Reduced prosocial motivation and effort in adolescents with conduct problems and callous-unemotional traits.

BACKGROUND: Prosocial behaviours - acts that benefit others - are of crucial importance for many species including humans. However, adolescents with conduct problems (CP), unlike their typically developing (TD) peers, demonstrate markedly reduced engagement in prosocial behaviours. This pattern is particularly pronounced in adolescents with CP and high levels of callous-unemotional traits (CP/HCU) who are at increased risk of developing psychopathy in adulthood. While a substantial amount of research has investigated the cognitive-affective mechanisms thought to underlie antisocial behaviour, much less is known about the mechanisms that could explain reduced prosocial behaviours in adolescents with CP. METHODS: Here we examined the willingness to exert effort to benefit oneself (self) and another person (other, prosocial condition) in children with CP/HCU, CP and lower levels of CU traits (CP/LCU) and their TD peers. The task captured both prosocial choices, and actual effort exerted following prosocial choices, in adolescent boys aged 11-16 (27 CP/HCU; 34 CP/LCU; 33 TD). We used computational modelling to reveal the mechanistic processes involved when choosing prosocial acts. RESULTS: We found that both CP/HCU and CP/LCU groups were more averse to initiating effortful prosocial acts than TD adolescents - both at a cognitive and at a behavioural level. Strikingly, even if they chose to initiate a prosocial act, the CP/HCU group exerted less effort following this prosocial choice than other groups. CONCLUSIONS: Our findings indicate that reduced exertion of effort to benefit others may be an important factor that differentiates adolescents with CP/HCU from their peers with CP/LCU. They offer new insights into what might drive low prosocial behaviour in adolescents with CP, including vulnerabilities that may particularly characterise those with high levels of CU traits.

Mapping potential pathways from polygenic liability through brain structure to psychological problems across the transition to adolescence.

BACKGROUND: We used a polygenic score for externalizing behavior (extPGS) and structural MRI to examine potential pathways from genetic liability to conduct problems via the brain across the adolescent transition. METHODS: Three annual assessments of child conduct problems, attention-deficit/hyperactivity problems, and internalizing problems were conducted across across 9-13 years of age among 4,475 children of European ancestry in the Adolescent Brain Cognitive DevelopmentSM Study (ABCD Study®). RESULTS: The extPGS predicted conduct problems in each wave (R2 = 2.0%-2.9%). Bifactor models revealed that the extPRS predicted variance specific to conduct problems (R2 = 1.7%-2.1%), but also variance that conduct problems shared with other measured problems (R2 = .8%-1.4%). Longitudinally, extPGS predicted levels of specific conduct problems (R2 = 2.0%), but not their slope of change across age. The extPGS was associated with total gray matter volume (TGMV; R2 = .4%) and lower TGMV predicted both specific conduct problems (R2 = 1.7%-2.1%) and the variance common to all problems in each wave (R2 = 1.6%-3.1%). A modest proportion of the polygenic liability specific to conduct problems in each wave was statistically mediated by TGMV. CONCLUSIONS: Across the adolescent transition, the extPGS predicted both variance specific to conduct problems and variance shared by all measured problems. The extPGS also was associated with TGMV, which robustly predicted conduct problems. Statistical mediation analyses suggested the hypothesis that polygenic variation influences individual differences in brain development that are related to the likelihood of conduct problems during the adolescent transition, justifying new research to test this causal hypothesis.

Physiological reactivity in children with high callous-unemotional and autistic traits: investigating unique and interactive effects.

Empathy deficits are a hallmark sign of both callous-unemotional (CU) and autistic traits. Despite these similarities, prior work did not investigate how these traits relate to physiological reactivity (heart rate and skin conductance) in response to emotional or empathy-eliciting stimuli. Understanding the physiological mechanisms associated with emotional processing deficits among individuals with autistic or CU traits is a critical step for improving both assessment and interventions. The current study was designed to investigate the unique and interactive contributions of CU and autistic traits in predicting physiological reactivity. Heart rate (HR) and skin conductance (SC) activity in response to sad, fearful and happy emotional videos were collected form young children. Participants for the current study (n = 163; Mage = 7.30, SD= 1.42; 44.2% girls) were recruited from a larger community sample of 1652 children and were selected based on their levels of empathy. Regression analysis revealed that boys, but not girls, with high levels of CU traits exhibited low SC reactivity during sad and fearful stimuli. No significant associations were revealed for autistic traits. Finally, an interesting interaction effect suggested that CU traits were associated with stronger HR reactivity to fear stimuli only when autistic traits were low. The identified differences in physiological reactivity can inform etiological hypothesis by providing evidence for the underlying physiological mechanisms related to emotional processing among children high in CU traits but not in autistic traits.

White matter microstructure of the extended limbic system in male and female youth with conduct disorder.

BACKGROUND: Previous studies of conduct disorder (CD) have reported structural and functional alterations in the limbic system. However, the white matter tracts that connect limbic regions have not been comprehensively studied. The uncinate fasciculus (UF), a tract connecting limbic to prefrontal regions, has been implicated in CD. However, CD-related alterations in other limbic tracts, such as the cingulum and the fornix, have not been investigated. Furthermore, few studies have examined the influence of sex and none have been adequately powered to test whether the relationship between CD and structural connectivity differs by sex. We examined whether adolescent males and females with CD exhibit differences in structural connectivity compared with typically developing controls. METHODS: We acquired diffusion-weighted magnetic resonance imaging data from 101 adolescents with CD (52 females) and 99 controls (50 females). Data were processed for deterministic spherical deconvolution tractography. Virtual dissections of the UF, the three subdivisions of the cingulum [retrosplenial cingulum (RSC), parahippocampal and subgenual cingulum], and the fornix were performed and measures of fractional anisotropy (FA) and hindrance-modulated orientational anisotropy (HMOA) were analysed. RESULTS: The CD group had lower FA and HMOA in the right RSC tract relative to controls. Importantly, these effects were moderated by sex - males with CD significantly lower FA compared to male controls, whereas CD and control females did not differ. CONCLUSIONS: Our results highlight the importance of considering sex when studying the neurobiological basis of CD. Sex differences in RSC connectivity may contribute to sex differences in the clinical presentation of CD.

Neural Responses to Signals for Behavior Change: Greater Within-Person Variability is Associated With Risk Factors for Substance Dependence.

BACKGROUND: An impaired ability to change behavior in the face of cues indicating a need for change is one means of defining risk for substance dependence. The present study used a cognitive task administered in a laboratory as a model of this process. It focused on 2 known and related correlates of risk (conduct disorder, borderline personality disorder) and examined their associations with reactivity to cues requesting a change in motor behavior. METHODS: A total of 224 teenagers, 14 to 19 years of age, performed a task during which white noise bursts were used to cue a requirement to reverse the mapping of right and left key press responses onto high- and low-frequency pure tones during a subsequent trial block. The amplitude of the P300 electroencephalographic (EEG) response to each cue was summarized by calculating its across-trial average as well as its intertrial variability (ITV). In addition, the number of motor response reversal failures (perseveration errors) was calculated. RESULTS: The ITV of the P300 response to cues for behavior change was superior to its average amplitude in revealing associations with risk: It was significantly greater among teenagers with more conduct problems and more borderline personality disorder symptoms in comparison with their less-affected peers. ITV was also positively correlated with perseveration errors. No group differences were found in P300 amplitude averaged over trials. CONCLUSIONS: The findings suggest that the measurement of intertrial variability in brain activity may be more valuable than the average level for revealing neurophysiological differences associated with impulsivity and personality risk factors for dependence. EEG measures may be particularly valuable in this context because they offer superior temporal resolution and signal-to-noise characteristics.

Callous-Unemotional Traits and Disorganized Attachment: Links with Disruptive Behaviors in Toddlers.

Children with callous-unemotional (CU) traits and children with disorganized attachment patterns are at heightened risk of poor psychological outcomes but little is known about the overlap between these constructs and their unique contributions to conduct problems in early childhood. This study examined associations between CU traits, disorganized attachment, and conduct problem (CP) severity in a sample of clinic-referred toddlers with behavioral problems. Mother-child dyads (n = 56; mean child age 19.50 months) completed parent-report questionnaires, a dyadic play session, and the Strange Situation Procedure to assess child attachment pattern. Significant positive associations were found between CU traits and disorganized attachment, independent of CP severity. CU traits but not disorganized attachment predicted CP severity. Results indicate that among toddlers with clinic-referred disruptive behavior problems, there are clear links between CU traits and attachment disorganization. Of the two constructs, however, CU traits appear to be most salient in the expression of CPs.

Emotion Processing in Children with Conduct Problems and Callous-Unemotional Traits: An Investigation of Speed, Accuracy, and Attention.

