Heritability, stability, and prevalence of tonic and phasic irritability as indicators of disruptive mood dysregulation disorder

Development and Validation of a Multi-Informant Scale for Assessing Youth Tonic and Phasic Irritability

Irritability is a common mental health issue in children and adolescents which strongly predicts later psychopathology and impairment. It can manifest in tonic (persistent angry mood) and phasic (short temper outbursts) forms, but research on this distinction is limited due to the lack of validated measures. We developed and evaluated the first multi-informant measure of tonic/phasic irritability for school-age children and adolescents. Data was collected from four samples including three community samples (a total of 1208 parents of 6-17-year-old children and 876 unrelated 13-17-year-old youth) and a small clinical sample (92 parents and their 10-17-year-old children). The Tonic and Phasic Irritability Scale (TAPIS) consists of 8 items measuring tonic, and 11 items measuring phasic, irritability. It demonstrated strong psychometric properties, including structural validity, test-retest stability, and construct validity. Consistent with the literature, tonic irritability was associated with internalizing problems (i.e., anxiety, depression), while phasic irritability was related to externalizing behaviors (e.g., aggression, conduct problems, substance use). The TAPIS exhibited measurement invariance across gender, age, informant, and history of mental health treatment. These findings provide preliminary support for the TAPIS' reliability and validity and demonstrate its promise helping to elucidate differences in the development and treatment of tonic and phasic irritability.

Multivariate prediction of temper outbursts in a sample of youth enriched for irritability using ecological momentary assessment data: A registered report

Irritability and temper outbursts are among the most common reasons youth are referred for psychiatric assessment and care. Identifying in vivo clinical variables that precede the onset of temper outbursts would provide valuable clinical utility. Here, we provide the rationale for a study testing the performance of a classifier trained to predict temper outbursts in a group of clinically-referred youth presenting with symptoms of irritability and temper outbursts. Due to the large sample sizes needed for multivariate classification studies, here, we demonstrated the feasibility of our approach using a relatively large preliminary dataset. Our preliminary data included digital based event sampling from an existing Ecological Momentary Assessment dataset consisting of n = 54 participants with a total of 932 time points. We used this data to develop a logistic regression-based classifier for predicting the temper outburst prospectively. Our initial evaluation provided encouraging evidence for the possibility of predicting the presence of a temper outburst based on individual's momentary clinical responses (e.g., whether the participant is feeling grouchy, hungry, happy, sad, anxious, tired, etc.) prior to the outburst event, as well as external features (e.g., time of day, day of week). However, due to the risk of false positive discoveries and overfitting, these preliminary results are insufficient to conclusively establish the discovery of predictive rules for irritability in Ecological Momentary Assessment data. To more rigorously assess this classifier, we will collect a large confirmatory set, consisting of at least an additional 20 subjects with an expected total of 400 time points, in which will perform confirmatory analyses of the precision and recall of the classifier already fit using preliminary data. This work will potentially provide the foundation for the identification of features predictive of risk and future development of novel mobile-device-based interventions in youth affected with severe and impairing psychopathology.

Network structure of phasic and tonic irritability in adults: A Bayesian Gaussian graphical model

BACKGROUND

Tonic (i.e., irritable mood) and phasic (i.e., temper outbursts) irritability are distinct constructs in childhood, yet there has been little work investigating their relations in adulthood. In particular, no study has examined the relations between these symptoms in the daily lives of adults. The present study seeks to address these gaps by applying a Bayesian Gaussian graphical model to daily diary data of tonic and phasic irritability in adults.

METHOD

A total of 122 participants (Mage = 34.94 [SD = 12.3] years, 52 % female) completed up to 18 days of daily diary, with questions on both tonic and phasic irritability. Contemporaneous, temporal, and between-person networks were constructed using 5 items of tonic and 11 items of phasic irritability. Predictability, centrality, density, and network loadings were also calculated.

RESULTS

Five main findings emerged. First, phasic and tonic irritability were connected in our contemporaneous and temporal networks but distinct in our between-person network. Second, phasic irritability symptoms demonstrated the most importance and influence across networks. Third, tonic irritability symptoms best connected the two subnetworks. Fourth, phasic irritability symptoms appeared to have the potential to be more responsive to interventions. Fifth, tonic irritability demonstrated robust associations with daily functional impairment.

