Exposure therapy for pediatric irritability: Theory and potential mechanisms

Autistic Symptoms, Irritability, and Executive Dysfunctions: Symptom Dynamics from Multi-Network Models

Socio-cognitive difficulties in individuals with autism spectrum disorder (ASD) are heterogenuous and often co-occur with irritability symptoms, such as angry/grouchy mood and temper outbursts. However, the specific relations between individual symptoms are not well-represented in conventional methods analyzing aggregated autistic symptoms and ASD diagnosis. Moreover, the cognitive-behavioral mechanisms linking ASD to irritability are largely unknown. This study investigated the dynamics between autistic (Social Responsiveness Scale) and irritability (Affective Reactivity Index) symptoms and executive functions (Cambridge Neuropsychological Test Automated Battery) in a sample of children and adolescents with ASD, their unaffected siblings, and neurotypical peers (N = 345, aged 6-18 years, 78.6% male). Three complementary networks across the entire sample were computed: (1) Gaussian graphical network estimating the conditional correlations between symptom nodes; (2) Relative importance network computing relative influence between symptoms; (3) Bayesian directed acyclic graph estimating predictive directionality between symptoms. Networks revealed numerous partial correlations within autistic (rs = .07-.56) and irritability (rs = .01-.45) symptoms and executive functions (rs = -.83 to .67) but weak connections between clusters. This segregated pattern converged in all directed and supplementary networks. Plausible predictive paths were found between social communication difficulties to autism mannerisms and between "angry frequently" to "lose temper easily." Autistic and irritability symptoms are two relatively independent families of symptoms. It is unlikely that executive dysfunctions explain elevated irritability in ASD. Findings underscore the need for researching other mood and cognitive-behavioral bridge symptoms, which may inform individualized treatments for co-occurring irritability in ASD.

An Expanded Conceptual Framework for Understanding Irritability in Childhood: The Role of Cognitive Control Processes

Children prone to irritability experience significant functional impairments and internalising and externalising problems. Contemporary models have sought to elucidate the underlying mechanisms in irritability, such as aberrant threat and reward biases to improve interventions. However, the cognitive control processes that underlie threat (e.g., attention towards threats) and reward (e.g., attention towards reward-related cues) biases and the factors which influence the differential activation of positive and negative valence systems and thus leading to maladaptive activation of cognitive control processes (i.e., proactive and reactive control) are unclear. Thus, we aim to integrate extant theoretical and empirical research to elucidate the cognitive control processes underlying threat and reward processing that contribute to irritability in middle childhood and provide a guiding framework for future research and treatment. We propose an expanded conceptual framework of irritability that includes broad intraindividual and environmental vulnerability factors and propose proximal 'setting' factors that activate the negative valence and positive valence systems and proactive and reactive cognitive control processes which underpin the expression and progression of irritability. We consider the implications of this expanded conceptualisation of irritability and provide suggestions for future research.

Associations between trauma exposure and irritability within the family unit: a network approach

BACKGROUND

Pediatric irritability is a pervasive psychiatric symptom, yet its etiology remains elusive. While trauma exposure may contribute to the development of irritability, empirical research is limited. This study examined the prevalence of irritability among trauma-exposed children, identified factors that differentiate trauma-exposed children with and without irritability, and employed a network analysis to uncover associations between irritability and trauma exposure in the family unit.

METHODS

Sample included 676 children (56.3% male, mean age = 9.67 ± 3.7 years) and their parents referred by the Connecticut Department of Children and Families to Fathers for Change - a psychotherapy intervention designed to reduce intimate partner violence (IPV) and child maltreatment. Child's trauma exposure, post-traumatic stress disorder (PTSD) symptoms, and irritability were assessed pre-intervention using self- and caregiver-report. Parents self-reported their childhood and adulthood trauma exposures, PTSD symptoms, irritability, psychopathology, and IPV.

RESULTS

Across caregiver- and child-reports, 16%-17% of children exhibited irritability. Irritable children experienced greater trauma exposure, interpersonal violence, emotional abuse, and PTSD severity. They had caregivers, particularly mothers, with greater trauma histories, IPV, and psychopathology. Network analysis revealed 10 nodes directly correlated to child's irritability including child's PTSD severity, parental IPV (specifically psychological violence), and parental psychopathology.

CONCLUSIONS

Results provide initial empirical evidence that pediatric irritability is linked to trauma exposure, suggesting trauma histories be considered in the diagnosis and treatment of irritability. Interventions addressing caregiver trauma, IPV, and psychopathology may ameliorate pediatric irritability. Future studies could benefit from adopting network approaches with longitudinal or time series data to elucidate causality and points of intervention.