This study aimed to assess whether callous-unemotional traits (CU) are associated with deficits in emotion recognition independent of externalizing behavior and whether such deficits can be explained by aberrant attention. As previous studies have produced inconsistent results, the current study included two different emotion recognition paradigms and assessed the potential influence of factors such as processing speed and attention. The study included N = 94 children (eight to 14 years) with an oversampling of children with conduct problems (CP) and varying levels of CU-traits. Independent of externalizing behavior, CU-traits were associated with slower recognition of angry, sad and fearful facial expressions but not with higher error rates. There was no evidence that the association between CU-traits and emotion processing could be explained by misguided attention. Our results implicate that in children with high levels of CU-traits emotion recognition deficits depend on deficits in processing speed.

Conduct Disorder: Biology and Developmental Trajectories.

For centuries, attempting a successful rehabilitation of youth with antisocial behaviors has challenged juvenile justice systems and society. More recently, advances in science and neuroimaging have permitted a deeper understanding of the biological underpinnings of antisocial behavior and psychopathic tendencies. This paper reviews biological findings in youth with conduct disorder, highlighting comparisons to biological findings in adults with antisocial personality disorder and psychopathy. Overall, youth with conduct disorder exhibit several biological findings that are similar to adults with antisocial personality disorder and psychopathy, consistent with theories that conduct disorder is a neurodevelopmental disorder that progresses to these adult conditions. There is evidence that treatment interventions might mitigate this progression and induce biological changes. Further, biological findings might guide interventions to rehabilitate youth and change the developmental trajectory of antisocial behaviors.

Callous and uncaring traits are associated with reductions in amygdala volume among youths with varying levels of conduct problems.

BACKGROUND: The emergence of callous unemotional (CU) traits, and associated externalizing behaviors, is believed to reflect underlying dysfunction in the amygdala. Studies of adults with CU traits or psychopathy have linked characteristic patterns of amygdala dysfunction to reduced amygdala volume, but studies in youths have not thus far found evidence of similar amygdala volume reductions. The current study examined the association between CU traits and amygdala volume by modeling CU traits and externalizing behavior as independent continuous variables, and explored the relative contributions of callous, uncaring, and unemotional traits. METHODS: CU traits and externalizing behavior problems were assessed in 148 youths using the Inventory of Callous Unemotional Traits (ICU) and the Child Behavior Checklist (CBCL). For a subset of participants (n = 93), high-resolution T1-weighted images were collected and volume estimates for the amygdala were extracted. RESULTS: Analyses revealed that CU traits were associated with increased externalizing behaviors and decreased bilateral amygdala volume. These results were driven by the callous and uncaring sub-factors of CU traits, with unemotional traits unrelated to either externalizing behaviors or amygdala volume. Results persisted after accounting for covariation between CU traits and externalizing behaviors. Bootstrap mediation analyses indicated that CU traits mediated the relationship between reduced amygdala volume and externalizing severity. CONCLUSIONS: These findings provide evidence that callous-uncaring traits account for reduced amygdala volume among youths with conduct problems. These findings provide a framework for further investigation of abnormal amygdala development as a key causal pathway for the development of callous-uncaring traits and conduct problems.

Genetic underpinnings of callous-unemotional traits and emotion recognition in children, adolescents, and emerging adults.

BACKGROUND: Callous-Unemotional (CU) and psychopathic traits are consistently associated with impaired recognition of others' emotions, specifically fear and sadness. However, no studies have examined whether the association between CU traits and emotion recognition deficits is due primarily to genetic or environmental factors. METHODS: The current study used data from 607 Caucasian twin pairs (N = 1,214 twins) to examine the phenotypic and genetic relationship between the Inventory of Callous-Unemotional Traits (ICU) and facial emotion recognition assessed via the laboratory-based Facial Expression Labeling Task (FELT). RESULTS: The uncaring/callous dimension of the ICU was significantly associated with impaired recognition of happiness, sadness, fear, surprise, and disgust. The unemotional ICU dimension was significantly associated with improved recognition of surprise and disgust. Total ICU score was significantly associated with impaired recognition of sadness. Significant genetic correlations were found for uncaring/callous traits and distress cue recognition (i.e. fear and sadness). The observed relationship between uncaring/callous traits and deficits in distress cue recognition was accounted for entirely by shared genetic influences. CONCLUSIONS: The results of the current study replicate previous findings demonstrating impaired emotion recognition among youth with elevated CU traits. We extend these findings by replicating them in an epidemiological sample not selected or enriched for pathological levels of CU traits. Furthermore, the current study is the first to investigate the genetic and environmental etiology of CU traits and emotion recognition, and results suggest genetic influences underlie the specific relationship between uncaring/callous traits and distress cue (fear/sadness) recognition in others.

