External validation of a bifactor model of oppositional defiant disorder

Predictive associations of executive functions and oppositional defiant problems and obsessive-compulsive problems in preschoolers

Oppositional defiant problems (ODP) and obsessive-compulsive problems (OCP) may co-occur in children, though the way they interact is not known. The aim of the study was to examine longitudinal associations between executive functions at age 3 and ODP, ODP dimensions, and OCP at age 6. The sample consisted of 622 preschoolers (50% were boys) from the general population. Executive functions were assessed by teachers using the Behavior Rating Inventory of Executive Functioning - Preschool version questionnaire when children were 3 years old, and ODP and OCP were informed by parents and teachers at the age of 6 years. Multiple linear regression analyses indicated that higher Inhibit and Emotional Control and lower Shift deficits were associated with higher ODP reported by teachers, while higher Shift but lower Inhibit deficits were related to higher OCP. Moreover, ODP and OCP shared difficulties on the Flexibility Index, which means that the capacity to modulate emotions and behavior according to contextual and environmental demands is compromised in both disorders. The findings inform etiology and prevention, pointing out not only the executive function specificities related to each problem, but also common cognitive challenges related to Flexibility. Young children could benefit from training and programs designed to improve executive function processes at an early age to prevent later behavioral difficulties.

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.

Trajectories of oppositional defiant disorder severity from adolescence to young adulthood and substance use, mental health, and behavioral problems

Background

Oppositional Defiant Disorder (ODD) is a disruptive behavioral disorder; however, increasing evidence emphasizes irritable mood as a primary symptom of ODD.

Objectives

This study investigated whether heterogeneous groups (classes) of individuals can be differentiated based on ODD sub-dimensions (irritability and defiance) or on overall ODD symptoms longitudinally. We also examine associations between ODD trajectory class and comorbid substance use (heavy episodic drinking, cannabis use), mental health (depression and anxiety) and behavioral symptoms (ADHD, aggression and substance use) in both adolescence and young adulthood (controlling for adolescent levels of each of these concerns).

Method

Data were from a randomly recruited community sample of 662 Canadian youth (T1 ages 12-18) followed biennially for 10 years (T6 ages 22-29).

Results

Growth mixture models revealed trajectories classes of ODD based on severity of symptoms. A three-class solution provided the best fit with Low (n = 119; 18%), Moderate (n = 473; 71.5%), and High (n = 70; 10.6%) ODD classes. Class trajectory differences were similarity based on symptoms severity (rather than type) for symptom sub-dimensions (irritability defiance). Adolescent and young adult substance use, mental health symptoms, and behavioral problems were significantly higher for the High ODD trajectory class compared to both other classes. Youth in the Moderate ODD trajectory class also showed higher comorbid symptoms in adolescence and young adulthood, compared to the Low ODD trajectory class.

Conclusion

Early identification of children and adolescents with high or moderate ODD symptoms and interventions that simultaneously address defiance and irritability are supported by the findings.

Oppositional defiant disorder

Oppositional defiant disorder (ODD) is a disruptive behaviour disorder involving an ongoing pattern of angry/irritable mood, argumentative/defiant behaviour and vindictiveness. Onset is typically before 8 years of age, although ODD can be diagnosed in both children and adults. This disorder is associated with substantial social and economic burden, and childhood ODD is one of the most common precursors of other mental health problems that can arise across the lifespan. The population prevalence of ODD is ~3 to 5%. A higher prevalence in males than females has been reported, particularly before adolescence. No single risk factor accounts for ODD. The development of this disorder seems to arise from the interaction of genetic and environmental factors, and mechanisms embedded in social relationships are understood to contribute to its maintenance. The treatment of ODD is often successful, and relatively brief parenting interventions produce large sized treatment effects in early childhood. Accordingly, ODD represents an important focus for research, practice and policy concerning early intervention and prevention in mental health.

