Systematic Review and Meta-analysis: Pharmacological and Nonpharmacological Interventions for Persistent Nonepisodic Irritability

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.

Examining the Use of Oral Aripiprazole in Patients With Autism Spectrum Disorder: A Study of Retrospective Chart Review at a University Medical Center

Objectives

The purpose of this study was to examine the patterns of use of oral aripiprazole treatment in children and adolescents diagnosed with autism spectrum disorder (ASD) at a university medical center in Korea.

Methods

We retrospectively reviewed the medical records of 164 outpatient children and adolescents diagnosed with ASD by child and adolescent psychiatrists. Patient demographic characteristics, clinical features, age and dose of aripiprazole treatment, associated adverse events, and concomitant medications, etc. were evaluated.

Results

Aripiprazole treatment was initiated at a mean age of 7.64 years, at a mean initial dose of 1.15 mg. Methylphenidate was often co-administered with aripiprazole. The most commonly reported adverse effects were increased appetite and weight gain, which in some cases led to discontinuation of medication.

Conclusion

A follow-up study is warranted to evaluate the efficacy and safety of aripiprazole treatment in Korean children and adolescents diagnosed with ASD, and it is crucial to consider their clinical characteristics and response to treatment in the evaluation.

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.

A New Behavioral Paradigm for Frustrative Nonreward in Juvenile Mice

Background

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

Methods

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

Results

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

Conclusions

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

An expert opinion on the pharmacological interventions for Disruptive Mood Dysregulation Disorder (DMDD)

INTRODUCTION

Disruptive Mood Dysregulation Disorder (DMDD) was officially introduced as a new diagnostic entity in the Diagnostic and Statistical Manual of Mental Disorder, Fifth Edition (DSM-5), under the category of depressive disorders.

AREAS COVERED

A comprehensive overview and a critical commentary on the currently investigated psychopharmacological approaches for the treatment of DMDD have been here provided.

EXPERT OPINION

Behavioral and psychosocial interventions should be considered as first-line treatment strategies. When ineffective or partially effective, psychopharmacological strategy is recommended. Overall, pharmacological strategy should be preferred in those individuals with psychiatric comorbidities (e.g. ADHD). Indeed, so far published studies on pharmacological strategies in DMDD are scant and heterogeneous (i.e. age, assessment tools, symptomatology profile, comorbidity, and so forth). Therefore, DMDD psychopharmacological guidelines are needed, particularly to guide clinicians toward the patient's typical symptom profile who could benefit from psychopharmacological strategy.

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

Background

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

Methods

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

Conclusion

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

Machine Learning-Based Aggression Detection in Children with ADHD Using Sensor-Based Physical Activity Monitoring

Aggression in children is highly prevalent and can have devastating consequences, yet there is currently no objective method to track its frequency in daily life. This study aims to investigate the use of wearable-sensor-derived physical activity data and machine learning to objectively identify physical-aggressive incidents in children. Participants (n = 39) aged 7 to 16 years, with and without ADHD, wore a waist-worn activity monitor (ActiGraph, GT3X+) for up to one week, three times over 12 months, while demographic, anthropometric, and clinical data were collected. Machine learning techniques, specifically random forest, were used to analyze patterns that identify physical-aggressive incident with 1-min time resolution. A total of 119 aggression episodes, lasting 7.3 ± 13.1 min for a total of 872 1-min epochs including 132 physical aggression epochs, were collected. The model achieved high precision (80.2%), accuracy (82.0%), recall (85.0%), F1 score (82.4%), and area under the curve (89.3%) to distinguish physical aggression epochs. The sensor-derived feature of vector magnitude (faster triaxial acceleration) was the second contributing feature in the model, and significantly distinguished aggression and non-aggression epochs. If validated in larger samples, this model could provide a practical and efficient solution for remotely detecting and managing aggressive incidents in children.

Editorial: A Cry for Help: We Need Nonpharmacological Randomized Controlled Trials for Pediatric Irritability

Research on the assessment, diagnosis, and treatment of clinically impairing irritability in children and adolescents has increased dramatically over the past several decades.^1-5 Increased attention can be traced to controversy arising in the 1990s regarding the nosological status of youth with severe nonepisodic irritability (for a review, see¹). Growing out of this work, disruptive mood dysregulation disorder was introduced in DSM-5.⁶ Critically, in recent years, irritability has been conceptualized as a symptom or feature manifesting transdiagnostically across numerous mood, anxiety, disruptive behavior, and neurodevelopmental disorders.^7,8 The comprehensive and timely meta-analysis by Breaux et al.⁹ in the current issue of the Journal reviews pharmacological and nonpharmacological interventions for this transdiagnostic conceptualization of irritability.

Editorial: Roads Less Traveled: New Directions for Novel Outcomes in Youth Irritability Research

Road metaphors are ubiquitous in youth mental health. Developmental psychopathology research is described in terms of pathways, trajectories, cascades, and transitions. Children's behavioral concerns are discussed as warning signs and rough spots. Although these metaphors have long been useful abstractions, modern quantitative methods and large-scale longitudinal studies have made it possible to empirically investigate the "roads" traveled by individuals across development. One goal here is to chart the paths most often followed by different subgroups of youth. Another goal involves surveying variables that nudge children toward (or away from) psychopathology and other key outcomes. These 2 goals-finding trajectories and predictors thereof-have important implications for research, intervention, and policy; and some of the most important studies, in our view, accomplish both.