Risk-Taking Behavior in Attention Deficit/Hyperactivity Disorder (ADHD): a Review of Potential Underlying Mechanisms and of Interventions.

PURPOSE OF REVIEW: Attention deficit/hyperactivity disorder (ADHD) is associated with several forms of risk-taking behavior (RTB). This paper aims to examine the scope of ADHD-related RTB, to highlight potential underlying mechanisms of this association, and to review initial evidence for interventions aimed to treat ADHD-related RTB. RECENT FINDINGS: Multiple lines of evidence indicate that ADHD is associated with real-life RTB across several domains (e.g., reckless driving, substance use, and unprotected sex), which is corroborated by evidence on laboratory risk-taking tasks. Several individual differences, some of them informed by decision theory, e.g., comorbid disorders, parental monitoring, and perceived enlarged benefits of RTB, may explain the link between ADHD and RTB. A number of studies showed that interventions designed for ADHD may reduce RTB. ADHD is linked to RTB across several domains. Decision theory may serve as a conceptual framework for understanding the underlying mechanisms, and thus may inform future research.

Parenting and Cortisol in Infancy Interactively Predict Conduct Problems and Callous-Unemotional Behaviors in Childhood.

This study examines observed maternal sensitivity, harsh-intrusion, and mental-state talk in infancy as predictors of conduct problems (CP) and callous-unemotional (CU) behaviors in middle childhood, as well as the extent to which infants' resting cortisol and cortisol reactivity moderate these associations. Using data from the Family Life Project (n = 1,292), results indicate that maternal sensitivity at 6 months predicts fewer CP at first grade, but only for infants who demonstrate high levels of cortisol reactivity. Maternal harsh intrusion predicts fewer empathic-prosocial behaviors, a component of CU behaviors, but only for infants who demonstrate high resting cortisol. Findings are discussed in the context of diathesis-stress and differential susceptibility models.

Hair and Salivary Testosterone, Hair Cortisol, and Externalizing Behaviors in Adolescents.

Although testosterone is associated with aggression in the popular imagination, previous research on the links between testosterone and human aggression has been inconsistent. This inconsistency might be because testosterone's effects on aggression depend on other moderators. In a large adolescent sample ( N = 984, of whom 460 provided hair samples), we examined associations between aggression and salivary testosterone, hair testosterone, and hair cortisol. Callous-unemotional traits, parental monitoring, and peer environment were examined as potential moderators of hormone-behavior associations. Salivary testosterone was not associated with aggression. Hair testosterone significantly predicted increased aggression, particularly at low levels of hair cortisol (i.e., Testosterone × Cortisol interaction). This study is the first to examine the relationship between hair hormones and externalizing behaviors and adds to the growing literature that indicates that androgenic effects on human behavior are contingent on aspects of the broader endocrine environment-in particular, levels of cortisol.

Low resting heart rate, sensation seeking and the course of antisocial behaviour across adolescence and young adulthood.

BACKGROUND: Low resting heart rate (RHR) is a consistent biological correlate of antisocial behaviour (ASB), however potential mechanisms have been largely unexplored. We hypothesise that lower RHR will be associated with higher ASB levels in mid-adolescence and persistence into adulthood, and that these associations will be explained, in part, by sensation seeking and callous-unemotional traits. METHODS: ASB was assessed repeatedly with young people from ages 15 to 21 years in a population-based birth cohort (ALSPAC). A longitudinal trajectory was derived and showed ASB decreasing across adolescence before stabilising in early adulthood. RHR was recorded at age 12 years, and mediators were assessed at age 14 years. RESULTS: After adjusting for socio-demographic confounders, there was evidence for a total effect of RHR on ASB levels in mid-adolescence [b(95% CI) = -0.08 (-0.14 to -0.02)], reflecting 0.08 more types of antisocial activity in the last year per 10 fewer heart beats per minute. This effect was almost entirely explained through sensation seeking [b(95% CI) = -0.06 (-0.08 to -0.04)]. After additionally adjusting for child and parent-related confounders, all effects weakened; however, there was still evidence of an indirect effect of RHR, via sensation seeking, on ASB levels in mid-adolescence [b(95% CI) = -0.01 (-0.03 to -0.003)]. There was no evidence for a total effect of RHR on ASB levels in early adulthood, and weak evidence of an indirect effect, via sensation seeking [b(95% CI) = -0.01 (-0.01 to -0.00)]. CONCLUSIONS: Lower RHR in childhood was associated with higher ASB levels in mid-adolescence, indirectly via sensation seeking.