Heterotypic and homotypic continuity in psychopathology: a narrative review

Psychopathology is a process: it unfolds over time and involves several different factors. To extend our knowledge of such process, it is vital to understand the trajectories that lead to developing and maintaining a specific disorder. The construct of continuity appears very useful to this aim. It refers to the consistency, similarity, and predictability of behaviors or internal states across different developmental phases. This paper aims to present a narrative review of the literature on homotypic and heterotypic continuity of psychopathology across the lifespan. A detailed search of the published literature was conducted using the PsycINFO Record and Medline (PubMed) databases. Articles were included in the review based on the following criteria: (1) publication dates ranging from January 1970 to October 2022; and (2) articles being written in the English language. To ensure a thorough investigation, multiple combinations of keywords such as "continuity," "psychopathology," "infancy," "childhood," "adolescence," "adulthood," "homotypic," and "heterotypic" were used. Articles were excluded if exclusively focused on epidemiologic data and if not specifically addressing the topic of psychopathology continuity. The literature yielded a total of 36 longitudinal studies and an additional 190 articles, spanning the research published between 1970 and 2022. Studies on continuity focus on the etiology of different forms of mental disorders and may represent a fundamental resource from both a theoretical and clinical perspective. Enhancing our understanding of the different trajectories beneath psychopathology may allow clinicians to implement more effective strategies, focusing both on prevention and intervention. Since literature highlights the importance of early detection of clinical signs of psychopathology, future research should focus more on infancy and pre-scholar age.

Latent classes of oppositional defiant disorder in adolescence and prediction to later psychopathology

Current conceptualizations of oppositional defiant disorder (ODD) place the symptoms of this disorder within three separate but related dimensions (i.e., angry/irritable mood, argumentative/defiant behavior, vindictiveness). Variable-centered models of these dimensions have yielded discrepant findings, limiting their clinical utility. The current study utilized person-centered latent class analysis based on self and parent report of ODD symptomatology from a community-based cohort study of 521 adolescents. We tested for sex, race, and age differences in the identified classes and investigated their ability to predict later symptoms of depression and conduct disorder (CD). Diagnostic information regarding ODD, depression, and CD were collected annually from adolescents (grades 6-9; 51.9% male; 48.7% White, 28.2% Black, 18.5% Asian) and a parent. Results provided evidence for three classes of ODD (high, medium, and low endorsement of symptoms), which demonstrated important developmental differences across time. Based on self-report, Black adolescents were more likely to be in the high and medium classes, while according to parent report, White adolescents were more likely to be in the high and medium classes. Membership in the high and medium classes predicted later increases in symptoms of depression and CD, with the high class showing the greatest risk for later psychopathology.

Co-Occurring Conduct Problems and Anxiety: Implications for the Functioning and Treatment of Youth with Oppositional Defiant Disorder

Conduct problems and anxiety symptoms commonly co-occur among youths with oppositional defiant disorder (ODD); however, how these symptoms influence functioning and treatment outcomes remains unclear. This study examined subtypes based on these co-occurring symptoms in a clinical sample of 134 youths (Mage = 9.67, 36.6% female, 83.6% white) with ODD and the predictive power of these subgroups for youth functioning and psychosocial treatment outcomes. The latent profile analysis (LPA) was used to identify subgroups based on parent- and self-reported conduct problems and anxiety symptoms. Differences among the subgroups in clinician-, parent-, and/or self-reported accounts of symptom severity, school performance, underlying processing known to be impaired across ODD, conduct and anxiety disorders, self-concept, and psychosocial treatment outcomes were examined. Four distinct profiles were identified: (1) Low Anxiety/Moderate Conduct Problems (n = 42); (2) High Anxiety/Moderate Conduct Problems (n = 33); (3) Moderate Anxiety/Moderate Conduct Problems (n = 40); and (4) Moderate Anxiety/High Conduct Problems (n = 19). The Moderate Anxiety/High Conduct Problems group exhibited more severe behavioral problems, greater difficulties with negative emotionality, emotional self-control, and executive functioning; they also demonstrated worse long-term treatment outcomes than the other subgroups. These findings suggest more homogeneous subgroups within and across diagnostic categories may result in a deeper understanding of ODD and could inform nosological systems and intervention efforts.

