Irritability in Youths: A Critical Integrative Review

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.

Annual Research Review: Micronutrients and their role in the treatment of paediatric mental illness

The aim of this narrative review is to summarize evidence relating the importance of nutrient intake from diet and supplementation for paediatric mental health. We begin by reviewing several mechanisms by which nutrients maximize brain health, including enabling metabolic reactions to occur, supporting mitochondrial function, reducing inflammation and assisting with detoxification. Circumstances that may contribute to an individual requiring additional nutrients beyond what are available in the diet, such as consumption of nutritionally depleted food, individual differences in biological need, long-term medication use and gut-brain health needs are then reviewed. These factors underpin the importance of tackling deficiencies relative to individual metabolic requirements with a broad spectrum of micronutrients, as opposed to a single nutrient approach, to address personal metabolic needs and/or environmentally induced nutrient depletions. The evidence for treating psychological symptoms with supplementary micronutrients is presented, summarizing research using broad-spectrum micronutrients in the treatment of mental health issues including aggression, autism spectrum disorder, attention-deficit/hyperactivity disorder and emotional dysregulation, often with medium between-group effect sizes compared with placebo, with clinically meaningful changes. The breadth and consistency of the findings highlight the importance of receiving a complete foundation of nutrients to optimize brain health; however, the small number of studies identifies the importance of future work to replicate these preliminary findings. Documented safety in 8-week randomized controlled trials with open-label extensions up to 16 weeks and longer-term follow-up for 1.5-5 years in smaller samples provide reassurance that this treatment approach does not result in serious adverse events. We provide recommendations for future research including consistency in micronutrient interventions, scalable delivery models, effectiveness and implementation studies and the need to investigate these interventions in the prevention and management of less-studied childhood psychiatric conditions.

On the regulation and dysregulation of emotions in child psychopathology: commentary on Blader et al. (2025)

Blader et al.'s (2025) recent annual review article makes an important contribution to the literature on emotion dysregulation in child and adolescent mental health. In addition to synthesizing the current evidence base, the authors put forth a cogent formalized view of emotion regulatory processes and how they go awry. Much has been written on emotion (dys)regulation and psychopathology (for overviews, see Lincoln et al., 2022; Paulus et al., 2021; Sheppes et al., 2015). It would therefore be reasonable to ask what novel contribution could be made by a new review article at this time. But for all that has been written, there is much work still to be done. Blader et al. (2025) admirably rise to meet this challenge. We hope this commentary amplifies and adds to their effort. Below, we reflect on a few aspects of their contribution and offer some further thoughts that may inform future work in this area.

Irritability as a Transdiagnostic Construct Across Childhood and Adolescence: A Systematic Review and Meta-analysis

This meta-analytic review examined irritability across childhood and adolescence as it relates to symptoms of common mental health disorders in these periods. Of key interest was whether the relationship between irritability and symptom severity varies according to symptom domain. This was tested at the level of broad symptom dimensions (internalizing versus externalizing problems) as well as discrete diagnostic domains (e.g., anxiety, depression, oppositional defiant disorder, conduct disorder, attention deficit hyperactivity disorder; autism spectrum disorder). Following PRISMA guidelines, a systematic search of five databases was conducted to identify studies reporting on associations between irritability and mental health symptoms in samples of children aged 2-18 years. Meta-analytic tests based on random effects models examined concurrent and longitudinal associations between irritability and symptom severity. Meta-regression tested potential moderators including symptom domain, child age, sex, informant type, and study quality. 119 studies met inclusion criteria with a total of 122,456 participants. A significant and positive association was found between irritability and severity of concurrent overall psychopathology in the order of a moderate effect size, while small to moderate effect sizes characterized the association between irritability and later mental health outcomes in prospective data. Further variation in this association was seen across specific diagnostic domains and methodological moderators. Findings support the conceptualization of irritability as a transdiagnostic construct reflecting emotion dysregulation across diverse forms of psychopathology in childhood and adolescence. Further research into the risk mechanisms underlying irritability is needed, in addition to translational approaches to early intervention.

