Association of Irritability and Anxiety With the Neural Mechanisms of Implicit Face Emotion Processing in Youths With Psychopathology

An investigation of the neural basis of anger attributions in irritable youth

Neurocognitive models of pediatric irritability suggest a prominent role of anger; however, few studies have investigated anger-related biases and their neural correlates. Resting state functional connectivity (rsFC) of the amygdala was examined in relation to anger attribution bias (AAB) in a sample of young children (5-9 years old; N = 60; 55% White, 26.7% Hispanic) with clinically significant irritability characterized by impairing emotional outbursts (IEOs). Children completed a resting state functional magnetic resonance imaging scan as well as the assessment of children's emotional skills (ACES), which yields three measures of AAB in the context of social situations, social behaviors, and facial expressions. ACES scores were entered into a general linear model to examine associations with rsFC of the bilateral amygdalae. Children with IEOs exhibited significant biases in attributing anger to others across all three ACES domains. Greater biases toward attributing anger in social situations were associated with reduced rsFC of the bilateral amygdalae with the fusiform/lingual gyri and lateral occipital cortex. Alternatively, greater biases toward attributing anger to facial expressions positively predicted right amygdala-precuneus rsFC. Greater bias toward attributing anger to others based on their behaviors was associated with heightened rsFC of the right amygdala with the left middle frontal gyrus. Findings extend previous work implicating functional connections among regions of default mode and frontoparietal networks in pediatric irritability. Longitudinal studies are needed to further investigate the putative role of AAB in the etiology and long-term outcomes of pediatric irritability. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Frustration Response and Regulation Among Irritable Children: Contributions of Chronic Irritability, Internalizing, and Externalizing Symptoms

OBJECTIVE

The need to understand and treat childhood chronic irritability (CI; i.e. frequent temper loss and angry/irritable mood) is imperative. CI predicts impairment across development and complex comorbidities with both internalizing and externalizing disorders. Research has emphasized frustration reactivity as a key mechanism of CI. However, there are understudied components of frustrative non-reward, particularly regulation-oriented frustration recovery, frustration tolerance, and cognitive control, that may further explain impairments specific to CI beyond comorbid symptoms.

METHOD

Sixty-three community children (N = 25 CI/38 non-CI) and a parent completed surveys and the computerized Frustration Go/No-Go (FGNG) and Mirror Tracing Persistence Task (MTPT). Analyses compared task performance and self-rated affect across youth with or without CI, with further comparison based on negative/positive screen for ADHD (N = 45-/18+).

RESULTS

In mixed effects models assessing change across task, the CI group did not demonstrate more intense frustration on the MTPT or rigged FGNG block but exhibited persisting frustration and inhibitory control difficulties into the FGNG recovery period; the CI+ADHD subgroup drove recovery effects. In GEE and logistic regression models including dimensional symptom clusters, only internalizing symptoms predicted child frustration intolerance and reactivity across tasks. ADHD severity was also associated with higher MTPT frustration reactivity, while oppositional behavior predicted lower frustration. Better frustration recovery was associated with lower irritability, but higher internalizing symptoms.

CONCLUSIONS

Co-occurring symptoms may better explain some frustration-related difficulties among youth with CI. Difficulties with postfrustration affect and inhibitory control recovery suggest the importance of characterizing CI by self-regulation impairments.

Pre-scan state anxiety is associated with greater right amygdala-hippocampal response to fearful versus happy faces among trait-anxious Latina girls

BACKGROUND

Unfamiliarity with academic research may contribute to higher levels of anticipatory state anxiety about affective neuroimaging tasks. Children with high trait anxiety display differences in brain response to fearful facial affect compared to non-anxious youth, but little is known about the influence of state anxiety on this association. Because reduced engagement in scientific research and greater mistrust among minoritized groups may lead to systematic differences in pre-scan state anxiety, it is crucial to understand the neural correlates of state anxiety during emotion processing so as to disambiguate sources of individual differences.

METHODS

The present study probed the interactive effects of pre-scan state anxiety, trait anxiety, and emotional valence (fearful vs. happy faces) on neural activation during implicit emotion processing in a community sample of 46 preadolescent Latina girls (8-13 years).

RESULTS

Among girls with mean and high levels of trait anxiety, pre-scan state anxiety was associated with greater right amygdala-hippocampal and left inferior parietal lobe response to fearful faces relative to happy faces.

CONCLUSIONS

Anticipatory state anxiety in the scanning context may cause children with moderate and high trait anxiety to be hypervigilant to threats, further compounding the effects of trait anxiety. Neuroimaging researchers should control for state anxiety so that systematic differences in brain activation resulting from MRI apprehension are not misleadingly attributed to demographic or environmental characteristics.

Facial emotion recognition in children and youth with attention-deficit/hyperactivity disorder and irritability

The ability to recognize emotions evident in people's faces contributes to social functioning and might be affected by ADHD and irritability. Given their high co-occurrence, we examined the relative contribution of ADHD and irritability to facial emotion recognition (FER). We hypothesized that irritability but not ADHD traits would predict increased likelihood of misrecognizing emotions as negative, and that FER performance would explain the association of ADHD and irritability traits with social skills. FER was measured using the Reading the Mind in the Eyes Test (RMET) in children (6-14 years old) referred for ADHD assessment (n = 304) and healthy controls (n = 128). ADHD, irritability and social skills were measured using parent ratings. We used repeated measure logistics regression, comparing the effects across emotion valence of images (i.e., neutral/positive/negative). High irritability but not ADHD diagnosis predicted lower RMET accuracy. ADHD traits predicted lower RMET accuracy in younger but not older participants, whereas irritability predicted poorer accuracy at all ages. ADHD traits predicted lower RMET accuracy across all emotion valences, whereas irritability predicted increased probability of misrecognizing neutral and positive but not negative emotions. Irritability did not increase the probability for erroneously recognizing emotions as negative. ADHD and irritability traits fully explained the association between RMET and social skills. ADHD and irritability traits might impact the ability to identify emotions portrayed in faces. However, irritability traits appear to selectively impair recognition of neutral and positive but not negative emotions. ADHD and irritability are important when examining the link between FER and social difficulties.

A Computational Model Reveals Learning Dynamics During Interpretation Bias Training With Clinical Applications

BACKGROUND

Some psychopathologies, including anxiety and irritability, are associated with biases when judging ambiguous social stimuli. Interventions targeting these biases, or interpretation bias training (IBT), are amenable to computational modeling to describe their associative learning mechanisms. Here, we translated ALCOVE (attention learning covering map), a model of category learning, to describe learning in youths with affective psychopathology when training on more positive judgments of ambiguous face emotions.

METHODS

A predominantly clinical sample comprised 71 youths (age range, 8-22 years) representing broad distributions of irritability and anxiety symptoms. Of these, 63 youths were included in the test sample by completing an IBT task with acceptable performance for computational modeling. We used a separate sample of 28 youths to translate ALCOVE for individual estimates of learning rate and generalization. In the test sample, we assessed associations between model learning estimates and irritability, anxiety, their shared variance (negative affectivity), and age.

RESULTS

Age and affective symptoms were associated with category learning during IBT. Lower learning rates were associated with higher negative affectivity common in anxiety and irritability. Lower generalization, or improved discrimination between face emotions, was associated with increasing age.

CONCLUSIONS

This work demonstrates a functional consequence of age- and symptom-related learning during interpretation bias. Learning measured by ALCOVE also revealed learning types not accounted for in the prior literature on IBT. This work more broadly demonstrates the utility of measurement models for understanding trial-by-trial processes and identifying individual learning styles.

Future Directions in Youth Irritability Research

Research on irritability in children and adolescents has proliferated over the last 20 years. The evidence shows the clinical and developmental significance of irritable mood and behavior in youth, and it has led to significant changes in mental health classification, diagnosis, and services. At the same time, this research (including our own) has led to relatively little new in terms of practical, empirically based guidance to improve interventions and outcomes. In this article, we briefly summarize some of these developments and current evidence-based practices. We then put forth two key substantive challenges (the "whats") for future research to address: (a) the need for more effective treatments, especially evaluating and adapting evidence-based treatments that are already well-established for problems related to irritability (e.g., cognitive-behavioral therapies for internalizing and externalizing problems); and (b) the need for a better mechanistic understanding of irritability's phenomenology (e.g., phasic vs. tonic irritability, how frustration unfolds) and putative underlying mechanisms (e.g., cognitive control, threat and reward dysfunction). Lastly, we suggest three methodological approaches (the "hows") that may expedite progress in such areas: (a) ecological momentary assessment, (b) digital health applications, and (c) leveraging existing datasets. We hope this article will be useful for students and early-career researchers interested in tackling some of these important questions to better meet the needs of severely irritable youth.