A broad internalizing dimension accounts for the genetic associations between personality and individual internalizing disorders

Much research has demonstrated that psychopathology can be described in terms of broad dimensions, representing liability for multiple psychiatric disorders. Broad spectra of psychopathology (e.g., internalizing and externalizing) are increasingly used as targets for research investigating the development, etiology, and course of psychopathology because they account for patterns of relatedness among disorders that were once presumed distinct. Thus, these spectra represent alluring targets due to their comprehensive and parsimonious nature. Nevertheless, little research has established the role of individual disorders over and above broad dimensions in the study of psychopathology. In the current study, we investigate whether there are unique etiological associations between individual internalizing disorders and personality traits after accounting for their etiological associations with a broad internalizing dimension. We used a community sample of twins (Npairs = 448) ages 4 to 19 to examine the etiological associations between internalizing psychopathology and Big Five personality dimensions. In terms of genetic covariation, a broad internalizing dimension was positively associated with neuroticism and negatively associated with extraversion, agreeableness, and conscientiousness. Moreover, internalizing accounted for most of the genetic variance shared between individual internalizing disorders and personality traits. Nevertheless, there were unique genetic associations between the following pairs of personality traits and disorders: neuroticism and social anxiety, extraversion and social anxiety, agreeableness and depression, and conscientiousness and compulsions. There was little evidence of environmental influences shared between internalizing and personality. In sum, a broad internalizing dimension adequately accounted for almost all of the etiologic covariation between internalizing disorders and personality, with several interesting exceptions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Co-developmental Trajectories of Defiant/Headstrong, Irritability, and Prosocial Emotions from Preschool Age to Early Adolescence

This study ascertains how the proposed subtypes and specifiers of oppositional defiant disorder (ODD) based on irritability and prosocial emotions co-develop and describes the clinical characteristics of the resultant classes. A sample of 488 community children was followed up from ages 3 to 12 years and assessed with categorical and dimensional measures answered by parents and teachers. Latent class growth analysis for three parallel processes [defiant/headstrong, irritability, and limited prosocial emotions (LPE)] identified a 4-class model with adequate entropy (.912) and posterior probabilities of class membership (≥ .921). Class 1 (n = 38, 7.9%) was made up of children with defiant/headstrong with chronic irritability and LPE. Class 2 (n = 128, 26.3%) was comprised of children with defiant/headstrong with chronic irritability and typical prosocial emotions. Class 3 (n = 101, 20.7%) clustered children with LPE without defiant/headstrong and without irritability. Class 4 (n = 220, 45.1%) included children with the lowest scores in all the processes. The classes were distinguishable and showed different clinical characteristics through development. These findings support the validity of ICD-11 ODD subtypes based on chronic irritability and may help to guide clinicians' decision-making regarding treating oppositionality in children.

Debate: Oppositional defiant disorder is a real disorder

Oppositional defiant disorder (ODD) is a valid mental health disorder, characterized by negativistic defiant behavior and angry, irritable mood. The very low and stable prevalence rate over development from early childhood into adulthood suggests that ODD does not erroneously medicalize normative childhood behavior. ODD is associated with significant impairments across multiple contexts and raises risks for other future psychopathology. Although simplistic tropes often suggest that ODD is merely the product of bad parenting, substantial evidence shows that it is instead influenced by a variety of factors, including genetic and neurobiological factors. Individuals with ODD evoke negative interactions with peers, teachers, coworkers, romantic partners, and parents. ODD is often misunderstood as being a mild form of conduct disorder (CD). Rather, in stark contrast to ODD, CD reflects a pattern of aggressive behaviors, violations of laws or status offenses, and psychopathic features. Mounting evidence for their distinction led to diagnostic changes distinguishing ODD and CD nearly a decade ago. Empirically supported treatments are available and help caregivers to develop specific parenting practices to meet the needs of children with ODD. Minimizing and mischaracterizing ODD increases the likelihood that families who are suffering may not seek the treatment that they need.