Irritability in Youths: A Critical Integrative Review

Irritability, defined as proneness to anger that may impair an individual's functioning, is common in youths. There has been a recent upsurge in relevant research. The authors combine systematic and narrative review approaches to integrate the latest clinical and translational findings and provide suggestions for addressing research gaps. Clinicians and researchers should assess irritability routinely, and specific assessment tools are now available. Informant effects are prominent, are stable, and vary by age and gender. The prevalence of irritability is particularly high among individuals with attention deficit hyperactivity disorder, autism spectrum disorder, and mood and anxiety disorders. Irritability is associated with impairment and suicidality risk independent of co-occurring diagnoses. Developmental trajectories of irritability (which may begin early in life) have been identified and are differentially associated with clinical outcomes. Youth irritability is associated with increased risk of anxiety, depression, behavioral problems, and suicidality later in life. Irritability is moderately heritable, and genetic associations differ based on age and comorbid illnesses. Parent management training is effective for treating psychological problems related to irritability, but its efficacy in treating irritability should be tested rigorously, as should novel mechanism-informed interventions (e.g., those targeting exposure to frustration). Associations between irritability and suicidality and the impact of cultural context are important, underresearched topics. Analyses of large, diverse longitudinal samples that extend into adulthood are needed. Data from both animal and human research indicate that aberrant responses to frustration and threat are central to the pathophysiology of irritability, revealing important translational opportunities.

Modeling Shared and Specific Variances of Irritability, Inattention, and Hyperactivity Yields Novel Insights Into White Matter Perturbations

OBJECTIVE

Irritability, inattention, and hyperactivity, which are common presentations of childhood psychopathology, have been associated with perturbed white matter microstructure. However, similar tracts have been implicated across these phenotypes; such non-specificity could be rooted in their high co-occurrence. To address this problem, we use a bifactor approach parsing unique and shared components of irritability, inattention, and hyperactivity, which we then relate to white matter microstructure.

METHOD

We developed a bifactor model based on the Conners Comprehensive Behavioral Rating Scale in a sample of youth with no psychiatric diagnosis or a primary diagnosis of attention-deficit/hyperactivity disorder or disruptive mood dysregulation disorder (n = 521). We applied the model to an independent yet sociodemographically and clinically comparable sample (n = 152), in which we tested associations between latent variables and fractional anisotropy (FA).

RESULTS

The bifactor model fit well (comparative fit index = 0.99; root mean square error of approximation = 0.07). The shared factor was positively associated with an independent measure of impulsivity (ρS = 0.88, pFDR < .001) and negatively related to whole-brain FA (r = -0.20), as well as FA of the corticospinal tract (all pFWE < .05). FA increased with age and deviation from this curve, indicating that altered white matter maturation was associated with the hyperactivity-specific factor (r = -0.16, pFWE < .05). Inattention-specific and irritability-specific factors were not linked to FA.

CONCLUSION

Perturbed white matter microstructure may represent a shared neurobiological mechanism of irritability, inattention, and hyperactivity related to heightened impulsivity. Furthermore, hyperactivity might be uniquely associated with a delay in white matter maturation.

An Exposure-Based Cognitive-Behavioral Therapy for Youth with Severe Irritability: Feasibility and Preliminary Efficacy

OBJECTIVE

Clinically impairing irritability and temper outbursts are among the most common psychiatric problems in youth and present transdiagnostically; however, few mechanistically informed treatments have been developed. Here, we test the acceptability, feasibility, and preliminary efficacy of a novel exposure-based treatment with integrated parent management skills for youth with severe irritability using a randomized between-subjects multiple baseline design.

METHOD

N = 41 patients (Age, Mean (SD) = 11.23 years (1.85), 62.5% male, 77.5% white) characterized by severe and impairing temper outbursts and irritability were randomized to different baseline observation durations (2, 4, or 6 weeks) prior to active treatment; 40 participants completed the 12 session treatment of exposure-based cognitive-behavioral therapy for irritability with integrated parent management skills. Masked clinician ratings were acquired throughout baseline and treatment phases, as well as 3- and 6-months post-treatment. To examine acceptability and feasibility, drop-out rates and adverse events were examined. Primary clinical outcome measures included clinician-administered measures of irritability severity and improvement. Secondary clinical outcome measures included multi-informant measures of irritability, depression, anxiety, and attention-deficit/hyperactivity disorder symptoms.

RESULTS

No patients dropped out once treatment began, and no adverse events were reported. Irritability symptoms improved during the active phase of treatment across all measurements (all βs > -0.04, ps < .011, Cohen's d range: -0.33 to -0.98). Treatment gains were maintained at follow-up (all βs(39) < -0.001, ps > .400). Sixty-five percent of patients were considered significantly improved or recovered post-treatment based on the primary clinician-rated outcome measure.

CONCLUSIONS

Results support acceptability, feasibility, and preliminary efficacy of this novel treatment for youth with severe irritability. Limitations and future directions are also discussed.

A New Behavioral Paradigm for Frustrative Nonreward in Juvenile Mice

Background

Irritability, defined as proneness to anger, can reach a pathological extent. It is a defining symptom of disruptive mood dysregulation disorder and one of the most common reasons youths present for psychiatric evaluation and care. Aberrant responses to frustrative nonreward (FNR), the response to omission of expected reward, are central to the pathophysiology of irritability. FNR is a translational construct to study irritability across species. The development of preclinical FNR models would advance mechanistic studies of the important and relatively understudied clinical phenomenon of irritability.