CONCLUSIONS

Tonic and phasic irritability symptoms demonstrate unique associations in the daily lives of adults. Future work should examine the differential potential of these symptoms to respond to targeted interventions.

Irritability and stress: Prospective, bidirectional relationships in adolescence

BACKGROUND

Irritability is a transdiagnostic risk factor for psychopathology and interpersonal problems in youth. However, there is little research on the role of life stress in irritability. The association between stress and irritability may be bidirectional, with irritability leading to stress exposure and stress aggravating irritability. Moreover, it is conceivable that there are sex differences in these relationships. Therefore, we examined the prospective, bidirectional relationships between irritability and stressful life events in a sample of adolescents while considering the role of biological sex.

METHODS

We tested multi-group path models investigating bidirectional associations of irritability with dependent and independent episodic stressors in a community sample of 520 adolescents (52.1 % male) across ages 12, 15, and 18.

RESULTS

All models had acceptable fit. For males, dependent stress at age 12 predicted irritability at age 15, which in turn predicted more stress at age 18. For females, irritability at age 12 predicted dependent stress at age 15, which in turn predicted more irritability at age 18. For independent events in males, irritability at age 15 predicted stress at age 18. For females, independent stress at age 12 predicted irritability at age 15, which in turn predicted more stress at age 18.

CONCLUSION

There are significant bidirectional relationships between irritability and episodic stressors, although the relationships varied depending on youth's age, sex, and role in contributing to stressor occurrence.

Neural Correlates of Irritability and Potential Moderating Effects of Inhibitory Control

Background

Irritability affects up to 20% of youth and is a primary reason for referral to pediatric mental health clinics. Irritability is thought to be associated with disruptions in processing of reward, threat, and cognitive control; however, empirical study of these associations at both the behavioral and neural level have yielded equivocal findings that may be driven by small sample sizes and differences in study design. Associations between irritability and brain connectivity between cognitive control and reward- or threat-processing circuits remain understudied. Furthermore, better inhibitory control has been linked to lower irritability and differential neural functioning among irritable youth, suggesting that good inhibitory control may serve as a protective factor.

Methods

We hypothesized that higher irritability scores would be associated with less positive (or negative) connectivity between cognitive control and threat-processing circuits and between cognitive control and reward-processing circuits in the Healthy Brain Network dataset (release 10.0; N = 4135). We also hypothesized that these associations would be moderated by inhibitory control such that weaker associations between irritability and connectivity would be detected in youths with better than with worse inhibitory control. Regression models were used to test whether associations between irritability and between-network connectivity were moderated by inhibitory control.

Results

Counter to our hypothesis, we detected higher irritability associated with reduced connectivity between threat- and reward-processing and cognitive control networks only in 5- to 9-year-old boys. Inhibitory control did not moderate associations of irritability with between-network connectivity.

Conclusions

Exploratory findings indicate that reduced between-network connectivity may underlie difficulty regulating negative emotions, leading to greater irritability.

Understanding the Etiology of Externalizing Problems in Young Children: The Roles of Callous-Unemotional Traits and Irritability

OBJECTIVE

Callous-unemotional traits (CU), characterized as a lack of guilt and empathy, and irritability, a tendency to show anger and frustration, are 2 risk factors for externalizing behavioral problems. Externalizing problems, CU, and irritability are all heritable. However, there is a dearth of studies examining the genetic and environmental associations between the 3 domains. The present study partitioned joint and independent etiological pathways from CU and irritability to externalizing problems.

METHOD

The sample consisted of 614 pairs of 3-year-old twins from the Boston University Twin Project. Primary caregivers reported twins' externalizing problems, CU, and irritability using the Child Behavior Checklist. Biometric Cholesky models were used to estimate common and unique genetic and environmental variances among the 3 domains.

RESULTS

There were common genetic, shared environmental and nonshared environmental factors operating across all 3 domains. In addition, there were unique genetic and nonshared environmental factors, independent of the common effects, linking externalizing problems and CU, and externalizing problems and irritability, respectively. There were also genetic and nonshared environmental influences unique to externalizing problems, independent of CU and irritability.

CONCLUSION

Common genetic as well as shared and nonshared environmental associations among externalizing problems, CU, and irritability suggest, to some extent, that etiological influences are common to all 3 constructs. However, distinct genetic and child-specific nonshared environmental links separately from CU and irritability to externalizing problems, reveals the heterogeneity of externalizing problems, and suggests that they should not be considered a unitary outcome.