Research Agenda in Childhood Impairing Emotional Outbursts: A Report of the AACAP Presidential Taskforce on Emotional Dysregulation

Objective

As part of the 2019-2021 presidential term of the American Academy of Child and Adolescent Psychiatry (AACAP), the AACAP Presidential Initiative on Emotion Dysregulation in Youth Taskforce was established. The aim was to address emotion dysregulation in children and adolescents, focusing on developing methods for clinicians to identify, characterize, and treat impairing emotional outbursts along with development of a research agenda that would guide relevant researchers and research funders. One method to characterize emotion dysregulation was accomplished by recommendations for use of a diagnostic code that is available in the DSM. The research agenda is presented here.

Method

The Taskforce specifically focused on aggressive behaviors and emotions associated with outbursts. The development of a research agenda took place over 2 years of examination of the current needs in the literature, with contributions from experts in the field. This work dovetailed with the efforts from the Congress on Pediatric Irritability and Dysregulation, which had been meeting since 2015 to advance research into the measurement, pathophysiology, and treatment of emotion regulation problems in youth. We concentrated on the central questions concerning the measurement of outbursts, key questions linking outbursts to other psychopathologies, and how behavior in outbursts is separable from typical behavior.

Results

A description of the qualitative data gathering process is provided here, along with the following: recommendations in the research areas of measurement; pathophysiology; delineating outbursts from other psychopathologies; exploring the cultural, social, and interpersonal aspects of outbursts; understanding the prevention and treatment of outbursts; and exploring how outbursts manifest and are treated based on setting. Specific examples of research opportunities and future directions are provided.

Conclusion

A call is made to funding agencies to examine the spaces within their strategic plans that will allow for engagement in critical efforts to improve the lives of children and adolescents with severe emotional outbursts-some of the most impaired individuals presenting for care in child and adolescent psychiatry.

Irritability in Children with Rasopathies, Insights into Emotional Dysregulation and Social Skills Impairments

Rasopathies, including Noonan Syndrome (NS) and Neurofibromatosis type 1 (NF1), are developmental disorders caused by germline mutations in genes of the RAS/mitogen-activated protein kinase pathway (RAS-MAPK). This study investigates irritability, a highly prevalent transdiagnostic construct, in children with Rasopathies and the impact of Rasopathy status on the associations between irritability, emotional dysregulation-related disorders, and social skills impairments. The sample comprise 174 children aged 4-17 (age mean = 9.49; 98 females), including 113 children with Rasopathies (NS n = 85, NF1 n = 28) and 61 age-sex-matched typically developed (TD) children. We used parent questionnaires (CBCL, SRS) to assess irritability, symptoms of ADHD, defiance, anxiety/depression, and social skills impairments while controlling for cognitive measures (IQ). Children with Rasopathies exhibited higher irritability than TD children (mean difference = 1.09; p < 0.001). Children with NS showed a weaker association between irritability and ADHD symptoms compared to TD children (p = .032, ηp 2 = .03) and a stronger association between irritability and social skills impairments compared to both TD (p = .033, ηp 2 = .03), and NF1 groups (p = .009, ηp 2 = .06). We present novel and clinically significant findings showing high irritability in children with Rasopathies. Our study provides syndrome-specific results, suggesting differences in the mechanisms involved in irritability, ADHD, and social processes in children with NS and NF1. In essence, children with Rasopathies showed a highly irritable profile associated with ADHD symptoms and social skills impairments, with a significantly stronger association between irritability and social processes in NS. Our results suggest that developing prevention and treatments targeting irritability can distinctly affect the trajectories of neurodevelopmental disorders in children with Rasopathies.

Concurrent and longitudinal neurostructural correlates of irritability in children

Irritability, or an increased proneness to frustration and anger, is common in youth; however, few studies have examined neurostructural correlates of irritability in children. The purpose of the current study was to examine concurrent and longitudinal associations between brain structure and irritability in a large sample of 9-10-year-old children. Participants included 10,647 children from the Adolescent Brain Cognitive Developmentsm Study (ABCD Study®). We related a latent irritability factor to gray matter volume, cortical thickness, and surface area in 68 cortical regions and to gray matter volume in 19 subcortical regions using structural equation modeling. Multiple comparisons were adjusted for using the false discovery rate (FDR). After controlling for age, sex, race/ethnicity, scanner model, parent's highest level of education, medication use, and total intracranial volume, irritability was associated with smaller volumes in primarily temporal and parietal regions at baseline. Longitudinal analyses showed that baseline gray matter volume did not predict irritability symptoms at the 3rd-year follow-up. No significant associations were found for cortical thickness or surface area. The current study demonstrates inverse associations between irritability and volume in regions implicated in emotional processing/social cognition, attention allocation, and movement/perception. We advance prior research by demonstrating that neurostructural differences associated with irritability are already apparent by age 9-10 years, extending this work to children and supporting theories positing socioemotional deficits as a key feature of irritability.

