A Latent Variable Approach to Differentiating Neural Mechanisms of Irritability and Anxiety in Youth

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.

Rationale and validation of a novel mobile application probing motor inhibition: Proof of concept of CALM-IT

Identification of behavioral mechanisms underlying psychopathology is essential for the development of novel targeted therapeutics. However, this work relies on rigorous, time-intensive, clinic-based laboratory research, making it difficult to translate research paradigms into tools that can be used by clinicians in the community. The broad adoption of smartphone technology provides a promising opportunity to bridge the gap between the mechanisms identified in the laboratory and the clinical interventions targeting them in the community. The goal of the current study is to develop a developmentally appropriate, engaging, novel mobile application called CALM-IT that probes a narrow biologically informed process, inhibitory control. We aim to leverage the rigorous and robust methods traditionally used in laboratory settings to validate this novel mechanism-driven but easily disseminatable tool that can be used by clinicians to probe inhibitory control in the community. The development of CALM-IT has significant implications for the ability to screen for inhibitory control deficits in the community by both clinicians and researchers. By facilitating assessment of inhibitory control outside of the laboratory setting, researchers could have access to larger and more diverse samples. Additionally, in the clinical setting, CALM-IT represents a novel clinical screening measure that could be used to determine personalized courses of treatment based on the presence of inhibitory control deficits.

Anger attacks are associated with persistently elevated irritability in MDD: findings from the EMBARC study

BACKGROUND

This report tests the association of self-reported symptoms of irritability with overt behavior of anger attacks (uncharacteristic sudden bouts of anger that are disproportionate to situation and associated with autonomic activation).

METHODS

Participants of the Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care study who completed Massachusetts General Hospital Anger Attacks questionnaire were included (n = 293). At each visit, the 17-item Hamilton Depression Rating Scale and the 16-item Concise Associated Symptom Tracking scale were used to measure depression, anxiety, and irritability. In those with anger attacks present v. those without anger attacks, separate t tests and mixed model analyses compared afore-mentioned symptoms at baseline and changes with treatment respectively. As anger attacks may occur without aggressive behaviors, analyses were repeated based only on the presence of aggressive behaviors.

RESULTS

At baseline, those with anger attacks (n = 109) v. those without anger attacks (n = 184) had similar levels of depression but higher levels of irritability [effect size (d) = 0.80] and anxiety (d = 0.32). With acute-phase treatment, participants with anger attacks experienced a greater reduction in irritability (p < 0.001) but not in depression (p = 0.813) or anxiety (p = 0.771) as compared to those without anger attacks. Yet, irritability levels at week-8 were higher in those with anger attacks (d = 0.32) than those without anger attacks. Similar results were found in participants with aggressive behaviors.

CONCLUSIONS

The presence of anger attacks in outpatients with major depressive disorder may identify a sub-group of patients with persistently elevated irritability.

Functional connectivity during frustration: a preliminary study of predictive modeling of irritability in youth

Irritability cuts across many pediatric disorders and is a common presenting complaint in child psychiatry; however, its neural mechanisms remain unclear. One core pathophysiological deficit of irritability is aberrant responses to frustrative nonreward. Here, we conducted a preliminary fMRI study to examine the ability of functional connectivity during frustrative nonreward to predict irritability in a transdiagnostic sample. This study included 69 youths (mean age = 14.55 years) with varying levels of irritability across diagnostic groups: disruptive mood dysregulation disorder (n = 20), attention-deficit/hyperactivity disorder (n = 14), anxiety disorder (n = 12), and controls (n = 23). During fMRI, participants completed a frustrating cognitive flexibility task. Frustration was evoked by manipulating task difficulty such that, on trials requiring cognitive flexibility, "frustration" blocks had a 50% error rate and some rigged feedback, while "nonfrustration" blocks had a 10% error rate. Frustration and nonfrustration blocks were randomly interspersed. Child and parent reports of the affective reactivity index were used as dimensional measures of irritability. Connectome-based predictive modeling, a machine learning approach, with tenfold cross-validation was conducted to identify networks predicting irritability. Connectivity during frustration (but not nonfrustration) blocks predicted child-reported irritability (ρ = 0.24, root mean square error = 2.02, p = 0.03, permutation testing, 1000 iterations, one-tailed). Results were adjusted for age, sex, medications, motion, ADHD, and anxiety symptoms. The predictive networks of irritability were primarily within motor-sensory networks; among motor-sensory, subcortical, and salience networks; and between these networks and frontoparietal and medial frontal networks. This study provides preliminary evidence that individual differences in irritability may be associated with functional connectivity during frustration, a phenotype-relevant state.

Attention bias to negative versus non-negative faces is related to negative affectivity in a transdiagnostic youth sample

This study identified a shared pathophysiological mechanism of pediatric anxiety and irritability. Clinically, anxiety and irritability are common, co-occurring problems, both characterized by high-arousal negative affective states. Behaviorally, anxiety and irritability are associated with aberrant threat processing. To build on these findings, we examined eye-tracking measures of attention bias in relation to the unique and shared features of anxiety and irritability in a transdiagnostic sample of youth (n = 97, 58% female, M_age = 13.03, SD_age = 2.82). We measured attention bias to negative versus non-negative emotional faces during a passive viewing task. We employed bifactor analysis to parse the unique and shared variance of anxiety and irritability symptoms from self- and parent-report questionnaires. Negative affectivity is the derived latent factor reflecting shared variance of anxiety and irritability. We found that higher negative affectivity was associated with looking longer at negative versus non-negative faces, reflecting a shared mechanism of anxiety and irritability. This finding suggests that modification of elevated attention to negative emotional faces may represent a common potential treatment target of anxiety and irritability.

Measuring Irritability in Early Childhood: A Psychometric Evaluation of the Affective Reactivity Index in a Clinical Sample of 3- to 8-Year-Old Children

The parent-report Affective Reactivity Index (ARI-P) is the most studied brief scale specifically developed to assess irritability, but relatively little is known about its performance in early childhood (i.e., ≤8 years). Support in such populations is particularly important given developmental shifts in what constitutes normative irritability across childhood. We examined the performance of the ARI-P in a diverse, treatment-seeking sample of children ages 3 to 8 years (N = 115; mean age = 5.56 years; 58.4% from ethnic/racial minority backgrounds). In this sample, confirmatory factor analysis supported the single-factor structure of the ARI-P previously identified with older youth. ARI-P scores showed large associations with another irritability index, as well as small-to-large associations with aggression, anxiety, depression, and attention problems, supporting the convergent and concurrent validity of the ARI-P when used with children in this younger age range. Findings support the ARI-P as a promising parent-report tool for assessing irritability in early childhood, particularly in clinical samples.

Emerging Evidence for Putative Neural Networks and Antecedents of Pediatric Anxiety in the Fetal, Neonatal, and Infant Periods

Anxiety disorders are the most prevalent psychiatric disorders in youth and are associated with profound individual impairment and public health costs. