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.

The utility of the irritability scale in Huntington's disease patients with evidence of irritability or aggression.

INTRODUCTION: Irritability, a common neuropsychiatric symptom in Huntington's disease (HD), lacks a standardized measurement. The Irritability Scale (IS), tailored for HD, has patient and informant versions, but variable interrater agreement has been reported frequently in previous studies. To enhance the clinical utility of the IS, this study aimed to identify the most reliable components estimating the underlying construct and develop a shortened version for time-limited contexts. METHODS: Participant and informant/observer concordance and the relationship of individual items to the complete IS scale were assessed. The short-form (SF) items were selected based on interrater agreement, exploratory factor analysis (EFA), and Item Response Theory (IRT) analysis results. Pair-wise correlation and covariance models were used to examine how SF predicted total IS score in 106 participants from the STAIR (Safety, Tolerability, and Activity of SRX246 in Irritable Subjects with Huntington's Disease) trial. Item Response Theory (IRT) analysis was used to evaluate the range and function of the selected items. RESULTS: IS interrater agreement was statistically significant (r = 0.33, p = .001). In combination with EFA factors and IRT analyses, five items were identified that showed good reliability and performance in differentiating levels of irritability. CONCLUSION: The proposed 5-item SF IS provided a reliable measure of the full scale and may be less burdensome for use in a clinical setting.

How are irritability and anhedonia symptoms linked? A network approach.

BACKGROUND: Anhedonia and irritability are two prevalent symptoms of major depressive disorder (MDD) that predict greater depression severity and poor outcomes, including suicidality. Although both symptoms have been proposed to result from paradoxical reward processing dysfunctions, the interactions between these symptoms remain unclear. Anhedonia is a multifaceted symptom reflecting impairments in multiple dimensions of reward processing (e.g., pleasure, desire, motivation, and effort) across distinct reward types (e.g., food, sensory experiences, social activities, hobbies) that may differentially interact with irritability. This study investigated the complex associations between anhedonia and irritability using network analysis. METHOD: Participants (N = 448, Mage = 33.29, SD = 14.58) reported their symptoms of irritability on the Brief Irritability Test (Holtzman et al., 2015) and anhedonia (i.e., pleasure, desire, motivation, and effort dimensions across four reward types) on the Dimensional Anhedonia Rating Scale (Rizvi et al., 2015). A regularized Gaussian Graphical Model was built to estimate the network structure between items. RESULTS: Irritability was negatively related to willingness to expand effort to obtain food/drinks (estimate = -0.18), social activities (-0.13), and hobbies (-0.12) rewards. Irritability was positively associated with a desire for food/drinks (0.12). LIMITATIONS: Only a small proportion (5.8%) of our sample was clinical and the study design was cross-sectional. CONCLUSION: A specific link between irritability and the effort dimension of the hedonic response across three reward types was identified. Investigating effort expenditure deficits with experimental paradigms may help us understand the mechanisms underlying the comorbidity between irritability and anhedonia in the context of MDD.

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.

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.

Neural Responses to Intranasal Oxytocin in Youths With Severe Irritability.

OBJECTIVE: The authors investigated the neural impact of intranasal oxytocin on emotion processing areas in youths with severe irritability in the context of disruptive mood and behavior disorders. METHODS: Fifty-two participants with severe irritability, as measured by a score ≥4 on the Affective Reactivity Index (ARI), with diagnoses of disruptive behavior disorders (DBDs) and/or disruptive mood dysregulation disorder (DMDD) were randomly assigned to treatment with intranasal oxytocin or placebo daily for 3 weeks. Assessments were conducted at baseline and at the end of the trial; the primary outcomes were measures of irritability on the ARI and ratings on the Clinical Global Impressions severity scale (CGI-S) focusing on DBD and DMDD symptoms, and secondary outcomes included the CGI improvement scale (CGI-I) and ratings of proactive and reactive aggressive behavior on the Reactive-Proactive Aggression Questionnaire. Forty-three participants (22 in the oxytocin group and 21 in the placebo group) completed pre- and posttreatment functional MRI (fMRI) scans with the affective Stroop task. RESULTS: Youths who received oxytocin showed significant improvement in CGI-S and CGI-I ratings compared with those who received placebo. In the fMRI data, blood-oxygen-level-dependent (BOLD) responses to emotional stimuli in the dorsomedial prefrontal cortex and posterior cingulate cortex were significantly reduced after oxytocin compared with placebo. These BOLD response changes were correlated with improvement in clinical severity. CONCLUSIONS: This study provides initial and preliminary evidence that intranasal oxytocin may induce neural-level changes in emotion processing in youths with irritability in the context of DBDs and DMDD. This may lead to symptom and severity changes in irritability.