Methods

We used FNR as a conceptual framework to develop a novel mouse behavioral paradigm named alternate poking reward omission. Juvenile mice were exposed to alternate poking reward omission and then examined with a battery of behavioral tests to determine the behavioral effect of FNR.

Results

FNR increased locomotion and aggression regardless of sex. These behavioral changes elicited by FNR resemble the symptoms observed in youth with severe irritability. FNR had no effect on anxiety-like, depression-like, or nonaggressive social behaviors.

Conclusions

Our alternate poking reward omission paradigm effectively elevated aggression and locomotion in juvenile mice. These frustration effects are directly related to behavioral symptoms of youth with severe irritability. Our novel behavioral paradigm lays the groundwork for further mechanistic studies of frustration and irritability in rodents.

Can peripheral psychophysiological markers predict response to exposure-based cognitive behavioral therapy in youth with severely impairing irritability? A study protocol

BACKGROUND

Irritability, an increased proneness to anger, is a primary reason youth present for psychiatric care. While initial evidence supports the efficacy of exposure-based cognitive behavioral therapy (CBT) for youth with clinically impairing irritability, treatment mechanisms remain unclear. Here, we propose to measure peripheral psychophysiological indicators of arousal-heart rate (HR)/electrodermal activity (EDA)-and regulation-heart rate variability (HRV)-during exposures to anger-inducing stimuli as potential predictors of treatment efficacy. The objective of this study is to evaluate whether in-situ biosensing data provides peripheral physiological indicators of in-session response to exposures.

METHODS

Blood volume pulse (BVP; from which HR and HRV canl be derived) and EDA will be collected ambulatorily using the Empatica EmbracePlus from 40 youth (all genders; ages 8-17) undergoing six in-person exposure treatment sessions, as part of a multiple-baseline trial of exposure-based CBT for clinically impairing irritability. Clinical ratings of irritability will be conducted at baseline, weekly throughout treatment, and at 3-month and 6-month follow-ups via the Clinical Global Impressions Scale (CGI) and the Affective Reactivity Index (ARI; clinician-, parent-, and child-report). Multilevel modeling will be used to assess within- and between-person changes in physiological arousal and regulation throughout exposure-based CBT and to determine whether individual differences are predictive of treatment response.

DISCUSSION

This study protocol leverages a wearable biosensor (Empatica) to continuously record HR/HRV (derived from BVP) and EDA during in-person exposure sessions for youth with clinically impairing irritability. Here, the goal is to identify changes in physiological arousal (EDA, HR) and regulation (HRV) over the course of treatment in tandem with changes in clinical symptoms.

TRIAL REGISTRATION

The participants in this study come from an overarching clinical trial (trial registration numbers: NCT02531893 first registered on 8/25/2015; last updated on 8/25/2023). The research project and all related materials were submitted and approved by the appropriate Institutional Review Board of the National Institute of Mental Health (NIMH).

Transactional associations of child irritability and anxiety with parent psychological control in Taiwanese school-aged children

Background

Child irritability and anxiety are associated with parent psychological control; yet their transactional relations over time are not well-characterized at the within-person level. Research addressing generalizability of past Western-based literature in non-Western, collectivist community samples is lacking.

Methods

Sample comprised 285 children aged 8.8-11.4 years (145 girls; Mage = 9.9 years, SD = 0.6) in Northern Taiwan. Participants were assessed at baseline (T1), 6-month (T2), and 12-month (T3) follow-ups. Child irritability and anxiety symptoms were assessed using parent-rated Child Behavior Checklist. Parent psychological control was assessed using the parent- and child-rated Psychological Control Scale. Within-person processes were specified using the random-intercept cross-lagged panel models.

Results

Models showed that psychological control predicted increased child irritability when analyzing parenting data from parents and children. However, the lagged effect from psychological control to child anxiety was only seen in parent-rated parenting data. We found limited evidence for a back-and-forth transactional pathway among constructs. Child irritability predicted increased child anxiety in all models.

Conclusions

Directional effects from psychological control to child irritability and anxiety support parent-involved interventions that prioritize collaborative parenting and positive reinforcement techniques. Future validations in combined clinical and typically developing samples and direct cross-cultural comparisons are warranted.

Parenting and childhood irritability: Negative emotion socialization and parental control moderate the development of irritability

Irritability, characterized by anger in response to frustration, is normative in childhood. While children typically show a decline in irritability from toddlerhood to school age, elevated irritability throughout childhood may predict later psychopathology. The current study (n = 78) examined associations between trajectories of irritability in early childhood (ages 2-7) and irritability in adolescence (age 12) and tested whether these associations are moderated by parenting behaviors. Results indicate that negative emotion socialization moderated trajectories of irritability - relative to children with low stable irritability, children who exhibited high stable irritability in early childhood and who had parents that exhibited greater negative emotion socialization behaviors had higher irritability in adolescence. Further, negative parental control behavior moderated trajectories of irritability - relative to children with low stable irritability, children who had high decreasing irritability in early childhood and who had parents who exhibited greater negative control behaviors had higher irritability in adolescence. In contrast, positive emotion socialization and control behaviors did not moderate the relations between early childhood irritability and later irritability in adolescence. These results suggest that both irritability in early childhood and negative parenting behaviors may jointly influence irritability in adolescence. The current study underscores the significance of negative parenting behaviors and could inform treatment.