STUDY PREREGISTRATION INFORMATION

Study Preregistration: Understanding the Etiology of Externalizing Problems in Young Children: The Roles of Callous-Unemotional Traits and Irritability; https://doi.org/10.1016/j.jaac.2023.09.549.

Early Predictors and Concurrent Correlates of Tonic and Phasic Irritability in Adolescence

Irritability is a common presenting problem in youth mental health settings that is thought to include two components: tonic (e.g., irritable, touchy mood) and phasic (e.g., temper outbursts), each with unique correlates and outcomes, including later internalizing and externalizing problems, respectively. However, we are unaware of any studies of early predictors of tonic and phasic irritability. We utilized data from a longitudinal study of a community sample of 3-year-old children followed to age 15 (n = 444). We conducted confirmatory factor analysis (CFA) of items from several self-report irritability measures at age 15, including the Affective Reactivity Index, the International Personality Item Pool, the Schedule for Non-Adaptive and Adaptive Personality Youth Version, and the Child Depression Inventory, and examined their early childhood predictors. The CFA identified dimensions consistent with tonic and phasic irritability. Tonic irritability at age 15 was uniquely associated with concurrent internalizing disorders and suicidal behavior while phasic irritability was uniquely associated with concurrent externalizing disorders. When adolescent tonic and phasic irritability were examined together, female sex and parental depressive and substance use disorders at age 3 uniquely predicted adolescent tonic irritability. Additionally, male sex, less parental education, greater laboratory-observed anger and impulsivity, ODD symptoms, higher irritability, and no parental substance use history at age 3 uniquely predicted adolescent phasic irritability. Youth-reported tonic and phasic irritability at age 15 appear to be distinguishable constructs with distinct concurrent correlates and early antecedents. Findings have important implications for research on the etiology of irritability and developing effective treatments.

Parent and Teacher Ratings of Tonic and Phasic Irritability in a Clinical Sample

Research on tonic (persistently angry or grumpy mood) and phasic (temper tantrums/outbursts) irritability in youth has utilized community samples and information from parents and youth. We examined whether tonic and phasic irritability are empirically distinguishable and have similar correlates using teacher, in addition to parent, reports in a clinical sample of children and adolescents. The sample included youth aged 5-18 evaluated at a university outpatient clinic, with complete information from 2481 parents and 2449 teachers. We conducted confirmatory factor analysis (CFA) using items from several parent- and teacher-report inventories and examined concurrent associations with psychopathology and functioning. The CFA supported a two-factor model consistent with tonic and phasic irritability in both parent- and teacher-reports. Parent-reported tonic irritability was associated with higher rates of depression and anxiety disorders, suicidality, and antidepressant medication use. Teacher-reported tonic irritability was associated with elevated rates of depression and antidepressant use. Both parent- and teacher-reported phasic irritability were linked to higher rates of ADHD combined type, oppositional defiant/conduct disorders, and referral for rages. Parent- and teacher-reported tonic and phasic irritability were all associated with impaired social functioning. Parents and teachers can distinguish tonic and phasic irritability, which are associated with internalizing and externalizing problems, respectively. Findings were generally consistent across informants, and with prior studies using community samples.

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.

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.

Future Directions: The Phenomenology of Irritable Mood and Outbursts: Hang Together or Hang Separately1

Recognition of the importance of irritable mood and outbursts has been increasing over the past several decades. This "Future Directions" aims to develop a set of recommendations for future research emphasizing that irritable mood and outbursts "hang together," but have important distinctions and thus also need to "hang separately." Outbursts that are the outcome of irritable mood may be quite different from outbursts that are the trigger or driving force that make youth and his/her environment miserable. What, then, is the relation between irritable mood and outbursts? As the field currently stands, we not only cannot answer this question, but we may also lack the tools to effectively do so. Here, we will propose recommendations for understanding the phenomenology of irritable mood and outbursts so that more directed and clinically useful assessment tools can be designed. We discuss the transdiagnostic and treatment implications that relate to improvements in measurement. We describe the need to do more than repurpose our current assessment tools, specifically interviews and rating scales, which were designed for different purposes. The future directions of the study and treatment of irritable mood and outbursts will require, among others, using universally accepted nomenclature, supporting the development of tools to measure the characteristics of each irritable mood and outbursts, understanding the effects of question order, informant, development and longitudinal course, and studying the ways in which outbursts and irritable mood respond to treatment.