Prevalence and correlates of irritability among U.S. adults

This study aimed to characterize the prevalence of irritability among U.S. adults, and the extent to which it co-occurs with major depressive and anxious symptoms. A non-probability internet survey of individuals 18 and older in 50 U.S. states and the District of Columbia was conducted between November 2, 2023, and January 8, 2024. Regression models with survey weighting were used to examine associations between the Brief Irritability Test (BITe5) and sociodemographic and clinical features. The survey cohort included 42,739 individuals, mean age 46.0 (SD 17.0) years; 25,001 (58.5%) identified as women, 17,281 (40.4%) as men, and 457 (1.1%) as nonbinary. A total of 1218(2.8%) identified as Asian American, 5971 (14.0%) as Black, 5348 (12.5%) as Hispanic, 1775 (4.2%) as another race, and 28,427 (66.5%) as white. Mean irritability score was 13.6 (SD 5.6) on a scale from 5 to 30. In linear regression models, irritability was greater among respondents who were female, younger, had lower levels of education, and lower household income. Greater irritability was associated with likelihood of thoughts of suicide in logistic regression models adjusted for sociodemographic features (OR 1.23, 95% CI 1.22-1.24). Among 1979 individuals without thoughts of suicide on the initial survey assessed for such thoughts on a subsequent survey, greater irritability was also associated with greater likelihood of thoughts of suicide being present (adjusted OR 1.17, 95% CI 1.12-1.23). The prevalence of irritability and its association with thoughts of suicide suggests the need to better understand its implications among adults outside of acute mood episodes.

Considering heterogeneity within negative emotionality can inform the distinction between diathesis-stress and differential susceptibility: Children's early anger and fear as moderators of effects of parental socialization on antisocial conduct

The importance of interactions between child temperament and parenting has been accepted ever since Thomas and Chess (1977) proposed their "goodness-of-fit" construct, but over the last three decades, pertinent research has grown exponentially. Researchers examining child characteristics that can moderate the effects of socialization have tested increasingly complex, nuanced, and sophisticated models, largely inspired by the highly influential frameworks of child plasticity or differential susceptibility (Belsky & Pluess, 2009). Yet, multiple questions remain unsettled. We addressed four such questions as applied to predicting children's observed disregard for rules at age 4.5 in a study of 200 community families from the US Midwest. (a) We examined children's observed negative emotionality at 16 months, most commonly seen as a plasticity "trait," but separating anger and fear proneness, which may differently moderate effects of socialization. (b) We examined two separate aspects of observed parental socialization at age 3, mutually responsive orientation and power assertion. (c) We distinguished analytically diathesis-stress from differential susceptibility. (d) We examined all effects in mother- and father-child relationships. We supported both diathesis-stress and differential susceptibility, depending on the facet of negative emotionality, the aspect of socialization considered, and parental gender, highlighting the nuanced nature of the processes involved.

Commentary: Who gets the credit for "discovering" ADHD and what is the question, really?

Recognition of hyperactivity, impulsivity, distractibility, and emotional lability as a clinical syndrome is at the heart of identifying whether there is a discoverer of the condition of attention deficit hyperactivity disorder (ADHD). Just as clinics of children diagnosed with ADHD do not capture a homogeneous group of boys and girls, however, history does not either. What different observers/clinicians have chosen to highlight reflects what is important to them and to the times in which they lived. The child/children described by Heinrich Hoffman (of Fidgety Phil fame) and George Still (who highlighted impulsive aggression as a moral defect), for instance, did not come with a list of criteria (with which even now we cannot always agree) to prove unequivocally that they had ADHD. Who cares! It is sufficient that they recognized the importance of certain co-occurring behaviors and shared their observations with us such that we can conclude our clinic's children were recognized by good past observers. ADHD-like children, like the poor, have probably always been with us.