Moderation of prior exposure to trauma on the inverse relationship between callous-unemotional traits and amygdala responses to fearful expressions: an exploratory study.

BACKGROUND: Previous work has shown that amygdala responsiveness to fearful expressions is inversely related to level of callous-unemotional (CU) traits (i.e. reduced guilt and empathy) in youth with conduct problems. However, some research has suggested that the relationship between pathophysiology and CU traits may be different in those youth with significant prior trauma exposure. METHODS: In experiment 1, 72 youth with varying levels of disruptive behavior and trauma exposure performed a gender discrimination task while viewing morphed fear expressions (0, 50, 100, 150 fear) and Blood Oxygenation Level Dependent responses were recorded. In experiment 2, 66 of these youth performed the Social Goals Task, which measures self-reports of the importance of specific social goals to the participant in provoking social situations. RESULTS: In experiment 1, a significant CU traits-by-trauma exposure interaction was observed within right amygdala; fear intensity-modulated amygdala responses negatively predicted CU traits for those youth with low levels of trauma but positively predicted CU traits for those with high levels of trauma. In experiment 2, a bootstrapped model revealed that the indirect effect of fear intensity amygdala response on social goal importance through CU traits is moderated by prior trauma exposure. CONCLUSIONS: This study, while exploratory, indicates that the pathophysiology associated with CU traits differs in youth as a function of prior trauma exposure. These data suggest that prior trauma exposure should be considered when evaluating potential interventions for youth with high CU traits.

Facial emotion recognition and eye movement behaviour in conduct disorder.

BACKGROUND: Conduct Disorder (CD) is associated with impairments in facial emotion recognition. However, it is unclear whether such deficits are explained by a failure to attend to emotionally informative face regions, such as the eyes, or by problems in the appraisal of emotional cues. METHOD: Male and female adolescents with CD and varying levels of callous-unemotional (CU) traits and age- and sex-matched typically developing (TD) controls (aged 13-18) categorised the emotion of dynamic and morphed static faces. Concurrent eye tracking was used to relate categorisation performance to participants' allocation of overt attention. RESULTS: Adolescents with CD were worse at emotion recognition than TD controls, with deficits observed across static and dynamic expressions. In addition, the CD group fixated less on the eyes when viewing fearful and sad expressions. Across all participants, higher levels of CU traits were associated with fear recognition deficits and reduced attention to the eyes of surprised faces. Within the CD group, however, higher CU traits were associated with better fear recognition. Overall, males were worse at recognising emotions than females and displayed a reduced tendency to fixate the eyes. DISCUSSION: Adolescents with CD, and particularly males, showed deficits in emotion recognition and fixated less on the eyes when viewing emotional faces. Individual differences in fixation behaviour predicted modest variations in emotion categorisation. However, group differences in fixation were small and did not explain the much larger group differences in categorisation performance, suggesting that CD-related deficits in emotion recognition were not mediated by abnormal fixation patterns.

Prospective test of the developmental propensity model of antisocial behavior: from childhood and adolescence into early adulthood.

BACKGROUND: The developmental propensity model of antisocial behavior posits that several dispositional characteristics of children transact with the environment to influence the likelihood of learning antisocial behavior across development. Specifically, greater dispositional negative emotionality, greater daring, and lower prosociality-operationally, the inverse of callousness- and lower cognitive abilities are each predicted to increase risk for developing antisocial behavior. METHODS: Prospective tests of key predictions derived from the model were conducted in a high-risk sample of 499 twins who were assessed on dispositions at 10-17 years of age and assessed for antisocial personality disorder (APD) symptoms at 22-31 years of age. Predictions were tested separately for parent and youth informants on the dispositions using multiple regressions that adjusted for oversampling, nonresponse, and clustering within twin pairs, controlling demographic factors and time since the first assessment. RESULTS: Consistent with predictions, greater numbers of APD symptoms in adulthood were independently predicted over a 10-15 year span by higher youth ratings on negative emotionality and daring and lower youth ratings on prosociality, and by parent ratings of greater negative emotionality and lower prosociality. A measure of working memory did not predict APD symptoms. CONCLUSIONS: These findings support future research on the role of these dispositions in the development of antisocial behavior.

Explaining the relationship between temperament and symptoms of psychiatric disorders from preschool to middle childhood: hybrid fixed and random effects models of Norwegian and Spanish children.