Evidence-Based Assessment of DSM-5 Disruptive, Impulse Control, and Conduct Disorders

The assessment of oppositional defiant disorder, conduct disorder, antisocial personality disorder, and intermittent explosive disorder-the Disruptive, Impulse Control and Conduct Disorders-can be affected by biases in clinical judgment, including overestimating concerns about distinguishing symptoms from normative behavior and stigma associated with diagnosing antisocial behavior. Recent nosological changes call for special attention during assessment to symptom dimensions of limited prosocial emotions and chronic irritability. The present review summarizes best practices for evidence-based assessment of these disorders and discusses tools to identify their symptoms. Despite the focus on disruptive behavior disorders, their high degree of overlap with disruptive mood dysregulation disorder can complicate assessment. Thus, the latter disorder is also included for discussion here. Good practice in the assessment of disruptive behavior disorders involves using several means of information gathering (e.g., clinical interview, standardized rating scales or checklists), ideally via multiple informants (e.g., parent-, teacher-, and self-report). A commitment to providing a full and accurate diagnostic assessment, with careful and attentive reference to diagnostic guidelines, will mitigate concerns regarding biases.

Validation of the Arabic version of the brief irritability test (Ar-BITe) in non-clinical adolescents

BACKGROUND

Despite the substantial clinical relevance of irritability in the development and maintenance of several mental disorders and its negative effects on functioning, no valid and reliable measures are available yet to identify the presence and consequences of irritability as a distinct construct among the Arabic-speaking populations. To bridge this gap, and help advance this field in the under-researched Arab region, we aimed to validate an Arabic-language version of the Brief Irritability Test (BITe).

METHODS

Eligible participants were native Arabic-speaking non-clinical adolescents from Lebanon; 527 participants aged 15.73 ± 1.81 years (56% females) completed the survey.

RESULTS

Utilizing the Confirmatory Factor Analysis approach, we found that the five items of the Arabic BITe loaded into a single factor structure. The scale showed excellent reliability, as both Cronbach's alpha and McDonald's omega coefficient values were of 0.88. Multi-group analyses showed invariance across sex groups in our sample at the configural, metric, and scalar levels. Female adolescents exhibited higher BITe scores than their male counterparts (14.01 vs. 13.25), but this difference did not reach the statistical significance. Good concurrent validity was supported based on positive correlations between irritability scores and measures of aggression, anger and hostility (r Pearson's coefficients ranging from 0.35 to 0.42), as well as positive correlations with insomnia symptoms scores.

CONCLUSION

The present findings allow us to conclude that the Arabic version of the BITe is a unidimensional, reliable, valid, brief, and economic self-report measure of the irritability construct for both male and female Arabic-speakers. Providing an Arabic validated version of the BITe will hopefully foster the research efforts of the Arab scientific community in this area, and promote the implementation of timely, evidence-informed and culturally-sensitive mental health interventions that appropriately address irritability-related problems and consequences among Arab young populations.

Longitudinal Stability and Interrelations of Tonic and Phasic Irritability in Adolescent Girls

Irritability is a transdiagnostic feature and a common mental health problem in adolescence. Prior studies indicate that irritability is composed of two correlated but separable dimensions, tonic irritability (i.e., irritable mood) and phasic irritability (i.e., temper outbursts), which are respectively associated with internalizing and externalizing outcomes. However, little is known about the stability and interrelations of tonic and phasic irritability. The current study examined the longitudinal interplay between tonic and phasic irritability during adolescence. A community sample of 544 girls (age 13.5-15.5 years) was assessed at 5 waves (over 3 years, in 9-month intervals). A random-intercept cross-lagged panel model was used to examine the within-person stability and longitudinal interrelations of tonic and phasic irritability. Pseudo-indicator models were used to help analyze all available data. Results suggest that tonic and phasic irritability had distinct patterns of development and co-development. Between individuals, tonic and phasic irritability showed moderate rank-order stability and high concurrent correlations. Within individuals, phasic irritability was found to positively predict both tonic and phasic irritability at the subsequent wave, whereas tonic irritability did not predict later phasic irritability and showed weaker within-person stability. These results suggest that increased or decreased phasic irritability in adolescent girls may signify continued increase or decrease in both tonic and phasic irritability. The study was among the first to demonstrate the discriminant validity of tonic and phasic irritability from a developmental perspective.

Is the distinction between tonic and phasic irritability meaningful in 3-year-old children?