Establishing the Relationship Between Attention Deficit Hyperactivity Disorder and Emotional Facial Expression Recognition Deficit: A Systematic Review

OBJECTIVE

In this review, we examined if there is a deficit in facial recognition of emotion (FER) in children, adolescents, and adults with attention deficit hyperactivity disorder (ADHD).

BACKGROUND

Emotional regulation is impaired in ADHD. Although a facial emotion recognition deficit has been described in this condition, the underlying causal mechanisms remain unclear.

METHODS

The search was performed in six databases in September 2022. Studies assessing children, adolescents, or adults with isolated or comorbid ADHD that evaluated participants using a FER task were included.

RESULTS

Twelve studies out of 385 were selected, with participants ranging in age from 6 to 37.1 years. A deficit in FER specific to ADHD, or secondary to comorbid autism spectrum disorder, anxiety, and oppositional symptoms, was found.

CONCLUSIONS

There is a FER deficit in patients with ADHD. Adults showed improved recognition accuracy, reflecting partial compensation. ADHD symptoms and comorbidities appear to influence FER deficits.

Associations between childhood irritability and neural reactivity to maternal feedback in adolescence

Early irritability, a transdiagnostic vulnerability for psychopathology, is associated with alterations in neural reactivity to emotional stimuli and reward; however, associations between childhood irritability and neural markers of risk may be mitigated by the quality of caregiving youth receive. We examined longitudinal relationships between irritability in childhood and young adolescents' neural activity of regions typically associated with emotion regulation and reward processing during processing of maternal feedback and tested whether these associations were moderated by youth's perceptions of the parent-child relationship quality. Eighty-one adolescents (Mage = 11.1 years) listened to maternal critical and praising feedback while undergoing functional magnetic resonance imaging. Age 3 irritability, assessed observationally, was negatively associated with age 11 neural reactivity to maternal criticism in a cluster in the right dorsolateral prefrontal cortex (dlPFC), particularly for youths who reported more positive maternal parenting. Given the role of the dlPFC activation in the effortful processing of emotional stimuli, decreased activation may reflect disengagement from negatively valenced interpersonal feedback in the context of a positive caregiving environment, thereby mitigating psychopathology risk associated with irritability.

Keeping up with the kids: the value of co-production in the study of irritability in youth depression and its underlying neural circuitry

Irritability is a core symptom of adolescent depression, characterized by an increased proneness to anger or frustration. Irritability in youth is associated with future mental health problems and impaired social functioning, suggesting that it may be an early indicator of emotion regulation difficulties. Adolescence is a period during which behavior is significantly impacted by one's environment. However, existing research on the neural basis of irritability typically use experimental paradigms that overlook the social context in which irritability occurs. Here, we bring together current findings on irritability in adolescent depression and the associated neurobiology and highlight directions for future research. Specifically, we emphasize the importance of co-produced research with young people as a means to improve the construct and ecological validity of research within the field. Ensuring that our research design and methodology accurately reflect to lives of young people today lays a strong foundation upon which to better understand adolescent depression and identify tractable targets for intervention.

Clinical Markers of Physical Violence in Patients with Bipolar Disorder in Manic States

Purpose

Identifying patients with bipolar disorder (BD) in manic states (BD-M) who are at a high risk of physical violence is a matter of clinical concern. This retrospective institution-based study aimed to identify simple, rapid, and inexpensive clinical markers of physical violence in patients with BD-M.

Patients and Methods

The anonymized sociodemographic variables (sex, age, years of education, marital status) and clinical ones (weight, height, body mass index, blood pressure, the score of BRMS, number of BD episodes, psychotic symptoms, history of violence, biochemical parameters, and blood routine parameters) of 316 BD-M participants were collected, and the risk of physical violence was identified using the Brøset Violence Checklist (BVC). Difference tests, correlation analyses, and multivariate linear regression analysis were performed to identify clinical markers for the risk of physical violence.

Results

The participants were categorized into groups at low (49, 15.51%), medium (129, 40.82%), and high (138, 43.67%) risk of physical violence. The number of BD episodes, serum uric acid (UA), free thyroxine (FT4) levels, history of violence, and monocyte-to-lymphocyte ratio (MLR) differed significantly between groups (all P<0.05). The number of BD episodes (r=0.152), FT3 (r=0.131) and FT4 (r=0.132) levels, history of violence (r=0.206), and MLR (r=-0.132) were significantly correlated with the risk of physical violence (all P<0.05). The existence of history of violence, number of BD episodes, UA, FT4, and MLR were identified as clinical markers of the risk of physical violence in patients with BD-M (all P<0.05).

Conclusion

These identified markers are readily available at initial presentation and may help in the timely assessment and treatment of patients with BD-M.

Robust caregiver-youth discrepancies in irritability ratings on the affective reactivity index: An investigation of its origins

OBJECTIVE

The Affective Reactivity Index (ARI) is widely used to assess young people's irritability symptoms, but youth and caregivers often diverge in their assessments. Such informant discrepancy might be rooted in poor psychometric properties, the differential conceptualization of irritability across informants, or reflect sociodemographic and clinical characteristics. We use an out-of-sample replication approach and leverage longitudinal data, available for a subset of the participants, to test these hypotheses.

METHOD

Across two independent samples (N_Cohort-1 = 765, 8-21 years; N_Cohort-2 = 1910, 6-21 years), we investigate the reliability and measurement invariance of the ARI, examine sociodemographic and clinical predictors of discrepant reporting and probe the utility of a bifactor model for cross-informant integration.

RESULTS

Despite good internal consistency and 6-week-retest-reliability of parent (Cohort-1: α = 0.92, ICC = 0.85; Cohort-2: α = 0.93) and youth forms (Cohort-1: α = 0.88, ICC = 0.78; Cohort-2: α = 0.82), we confirm substantial informant discrepancy in ARI ratings (3 points on a scale from 0 to 12), which is stable over six weeks (ICC = 0.53). Measurement invariance across informants was weak, indicating that parents and youth may interpret ARI items differently. Irritability severity and diagnostic status predicted informant-discrepancy, albeit in opposing directions: higher severity was linked to relative, higher irritability-ratings by youth (Cohort-1: β = -0.06, p < .001; Cohort-2: β = -0.06, p < .001), while diagnoses of Disruptive Mood Dysregulation Disorder (Cohort-1: β = 0.44, p < .001; Cohort-2: β = 0.84, p < .001) and Oppositional Defiant Disorder (Cohort-1: β = 0.41, p < .001; Cohort-2: β = 0.42, p < .001) predicted relative higher irritability-ratings by caregivers. In both datasets, a bifactor model parsing informant-specific from shared irritability-related variance fit the data well (CFI = 0.99, RMSEA = 0.05; N₂: CFI = 0.99; RMSEA = 0.04).

CONCLUSION

Parent and youth ARI reports and their discrepancy are reliable and reflect different interpretations of the scale items; hence they should not be averaged. This finding also suggests that irritability is not a unitary construct. Future work should investigate and model how different aspects of irritability might differ in their impact on the responses of specific informants.

Cross-sectional and Longitudinal Associations of Anxiety and Irritability With Adolescents' Neural Responses to Cognitive Conflict

BACKGROUND

Psychiatric symptoms are commonly comorbid in childhood. The ability to disentangle unique and shared correlates of comorbid symptoms facilitates personalized medicine. Cognitive control is implicated broadly in psychopathology, including in pediatric disorders characterized by anxiety and irritability. To disentangle cognitive control correlates of anxiety versus irritability, the current study leveraged both cross-sectional and longitudinal data from early childhood into adolescence.

METHODS

For this study, 89 participants were recruited from a large longitudinal research study on early-life temperament to investigate associations of developmental trajectories of anxiety and irritability symptoms (from ages 2 to 15) as well as associations of anxiety and irritability symptoms measured cross-sectionally at age 15 with neural substrates of conflict and error processing assessed at age 15 using the flanker task.

RESULTS

Results of whole-brain multivariate linear models revealed that anxiety at age 15 was uniquely associated with decreased neural response to conflict across multiple regions implicated in attentional control and conflict adaptation. Conversely, irritability at age 15 was uniquely associated with increased neural response to conflict in regions implicated in response inhibition. Developmental trajectories of anxiety and irritability interacted in relation to neural responses to both error and conflict.