Network analysis of ecological momentary assessment identifies frustration as a central node in irritability

BACKGROUND

Irritability presents transdiagnostically, commonly occurring with anxiety and other mood symptoms. However, little is known about the temporal and dynamic interplay among irritability-related clinical phenomena. Using a novel network analytic approach with smartphone-based ecological momentary assessment (EMA), we examined how irritability and other anxiety and mood symptoms were connected.

METHODS

Sample included 152 youth ages 8-18 years (M ± SD = 12.28 ± 2.53; 69.74% male; 65.79% White) across several diagnostic groups enriched for irritability including disruptive mood dysregulation disorder (n = 34), oppositional defiant disorder (n = 9), attention-deficit/hyperactivity disorder (n = 47), anxiety disorder (n = 29), and healthy comparisons (n = 33). Participants completed EMA on irritability-related constructs and other mood and anxiety symptoms three times a day for 7 days. EMA probed symptoms on two timescales: "since the last prompt" (between-prompt) versus "at the time of the prompt" (momentary). Irritability was also assessed using parent-, child- and clinician-reports (Affective Reactivity Index; ARI), following EMA. Multilevel vector autoregressive (mlVAR) models estimated a temporal, a contemporaneous within-subject and a between-subject network of symptoms, separately for between-prompt and momentary symptoms.

RESULTS

For between-prompt symptoms, frustration emerged as the most central node in both within- and between-subject networks and predicted more mood changes at the next timepoint in the temporal network. For momentary symptoms, sadness and anger emerged as the most central node in the within- and between-subject network, respectively. While anger was positively related to sadness within individuals and measurement occasions, anger was more broadly positively related to sadness, mood lability, and worry between/across individuals. Finally, mean levels, not variability, of EMA-indexed irritability were strongly related to ARI scores.

CONCLUSIONS

This study advances current understanding of symptom-level and temporal dynamics of irritability. Results suggest frustration as a potential clinically relevant treatment target. Future experimental work and clinical trials that systematically manipulate irritability-related features (e.g. frustration, unfairness) will elucidate the causal relations among clinical variables.

A New Behavioral Paradigm for Frustrative Non-reward Reveals a Global Change in Brain Networks by Frustration

Background

Irritability, defined as proneness to anger, can reach a pathological extent. It is a defining symptom of Disruptive Mood Dysregulation Disorder (DMDD) and one of the most common reasons youth presents for psychiatric evaluation and care. Aberrant responses to frustrative non-reward (FNR, the response to omission of expected reward) are central to the pathophysiology of irritability. FNR is a translational construct to study irritability across species. The development of preclinical FNR models would advance mechanistic studies of the important and relatively understudied clinical phenomenon of irritability.

Methods

We used FNR as a conceptual framework to develop a novel mouse behavioral paradigm named Alternate Poking Reward Omission (APRO). After APRO, mice were examined with a battery of behavioral tests and processed for whole brain c-Fos imaging. FNR increases locomotion and aggression in mice regardless of sex. These behavioral changes resemble the symptoms observed in youth with severe irritability. There is no change in anxiety-like, depression-like, or non-aggressive social behaviors. FNR increases c-Fos+ neurons in 13 subregions of thalamus, iso-cortex and hippocampus including the prelimbic, ACC, hippocampus, dorsal thalamus, cuneiform nucleus, pons, and pallidum areas. FNR also shifts the brain network towards a more global processing mode.

Conclusion

Our novel FNR paradigm produces a frustration effect and alters brain processing in ways resembling the symptoms and brain network reconfiguration observed in youth with severe irritability. The novel behavioral paradigm and identified brain regions lay the groundwork for further mechanistic studies of frustration and irritability in rodents.

Inhibitory Control in Early Childhood Aggression Subtypes: Mediation by Irritability

The present study tested irritability as a mediator of inhibitory control's (IC) associations with crossed form and function aggression subtypes over one year in early childhood (N = 300, M_age = 44.70 months, SD = 4.38 months). We hypothesized lower IC would predict increases in irritability, which would in turn predict increases in aggression overall (severity) and a predominance of reactive over proactive subtypes (directionality), and considered moderation by gender. Irritability mediated IC's relations in the predicted direction for physical severity for girls only and relational severity for both genders. Lower IC predicted increases in irritability, which in turn predicted increasing predominance of reactive over proactive physical and relational aggression. The predicted indirect effect was significant for physical but not relational directionality. Findings highlight the viability of directionality scores for disentangling these effects, and that developmental associations between IC, irritability, and reactive functions of aggression are evident in early childhood.