Irritability encompasses both normative misbehavior in early childhood and clinically significant problems across development. Recent studies have distinguished between tonic (i.e., persistently angry or grumpy mood) and phasic (i.e., temper tantrums or outbursts) forms of irritability and shown that they have different implications for psychopathology and functioning. However, data on this distinction in young (i.e., preschool aged) children are nonexistent. We utilized data from a longitudinal study of a community sample of 462 3-year-olds followed to age 15. We conducted confirmatory factor analysis (CFA) using items from a diagnostic interview and several parent-report inventories and examined concurrent and prospective associations with clinically relevant variables. The CFA identified dimensions consistent with tonic and phasic irritability. Tonic irritability was independently associated with concurrent parent-reported temperamental negative affectivity and surgency, and depressive and oppositional defiant (ODD) disorders, and predicted higher rates of disruptive behavior disorders (DBD) and suicidal behavior in later childhood and adolescence. Phasic irritability was independently associated with concurrent laboratory observations of child impulsivity, parent-reported temperamental negative affectivity, surgency, and low effortful control, maladaptive parenting, and generalized anxiety disorder (GAD), attention-deficit hyperactivity disorder (ADHD), and ODD, but it did not predict later psychopathology. Tonic and phasic irritability are separable in 3-year-old children, but their correlates and outcomes are not as distinct as in older youth. This may reflect the greater difficulty characterizing normative and pathological irritability in the preschool period.

Validation and Analysis of the Psychometric Properties of Two Irritability-Measuring Tools: The Affective Reactivity Index (ARI) and the Born-Steiner Irritability Scale (BSIS) in the Italian Adult and Adolescent Populations

Irritability is a transdiagnostic symptom that affects quality of life during the lifespan of individuals. The objective of the present research was to validate two assessment tools, namely the Affective Reactivity Index (ARI) and the Born-Steiner Irritability Scale (BSIS). We investigated internal consistency as measured with Cronbach's alpha, test-retest with intraclass correlation coefficient (ICC) and convergent validity confronting ARI and BSIS scores with the strength and difficulties questionnaire (SDQ). Our results revealed ARI good internal consistency with a Cronbach's α of 0.79 for adolescent and 0.78 for adults. The BSIS also demonstrated good internal consistency for both samples with Cronbach's α = 0.87. Test-retest analysis showed excellent values for both tools. Convergent validity showed positive and significant correlation with SDW, albeit weak for some sub-scales. In conclusion, we found ARI and BSIS to be good tools for measuring irritability in adolescents and adults, and now, Italian healthcare professionals can use it with more confidence.

Tonic and phasic irritability in 6-year-old children: differential correlates and outcomes

OBJECTIVE

Irritability is a common and clinically important problem in children and adolescents and a risk factor for later psychopathology and impairment. Irritability can manifest in both tonic (e.g., irritable, touchy mood) and phasic (e.g., temper outburst) forms, and recent studies of adolescents suggest that they predict different outcomes. However, no studies have examined whether tonic and phasic irritability are empirically distinguishable in 6-year-old children and whether they have distinct correlates and outcomes.

METHOD

We utilized data from a longitudinal study of an unselected community sample of four hundred fifty-two 6-year-olds followed at 3-year intervals to age 15. We conducted confirmatory factor analysis (CFA) using relevant items from a diagnostic interview and several parent-report inventories.

RESULTS

The CFA identified dimensions that were consistent with tonic and phasic irritability. Tonic irritability was independently associated with concurrent parent-reported temperamental negative affectivity and internalizing and externalizing disorders at age 6 and predicted higher rates of internalizing psychopathology, and suicidal ideation, in adolescence. Phasic irritability was independently associated with concurrent parent-reported temperamental negative affectivity, surgency, and low effortful control, maladaptive parenting styles and practices, and externalizing disorders at age 6, and predicted higher rates of externalizing psychopathology in adolescence.

CONCLUSIONS

Tonic and phasic irritability in 6-year-old children appear to be distinguishable constructs with different temperament and parenting correlates and psychopathological outcomes. Distinguishing these components has implications for research on the etiology and pathophysiology of irritability and developing effective treatments.