Novel Assessment of the Impact of Irritability on Physiological and Psychological Frustration Responses in Adolescents.

OBJECTIVE: Irritability, typically defined as a proneness to anger, particularly in response to frustration, falls at the intersection of emotion and disruptive behavior. Despite well-defined translational models, there are few convergent findings regarding the pathophysiology of irritability. Most studies utilize computer-based tasks to examine neural responses to frustration, with little work examining stress-related responding to frustration in social contexts. The present study is the first to utilize the novel Frustration Social Stressor for Adolescents (FSS-A) to examine associations between adolescent irritability and psychological and physiological responses to frustration. METHOD: The FSS-A was completed by a predominantly male, racially, ethnically, and socioeconomically diverse sample of 64 12- to 17-year-olds, who were originally recruited as children with varying levels of irritability. Current irritability was assessed using the Multidimensional Assessment Profiles-Temper Loss scale (MAP-TL-Youth). Adolescents rated state anger and anxiety before and after the FSS-A, and usable salivary cortisol data were collected from 43 participants. RESULTS: Higher MAP-TL-Youth scores were associated with greater increases in anger during the FSS-A, but not increases in anxiety, or alterations in cortisol. Pre-task state anger negatively predicted the slope of the rise in cortisol observed in anticipation of the FSS-A. CONCLUSIONS: Results provide support for unique associations between adolescent irritability and anger during, and in anticipation of, frustrating social interactions. Such findings lay a foundation for future work aimed at informing physiological models and intervention targets.

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.

Phasic Versus Tonic Irritability and Associations with Family Accommodation Among Youth with Selective Mutism: A Latent Profile Analysis.

Clinical presentations of selective mutism (SM) vary widely across affected youth. Although studies have explored general externalizing problems in youth with SM, research has not specifically examined patterns of irritability. Relatedly, research has not considered how affected families differentially accommodate the anxiety of youth with SM as a function of the child's temper outbursts (i.e., phasic irritability) and general angry mood (i.e., tonic irritability). Data were drawn from a sample of treatment-seeking children and adolescents with a primary diagnosis of selective mutism (N = 152; Mean age = 6.12 years; 67.11% female), and their caregivers. Latent profile analysis (LPA) was used to identify distinct profiles in SM youth that were characterized by varying levels of phasic and/or tonic irritability. Analyses further examined whether these different profiles were associated with different levels of family accommodation and global impairment. LPA identified 5 profiles: SM with No irritability, SM with Low Phasic Irritability, SM with High Phasic Irritability, SM with High Phasic and Moderate Tonic Irritability, and SM with High Phasic and High Tonic Irritability. Patterns of family accommodation and global impairment were highest among youth belonging to profiles characterized by high phasic irritability. Findings highlight separable patterns of irritability across youth with SM, with phasic irritability (i.e., temper outbursts) appearing particularly linked with increased family accommodation and overall global impairment. Assessing phasic irritability is critical for optimizing treatment in youth with SM and can be useful for flagging possible patterns of family accommodation contributing to overall impairment.

Executive function in children with disruptive mood dysregulation disorder compared to attention-deficit/hyperactivity disorder and oppositional defiant disorder, and in children with different irritability levels.