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.

The Feasibility, Acceptability, and Efficacy of Positive Search Training for Irritable Youth: A Single-Case Experimental Design

Although irritability is common in youth, research on treatment is in its infancy. Threat biases are more pronounced in irritable compared to low irritable youth, similar to evidence found in anxious youth. Therefore, interventions targeting these biases may be promising for reducing irritability. This study utilised a multiple baseline case series design to determine the feasibility, acceptability, and efficacy of positive search training (PST) for irritable children. Three children were included who met criteria for a principal diagnosis of Disruptive Mood Dysregulation Disorder (DMDD), and a secondary diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) or Major Depressive Disorder (MDD). PST was feasible with two of the three participants; one child refused to continue after one session. For the two participants who completed PST, acceptability was stable with moderate-to-high ratings of engagement and enjoyment, and high and stable treatment-relevant verbalisations of the key strategies. Both cases showed declines in DMDD severity across treatment and no longer met criteria at post-treatment. Both participants met criteria for Oppositional Defiant Disorder (ODD) at post-treatment (considered less severe for irritability than DMDD). Declines in parent-reported irritability occurred for both cases, however some returns to baseline were observed. Overall, PST for irritable youth shows promise as an acceptable and feasible intervention. Further studies are needed combining PST with strategies for secondary diagnoses, given its high comorbidity with disruptive behaviour disorders.

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.

Associations of Irritability With Functional Connectivity of Amygdala and Nucleus Accumbens in Adolescents and Young Adults With ADHD

OBJECTIVE

Irritability is a common characteristic in ADHD. We examined whether dysfunction in neural connections supporting threat and reward processing was related to irritability in adolescents and young adults with ADHD.

METHOD

We used resting-state fMRI to assess connectivity of amygdala and nucleus accumbens seeds in those with ADHD (n = 34) and an age- and gender-matched typically-developing comparison group (n = 34).

RESULTS

In those with ADHD, irritability was associated with atypical functional connectivity of both seed regions. Amygdala seeds showed greater connectivity with right inferior frontal gyrus and caudate/putamen, and less connectivity with precuneus. Nucleus accumbens seeds showed altered connectivity with middle temporal gyrus and precuneus.

CONCLUSION

The irritability-ADHD presentation is associated with atypical functional connectivity of reward and threat processing regions with cognitive control and emotion processing regions. These patterns provide novel evidence for irritability-associated neural underpinnings in adolescents and young adults with ADHD. The findings suggest cognitive and behavioral treatments that address response to reward, including omission of an expected reward and irritability, may be beneficial for ADHD.

Characterizing the Neural Correlates of Response Inhibition and Error Processing in Children With Symptoms of Irritability and/or Attention-Deficit/Hyperactivity Disorder in the ABCD Study®

Attention-deficit/hyperactivity disorder (ADHD), characterized by symptoms of inattention and/or hyperactivity and impulsivity, is a neurodevelopmental disorder associated with executive dysfunctions, including response inhibition and error processing. Research has documented a common co-occurrence between ADHD and pediatric irritability. The latter is more characterized by affective symptoms, specifically frequent temper outbursts and low frustration tolerance relative to typically developing peers. Shared and non-shared neural correlates of youths with varied profiles of ADHD and irritability symptoms during childhood remain largely unknown. This study first classified a large sample of youths in the Adolescent Brain Cognitive Development (ABCD) study at baseline into distinct phenotypic groups based on ADHD and irritability symptoms (N = 11,748), and then examined shared and non-shared neural correlates of response inhibition and error processing during the Stop Signal Task in a subset of sample with quality neuroimaging data (N = 5,948). Latent class analysis (LCA) revealed four phenotypic groups, i.e., high ADHD with co-occurring irritability symptoms (n = 787, 6.7%), moderate ADHD with low irritability symptoms (n = 901, 7.7%), high irritability with no ADHD symptoms (n = 279, 2.4%), and typically developing peers with low ADHD and low irritability symptoms (n = 9,781, 83.3%). Latent variable modeling revealed group differences in the neural coactivation network supporting response inhibition in the fronto-parietal regions, but limited differences in error processing across frontal and posterior regions. These neural differences were marked by decreased coactivation in the irritability only group relative to youths with ADHD and co-occurring irritability symptoms and typically developing peers during response inhibition. Together, this study provided initial evidence for differential neural mechanisms of response inhibition associated with ADHD, irritability, and their co-occurrence. Precision medicine attending to individual differences in ADHD and irritability symptoms and the underlying mechanisms are warranted when treating affected children and families.

Irritability and mental health profiles among children and adolescents: A result of latent profile analysis

BACKGROUND

Irritability is a transdiagnostic symptom that accompanies both internalizing and externalizing problems. However, there has been a scarcity of research concerning the relationships between irritability and mental health profiles among children and adolescents.

AIM

This study aimed to identify latent profiles in children and adolescents using anxiety, depression, oppositionality, and irritability. In addition, the profiles were further examined in their relationships with mental health symptoms.