Psychometric Validation of the Greek Version of the Scale “Temper Loss” of the Questionnaire “Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB)”

It has become increasingly evident that vulnerability to psychopathology is identifiable early in life. A body of evidence suggests that the recognition and prevention of a spectrum of typical/atypical behaviors in preschoolers can lead to earlier diagnosis and treatment. The Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB) is a parent-completed instrument that has been developed recently to differentiate normative misbehaviors in early childhood from markers of clinical risk. The aim of the present study was to validate the “Temper Loss” Subscale in the Greek language and to assess its psychometric properties in healthy children. An on-print parent-report survey was conducted among Greek children, aged between 3 and 5.5 years. The survey included the MAP-DB and the Child Behavior Checklist (CBCL). A total of 400 respondents participated in the study. The analysis suggested that the Greek version of the MAP-DB’s “Temper Loss” scale has good psychometric properties. The results of the Exploratory Factor Analysis (EFA) of the 22 items were able to explain 64.4% of the total variance. Internal consistency for the one subscale was satisfactory, with Cronbach’s alpha at 0.970. This scale can be used by researchers and practitioners for the evaluation of dimensional phenotypes in early childhood.

ADHD and ODD Dimensions: Time Varying Prediction of Internalizing Problems from Childhood to Adolescence

OBJECTIVE

Although childhood ADHD is a risk factor for internalizing problems, it consists of separable inattention and hyperactivity dimensions that differentially predict outcomes. Oppositional defiant disorder also consists of separable dimensions (i.e., irritable, oppositional), co-occurs with ADHD, and predicts internalizing outcomes. To discern independent associations with internalizing problems, dimensions must be considered simultaneously.

METHODS

Controlling for age, sex, and race, we tested inattention, hyperactivity, irritability, and oppositionality as time-varying predictors of 6 to 7-year prospective change in parent- and teacher-rated internalizing problems in 230 ethnically- diverse (50% Caucasian) 5 to 10 year old youth (M = 7.4 years, 68% male) with (n = 120) and without ADHD (n = 110).

RESULTS

Escalating inattention and irritability, but not hyperactivity and oppositionality, uniquely predicted internalizing problems.

CONCLUSION

These findings suggest that inattention and irritability are unique risk factors for later internalizing problems. These dimensions may catalyze internalizing problems across development and constitute important intervention targets.

Understanding Phasic Irritability: Anger and Distress in Children's Temper Outbursts

Pediatric irritability can be highly impairing and is implicated in adverse outcomes. The phasic component, characterized by temper outbursts, is a frequent impetus to seek treatment. This study tested whether a previously described anger-distress model of tantrums applies to an outpatient sample of school-age children with clinically impairing temper outbursts (TO; 5.0-9.9 years; N = 86), and examined the clinical relevance of resulting factors through associations with measures of psychopathology, and differences between children with TO and two groups without: children with ADHD (n = 60) and healthy controls (n = 45). Factor analyses established a three-factor model: High Anger, Low Anger, Distress. These factors had unique associations with measures of irritability, externalizing problems, and internalizing problems in the TO group. Additionally, an interaction between groups and outburst factors emerged. Results provide evidence for the presence and clinical utility of the anger-distress model in children's outbursts and suggest avenues for future pediatric irritability research.

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.

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.

Additional Evidence for Neuropsychiatric Manifestations in Mosaic Trisomy 20: A Case Report and Brief Review

Mosaic trisomy 20 is a genetic condition in which three chromosomes 20 are found in some cells. Its clinical phenotype seems to be highly variable, with most features not reported across all individuals and not considered pathognomonic of the condition. Limited and recent evidence indicates that neuropsychiatric manifestations may be more present in the context of trisomy 20 than was once thought. Here, we present a case of a 14-year-old female adolescent of White/Caucasian ethnicity with mosaic trisomy 20, who was admitted twice to an inpatient Child and Adolescent Neuropsychiatry Unit for persisting self-injury and suicidal ideation. A severe and complex neuropsychiatric presentation emerged at the cognitive, emotional, and behavioral levels, including mild neurodevelopmental issues, isolation, socio-relational difficulties, depressed mood, temper outbursts, irritability, low self-esteem, lack of interest, social anxiety, panic attacks, self-cutting, and low-average-range and heterogeneous intelligence quotient profile. Particularly, the patient was considered at high risk of causing harm, mainly to self, and appeared to be only partially responsive to medication, even when polypharmacy was attempted to improve clinical response. Except for school bullying, no other severe environmental risk factors were present in the patient’s history. The patient received a diagnosis of disruptive mood dysregulation disorder.