Reciprocal relations between dimensions of Oppositional defiant problems and callous-unemotional traits

Although irritability, headstrong/defiant behavior, and callous-unemotional traits (CU traits) often co-occur, the prospective associations between them are not well known. A general population sample of 622 children was followed up yearly from ages 3 to 12 years and assessed using dimensional measures of irritability, headstrong/defiant, and CU traits with teacher provided information. A random intercept cross-lagged panel model, accounting for all unmeasured time-invariant confounding using the children as their own controls, revealed cross-lagged reciprocal associations between increased headstrong/defiant and increased CU traits at all ages and a unidirectional association from headstrong/defiant to irritability. The findings are consistent with headstrong/defiant behavior and CU traits mutually influencing each other over time and headstrong/defiant behavior enhancing irritability. School-based intervention and prevention programs should take these findings into consideration. They also suggest that irritability acts as a distinct developmental dimension of headstrong/defiant and callous-unemotional behaviors and needs to be addressed independently.

Irritability and Emotional Impulsivity as Core Feature of ADHD and ODD in Children

The categorical approach of diagnosing mental disorders entails the problem of frequently occurring comorbidities, suggesting a more parsimonious structure of psychopathology. In this study, we therefore aim to assess how affective dysregulation (AD) is associated with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) in children. To assess AD in children aged 8–12 years (n = 391), we employed the parent version of a newly constructed parent rating scale. Following item reduction, we conducted exploratory and confirmatory factor analyses to establish a factorial structure of AD. One core dimension was identified, comprising irritability and emotional impulsivity, and two smaller dimensions, comprising positive emotionality and exuberance. Subsequently, we examined five different latent factor models – a unidimensional model, a first-order correlated factor model, a second-order correlated factor model, a traditional bifactor model, and a bifactor S-1 model, in which the first-order factor AD-Irritability/Emotional Impulsivity (II) was modeled as the general reference factor. A bifactor S-1 model with the a priori defined general reference domain AD-II provided the best fit to our data and was straightforward to interpret. This model showed excellent model fit and no anomalous factor loadings. This still held true, when comparing it to bifactor S-1 models with ADHD/ODD-related reference factors. Differential correlations with emotion regulation skills and the established Parent Proxy Anger Scale validate the interpretation of the different dimensions. Our results suggest that irritability/emotional impulsivity might be a common core feature of ADHD and ODD.

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

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

The Irritable and Oppositional Dimensions of Oppositional Defiant Disorder: Integral Factors in the Explanation of Affective and Behavioral Psychopathology

Oppositional defiant disorder includes distinct but inseparable dimensions of chronic irritability and oppositional behavior. The dimensions have been identified in early childhood to adulthood, and show discriminant associations with internalizing and externalizing psychopathology. The introduction of disruptive mood dysregulation disorders and the requirements that it take precedence over oppositional defiant disorder diagnostically are not supported by evidence and introduce confusion about the structure and linkages of irritability and oppositional behavior, and obscure the importance of the behavioral dimension in explaining and predicting poor outcomes. A dimensional framework with irritability, oppositionality, callous-unemotional traits, and aggression may more fully describe antisocial outcomes.