METHOD

The study analyzed data from 1867 children and adolescents aged 6-15 years from the COVID-19 Online-Survey for Children and Adolescents in Japan (J-COSCA). Parent-reported questionnaires were used in this study.

RESULTS

A latent profile analysis detected five latent profiles. High oppositionality characterized the first profile ("oppositional": n = 405, 22%). High levels of depression and other less pronounced symptoms characterized the second profile ("depressed": n = 276, 15%). The third profile ("average": n = 602, 33%) presented average symptoms of anxiety, depression and oppositionality and low irritability. The fourth profile ("well-adjusted": n = 235, 13%) presented low values for all the applicable symptoms. The last profile ("comorbid": n = 308, 17%) exhibited high values for all the symptoms and the highest level of irritability of the five profiles.

LIMITATION

We analyzed the data from a community sample alone after capturing it using parent-reported questionnaires.

CONCLUSION

This study revealed that the five profiles (oppositional, depressed, average, well-adjusted, and comorbid) were identified, and children and adolescents in the comorbid profiles had high irritability as well as high anxiety, depression, and oppositionality.

Efficacy of cognitive behavioral therapy on aggressive behavior in children with attention deficit hyperactivity disorder and emotion dysregulation: study protocol of a randomized controlled trial

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is frequently associated with emotional dysregulation (ED). ED is characterized by excessive and inappropriate emotional reactions compared to social norms, uncontrolled and rapid shifts in emotion, and attention focused on emotional stimuli. Few studies have evaluated non-pharmacological interventions to improve ED in children with ADHD. The current randomized controlled trial assesses the efficacy of a cognitive behavioral therapy (CBT) intervention compared with a theater-based intervention (TBI) in children with ADHD and ED.

METHODS

Sixty-eight 7- to 13-year-old children with ADHD and ED will be recruited and randomly assigned to the CBT or TBI group. CBT aims to reduce ED by teaching anger management strategies. TBI seeks to reduce ED by improving emotion understanding and expression through mimics and movement. In both groups, children participate in 15 1-h sessions, and parents participate in 8 sessions of a parent management program. The primary outcome measure is the change in the "Aggression" sub-score of the Child Behavior Checklist (CBCL). Secondary outcome measures include overall impairment (Children's Global Assessment Scale, Strengths and Difficulties Questionnaire), personality profile (Hierarchical Personality Inventory for Children), executive function (Behavioral Rating Inventory of Executive Function), quality of life (Kidscreen-27), parental stress (Parenting Stress Index, 4th edition), parental depression (Beck Depression Inventory-II), and impact of child disorders on the quality of the family life (Parental Quality of Life and Developmental Disorder).

DISCUSSION

Children with ADHD and ED are at risk of functional impairment and poor outcomes and have specific therapeutic needs. This randomized controlled trial wants to assess non-pharmacological treatment options for this population.

TRIAL REGISTRATION

Clinicaltrials.gov. NCT03176108 . Registered on June 5, 2017.

A Mini-Review of Pharmacological and Psychosocial Interventions for Reducing Irritability Among Youth With ADHD

Approximately a third of children and adolescents with attention-deficit/hyperactivity disorder (ADHD) experience significant irritability; despite this, no study has reviewed whether interventions for youth with ADHD can improve irritability. This mini review sought to address this gap in the literature by discussing existing pharmacological and psychosocial interventions for irritability among children and adolescents with ADHD. A literature search was conducted in April 2021, with a total of 12 intervention articles identified (six pharmacological, one psychosocial, five combined). Studies were excluded if they did not involve an intervention, a measure of irritability, or the population was not youth with ADHD. Of these articles, two were with an ADHD only sample; seven included ADHD with comorbid disruptive behavior, disruptive mood dysregulation disorder (DMDD), or severe mood dysregulation (SMD); and three included ADHD with comorbid autism spectrum disorder (ASD). Findings suggest that central nervous system stimulants used alone or in combination with behavior therapy are effective at reducing irritability in youth with ADHD only or comorbid ADHD and DMDD/SMD. Less evidence was found for the efficacy of guanfacine and atomoxetine for youth with ADHD only or comorbid ADHD and ASD. Parent training alone or in combination with atomoxetine was found to be effective at reducing irritability in youth with comorbid ADHD and ASD. Future research assessing the efficacy of other psychosocial interventions, particularly cognitive behavioral therapy is necessary, as are randomized trials assessing intervention sequencing and intensity among youth with ADHD. Researchers are advised to utilize well-validated measures of irritability in future research.

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.

Cardiovascular reactivity as a measure of irritability in a transdiagnostic sample of youth: Preliminary associations

OBJECTIVES

Irritability is a transdiagnostic symptom in developmental psychopathology, conceptualized as a low threshold for frustration and increased proneness to anger. While central to emotion regulation, there is a vital need for empirical studies to explore the relationship between irritability and underlying physiological mechanisms of cardiovascular arousal.