BACKGROUND: Four explanations for the concurrent and prospective associations between temperament and psychopathology in children have been suggested: predisposition, complication/scar, common cause/continuity, and pathoplasty/exacerbation. Because the confounding effects of common causes have not been ruled out in prior work, the support for the various explanations is uncertain. METHODS: Screen-stratified community samples of 4-year olds in Trondheim, Norway (n = 1,042), and 3-year olds in Barcelona, Spain (n = 622), were assessed biennially for symptoms of attention-deficit/hyperactivity (ADHD), oppositional defiant (ODD), conduct (CD), anxiety, and depressive disorders through interviewer-based psychiatric interviews across four waves of data collection. The parents completed child temperament ratings. The data were analyzed with random and fixed effects regression adjusted for all time-invariant unmeasured confounders (e.g., genetics, common methods bias, item overlap). RESULTS: In both Norway and Spain and across ages, negative affect predisposed children to symptoms of all disorders except CD, low effortful control predisposed children to ADHD and ODD-symptoms, and surgency predisposed children to increased ADHD-symptoms. Complication effects were observed in the Spanish children for ADHD-symptoms, which increased surgency and diminished effortful control, and for ODD-symptoms, which decreased surgency. The common cause and pathoplasty/exacerbation explanations were not supported. CONCLUSIONS: The present results are consistent with the view that temperament plays a causal role in the development of symptoms of psychiatric disorders in children. Because temperament is malleable, interventions targeting the affective, attentional, and behavioral regulatory components of temperament may reduce psychopathology in children.

Maternal sensitivity to distress, attachment and the development of callous-unemotional traits in young children.

BACKGROUND: Callous-unemotional (CU) traits are characterized by a lack of responsiveness to the emotions of others, particularly negative emotions. A parenting environment where the child's own distress emotions are sensitively responded to may help foster the child's ability to respond to the emotions of others. We tested whether maternal sensitivity to distress, and other parenting characteristics, were associated with CU traits over the preschool period, and examined whether this was mediated via infant attachment status. METHOD: In an epidemiological cohort, CU traits were assessed at age 2.5, 3.5, and 5.0 years by mother report. Dimensions of parenting were assessed in free play at age 29 weeks in a stratified subsample of 272, and attachment status at 14 months (n = 265). Structural equation modelling with maximum likelihood estimation was used to examine predictions from parenting dimensions and attachment status. RESULTS: A parenting factor comprised of sensitivity to distress (n = 207), sensitivity to non-distress, positive regard toward the infant (or warmth), and intrusiveness, predicted child CU traits (p = .023). This effect was accounted for mainly by sensitivity to distress (p = .008) and positive regard (p = .023) which showed a synergistic effect as evidenced by a significant interaction (p = .01). This arose because the combination of low sensitivity to distress and low positive regard created the risk for elevated CU traits. Although sensitivity and positive regard predicted attachment security and disorganization, there were no associations between attachment status and CU traits. CONCLUSIONS: The finding of contributions from both sensitivity to distress and positive regard to reduced CU traits suggests that children's responsiveness to others' emotions may be increased by their own mothers' responsiveness to them and their mothers' warmth. There was no evidence that this was mediated via attachment status. Implications for intervention and future directions are discussed.

Externalizing behavior severity in youths with callous-unemotional traits corresponds to patterns of amygdala activity and connectivity during judgments of causing fear.

Callous-unemotional (CU) traits characterize a subgroup of youths with conduct problems who exhibit low empathy, fearlessness, and elevated externalizing behaviors. The current study examines the role of aberrant amygdala activity and functional connectivity during a socioemotional judgment task in youths with CU traits, and links these deficits to externalizing behaviors. Functional magnetic resonance imaging was used to compare neural responses in 18 healthy youths and 30 youths with conduct problems and varying levels of CU traits as they evaluated the acceptability of causing another person to experience each of several emotions, including fear. Neuroimaging analyses examined blood oxygenation level dependent responses and task-dependent functional connectivity. High-CU youths exhibited left amygdala hypoactivation relative to healthy controls and low-CU youths primarily during evaluations of causing others fear. CU traits moderated the relationship between externalizing behavior and both amygdala activity and patterns of functional connectivity. The present data suggest that CU youths' aberrant amygdala activity and connectivity affect how they make judgments about the acceptability of causing others emotional distress, and that these aberrations represent risk factors for externalizing behaviors like rule breaking and aggression. These findings suggest that reducing externalizing behaviors in high-CU youths may require interventions that influence affective sensitivity.