CONCLUSIONS

Our findings suggest that neural correlates of conflict processing may relate uniquely to anxiety and irritability. Continued cross-symptom research on the neural correlates of cognitive control could stimulate advances in individualized treatment for anxiety and irritability during child and adolescent development.

Systematic Review and Meta-analysis: Task-based fMRI Studies in Youths With Irritability

OBJECTIVE

Childhood irritability, operationalized as disproportionate and frequent temper tantrums and low frustration tolerance relative to peers, is a transdiagnostic symptom across many pediatric disorders. Studies using task-dependent functional magnetic resonance imaging (fMRI) to probe neural dysfunction in irritability have increased. However, an integrated review summarizing the published methods and synthesized fMRI results remains lacking.

METHOD

We conducted a systematic search using irritability terms and task functional neuroimaging in key databases in March 2021, and identified 30 studies for our systematic review. Sample characteristics and fMRI methods were summarized. A subset of 28 studies met the criteria for extracting coordinate-based data for quantitative meta-analysis. Ten activation-likelihood estimations were performed to examine neural convergence across irritability measures and fMRI task domains.

RESULTS

Systematic review revealed small sample sizes (median = 58, mean age range = 8-16 years) with heterogeneous sample characteristics, irritability measures, tasks, and analytical procedures. Meta-analyses found no evidence for neural activation convergence of irritability across neurocognitive functions related to emotional reactivity, cognitive control, and reward processing, or within each domain. Sensitivity analyses partialing out variances driven by heterogeneous tasks, irritability measures, stimulus types, and developmental ages all yielded null findings. Results were compared with a review on irritability-related structural anomalies from 11 studies.

CONCLUSION

The lack of neural convergence suggests a need for common, standardized irritability assessments and more homogeneous fMRI tasks. Thoughtfully designed fMRI studies probing commonly defined neurocognitive functions may be more fruitful to elucidate the neural mechanisms of irritability. Open science practices, data mining in large neuroscience databases, and standardized analytical methods promote meaningful collaboration in irritability research.

Diagnostic instruments for the assessment of disruptive mood dysregulation disorder: a systematic review of the literature

Disruptive mood dysregulation disorder (DMDD) involves non-episodic irritability and frequent severe temper outbursts in children. Since the inclusion of the diagnosis in the DSM-5, there is no established gold-standard in the assessment of DMDD. In this systematic review of the literature, we provide a synopsis of existing diagnostic instruments for DMDD. Bibliographic databases were searched for any studies assessing DMDD. The systematic search of the literature yielded K = 1167 hits, of which n = 110 studies were included. The most frequently used measure was the Kiddie Schedule for Affective Disorders and Schizophrenia DMDD module (25%). Other studies derived diagnostic criteria from interviews not specifically designed to measure DMDD (47%), chart review (7%), clinical diagnosis without any specific instrument (6%) or did not provide information about the assessment (9%). Three structured interviews designed to diagnose DMDD were used in six studies (6%). Interrater reliability was reported in 36% of studies (ranging from κ = 0.6-1) while other psychometric properties were rarely reported. This systematic review points to a variety of existing diagnostic measures for DMDD with good reliability. Consistent reporting of psychometric properties of recently developed DMDD interviews, as well as their further refinement, may help to ascertain the validity of the diagnosis.

Context-dependent amygdala-prefrontal connectivity during the dot-probe task varies by irritability and attention bias to angry faces

Irritability, defined as proneness to anger, is among the most common reasons youth are seen for psychiatric care. Youth with irritability demonstrate aberrant processing of anger-related stimuli; however, the neural mechanisms remain unknown. We applied a drift-diffusion model (DDM), a computational tool, to derive a latent behavioral metric of attentional bias to angry faces in youth with varying levels of irritability during functional magnetic resonance imaging (fMRI). We examined associations among irritability, task behavior using a DDM-based index for preferential allocation of attention to angry faces (i.e., extra-decisional time bias; Δt₀), and amygdala context-dependent connectivity during the dot-probe task. Our transdiagnostic sample, enriched for irritability, included 351 youth (ages 8-18; M = 12.92 years, 51% male, with primary diagnoses of either attention deficit/hyperactivity disorder [ADHD], disruptive mood dysregulation disorder [DMDD], an anxiety disorder, or healthy controls). Models accounted for age, sex, in-scanner motion, and co-occurring symptoms of anxiety. Youth and parents rated youth's irritability using the Affective Reactivity Index. An fMRI dot-probe task was used to assess attention orienting to angry faces. In the angry-incongruent vs. angry-congruent contrast, amygdala connectivity with the bilateral inferior frontal gyrus (IFG), insula, caudate, and thalamus/pulvinar was modulated by irritability level and attention bias to angry faces, Δt₀, all ts₃₅₀ > 4.46, ps < 0.001. In youth with high irritability, elevated Δt₀ was associated with a weaker amygdala connectivity. In contrast, in youth with low irritability, elevated Δt₀ was associated with stronger connectivity in those regions. No main effect emerged for irritability. As irritability is associated with reactive aggression, these results suggest a potential neural regulatory deficit in irritable youth who have elevated attention bias to angry cues.

Amygdala-prefrontal connectivity in children with maladaptive aggression is modulated by social impairment

Aggressive behavior is common across childhood-onset psychiatric disorders and is associated with impairments in social cognition and communication. The present study examined whether amygdala connectivity and reactivity during face emotion processing in children with maladaptive aggression are moderated by social impairment. This cross-sectional study included a well-characterized transdiagnostic sample of 101 children of age 8-16 years old with clinically significant levels of aggressive behavior and 32 typically developing children without aggressive behavior. Children completed a face emotion perception task of fearful and calm faces during functional magnetic resonance imaging. Aggressive behavior and social functioning were measured by standardized parent ratings. Relative to controls, children with aggressive behavior showed reduced connectivity between the amygdala and the dorsolateral prefrontal cortex (PFC) during implicit emotion processing. In children with aggressive behavior, the association between reduced amygdala-ventrolateral PFC connectivity and greater severity of aggression was moderated by greater social impairment. Amygdala reactivity to fearful faces was also associated with severity of aggressive behavior for children without social deficits but not for children with social deficits. Social impairments entail difficulties in interpreting social cues and enacting socially appropriate responses to frustration or provocation, which increase the propensity for an aggressive response via diminished connectivity between the amygdala and the ventral PFC.

Korean Validation of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire

OBJECTIVE

The Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A) has been validated in more than 30 languages and is noted for its broad application in research and clinical settings. This study presents the first attempt to examine the reliability and validity of the TEMPS-A in Korea.

METHODS

A total of 540 non-clinical participants completed the Korean TEMPS-A, which was adapted from the original English version via a comprehensive translation procedure. Reliability was assessed using Cronbach's α, and associations between temperaments were examined using Spearman's correlation coefficient. Exploratory factor analysis (EFA) was performed, and differences in TEMPS-A scores between the gender- and age-based groups were examined using Kruskal-Wallis analysis.

RESULTS

The Korean TEMPS-A exhibited excellent internal consistency (0.70-0.91) and significant correlations between subscales. EFA resulted in a two-factor structure: Factor I (depressive, cyclothymic, irritable, and anxious) and Factor II (hyperthymic). Gender and age group differences were observed.

CONCLUSION

Overall, our results suggest that TEMPS-A is a reliable and valid measure of affective temperaments for the Korean population. This study opens new possibilities for further research on affective temperaments and their related traits.

Executive functioning moderates neural mechanisms of irritability during reward processing in youth

Pediatric irritability is the most robust indicator of transdiagnostic psychopathology risk. It is associated with altered neural reward processing, including neural networks related to cognitive control, and better cognitive control has been hypothesized to mitigate irritability. We evaluated the relationship of executive functioning (EF) with irritability-related neural correlates of reward processing in youths with varying levels of irritability. Participants (N = 51, mean age=13.80 years, SD=1.94) completed a monetary incentive delay task during multiband fMRI acquisition. Irritability and EF were measured via the Affective Reactivity Index and the NIH Toolbox cognition battery, respectively. Whole-brain analyses, controlling for age, examined the moderating role of EF on irritability-related brain activation and connectivity (seeds: striatum, amygdala) during reward anticipation and performance feedback. Irritability-related neural patterns during reward processing depended on EF, in occipital areas during reward anticipation and limbic, frontal, and temporal networks during performance feedback. Higher irritability combined with higher EF was associated with neural patterns opposite to those observed for higher irritability with lower co-occurring EF. Although preliminary, findings suggest that EF may buffer irritability-related reward processing deficits. Additionally, individual differences in EF and their relation to irritability may be related to varied etiologic mechanisms of irritability with important implications for personalized prevention and intervention.

Cortico-amygdalar connectivity and externalizing/internalizing behavior in children with neurodevelopmental disorders

Background

Externalizing and internalizing behaviors contribute to clinical impairment in children with neurodevelopmental disorders (NDDs). Although associations between externalizing or internalizing behaviors and cortico-amygdalar connectivity have been found in clinical and non-clinical pediatric samples, no previous study has examined whether similar shared associations are present across children with different NDDs.

Methods

Multi-modal neuroimaging and behavioral data from the Province of Ontario Neurodevelopmental Disorders (POND) Network were used. POND participants aged 6–18 years with a primary diagnosis of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD) or obsessive–compulsive disorder (OCD), as well as typically developing children (TDC) with T1-weighted, resting-state fMRI or diffusion weighted imaging (DWI) and parent-report Child Behavioral Checklist (CBCL) data available, were analyzed (total n = 346). Associations between externalizing or internalizing behavior and cortico-amygdalar structural and functional connectivity indices were examined using linear regressions, controlling for age, gender, and image-modality specific covariates. Behavior-by-diagnosis interaction effects were also examined.

Results

No significant linear associations (or diagnosis-by-behavior interaction effects) were found between CBCL-measured externalizing or internalizing behaviors and any of the connectivity indices examined. Post-hoc bootstrapping analyses indicated stability and reliability of these null results.

Conclusions

The current study provides evidence towards an absence of a shared linear relationship between internalizing or externalizing behaviors and cortico-amygdalar connectivity properties across a transdiagnostic sample of children with different primary NDD diagnoses and TDC. Different methodological approaches, including incorporation of multi-dimensional behavioral data (e.g., task-based fMRI) or clustering approaches may be needed to clarify complex brain-behavior relationships relevant to externalizing/internalizing behaviors in heterogeneous clinical NDD populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00429-022-02483-0.

Investigating the associations between irritability and hot and cool executive functioning in those with ADHD

BACKGROUND

Irritability is especially pertinent to those with Attention Deficit Hyperactivity Disorder (ADHD) as it is highly prevalent and associated with a more severe clinical presentation and poorer longitudinal outcomes. Preliminary evidence suggests that top-down cognitive processes taking place in emotional contexts (i.e., hot executive functions) as opposed to those evoked in abstract scenarios (i.e., cool executive functions) may be relevant to the presentation of irritability in ADHD. This study explored the cognitive mechanisms underlying irritability in young people with ADHD, hypothesising that irritability would be associated with hot, but not cool, executive function impairments.

METHODS

Our sample included 219 individuals with ADHD. A composite irritability score was derived extracting items from a parent interview, with scores ranging from 0 to 5. Associations were investigated using linear regression analyses, between irritability and four hot tasks measuring sensitivity to risk, risk-taking behaviour following reward or punishment, acceptance of reward delay and reaction to unfair behaviour from others, and two cool tasks measuring set-shifting and motor inhibition.

RESULTS

As hypothesised, there were no significant associations between irritability and cool executive functions in those with ADHD; however, contrary to expectations, there was also no significant evidence that hot executive functions were associated with irritability.

CONCLUSIONS

These results, in a large well characterised sample and using a comprehensive task battery, suggest that the variation in irritability in those with ADHD may not be associated with differences in hot or cool executive function performance.

Large-scale functional brain networks of maladaptive childhood aggression identified by connectome-based predictive modeling

Disruptions in frontoparietal networks supporting emotion regulation have been long implicated in maladaptive childhood aggression. However, the association of connectivity between large-scale functional networks with aggressive behavior has not been tested. The present study examined whether the functional organization of the connectome predicts severity of aggression in children. This cross-sectional study included a transdiagnostic sample of 100 children with aggressive behavior (27 females) and 29 healthy controls without aggression or psychiatric disorders (13 females). Severity of aggression was indexed by the total score on the parent-rated Reactive-Proactive Aggression Questionnaire. During fMRI, participants completed a face emotion perception task of fearful and calm faces. Connectome-based predictive modeling with internal cross-validation was conducted to identify brain networks that predicted aggression severity. The replication and generalizability of the aggression predictive model was then tested in an independent sample of children from the Adolescent Brain Cognitive Development (ABCD) study. Connectivity predictive of aggression was identified within and between networks implicated in cognitive control (medial-frontal, frontoparietal), social functioning (default mode, salience), and emotion processing (subcortical, sensorimotor) (r = 0.31, RMSE = 9.05, p = 0.005). Out-of-sample replication (p < 0.002) and generalization (p = 0.007) of findings predicting aggression from the functional connectome was demonstrated in an independent sample of children from the ABCD study (n = 1791; n = 1701). Individual differences in large-scale functional networks contribute to variability in maladaptive aggression in children with psychiatric disorders. Linking these individual differences in the connectome to variation in behavioral phenotypes will advance identification of neural biomarkers of maladaptive childhood aggression to inform targeted treatments.

Using ecological momentary assessment to enhance irritability phenotyping in a transdiagnostic sample of youth

Irritability is a transdiagnostic symptom dimension in developmental psychopathology, closely related to the Research Domain Criteria (RDoC) construct of frustrative nonreward. Consistent with the RDoC framework and calls for transdiagnostic, developmentally-sensitive assessment methods, we report data from a smartphone-based, naturalistic ecological momentary assessment (EMA) study of irritability. We assessed 109 children and adolescents (Mage = 12.55 years; 75.20% male) encompassing several diagnostic groups – disruptive mood dysregulation disorder (DMDD), attention-deficit/hyperactivity disorder (ADHD), anxiety disorders (ANX), healthy volunteers (HV). The participants rated symptoms three times per day for 1 week. Compliance with the EMA protocol was high. As tested using multilevel modeling, EMA ratings of irritability were strongly and consistently associated with in-clinic, gold-standard measures of irritability. Further, EMA ratings of irritability were significantly related to subjective frustration during a laboratory task eliciting frustrative nonreward. Irritability levels exhibited an expected graduated pattern across diagnostic groups, and the different EMA items measuring irritability were significantly associated with one another within all groups, supporting the transdiagnostic phenomenology of irritability. Additional analyses utilized EMA ratings of anxiety as a comparison with respect to convergent validity and transdiagnostic phenomenology. The results support new measurement tools that can be used in future studies of irritability and frustrative nonreward.

Interaction of irritability and anxiety on emotional responding and emotion regulation: a functional MRI study

BACKGROUND

Irritability and anxiety frequently co-occur in pediatric populations. Studies separately looking at the neural correlates of these symptoms have identified engagement of similar neural systems - particularly those implicated in emotional processing. Both irritability and anxiety can be considered negative valence emotional states that might relate to emotion dysregulation. However, previous work has not examined the neural responding during the performance of an emotion regulation task as a function of interaction between irritability and anxiety simultaneously.

METHODS

This fMRI study involved 155 participants (90 with significant psychopathologies and 92 male) who performed the Affective Stroop Task, designed to engage emotion regulation as a function of task demands. The Affective Reactivity Index (ARI) was used to index irritability and the Screen for Child Anxiety Related Emotional Disorders (SCARED) was used to index anxiety.

RESULTS

Levels of irritability, but not anxiety, was positively correlated with responses to visual images within the right rostro-medial prefrontal cortex and left anterior cingulate cortex during view trials. The second region of ventral anterior cingulate cortex showed a condition-by-emotion-by-ARI score-by-SCARED score interaction. Specifically, anxiety level was significantly correlated with a decreased differential BOLD response to negative relative to neutral view trials but only in the presence of relatively high irritability.

CONCLUSIONS

Atypical maintenance of emotional stimuli within the rostro-medial prefrontal cortex may exacerbate the difficulties faced by adolescents with irritability. Moreover, increased anxiety combined with significant irritability may disrupt an automatic emotional conflict-based form of emotion regulation that is particularly associated with the ventral anterior cingulate cortex.

Neural correlates of extinguished threat recall underlying the commonality between pediatric anxiety and irritability

BACKGROUND

Anxiety and irritability frequently co-occur in youth and are mediated by aberrant threat responses. However, empirical evidence on neural mechanisms underlying this co-occurrence is limited. To address this, we apply data-driven latent phenotyping to data from a prior report of a well-validated threat extinction recall fMRI paradigm.