Helping Clinicians to Detect ODD in Children with ADHD in Clinical Settings

The objectives of this study were to provide a basic tool for pediatricians or other physicians to suspect and detect ODD in children with ADHD and to distinguish the symptomatic profile of ODD from ADHD. 101 subjects with ADHD, 83 with both ADHD and ODD and 342 controls aged 8 to 15 years were included in the study. A semi-structured interview was performed for evaluation of psychiatric diagnoses. Both parents and teachers completed DSM-IV Disruptive Behavior Disorders Rating Scale. We found differences among all three diagnostic subsamples in two-by-two analyses for all dimensions (Inattention, Hyperactivity/Impulsivity and ODD) both according to parent and teacher reports (p < 0.03 for all analyses). Based on parental ODD scores, ROC Curve analyses between 'only ADHD' and 'ADHD+ODD' groups showed that AUC was equal 0.80 (95%CI = 0.73-0.86) and the best cutoff point for ODD diagnosis in the ADHD subjects was 0.68. This study demonstrates the presence of a basic tool for detection and suspicion of ODD in children with ADHD for primary care clinicians or pediatricians in clinical settings. Findings also indicate that patients with ODD and ADHD have more severe inattention, hyperactivity/impulsivity and oppositional symptoms than those with only ADHD have.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): II. Externalizing superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical effort to address limitations of traditional mental disorder diagnoses. These include arbitrary boundaries between disorder and normality, disorder co-occurrence in the modal case, heterogeneity of presentation within dis-orders, and instability of diagnosis within patients. This paper reviews the evidence on the validity and utility of the disinhibited externalizing and antagonistic externalizing spectra of HiTOP, which together constitute a broad externalizing superspectrum. These spectra are composed of elements subsumed within a variety of mental disorders described in recent DSM nosologies, including most notably substance use disorders and "Cluster B" personality disorders. The externalizing superspectrum ranges from normative levels of impulse control and self-assertion, to maladaptive disinhibition and antagonism, to extensive polysubstance involvement and personality psychopathology. A rich literature supports the validity of the externalizing superspectrum, and the disinhibited and antagonistic spectra. This evidence encompasses common genetic influences, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, and treatment response. The structure of these validators mirrors the structure of the phenotypic externalizing superspectrum, with some correlates more specific to disinhibited or antagonistic spectra, and others relevant to the entire externalizing superspectrum, underlining the hierarchical structure of the domain. Compared with traditional diagnostic categories, the externalizing superspectrum conceptualization shows improved utility, reliability, explanatory capacity, and clinical applicability. The externalizing superspectrum is one aspect of the general approach to psychopathology offered by HiTOP and can make diagnostic classification more useful in both research and the clinic.

Is an irritable ADHD profile traceable using personality dimensions? Replicability, stability, and predictive value over time of data-driven profiles

Pediatric attention deficit/hyperactivity disorder (ADHD) is a heterogeneous condition. In particular, children with ADHD display varying profiles of dispositional traits, as assessed through temperament and personality questionnaires. Previous data-driven community detection analyses based on temperament dimensions identified an irritable profile of patients with ADHD, uniquely characterized by elevated emotional dysregulation symptoms. Belonging to this profile increased the risk of developing comorbid disorders. Here, we investigated whether we could replicate this profile in a sample of 178 children with ADHD, using community detection based on personality dimensions. Stability of the identified profiles, of individual classifications, and clinical prediction were longitudinally assessed over a 1-year interval. Three personality profiles were detected: The first two profiles had high levels of neuroticism, with the first displaying higher ADHD severity and lower openness to experience (profile 1; N = 38), and the second lower agreeableness (profile 2; N = 73). The third profile displayed scores closer to the normative range on all five factors (profile 3; N = 67). The identified profiles did only partially replicate the temperament-based profiles previously reported, as higher levels of neuroticism were found in two of the three detected profiles. Nonetheless, despite changes in individual classifications, the profiles themselves were highly stable over time and of clinical predictive value. Whereas children belonging to profiles 1 and 2 benefited from starting medication, children in profile 3 did not. Hence, belonging to an emotionally dysregulated profile at baseline predicted the effect of medication at follow-up over and above initial ADHD symptom severity. This finding suggests that personality profiles could play a role in predicting treatment response in ADHD.

Machine learning-based prediction of persistent oppositional defiant behavior for 5 years

BACKGROUND

Early detection of oppositional defiant behavior is warranted for timely intervention in children at risk. This study aimed to build a predictive model of persistent oppositional defiant behavior based on a machine learning algorithm.

METHODS

With nationwide cohort data collected from 2012 to 2017, a tree-based ensemble model, random forest, was exploited to build a predictive model for persistent oppositional defiant behavior. The persistent oppositional defiant behavior was defined by the presence of oppositional defiant behavior for all the five years. The area under the receiver operating characteristic curve (AUC), overall accuracy, sensitivity, specificity, and Matthew's correlation coefficients (MCC) were measured.

RESULTS

Data of 1,323 children were used for building the machine learning-based predictive model. The baseline mean ± standard deviation month-age of the participants was 51.0 ± 1.2 months. The proportion of persistent oppositional defiant behavior was 0.98% (13/1323). In the hold-out test set, the overall accuracy, AUC, sensitivity, specificity, and MCC were 0.955, 0.982, 1.000, 0.954, and 0.417, respectively.