METHODS

We examined the relationship between irritability and cardiovascular arousal (i.e., heart rate [HR] and heart rate variability [HRV]) in a transdiagnostic sample of 51 youth (M = 12.63 years, SD = 2.25; 62.7% male). Data was collected using the Empatica E4 during a laboratory stop-signal task. In addition, the impact of motion activity, age, medication, and sleep on cardiovascular responses was explored.

RESULTS

Main findings showed that irritability was associated with increased HR and decreased HRV during task performance.

CONCLUSIONS

Findings support the role of peripheral physiological dysregulation in youth with emotion regulation problems and suggest the potential use of available wearable consumer electronics as an objective measure of irritability and physiological arousal in a transdiagnostic sample of youth.

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.

Phasic Versus Tonic Irritability: Differential Associations With Attention-Deficit/Hyperactivity Disorder Symptoms

OBJECTIVE

Irritability is a multifaceted construct in pediatric psychopathology. It has been conceptualized as having a phasic dimension and a tonic dimension. Disruptive mood dysregulation disorder is defined by the presence of both dimensions. Severe irritability, or disruptive mood dysregulation disorder, is highly comorbid with attention-deficit/hyperactivity disorder (ADHD). However, it is unknown whether the presence of ADHD modulates the expression of phasic and tonic irritability.

METHOD

A data-driven, latent variable approach was used to examine irritability and ADHD symptoms in a transdiagnostic pediatric sample (N = 489) with primary disruptive mood dysregulation disorder, ADHD, subclinical irritability symptoms, or no diagnosis. Using latent profile analyses, we identified 4 classes: high levels of both irritability and ADHD symptoms, high levels of irritability and moderate levels of ADHD symptoms, moderate levels of irritability and high levels of ADHD symptoms, and low levels of both irritability and ADHD symptoms. Confirmatory factor analysis operationalized phasic irritability and tonic irritability.

RESULTS

As expected, the 2 latent classes characterized by high overall irritability exhibited the highest levels of both phasic and tonic irritability. However, between these 2 high irritability classes, highly comorbid ADHD symptoms were associated with significantly greater phasic irritability than were moderately comorbid ADHD symptoms. In contrast, the 2 high irritability groups did not differ on levels of tonic irritability.

CONCLUSION

These findings suggest that phasic, but not tonic, irritability has a significant association with ADHD symptoms and that phasic and tonic might be distinct, though highly related, irritability dimensions. Future research should investigate potential mechanisms underlying this differential association.

Chronic Irritability in Youth: A Reprise on Challenges and Opportunities Toward Meeting Unmet Clinical Needs

This commentary focuses on irritability, one subtype of emotion dysregulation. We review literature demonstrating that irritability is not a developmental phenotype of bipolar disorder, but is longitudinally associated with unipolar depression and anxiety and genetically associated with unipolar depression, anxiety, and attention-deficit hyperactivity disorder. We describe how irritability is amenable to translational research, in part because of the relevance of frustrative nonreward, a model developed in rodents, to human irritability. Last, we demonstrate how such research has suggested a novel exposure-based intervention for irritability.

Irritability in Children and Adolescents With OCD

Irritability is a common, impairing transdiagnostic symptom in childhood psychopathology, though it has not been comprehensively studied in pediatric obsessive-compulsive disorder (OCD). Further, the central cognitive behavioral treatment component for OCD, exposure and response prevention therapy (ERP), has been recently proposed as a treatment for irritability. This study aimed to evaluate whether certain clinical characteristics are associated with irritability in pediatric OCD and whether irritability reduces following ERP. Participants were 161 youth (ages 7-17) with OCD and a caregiver participating in a randomized controlled trial of D-cycloserine or pill placebo augmented ERP. Participants completed validated assessments during treatment. Irritability was significantly and positively associated with depressive symptoms, defiance, functional impairment, and family accommodation, but was not associated with pretreatment OCD severity, symptom dimensions, obsessive beliefs. Irritability significantly declined following treatment, with over half of youth with any pretreatment irritability experiencing clinically significant change, though this change was not related to OCD improvement. Results suggest that irritability may be a marker of psychiatric comorbidity, parental accommodation, and impairment in youth with OCD. Implications for the exposure-based treatment of irritability are discussed.

Preventing Irritability and Temper Outbursts in Youth by Building Resilience

Severe irritability and temper outbursts are risk factors for the onset of serious and lifelong mood disorders. In treating children and adolescents with severe irritability, clinicians should evaluate and address safety issues before acute stabilization of symptoms. Then, clinicians can initiate interventions to prevent the onset or relapses of the undesired behavior and its functional consequences. This review summarizes primary, secondary, and tertiary relapse prevention strategies, with an emphasis on strategies that build resilience in youth that mitigate the onset, recurrence, and progression of emotion dysregulation.