METHODS

Participants included 59 youth (28 anxiety disorder, 31 healthy volunteers; Mage=13.15 yrs) drawn from a transdiagnostic sample of 331 youth, in which bifactor analysis was conducted to derive latent factors representing shared vs. unique variance of dimensionally-assessed anxiety and irritability. Participants underwent threat conditioning and extinction. Approximately three weeks later, during extinction recall fMRI, participants made threat-safety discriminations under two task conditions: current threat appraisal and explicit recall of threat contingencies. Linear mixed-effects analyses examined associations of a "negative affectivity" factor reflecting shared anxiety and irritability variance with whole-brain activation and task-dependent amygdala connectivity.

RESULTS

During recall of threat-safety contingencies, higher negative affectivity was associated with greater prefrontal (ventrolateral/ventromedial, dorsolateral, orbitofrontal), motor, temporal, parietal, and occipital activation. During threat appraisal, higher negative affectivity was associated with greater amygdala-inferior parietal lobule connectivity to threat/safety ambiguity.

LIMITATIONS

Sample included only healthy youth and youth with anxiety disorders. Results may not generalize to other diagnoses for which anxiety and irritability are also common, and our negative affectivity factor should be interpreted as anxiety disorders with elevated irritability. Reliability of some subfactors was poor.

CONCLUSIONS

Aberrant amygdala-prefrontal-parietal circuitry during extinction recall of threat-safety stimuli may be a mechanism underlying the co-occurrence of pediatric anxiety and irritability.

Network-wise surface-based morphometric insight into the cortical neural circuitry underlying irritability in adolescents

Previous studies examining structural brain correlates of irritability have taken a region-specific approach and have been relatively inconsistent. In a sample of adolescents with and without clinically impairing irritability, the current study examines: (i) cortical volume (CV) in canonical functional networks; (ii) the association between the CV of functional networks and severity of irritability; and (iii) the extent to which IQ mediates the association between structural abnormalities and severity of irritability. Structural MRI and IQ data were collected from 130 adolescents with high irritability (mean age = 15.54±1.83 years, 58 females, self-reported Affective Reactivity Index [ARI] ≥ 4) and 119 adolescents with low irritability (mean age = 15.10±1.93 years, 39 females, self-reported ARI < 4). Subject-specific network-wise CV was estimated after parcellating the whole brain into 17 previously reported functional networks. Our Multivariate Analysis of Covariance (MANCOVA) revealed that adolescents with high irritability had significantly reduced CV of the bilateral control and default-mode networks (p < 0.05) relative to adolescents with low irritability. Multiple regression analyses showed a significant negative association between the control network CV and the severity of irritability. Mediation analysis showed that IQ partially mediated the association between the control network CV and the severity of irritability. Follow-up analysis on subcortical volume (SCV) showed that adolescents with high irritability had reduced bilateral SCV within the amygdala relative to adolescents with low irritability. Reduced CV within bilateral control and default networks and reduced SCV within bilateral amygdala may represent core features of the pathophysiology of irritability. The current data also indicate the potential importance of a patient's IQ in determining how pathophysiology related to the control network is expressed.

Linking irritability and functional brain networks: A transdiagnostic case for expanding consideration of development and environment in RDoC

The National Institute of Mental Health Research Domain Criteria (RDoC) framework promotes the dimensional and transdiagnostic operationalization of psychopathology, but consideration of the neurodevelopmental foundations of mental health problems requires deeper examination. Irritability, the dispositional tendency to angry emotion that has both mood and behavioral elements, is dimensional, transdiagnostic, and observable early in life-a promising target for the identification of early neural indicators or risk factors for psychopathology. Here, we examine functional brain networks linked to irritability from preschool to adulthood and discuss how development and early experience may influence these neural substrates. Functional connectivity measured with fMRI varies according to irritability and indicates the atypical coordination of several functional networks involved in emotion generation, emotion perception, attention, internalization, and cognitive control. We lay out an agenda to improve our understanding and detection of atypical brain:behavior patterns through advances in the characterization of both functional networks and irritability as well as the consideration and operationalization of developmental and early life environmental influences on this pathway.

Modulation of Amygdala Response by Cognitive Conflict in Adolescents with Conduct Problems and Varying Levels of CU Traits

Adolescents with conduct problems and low callous-unemotional traits are characterised by high levels of reactive aggression. Prior studies suggest that they can have exaggerated neural and behavioural responses to negative emotional stimuli, accompanied by compromised affect regulation and atypical engagement of prefrontal areas during cognitive control. This pattern may in part explain their symptoms. Clarifying how neurocognitive responses to negative emotional stimuli can be modulated in this group has potential translational relevance. We present fMRI data from a cognitive conflict task in which the requirement to visually scan emotional (vs. calm) faces was held constant across low and high levels of cognitive conflict. Participants were 17 adolescent males with conduct problems and low levels of callous-unemotional traits (CP/LCU); 17 adolescents with conduct problems and high levels of callous-unemotional traits (CP/HCU, who typically show blunted reactivity to fear), and 18 typically developing controls (age range 10-16). Control participants showed typical attenuation of amygdala response to fear relative to calm faces under high (relative to low) conflict, replicating previous findings in a healthy adult sample. In contrast, children with CP/LCU showed a reduced (left amygdala) or reversed (right amygdala) attenuation effect under high cognitive conflict conditions. Children with CP/HCU did not differ from controls. Findings suggest atypical modulation of amygdala response as a function of task demands, and raise the possibility that those with CP/LCU are unable to implement typical regulation of amygdala response when cognitive task demands are high.

Irritability-related neural responses to frustrative nonreward in adolescents with trauma histories: A preliminary investigation

Irritability, conceptualized as a lowered frustration response threshold to blocked goal attainment (i.e., frustrative nonreward), is a common, detrimental symptom in adolescence. Yet, neural mechanisms of irritability are not well understood. This preliminary study aims to identify irritability-related neural patterns using a novel frustrative nonreward paradigm. Our study used a diverse sample of N = 31 non-White adolescent participants (mean age 14.53 years, SD = 1.74; 83.87% Hispanic/Latinx) to improve generalizability. During fMRI acquisition, participants performed a child-friendly monetary incentive delay task, modified to provide incorrect, negative feedback on performance. Irritability was associated with alterations in amygdala connectivity with basal ganglia, prefrontal, temporal, and parietal regions, and in activation of prefrontal and posterior cortical structures. Across clusters, youths with greater irritability showed activation/connectivity differences between reward blocked versus received conditions in the opposite direction compared to youths with lowered irritability. Alterations in amygdala-temporoparietal connectivity and lingual gyrus activation demonstrated an altered irritability-related recovery effect from the previous trial. These findings support the central role of frustrative nonreward as a key irritability pathway. Our work is one of the first to document neural correlates of difficult recovery from frustration characteristic of irritability and provides insight into novel treatment targets for irritability in diverse populations.

Structural atrophy of the right superior frontal gyrus in adolescents with severe irritability

Severe irritability is common in youths with psychiatric disorders and results in significant dysfunction across domains (academic, social, and familial). Prior structural MRI studies in the pediatric population demonstrated that aberrations of cortical thickness (CT) and gray matter volume (GMV) in the fronto‐striatal‐temporal regions which have been associated with irritability. However, the directions of the correlations between structural alteration and irritability in the individual indices were not consistent. Thus, we aim to address this by implementing comprehensive assessments of CT, GMV, and local gyrification index (LGI) simultaneously in youths with severe levels of irritability by voxel‐based morphometry and surface‐based morphometry. One hundred and eight adolescents (46 youths with severe irritability and 62 healthy youths, average age = 14.08 years, standard deviation = 2.36) were scanned with a T1‐weighted MRI sequence. The severity of irritability was measured using the affective reactivity index. In youths with severe irritability, there was decreased CT, GMV, and LGI in the right superior frontal gyrus (SFG) compared to healthy youths, and negative correlations between these indices of the SFG and irritability. Our findings suggest that structural deficits in the SFG, potentially related to its role in inhibitory control, may be critical for the neurobiology of irritability.