Addressing current challenges in research on disruptive mood dysregulation disorder (DMDD), this study aims to compare executive function in children with DMDD, children with attention-deficit/hyperactivity disorder (ADHD), and children with oppositional defiant disorder (ODD). We also explore associations between irritability, a key DMDD characteristic, and executive function in a clinical sample regardless of diagnosis. Our sample include children (6-12 years) referred to child psychiatric clinics. Measures of daily-life (parent-reported questionnaire) and performance-based (neuropsychological tasks) executive function were applied. Identifying diagnoses, clinicians administered a standardized semi-structured diagnostic interview with parents. Irritability was assessed by parent-report. First, we compared executive function in DMDD (without ADHD/ODD), ADHD (without DMDD/ODD), ODD (without DMDD/ADHD) and DMDD + ADHD (without ODD). Second, we analyzed associations between executive function and irritability using the total sample. In daily life, children with DMDD showed clinically elevated and significantly worse emotion control scores compared to children with ADHD, and clinically elevated scores on cognitive flexibility compared to norm scores. Children with DMDD had significantly less working memory problems than those with ADHD. No differences were found between DMDD and ODD. Increased irritability was positively associated with emotional dyscontrol and cognitive inflexibility. For performance-based executive function, no diagnostic differences or associations with irritability were observed. We discuss how, in daily life, children with high irritability-levels get overwhelmed by feelings without accompanying regulatory capacities.

Neuropsychological mechanisms of social difficulties in disruptive mood dysregulation disorder versus oppositional defiant disorder.

Children with Disruptive Mood Dysregulation Disorder (DMDD) or Oppositional Defiant Disorder (ODD) are characterized by irritability and social difficulties. However, the mechanisms underlying these disorders could be different. This study explores differences in social cognition and executive function (EF) across DMDD and ODD and the influence of these factors and their interaction on social problems in both groups. Children with DMDD (n = 53, Mage = 9.3) or ODD (n = 39, Mage = 9.6) completed neuropsychological tasks measuring social cognition (Theory of Mind and Face-Emotion Recognition) and EF (cognitive flexibility, inhibition, and working memory). Parents reported social problems. More than one-third of the children with DMDD and almost two-thirds of those with ODD showed clear difficulties with Theory of Mind. Most children with DMDD (51-64%) or ODD (67-83%) showed difficulties with EF. In children with DMDD, worse EF (ß = -.36) was associated with more social problems, whereas in children with ODD, better EF (ß = .44) was associated with more social problems. In those with ODD, but not in those with DMDD, the interaction between social cognition and EF contributed to the explained variance of social problems (ß = -1.97). Based on the observed interaction pattern, enhanced EF may lead to increased social problems among children with ODD who also exhibit social cognition difficulties. This study suggests the existence of distinct neuropsychological mechanisms underlying the social issues observed in children with DMDD versus those with ODD.

Irritability as a Transdiagnostic Risk Factor for Functional Impairment in Autistic and Non-autistic Toddlers and Preschoolers.

Trait irritability in toddlerhood is a powerful risk factor for later internalizing and externalizing challenges in non-autistic children, but the predictive clinical utility of irritability is unknown in autism. Irritability is a trait-level emotional response (i.e., frustration) to a blocked goal and is one source of disruptive behavior. Irritability has two facets: Frustration is the degree to which emotion is elevated after a blocked goal, while soothability is the rate of recovery from peak distress. We aimed to: (1) compare and describe the two facets of irritability in non-autistic and young autistic children, and (2) assess whether children's reward sensitivity and executive function moderate the relation between irritability and clinical symptoms. Participants were 90 autistic (n=43) and non-autistic (n = 47) 2- and 4-year-olds. Autistic children did not have different levels of frustration but were more difficult to soothe compared to non-autistic children, according to parents. Further, frustration and soothability were less strongly correlated for autistic compared to non-autistic children. For all children, executive function (specifically, inhibition) moderated, or ameliorated the strength of, the relation between irritability (both soothability and frustration) and externalizing challenges. This study provides evidence for irritability as a transdiagnostic risk factor for clinically significant emotion regulation challenges. Further, the effect of trait irritability may be ameliorated by children's executive function in a transdiagnostic manner. Future work should examine the unique aspects of soothability to how irritability presents within autism, as well as evaluate and modify emotion regulation interventions for autistic toddlers and preschoolers.