The association of phasic irritability (aggressive outbursts) and tonic irritability (irritable mood) to depression occurrences, symptoms, and subtypes

BACKGROUND

Research among adults has rarely differentiated between tonic irritability (i.e., irritable mood) and phasic irritability (i.e., aggressive outbursts) with respect to multiple dimensions of depression. The current study explored both tonic and phasic irritability in relation to depression severity, depression chronicity, age of depression onset, individual depressive symptom, and depression subtypes.

METHODS

The study included participants (N = 5692) from the National Comorbidity Survey - Replication (NCS-R) part two. The NCS-R used lay-administered, fully standardized diagnostic interviews. The current study implemented linear models, generalized linear models, Cox proportional hazard model, and latent class regression.

RESULTS

Both types of irritability were significantly associated with greater risk for MDD diagnosis, as well as risk for having at least one depressive symptom, early MDE onset, and MDE chronicity. Both phasic and tonic irritability were associated with greater odds of specific depressive symptoms and were differentially related to distinct depressive symptom constellations. Phasic irritability related only to severe depression. Lastly, both phasic and tonic irritability was associated with suicidal ideation, but only phasic irritability was associated with a suicide plan and attempt, above and beyond depression subtypes.

CONCLUSIONS

Both phasic and tonic irritability differentially related to almost all aspects of depression in adults. Specifically, tonic irritability showed overall stronger associations with various depressive features, whereas phasic irritability marked higher depressive severity.

Differential outcomes of tonic and phasic irritability in adolescent girls

BACKGROUND

Irritable mood is a transdiagnostic clinical feature that is present in multiple psychiatric disorders. Although irritability is frequently examined as a unitary construct, two dimensions of irritability, tonic (i.e., irritable mood) and phasic (i.e., temper outbursts), have been hypothesized. However, few studies have examined whether tonic and phasic irritability are empirically separable and predict different forms of psychopathology.

METHODS

We utilized data from a longitudinal study of a community sample of 550 girls (age 13.5-15.5 years) followed at 9-month intervals for 3 years. We conducted exploratory factor analysis (EFA) using items from three self-report inventories: the International Personality Item Pool Anger scale, Temperament and Affectivity Inventory Anger scale, and Buss-Perry Aggression Questionnaire Anger scale.

RESULTS

The EFA identified dimensions that were consistent with tonic and phasic irritability. Tonic irritability at baseline independently predicted the development of depressive disorders and generalized anxiety disorder (GAD) in subsequent waves. Phasic irritability independently predicted a decreased probability of GAD, but an increased probability of oppositional defiant, conduct, and substance use disorder, and greater risky sexual behavior and relational aggression during the follow-up.

CONCLUSIONS

Tonic and phasic irritability appear to be separable constructs with unique implications for later psychopathology and related behavior among adolescent girls. It is important to consider this distinction in research on the etiology and pathophysiology of irritability and developing effective treatments.

How and Why Are Irritability and Depression Linked?

Based on its course over time, irritability is linked to depression cross-sectionally and longitudinally. Cross-sectionally, irritability takes an episodic form as a symptom in pediatric depression; yet, irritability in the absence of depressed mood or anhedonia is rare. Longitudinally, chronic irritability has been shown to predict depression rather than bipolar disorder or externalizing disorders. Evidence suggests that the link between irritability and depression is explained mostly by shared genetic risk. Both conditions are also associated with higher rates of family history of depression, childhood temperaments and personality styles, and negative parenting styles. The treatment implications are discussed.

Irritability as a Transdiagnostic Vulnerability Trait:Current Issues and Future Directions

In recent years, irritability has received increasing attention among mental health professionals given its transdiagnostic associations with diverse forms of psychopathology. In contrast to other emotional states and traits, however, literature addressing associations between irritability and related temperament and personality constructs is limited. In addition, those who study irritability have diverse perspectives on its neurobiological substrates. In this comment, we situate irritability in the literatures on child temperament and adult personality, and describe a model in which irritability derives from low tonic dopamine (DA) levels and low phasic DA reactivity in subcortical neural structures implicated in appetitive responding. We note that different findings often emerge in neuroimaging studies when irritability is assessed in circumscribed diagnostic groups versus representative samples. We conclude with directions for future research, and propose that more authors use hierarchical Bayesian modeling, which captures functional dependencies between irritability and other dispositional traits (e.g., trait anxiety) that standard regression models are insensitive too. Treatment implications are also considered.