Rationale and validation of a novel mobile application probing motor inhibition: Proof of concept of CALM-IT

Identification of behavioral mechanisms underlying psychopathology is essential for the development of novel targeted therapeutics. However, this work relies on rigorous, time-intensive, clinic-based laboratory research, making it difficult to translate research paradigms into tools that can be used by clinicians in the community. The broad adoption of smartphone technology provides a promising opportunity to bridge the gap between the mechanisms identified in the laboratory and the clinical interventions targeting them in the community. The goal of the current study is to develop a developmentally appropriate, engaging, novel mobile application called CALM-IT that probes a narrow biologically informed process, inhibitory control. We aim to leverage the rigorous and robust methods traditionally used in laboratory settings to validate this novel mechanism-driven but easily disseminatable tool that can be used by clinicians to probe inhibitory control in the community. The development of CALM-IT has significant implications for the ability to screen for inhibitory control deficits in the community by both clinicians and researchers. By facilitating assessment of inhibitory control outside of the laboratory setting, researchers could have access to larger and more diverse samples. Additionally, in the clinical setting, CALM-IT represents a novel clinical screening measure that could be used to determine personalized courses of treatment based on the presence of inhibitory control deficits.

Anger attacks are associated with persistently elevated irritability in MDD: findings from the EMBARC study

BACKGROUND

This report tests the association of self-reported symptoms of irritability with overt behavior of anger attacks (uncharacteristic sudden bouts of anger that are disproportionate to situation and associated with autonomic activation).

METHODS

Participants of the Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care study who completed Massachusetts General Hospital Anger Attacks questionnaire were included (n = 293). At each visit, the 17-item Hamilton Depression Rating Scale and the 16-item Concise Associated Symptom Tracking scale were used to measure depression, anxiety, and irritability. In those with anger attacks present v. those without anger attacks, separate t tests and mixed model analyses compared afore-mentioned symptoms at baseline and changes with treatment respectively. As anger attacks may occur without aggressive behaviors, analyses were repeated based only on the presence of aggressive behaviors.

RESULTS

At baseline, those with anger attacks (n = 109) v. those without anger attacks (n = 184) had similar levels of depression but higher levels of irritability [effect size (d) = 0.80] and anxiety (d = 0.32). With acute-phase treatment, participants with anger attacks experienced a greater reduction in irritability (p < 0.001) but not in depression (p = 0.813) or anxiety (p = 0.771) as compared to those without anger attacks. Yet, irritability levels at week-8 were higher in those with anger attacks (d = 0.32) than those without anger attacks. Similar results were found in participants with aggressive behaviors.

CONCLUSIONS

The presence of anger attacks in outpatients with major depressive disorder may identify a sub-group of patients with persistently elevated irritability.

Irritability in Mood Disorders: Neurobiological Underpinnings and Implications for Pharmacological Intervention

Feeling irritable is a common experience, both in health and disease. In the context of psychiatric illnesses, it is a transdiagnostic phenomenon that features across all ages, and often causes significant distress and impairment. In mood disorders, irritability is near ubiquitous and plays a central role in diagnosis and yet, despite its prevalence, it remains poorly understood. A neurobiological model of irritability posits that, in children and adolescents, it is consequent upon deficits in reward and threat processing, involving regions such as the amygdala and frontal cortices. In comparison, in adults with mood disorders, the few studies that have been conducted implicate the amygdala, orbitofrontal cortices, and hypothalamus; however, the patterns of activity in these areas are at variance with the findings in youth. These age-related differences seem to extend to the neurochemistry of irritability, with links between increased monoamine transmission and irritability evident in adults, but aberrant levels of, and responses to, dopamine in youth. Presently, there are no specific treatments that have significant efficacy in reducing irritability in mood disorders. However, treatments that hold some potential and warrant further exploration include agents that act on serotonergic and dopaminergic systems, especially as irritability may serve as a prognostic indicator for overall clinical responsiveness to specific medications. Therefore, for understanding and treatment of irritability to advance meaningfully, it is imperative that an accurate definition and means of measuring irritability are developed. To achieve this, it is necessary that the subjective experience of irritability, both in health and illness, is better understood. These insights will inform an accurate, comprehensive, and valid interrogation of the qualities of irritability in health and illness, and allow not only a clinical appreciation of the phenomenon, but also a deeper understanding of its important role within the development and manifestation of mood disorders.

Functional connectivity during frustration: a preliminary study of predictive modeling of irritability in youth

Irritability cuts across many pediatric disorders and is a common presenting complaint in child psychiatry; however, its neural mechanisms remain unclear. One core pathophysiological deficit of irritability is aberrant responses to frustrative nonreward. Here, we conducted a preliminary fMRI study to examine the ability of functional connectivity during frustrative nonreward to predict irritability in a transdiagnostic sample. This study included 69 youths (mean age = 14.55 years) with varying levels of irritability across diagnostic groups: disruptive mood dysregulation disorder (n = 20), attention-deficit/hyperactivity disorder (n = 14), anxiety disorder (n = 12), and controls (n = 23). During fMRI, participants completed a frustrating cognitive flexibility task. Frustration was evoked by manipulating task difficulty such that, on trials requiring cognitive flexibility, "frustration" blocks had a 50% error rate and some rigged feedback, while "nonfrustration" blocks had a 10% error rate. Frustration and nonfrustration blocks were randomly interspersed. Child and parent reports of the affective reactivity index were used as dimensional measures of irritability. Connectome-based predictive modeling, a machine learning approach, with tenfold cross-validation was conducted to identify networks predicting irritability. Connectivity during frustration (but not nonfrustration) blocks predicted child-reported irritability (ρ = 0.24, root mean square error = 2.02, p = 0.03, permutation testing, 1000 iterations, one-tailed). Results were adjusted for age, sex, medications, motion, ADHD, and anxiety symptoms. The predictive networks of irritability were primarily within motor-sensory networks; among motor-sensory, subcortical, and salience networks; and between these networks and frontoparietal and medial frontal networks. This study provides preliminary evidence that individual differences in irritability may be associated with functional connectivity during frustration, a phenotype-relevant state.

Affective Dysregulation in Children Is Associated With Difficulties in Response Control in Emotional Ambiguous Situations

BACKGROUND

Affective dysregulation (AD), or synonymously "irritability," is a transdiagnostic construct that serves as a diagnostic criterion in various childhood mental disorders. It is characterized by severe or persistent outbursts of anger and aggression. Emotional self-regulation is highly dependent on the ability to process relevant and ignore conflicting emotional information. Understanding neurophysiological mechanisms underlying impairment in AD may provide a starting point for research on pharmacological treatment options and evaluation of psychotherapeutic intervention.

METHODS

A total of 120 children 8 to 12 years of age (63 with AD and 57 typically developing) were examined using an emotional Stroop task. Signal-decomposed electroencephalographic recordings providing information about the affected sensory-perceptual, response selection, or motor information processing stage were combined with source localization.

RESULTS

Behavioral performance revealed dysfunctional cognitive-emotional conflict monitoring in children with AD, suggesting difficulties in differentiating between conflicting and nonconflicting cognitive-emotional information. This was confirmed by the electroencephalographic data showing that they cannot intensify response selection processes during conflicting cognitive-emotional situations. Typically developing children were able to do so and activated a functional-neuroanatomical network comprising the left inferior parietal cortex (Brodmann area 40), right middle frontal (Brodmann area 10), and right inferior/orbitofrontal (Brodmann area 47) regions. Purely sensory-perceptual selection and motor execution processes were not modulated in AD, as evidenced by Bayesian analyses.

CONCLUSIONS

Behavioral and electroencephalogram data suggest that children with AD cannot adequately modulate controlled response selection processes given emotionally ambiguous information. Which neurotransmitter systems underlie these deficits and how they can be improved are important questions for future research.

Cognitive Control in Pediatric Obsessive-Compulsive and Anxiety Disorders: Brain-Behavioral Targets for Early Intervention

The DSM provides distinct criteria for obsessive-compulsive disorder (OCD) and various types of anxiety disorders, but phenomenological overlap, high rates of comorbidity, and early onset suggest common underlying mechanisms. This notion is further supported by use of the same treatments-cognitive behavioral therapy and serotonin reuptake inhibitor medication-for managing both OCD and non-OCD anxiety disorders in clinical settings. While early intervention with these gold standard treatments is recommended for pediatric OCD and anxiety disorders, young patients often remain symptomatic even after treatment. To guide the development of novel, mechanistically targeted treatments to better resolve OCD and anxiety symptoms, the identification of neural circuits underlying psychological constructs with relevance across disorders has been recommended. One construct that may be relevant for understanding pediatric OCD and anxiety disorders is cognitive control, given the difficulty that young patients experience in dismissing obsessions, compulsions, and worry despite recognition that these symptoms are excessive and unreasonable. In this review, we examine findings from a growing body of literature implicating brain-behavioral markers of cognitive control in pediatric OCD and anxiety disorders, including before and after treatment. We conclude by suggesting that interventions designed to enhance the functioning of the task control circuits underlying cognitive control may facilitate brain maturation to help affected youth overcome symptoms.