Emotion regulation as central to psychopathology across childhood and adolescence: a commentary on Nobakht et al. (2023).

An important goal of clinical/developmental research is to identify factors contributing to the onset and maintenance of psychopathology - particularly factors that could be modified through intervention. Large-scale, multi-informant, longitudinal studies provide valuable opportunities for testing such etiological hypotheses, as illustrated by Nobakht et al.'s recent six-wave cohort study spanning ages 4-14. At a within-person level, emotion regulation (ER) deficits consistently predicted oppositional defiant disorder (ODD) symptoms (including both irritability and defiance), whereas victimization did not. These results comport with growing evidence highlighting ER's centrality to ODD and psychopathology more broadly. While the ER findings carry promising implications, caution is warranted in interpreting the results for victimization given that its association with psychopathology is well-documented. More research is needed to test precise questions about within- and between-person processes involving ER, victimization, and psychopathology across development. Pressing research questions include whether, how, and when youths' ER can be modified, and with what effects on clinical outcomes.

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

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

A network approach to the investigation of childhood irritability: probing frustration using social stimuli.

BACKGROUND: Self-regulation in early childhood develops within a social context. Variations in such development can be attributed to inter-individual behavioral differences, which can be captured both as facets of temperament and across a normal:abnormal dimensional spectrum. With increasing emphasis on irritability as a robust early-life transdiagnostic indicator of broad psychopathological risk, linkage to neural mechanisms is imperative. Currently, there is inconsistency in the identification of neural circuits that underlie irritability in children, especially in social contexts. This study aimed to address this gap by utilizing a functional magnetic resonance imaging (fMRI) paradigm to investigate pediatric anger/frustration using social stimuli. METHODS: Seventy-three children (M = 6 years, SD = 0.565) were recruited from a larger longitudinal study on irritability development. Caregivers completed questionnaires assessing irritable temperament and clinical symptoms of irritability. Children participated in a frustration task during fMRI scanning that was designed to induce frustration through loss of a desired prize to an animated character. Data were analyzed using both general linear modeling (GLM) and independent components analysis (ICA) and examined from the temperament and clinical perspectives. RESULTS: ICA results uncovered an overarching network structure above and beyond what was revealed by traditional GLM analyses. Results showed that greater temperamental irritability was associated with significantly diminished spatial extent of activation and low-frequency power in a network comprised of the posterior superior temporal sulcus (pSTS) and the precuneus (p < .05, FDR-corrected). However, greater severity along the spectrum of clinical expression of irritability was associated with significantly increased extent and intensity of spatial activation as well as low- and high-frequency neural signal power in the right caudate (p < .05, FDR-corrected). CONCLUSIONS: Our findings point to specific neural circuitry underlying pediatric irritability in the context of frustration using social stimuli. Results suggest that a deliberate focus on the construction of network-based neurodevelopmental profiles and social interaction along the normal:abnormal irritability spectrum is warranted to further identify comprehensive transdiagnostic substrates of the irritability.

Biopsychosocial contributors to irritability in individuals with shoulder or low back pain.

OBJECTIVES: Irritability is a foundational clinical reasoning concept in rehabilitation to evaluate reactivity of the examination and treatment. While originally theorized to reflect tissue damage, a large body of evidence supports pain is a biopsychosocial experience impacted by pain sensitivity and psychological factors. Therefore, the purpose of this study was to examine biopsychosocial contributors to irritability. METHODS: 40 patients with shoulder (n = 20) and low back (n = 20) pain underwent Quantitative Sensory Testing (QST) (Pressure Pain Threshold, Heat Pain Threshold, Conditioned Pain Modulation, Temporal Summation), completed pain-related psychological questionnaires, an Exercise-Induced Hypoalgesia protocol, and standardized irritability assessment based on Clinical Practice Guidelines. Participants were then categorized as irritable or not irritable based on Maitland's criteria and by irritability level based on Clinical Practice Guidelines. An independent samples t-test examined for differences in QST and psychological factors by irritability category. A MANOVA examined for differences in QST and psychological factors by irritability level (high, moderate, low). RESULTS: Significantly lower heat and pressure pain thresholds at multiple locations (p < 0.05), as well as less efficient conditioned pain modulation (p = 0.02), were demonstrated in individuals categorized as irritable. Heat and pressure pain thresholds were also significantly lower in patients with high irritability compared to other levels. Significantly higher depression and anger, as well as lower self-efficacy, were reported in individuals with an irritable presentation. DISCUSSION/CONCLUSION: Biopsychosocial factors, including widespread hyperalgesia and elevated psychological factors, may contribute to an irritable presentation.

