagnostic symptom in psychopathology. Determining the underlying cause of aggression will help to guide treatment.

Maladaptive Aggression: With a Focus on Impulsive Aggression in Children and Adolescents

Objective: Aggressive behavior is among the most common reasons for referral to psychiatric clinics and confers significant burden on individuals. Aggression remains poorly defined; there is currently no consensus on the best ways to recognize, diagnose, and treat aggression in clinical settings. In this review, we synthesize the available literature on aggression in children and adolescents and propose the concept of impulsive aggression (IA) as an important construct associated with diverse and enduring psychopathology. Methods: Articles were identified and screened from online repositories, including PubMed, PsychInfo, the Cochrane Database, EMBase, and relevant book chapters, using combinations of search terms such as "aggression," "aggressive behavio(u)r," "maladaptive aggression," "juvenile," and "developmental trajectory." These were evaluated for quality of research before being incorporated into the article. The final report references 142 sources, published from 1987 to 2019. Results: Aggression can be either adaptive or maladaptive in nature, and the latter may require psychosocial and biomedical interventions when it occurs in the context of central nervous system psychopathology. Aggression can be categorized into various subtypes, including reactive/proactive, overt/covert, relational, and IA. IA in psychiatric or neurological disorders is reviewed along with current treatments, and an algorithm for systematic evaluation of aggression in the clinical setting is proposed. Conclusions: IA is a treatable form of maladaptive aggression that is distinct from other aggression subtypes. It occurs across diverse psychiatric and neurological diagnoses and affects a substantial subpopulation. IA can serve as an important construct in clinical practice and has considerable potential to advance research.

Serotonin and aggressive behaviour in children and adolescents: a systematic review

OBJECTIVE

The role of serotonin (5-HT) in human aggression has been the subject of a large number of studies, mostly with adults. Meta-analyses indicate a small but significant inverse relationship between central nervous 5-HT availability and aggression, but genetically informed studies suggest two pathways: one to reactive aggression and the other to proactive aggression.

METHOD

We conducted a systemic review on central nervous 5-HT function in children and adolescents, with attention to the function of aggression.

RESULTS

In total, 675 articles were screened for relevance, with 45 reviewed. These included blood assays (e.g. plasma, 5-HIAA; platelet 5-HTR_2A ), epigenetic studies, retrospective PET studies and 5-HT challenge paradigms (e.g. tryptophan depletion). Overall, findings were mixed, with support both for negative and for positive associations of central nervous 5-HT function with aggression in children and adolescents.

CONCLUSION

We propose factors that may be blurring the picture, including problems in the conceptualization and measurement of aggression in young people, the lack of prospective designs and the bias towards clinical samples of boys. Research needs to account for variance in the both motivation for and implementation of aggression, and look to the behavioural economics literature to consider the roles of reward, vengeance and self-control more clearly.

Assessing the Proactive and Reactive Dimensions of Criminal Thought Process: Divergent Patterns of Correlation With Variable- and Person-Level Measures of Criminal Risk and Future Outcome

The goal of this study was to determine whether measures of proactive and reactive criminal thinking display divergent patterns of correlation with outside criteria. A sample of 3,039 male medium-security federal prisoners who completed the Psychological Inventory of Criminal Thinking Styles (PICTS) served as participants in this study. Despite being highly correlated (r = .75), the PICTS proactive and reactive scales displayed divergent patterns of correlation with the eight risk/outcome measures. As predicted, the proactive scale corresponded with lower criminal risk, older age of first conviction, and decreased odds of prior substance misuse and mental illness, whereas the reactive scale corresponded with higher criminal risk, earlier age of first conviction, greater odds of prior substance misuse and mental illness, and more evidence of subsequent arrest. Contrary to predictions, the proactive scale was associated with increased rather than decreased commission of disciplinary infractions in prison. When participants with elevated proactive scores were compared to participants with elevated reactive scores on the eight risk/outcome variables, the results revealed that the two profiles were moderately negatively correlated. Thus, although proactive criminal thinking is associated with below-average criminal risk and below-average future negative outcomes, reactive criminal thinking does just the opposite.