Shared and Anxiety-Specific Pediatric Psychopathology Dimensions Manifest Distributed Neural Correlates

BACKGROUND

Imaging research has not yet delivered reliable psychiatric biomarkers. One challenge, particularly among youth, is high comorbidity. This challenge might be met through canonical correlation analysis designed to model mutual dependencies between symptom dimensions and neural measures. We mapped the multivariate associations that intrinsic functional connectivity manifests with pediatric symptoms of anxiety, irritability, and attention-deficit/hyperactivity disorder (ADHD) as common, impactful, co-occurring problems. We evaluate the replicability of such latent dimensions in an independent sample.

METHODS

We obtained ratings of anxiety, irritability, and ADHD, and 10 minutes of resting-state functional magnetic resonance imaging data, from two independent cohorts. Both cohorts (discovery: n = 182; replication: n = 326) included treatment-seeking youth with anxiety disorders, with disruptive mood dysregulation disorder, with ADHD, or without psychopathology. Functional connectivity was modeled as partial correlations among 216 brain areas. Using canonical correlation analysis and independent component analysis jointly we sought maximally correlated, maximally interpretable latent dimensions of brain connectivity and clinical symptoms.

RESULTS

We identified seven canonical variates in the discovery and five in the replication cohort. Of these canonical variates, three exhibited similarities across datasets: two variates consistently captured shared aspects of irritability, ADHD, and anxiety, while the third was specific to anxiety. Across cohorts, canonical variates did not relate to specific resting-state networks but comprised edges interconnecting established networks within and across both hemispheres.

CONCLUSIONS

Findings revealed two replicable types of clinical variates, one related to multiple symptom dimensions and a second relatively specific to anxiety. Both types involved a multitude of broadly distributed, weak brain connections as opposed to strong connections encompassing known resting-state networks.

Childhood conduct problems are associated with reduced white matter fibre density and morphology

Childhood conduct problems are an important public health issue as these children are at-risk of adverse outcomes. Studies using diffusion Magnetic Resonance Imaging (dMRI) have found that conduct problems in adults are characterised by abnormal white-matter microstructure within a range of white matter pathways underpinning socio-emotional processing, while evidence within children and adolescents has been less conclusive based on non-specific diffusion tensor imaging metrics. Fixel-based analysis (FBA) provides measures of fibre density and morphology that are more sensitive to developmental changes in white matter microstructure. The current study used FBA to investigate whether childhood conduct problems were related both cross-sectionally and longitudinally to microstructural alterations within the fornix, inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and the uncinate fasciculus (UF). dMRI data was obtained for 130 children across two time-points in a community sample with high levels of externalising difficulties (age: time-point 1 = 9.47 - 11.86 years, time-point 2 = 10.67 -13.45 years). Conduct problems were indexed at each time-point using the Conduct Problems subscale of the parent-informant Strengths and Difficulties Questionnaire (SDQ). Conduct problems were related to lower fibre density in the fornix at both time-points, and in the ILF at time-point 2. We also observed lower fibre cross-section in the UF at time-point 1. The change in conduct problems did not predict longitudinal changes in white-matter microstructure across time-points. The current study suggests that childhood conduct problems are related to reduced fibre-specific microstructure within white matter fibre pathways implicated in socio-emotional functioning.

Irritability through Research Domain Criteria: an opportunity for transdiagnostic conceptualisation

Irritability is a transdiagnostic phenomenon that, despite its ubiquity and significant impact, is poorly conceptualised, defined and measured. As it lacks specificity, efforts to examine irritability in adults by using a diagnostic category perspective have been hamstrung. Therefore, using a Research Domain Criteria (RDoC) approach to examine irritability in adults, which spans many constructs and domains, may have a better chance of yielding underlying mechanisms that can then be mapped onto various diagnostic categories. Recently, a model has been proposed for irritability in children and adolescents that uses the RDoC framework; however, this model, which accounts for chronic, persistent irritability, may not necessarily transpose to adults. Therefore, use of the RDoC framework to examine irritability in adults is urgently needed, as it may shed light on this currently amorphous phenomenon and the many disorders within which it operates.

Neural mechanisms of reward processing in adolescent irritability

Irritability is impairing and prevalent across pediatric psychiatric disorders and typical development, yet its neural mechanisms are largely unknown. This study evaluated the relation between adolescent irritability and reward-related brain function as a candidate neural mechanism. Adolescents from intervention-seeking families in the community (N = 52; mean age = 13.80, SD = 1.94) completed a monetary incentive delay task to assess reward anticipation and feedback (reward receipt and omission) during fMRI acquisition. Whole-brain analyses, controlling for age, examined brain activation and striatal and amygdala connectivity in relation to irritability. Irritability was measured using the parent- and youth-reported Affective Reactivity Index. Irritability was associated with altered reward processing-related activation and connectivity in multiple networks during reward anticipation and feedback, including increased striatal activation and altered ventral striatum connectivity with prefrontal areas. Our findings suggest that irritability is associated with altered neural patterns during reward processing and that aberrant prefrontal cortex-mediated top-down control may be related to irritability. These findings inform our understanding of the etiology of youth irritability and the development of mechanism-based interventions.

Amygdala Functional Connectivity Is Associated With Emotion Regulation and Amygdala Reactivity in 4- to 6-Year-Olds

OBJECTIVE

Emotion dysregulation has been suggested to be a potent risk factor for multiple psychiatric conditions. Altered amygdala-prefrontal cortex (PFC) connectivity has been consistently linked to emotion dysregulation. Recent data indicate that amygdala-PFC functional connectivity undergoes a prolonged period of development, with amygdala reactivity during early childhood potentially shaping this unfolding process. Little is known about the relationships between amygdala-PFC functional connectivity, amygdala reactivity, and emotion regulation during early childhood. This information is likely critical for understanding early emotion dysregulation as a transdiagnostic risk factor for psychopathology. The current study examined the relationships between amygdala functional connectivity, amygdala reactivity, and emotion regulation in preschoolers.

METHOD

A total of 66 medication-naive 4- to 6-year-olds participated in a study where resting-state functional magnetic resonance imaging (rs-fMRI) and parent-reported child emotion regulation ability data were collected. fMRI data collected during a face viewing task was also available for 24 children.

RESULTS

Right amygdala-medial PFC (mPFC) functional connectivity was positively associated with child emotion regulation ability and negatively associated with child negative affect and right amygdala reactivity to facial expressions of emotion. Right amygdala-mPFC functional connectivity also statistically mediated the relationship between heightened right amygdala reactivity and elevated child negative affect.

CONCLUSION

Study findings suggest that amygdala-mPFC functional connectivity during early childhood, and its relationships with amygdala reactivity and emotion regulation during this highly sensitive developmental period, may play an important role in early emotional development. These results inform the neurodevelopmental biology of emotion regulation and its potential relationship with risk for psychopathology.

Callous-Unemotional Traits Moderate the Relationship Between Irritability and Threatening Responding

Background: Irritability and callous-unemotional (CU; reduced guilt/empathy) traits vary dimensionally in the typically developing population but may be particularly marked in youth with conduct disorder (CD). While these dimensional traits are positively correlated, they have been associated with divergent forms of dysfunction, particularly with respect to threat processing (i.e., irritability with increased, and CU traits with decreased, threat responsiveness). This suggests that interactions between these two dimensions may be complex at the neurobiological level. However, this issue has received minimal empirical attention. Methods: The study included 105 adolescents (typically developing and cases with CD; N = 59). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding. Results: Significant irritability-by-CU traits-by-Direction-by-Emotion interactions were seen within right thalamus/PAG, left lingual gyrus and right fusiform gyrus; irritability was positively associated with the BOLD response for Looming Threatening vs. Receding Threatening trials, particularly for youth with low CU traits. In contrast, CU traits were negatively associated with the same differential BOLD response but particularly for youth showing higher levels of irritability. Similar findings were seen within left ventral anterior and posterior cingulate cortices, though the addition of the interaction with CU traits was only seen at slightly more lenient thresholds. Conclusions: The results support previous work linking irritability to increased, and CU traits to reduced, threat responsiveness. However, for adolescents with high irritability, if CU traits are also high, the underlying neuropathology appears to relate to reduced, rather than increased, threat responsiveness.