A cross-sectional analysis of the relationships between anxiety sensitivity and youth irritability: the mediated roles of insomnia and selective attention for threat.

BACKGROUND: Irritability is common in multiple psychiatric disorders and is hallmark of disruptive mood dysregulation disorder. Child irritability is associated with higher risk of suicide and adulthood mental health problems. However, the psychological mechanisms of irritability are understudied. This study examined the relationship between anxiety sensitivity and irritability among youth, and further explored three possible mediated factors: selective attention for threat, delayed reward discounting, and insomnia. METHODS: Participants were 1417 students (51.7% male; mean age 13.83 years, SD = 1.48) recruited from one high school in Hunan province, China. Self-report questionnaires were used to measure irritability (The Affective Reactivity Index and The Brief Irritability Test), anxiety sensitivity (The Childhood Anxiety Sensitivity Index), selective attention for threat (The Davos Assessment of Cognitive Biases Scale-attention for threat bias subscale), insomnia (The Youth Self-Rating Insomnia Scale), and delayed reward discounting (The 27-item Monetary Choice Questionnaire). Structural equation modal (SEM) was performed to examine mediated relations. RESULTS: Anxiety sensitivity was modestly related to irritability and insomnia (r from 0.25 to 0.54) and slightly correlated with selective attention for threat (r from 0.12 to 0.28). However, there is no significant relationship of delayed rewards discounting with anxiety sensitivity and irritability. The results of SEM showed that selective attention for threat (indirect effect estimate = 0.04) and insomnia (indirect effect estimate = 0.20) partially mediate the relationship between anxiety sensitivity and irritability, which explained 34% variation. CONCLUSIONS: Anxiety sensitivity is an important susceptibility factor for irritability. Selective attention for threat and insomnia are two mediated mechanisms to understand the relationship between anxiety sensitivity and irritability.

Characteristic Similarities of Irritability Between Autism and Disruptive Mood Dysregulation Disorder.

Objective: Irritability in children with autism spectrum disorder (ASD) is prominent and often leads to distress to both autistic children and their families. However, the nature of irritability in autism and the difference from nonautistic children have rarely been examined. This study aimed to investigate the clinical characteristics of irritability in autism, and to compare the symptom profiles with those of disruptive mood dysregulation disorder (DMDD) in nonautistic children. Methods: Fifty-six children aged 7-17 years (mean age 10.36 ± 3.05) were recruited into this study (21 with DMDD, 21 with high-functioning autism [hfASD], and 14 healthy volunteers [HV]). Their parents completed the Aberrant Behavior Checklist-Irritability (ABC-I) subscale and the Strengths and Difficulties Questionnaire (SDQ) parent report form. The ABC-I subscale was analyzed as a whole and broken into subsets (ABC-I-Irritability, ABC-I-Agitation, and ABC-I-Crying). The symptom profiles of irritability and the association with psychosocial difficulties were compared between groups. Results: The ABC-I-Irritability scores of children with hfASD closely matched to those of children with DMDD. In addition, both DMDD and hfASD groups could be differentiated from HV group in five of the six items except "depressed mood." However, in the ABC-I-Agitation scale, children with DMDD, but not hfASD, had higher scores in "Aggressive to other patients and staff" and "Stamps feet while banging objects or slamming doors" than HV. Regarding psychosocial outcomes, irritability in children with DMDD and hfASD were associated with emotional problems as measured by the SDQ. Moreover, irritability in DMDD was associated with conduct problems, and the hfASD group exhibited the similar trend. Conclusions: Symptom profiles of irritability and the associated emotional and conduct problems in children with hfASD were similar to those of DMDD in the nonautistic population. Future studies are warranted to explore the underlying neurophysiological mechanisms of irritability between autistic and nonautistic children for further insight into the nature of irritability in autism.