Understanding irritability through the lens of self-regulatory control processes in children and adolescents: a systematic review

Among youths, pathological irritability is highly prevalent and severely disabling. As a frequent symptom, it often leads to referrals to child and adolescent mental health services. Self-regulatory control (SRC) processes are a set of socio-psycho-physiological processes that allow individuals to adapt to their ever-changing environments. This conceptual framework may enhance the current understanding of the cognitive, emotional, behavioural and social dysregulations underlying irritability. The present systematic review (PROSPERO registration: #CRD42022370390) aims to synthesize existing studies that examine irritability through the lens of SRC processes among youths (< 18 years of age). We conducted a comprehensive literature search among six bibliographic databases: Embase.com, Medline ALL Ovid, APA PsycInfo Ovid, Web of Science Core Collection, the Cochrane Database of Systematic Reviews Wiley and ProQuest Dissertations & Theses A&I. Additional searches were performed using citation tracing strategies. The retrieved reports totalled 2612, of which we included 82 (i.e., articles) from 74 studies. More than 85% of reports were published during the last 6 years, highlighting the topicality of this work. The studies sampled n = 26,764 participants (n = 12,384 girls and n = 12,905 boys, n = 1475 no information) with an average age of 8.08 years (SD = 5.26). The included reports suggest that irritability has an association with lower effortful control, lower cognitive control and delay intolerance. Further, evidence indicates both cross-sectional and longitudinal associations between irritability and a lack of regulation skills for positive and negative emotions, particularly anger. Physiological regulation seems to moderate the association between irritability and psychopathology. Finally, the mutual influence between a child's irritability and parenting practice has been established in several studies. This review uses the lens of SRC to illustrate the current understanding of irritability in psychopathology, discusses important gaps in the literature, and highlights new avenues for further research.

Examining the influence of episode number and age of onset on individual depressive symptoms across episodes of major depression

Major depression is characterized by an episodic course with symptom manifestations differing across episodes. Previous work has found that symptom presentation differs across age. However, studies of symptom presentation have largely focused on symptoms in individual episodes, requiring further investigation of longitudinal symptom change. This study explored the impact of the initial age of onset, the number of episodes, and age of onset of each episode on individual depressive symptoms, while accounting for episode severity. We used data from the Oregon Adolescent Depression Project (N = 629) examining participants with at least one major depressive episode, assessed by diagnostic interview, across a 15-year follow-up. Multilevel logistic regression models revealed that approximately 20-25% of the main effects were significant and some were qualified by cross-level interactions. However, only a few associations remained robust after correcting for multiple comparisons. Specifically, older initial age of onset was associated with fatigue, younger initial age of onset for the first episode was associated with suicidal ideation, and a lower episode number was associated with weight loss. These findings highlight potential initial age of onset and scar effects influencing symptom manifestation, but require replication.

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.

The Affective Side of Disruptive Behavior: Toward Better Understanding, Assessment, and Treatment

Historically, much of the progress made in youth mental health research can be classified as focusing on externalizing problems, characterized by disruptive behavior (e.g. aggression, defiance), or internalizing problems, characterized by intense negative affect (e.g. depression, anxiety). Until recently, however, less attention has been given to topics that lie somewhere in between these domains, topics that we collectively refer to as the affective side of disruptive behavior. Like the far side of the moon, the affective side of disruptive behavior captures facets of the phenomenon that may be less obvious or commonly overlooked, but are nonetheless critical to understand. This affective side clarifies socially disruptive aspects of traditionally "externalizing" behavior by elucidating proximal causation via intense negative affect (traditionally "internalizing"). Such problems include irritability, frustration, anger, temper loss, emotional outbursts, and reactive aggression. Given a recent explosion of research in these areas, efforts toward integration are now needed. This special issue was developed to help address this need. Beyond the present introductory article, this collection includes 4 empirical articles on developmental psychopathology topics, 4 empirical articles on applied treatment/assessment topics, 1 evidence base update review article on measurement, and 2 future directions review articles concerning outbursts, mood, dispositions, and youth psychopathology more broadly. By deliberatively investigating the affective side of disruptive behavior, we hope these articles will help bring about better understanding, assessment, and treatment of these challenging problems, for the benefit of youth and families.