Face Emotion Processing in Pediatric Irritability: Neural Mechanisms in a Sample Enriched for Irritability With Autism Spectrum Disorder

OBJECTIVE

Characterizing the pathophysiology of irritability symptoms from a dimensional perspective above and beyond diagnostic boundaries is key to developing mechanism-based interventions that can be applied broadly. Face emotion processing deficits are present in youths with elevated levels of irritability. The present study aimed to identify the neural mechanisms of face emotion processing in a sample enriched for irritability by including youths with high-functioning autism spectrum disorder (HF-ASD).

METHOD

Youths (N = 120, age = 8.3-19.2 years) completed an implicit face emotion task during functional magnetic resonance imaging. We evaluated how irritability, measured dimensionally, above and beyond diagnostic group, relates to whole-brain neural activation and amygdala connectivity in response to face emotions.

RESULTS

Both neural activation and amygdala connectivity differed as a function of irritability level and face emotion in the prefrontal cortex. Youths with higher irritability levels had decreased activation in response to both fearful and happy faces in the left middle frontal gyrus and to happy faces in the left inferior frontal gyrus. Furthermore, increased irritability levels were associated with altered right amygdala connectivity to the left superior frontal gyrus when viewing fearful and sad faces.

CONCLUSION

The neural mechanisms of face emotion processing differ in youths with higher irritability compared to their less irritable peers. The findings suggest that these irritability mechanisms may be common to both typically developing and HF-ASD youths. Understanding the neural mechanisms of pediatric irritability symptoms that cut across diagnostic boundaries may be leveraged for future intervention development.

Temporal Discounting Impulsivity and Its Association with Conduct Disorder and Irritability

Objectives: Temporal reward discounting impulsivity (TDI) reflects a propensity to choose smaller immediate rather than larger delayed rewards relative to age/IQ-matched peers. Previous work with adults has linked TDI to an increased risk for antisocial behavior but also psychopathology in general. However, little work has examined TDI in adolescents with conduct disorder (CD), or considered whether TDI might be associated dimensionally with traits associated with antisocial behavior, that is, impulsivity, irritability, and/or callous-unemotional traits. In this study TDI was investigated in a large adolescent group with varying levels of antisocial behavior. Methods: Participants consisted of 195 adolescents (67 with CD, 77 in a psychiatric comparison group and 51 typically developing adolescents). Participants performed a temporal discounting task and individual differences were measured through the Connors rating scale for attention-deficit/hyperactivity disorder (impulsivity), Affective Reactivity Index (irritability), and Inventory of Callous-Unemotional traits. Results: The adolescents with CD and those in the psychiatric comparison group showed significantly greater TDI than typically developing adolescents. However, these group differences were abolished when dimensional covariates were included. Irritability was significantly associated with TDI. Conclusions: We conclude that TDI reflects a transdiagnostic form of dysfunction that particularly manifests in adolescents with increased irritability.

Feasibility and acceptability of a brief cognitive-behavioral group intervention for chronic irritability in youth

Chronic irritability is a core feature of oppositional defiant disorder (ODD) and disruptive mood dysregulation disorder (DMDD), but few irritability-specific interventions have been tested. Existing evidence-based treatments for disruptive behavior problems offer a strong template. This pilot study was conducted to develop and evaluate a brief irritability-specific module of a validated cognitive-behavioral group intervention for children (Stop Now And Plan (SNAP) Program). Stop now and plan for irritability (I-SNAP) retained core elements of SNAP in a shortened 6-week format. Community families with irritable children (M = 8.44 years, SD = 1.42) were recruited for parent and child emotion regulation skills groups. Of 18 children enrolled (72% male), 14 completed (78%). Half of children attended all six sessions, though homework compliance was lower. All parents reported favorable impressions and would recommend I-SNAP to others. Significant improvements were seen from pre- to post-treatment across parent-reported irritability, ODD symptoms, emotion regulation, and disciplinary effectiveness. This pilot study provides initial support suggesting I-SNAP may be feasible to implement and acceptable to parents. In addition, pilot analyses demonstrated that this brief group intervention was associated with positive outcomes consistent with treatment targets. This preliminary evidence supports the need for further research to assess I-SNAP's effects on irritability relative to control groups.

Neural and behavioral correlates of inhibitory control in youths with varying levels of irritability

BACKGROUND

Irritability, a relatively lowered threshold for anger, is prevalent in typically and atypically developing youths. Inhibitory control, the ability to suppress behaviors counter to goals, is essential for regulating emotions, including anger. Understanding how irritability relates to behavioral and neural markers of inhibitory control may inform interventions.

METHODS

Youths (N=52; mean age=13.78) completed a Flanker task on an iPad to measure behavioral correlates of inhibitory control; a subsample (n=19; mean age=13.21) additionally completed a similar task while undergoing fMRI acquisition to evaluate inhibitory control on a neural level. Irritability was measured using the Affective Reactivity Index. Associations between irritability and inhibitory control were evaluated behaviorally (via Pearson correlations), and neurally (via ANCOVAs with whole-brain activation and amygdala connectivity).

RESULTS

fMRI results indicated that higher levels of irritability were associated with aberrant activation (in middle frontal gyrus, amygdala/parahippocampal gyrus, anterior cingulate, lentiform nucleus/striatum) and left amygdala connectivity (with middle temporal gyrus, parahippocampal gyrus, posterior cingulate, fusiform gyrus, and thalamus). Behavioral results were mixed.

LIMITATIONS

Longitudinal studies are needed to characterize changes in neural circuitry and delineate whether the brain profiles precede or are a consequence of symptoms. Larger samples powered to examine multiple irritability-related symptom dimensions will be necessary to elucidate shared vs. disorder-specific irritability mechanisms.

CONCLUSIONS

Findings suggest that pediatric irritability may be related to neural processes involving inhibitory control. Further, findings underscore the importance of neuroimaging in investigating symptom dimensions such as irritability, as neuroimaging may be more sensitive in detecting underlying abnormalities compared to behavioral data alone.

Multi-method assessment of irritability and differential linkages to neurophysiological indicators of attention allocation to emotional faces in young children

Facilitated attention toward angry stimuli (attention bias) may contribute to anger proneness and temper outbursts exhibited by children with high irritability. However, most studies linking attention bias and irritability rely on behavioral measures with limited precision and no studies have explored these associations in young children. The present study explores irritability-related attention biases toward anger in young children (N = 128; ages 4-7 years) engaged in a dot-probe task with emotional faces, as assessed with event-related brain potential (ERP) indices of early selective attention and multi-method assessment of irritability. Irritability assessed via semi-structured clinical interview predicted larger anterior N1 amplitudes to all faces. In contrast, irritability assessed via a laboratory observation paradigm predicted reduced P1 amplitudes to angry relative to neutral faces. These findings suggest that altered early attentional processing occurs in young children with high irritability; however, the nature of these patterns may vary with methodological features of the irritability assessments. Future investigations using different assessment tools may provide greater clarity regarding the underlying neurocognitive correlates of irritability. Such studies may also contribute to the ongoing debates about how to best define and measure irritability across the developmental spectrum in a manner that is most informative for linkage to neural processes.

Attention shifting in the context of emotional faces: Disentangling neural mechanisms of irritability from anxiety

BACKGROUND

Irritability predicts concurrent and prospective psychiatric disorders across the lifespan. Anxiety commonly co-occurs with irritability, and such comorbidity complicates care. Understanding the mechanisms of comorbid traits is necessary to inform treatment decisions. This study aimed to disentangle neural mechanisms of irritability from anxiety in the context of attentional shifting toward and away from emotional faces in youths from treatment-seeking families.

METHODS

Youths (N = 45), mean age = 14.01 years (standard deviation = 1.89) completed a dot-probe task during functional magnetic resonance imaging acquisition. Whole-brain activation analyses evaluated the effect of irritability on neural reactivity in the context of varying attentional shifting toward and away from emotional faces, both depending on and above and beyond anxiety (i.e., with anxiety as [a] a moderator and [b] a covariate, respectively).

RESULTS

Higher irritability levels related to distinct task-related patterns of cuneus activation, depending on comorbid anxiety levels. Increased irritability also related to distinct task-related patterns of parietal, temporal, occipital, and cerebellar activation, controlling for anxiety. Overall, youths with higher levels of irritability evinced more pronounced fluctuations in neural reactivity across task conditions.

CONCLUSION

The present study contributes to a literature delineating the unique and shared neural mechanisms of overlapping symptom dimensions, which will be necessary to ultimately build a brain- and behavior-based nosology that forms the basis for more targeted and effective treatments.