Characterizing the spectrum of irritability in preadolescence: Dimensional and pragmatic applications.

OBJECTIVES: Characterize the dimensional spectrum of preadolescent (PA) irritability, a robust transdiagnostic vulnerability marker, using the youth version of the Multidimensional Assessment Profiles Temper Loss (MAPS-TL-Youth) scale including common and with developmentally specific items. Based on this, derive and validate a clinically optimized irritability screener to flag psychopathology risk in preadolescents. METHODS: The normal:abnormal irritability spectrum was modeled using MAPS-TL-Youth data from the Multidimensional Assessment of Preschoolers Study (MAPS) Study PA wave (n = 340) via item response theory. Both cross-cutting core items from the MAPS scales and developmentally specific items were used to generate this dimension. Stepwise logistic regression was then used to optimize MAPS-TL-Youth irritability items in relation to Kiddie Schedule of Affective Disorders and Schizophrenia impairment to generate a clinically optimized irritability screener. Receiver operator characteristic analysis identified the irritability threshold for the screener. For the first time, youth self-report of their own irritability on the MAPS-TL was also modeled via the MAPS-TL-Youth-Self-Report (MAPS-TL-Youth-SR). RESULTS: Irritability was unidimensional and ranged from mild and common to severe and rare behaviors. Developmentally specific items allowed detection of more severe irritability. Items for the screener were identified in relation to concurrent impairment. These included low frustration tolerance and pathognomonic severe behaviors. The clinically optimized screener demonstrated very good sensitively (87%) and specificity (81%) in regard to concurrent irritability-related DSM disorders. Modeling of the MAPS-TL-Youth-SR yielded similar results. CONCLUSION: Characterizing the normal: abnormal spectrum of irritability in preadolescence advances application of Research Domain Criteria methods to this developmental period. This foundational work yielded two developmentally specified tools for irritability characterization in preadolescence: a nuanced dimensional scale to precisely characterize the full normal-abnormal irritability spectrum, and a pragmatic, clinically optimized screener suitable for real world use. Future application in mechanistic and clinical studies will be important for establishing validity and incremental utility.

Developmentally specified characterization of the irritability spectrum at early school age: Implications for pragmatic mental health screening.

OBJECTIVES: Developmentally specified measures that identify clinically salient irritability are needed for early school-age youth to meaningfully capture this transdiagnostic risk factor for psychopathology. Thus, the current study modeled the normal:abnormal irritability spectrum and generated a clinically optimized screening tool for this population. METHODS: The irritability spectrum was modeled via the youth version of the Multidimensional Assessment Profile Scales-Temper Loss Scale (MAPS-TL-Youth) in children (n = 474; 6.0-8.9 years) using item response theory (IRT). Both cross-cutting core irritability items from the early childhood version and new developmentally specific items were included. Items uniquely associated with impairment were identified and used to derive a brief, clinically optimized irritability screener. Longitudinal data were then utilized to test the predictive utility of this clinically optimized screener in preadolescence (n = 348; 8.0-12.9 years). RESULTS: Most children exhibit irritability regularly, but daily occurrence was rare. Of the top 10 most severe items from the IRT analyses, 9 were from the developmentally specific items added for the MAPS-TL Youth version. Two items associated with concurrent impairment were identified for the clinically optimized irritability screener ("Become frustrated easily" and "Act irritable"). The MAPS-TL-Youth clinically optimized screener demonstrated good sensitivity (69%) and specificity (84%) in relation to concurrent DSM 5 irritability-related diagnoses. Youth with elevated scores on the screener at early school age (ESA) had more than 7x greater odds of irritability-related psychopathology at pre-adolescence. CONCLUSIONS: The MAPS-TL-Youth characterized the developmental spectrum of irritability at ESA and a clinically optimized screener showed promise at predicting psychopathology risk. Rigorous testing of clinical applications is a critical next step.