Developmental Considerations in Obsessive Compulsive Disorder: Comparing Pediatric and Adult-Onset Cases

There appear to be two peaks of incidence of Obsessive Compulsive Disorder (OCD), one with a pre-adolescent onset and another in early adulthood. As new cases are added, the cumulative prevalence of OCD increases, but the great majority of cases have an onset in youth. The notion that early onset OCD represents a unique developmental subtype of the disorder has been considered by many researchers based on several specific age-related factors. Ascertainment and early intervention in affected youth is critical to abbreviate the functional impairments associated with untreated illness. In this paper we review the clinical, familial and translational biomarker correlates seen in early onset OCD that support the notion of a developmental subtype and discuss implications for research and treatment aimed at this cohort. The importance of cognitive, academic and social development tasks of childhood and adolescence, illness-specific and familial factors, and immune-mediated inflammatory factors are discussed, with their implications for management.

Computational Modeling of Attentional Impairments in Disruptive Mood Dysregulation and Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Computational models provide information about cognitive components underlying behavior. When applied to psychopathology-relevant processes, they offer additional insight to observed differences in behavioral performance. Drift diffusion models have been successfully applied to investigate processing efficiency during binary choice tasks. Using these models, we examine the association between psychopathology (irritability and inattention/hyperactivity) and processing efficiency under different attentional demands.

METHOD

A total of 187 youths with attention-deficit/hyperactivity disorder (ADHD), disruptive mood dysregulation disorder (DMDD), both disorders, or no major psychopathology (age, mean ± SD, 13.09 ± 2.55 y, 34% female) completed an Eriksen Flanker task. Of these, 87 youths provided complete data on dimensional measures of the core symptom of DMDD (irritability) and those of ADHD (inattention and hyperactivity).

RESULTS

In a categorical diagnosis-based analysis (n = 187), we found significant interactive effects among ADHD, DMDD, and task condition on processing efficiency, whereby changes in processing efficiency between conflict and nonconflict conditions were larger in youths without psychopathology compared with patients. Analysis of symptom severity (n = 87) across diagnoses similarly revealed an interaction between symptom dimensions and task condition on processing efficiency. Irritability moderated the magnitude of association between inattention symptoms and difference in processing efficiency between conflict and nonconflict conditions.

CONCLUSION

Adapting processing efficiency to cognitive demands may represent a shared cognitive endophenotype for both ADHD and DMDD. Highly irritable and/or inattentive youth may have difficulty adjusting processing efficiency to changing task demands, possibly reflecting impairments in cognitive flexibility.

Cross-Sectional Associations Among Symptoms of Pain, Irritability, and Depression and How These Symptoms Relate to Social Functioning and Quality of Life: Findings From the EMBARC and STRIDE Studies and the VitalSign6 Project

OBJECTIVE

The aim of this report was to evaluate the psychometric properties of the Pain Frequency, Intensity, and Burden Scale (P-FIBS), a brief measure of pain, as well as the association of pain with irritability and depression and how these symptoms relate to functional impairments.

METHODS

Participants of 2 randomized controlled trials (Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care [EMBARC; n = 251 with DSM-IV diagnosis of major depressive disorder; study duration: August 2011-December 2015] and STimulant Reduction Intervention Using Dosed Exercise [STRIDE; n = 302 with DSM-IV diagnosis of stimulant abuse or dependence; study-duration: July 2010-February 2013]) and treatment-seeking patients in primary care clinics from an ongoing quality-improvement project (VitalSign6; n = 4,370; project duration: August 2014-July 2019) were included. Psychometric properties of the P-FIBS were evaluated with confirmatory factor and item response theory analyses in EMBARC and VitalSign6. The approach of Baron and Kenny was used to assess whether irritability accounted for the effect of pain on depression.

RESULTS

Cronbach α (0.84-0.89) and model fits for single-factor structure of P-FIBS were acceptable. Pain was positively correlated with irritability (r = 0.22-0.29) and depression (r = 0.10-0.33). Irritability accounted for 40.7%-65.5% of the effect of pain on depression. Higher irritability and depression were associated with poorer social functioning, quality of life, and productivity in work- and non-work-related activities. Pain was associated with non-work-related activity impairments even after controlling for irritability and depression.

CONCLUSIONS

The P-FIBS is a brief and reliable measure of pain. Irritability is associated with pain and accounts for a large proportion of the effect of pain on depression. Symptoms of pain, irritability, and depression are associated with functional impairments.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT01407094 (EMBARC), NCT01141608 (STRIDE).

Attention-Deficit Hyperactivity Disorder and the Dysregulation of Emotion Generation and Emotional Expression

Individuals with attention-deficit/hyperactivity disorder (ADHD) frequently experience strong reactions to emotionally evocative situations. Difficulties modulating anger and other upsets have clinically significant behavioral consequences. Those with ADHD may have anomalies in emotion generation, emotion expression, or both that predispose to these problems. The association between ADHD and emotion dysregulation raises Important clinical and research issues, including possible heterogeneity in the mechanisms by which they are related. Although first-line treatments for ADHD often help to resolve emotional dysregulation symptoms as well, the evidence base for widespread practice of combination pharmacotherapy remains sparse. Psychosocial treatments that engage processes underlying emotional dysregulation are in development.

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.