CONCLUSION

Our study demonstrated that the machine learning-based approach is useful for predicting persistent oppositional defiant behavior in preschool-aged children.

The Bifactor S-1 Model: a Psychometrically Sounder Alternative to Test the Structure of ADHD and ODD?

Questions persist about whether attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder are in fact distinct from one another. When such questions arise, ODD is often suggested to be subsumed under one or the other condition. Modeling approaches that can evaluate whether specific subfactors can be distinguished from general psychopathology are of great interest, and the general bifactor model has been increasingly applied in studies evaluating the structure of psychopathology. However, evidence for bias in the model, the frequency of anomalous indicators, and theoretical concerns about the applicability of the general bifactor model to these questions raise doubts about whether it is reliable or appropriate to do so. Burns and colleagues propose the bifactor S-1 model as a psychometrically sounder alternative. Their systematic examination provides a compelling argument that it is psychometrically sounder, but it is not clear that it is a true alternative. It may not be answering the same questions, cannot test hypotheses regarding the same sets of specific subfactors, and relies on a priori decisions on the part of the researcher that may change the interpretation of the results. The bifactor S-1 model approach appears to be a valuable, psychometrically sound approach to test the structure of psychopathology, particularly in regard to ADHD and ODD.

Irritability and Limited Prosocial Emotions/Callous-Unemotional Traits in Elementary-School-Age Children

Affective traits, including irritability and limited prosocial emotions/callous-unemotional traits (LPE/CU), each explain significant variance in youth conduct problems but few studies have examined these constructs simultaneously. This study examined whether irritability, LPE/CU, or their combination explained significant variance in measures of internalizing or externalizing psychopathology, aggression, peer problems, impairment, or parenting. Participants were 219 elementary-school-age children, including 178 with attention-deficit/hyperactivity disorder, oppositional defiant disorder, and/or conduct disorder and 41 typically developing children. Results of analyses showed that irritability and LPE/CU had significant and sometimes unique associations with measures of child behavior, impairment, and parenting. There was also evidence that the interaction between irritability and LPE/CU was significantly associated with aggression and impairment. These findings suggest that irritability and LPE/CU should be examined together when assessing and treating conduct problems in youth.

Assessing the Irritable and Defiant Dimensions of Youth Oppositional Behavior Using CBCL and YSR Items

Research suggests that irritability and defiance are distinct dimensions of youth oppositionality that are differentially associated with internalizing and conduct problems, respectively. Because much of this evidence has emerged with limited psychometric evaluation, we conducted the first multi-informant examination of selected Child Behavior Checklist (CBCL) and Youth Self Report (YSR) items for measuring irritability and defiance in a large clinical sample. Clinically referred youths (N = 1,030; ages 6-15; 43% female, 42% ethnic minority) were assessed prior to treatment using multi-informant rating scales and diagnostic interviews. Analyses examined factor structure, invariance, internal consistency, multi-informant patterns, and convergent, discriminant, and criterion validity with internalizing and externalizing problems/disorders. A correlated 2-factor model of irritability (stubborn/sullen/irritable, mood, temper) and defiance (argues, disobeys-home, disobeys-school) fit well for both informants. Adequate measurement invariance and scale consistency was consistently found for parent-report but not youth-report. With both informants, all hypothesized convergent and discriminant validity associations were supported: irritability and defiance with internalizing and conduct scales, respectively. However, hypothesized criterion validity associations were largely found only by parent-report: irritability with anxiety and depressive disorders, defiance with conduct disorder, and both with oppositional defiant disorder. Results consistently supported the reliability and validity of the CBCL irritability and defiance scales, with somewhat less consistent support for the YSR scales. Thus, CBCL items may provide psychometrically sound assessment of irritability and defiance, whereas further research is needed to advance youth-report and multi-informant strategies. Results also provide further support for a two subdimension model of oppositional defiant disorder symptoms that includes irritability and defiance.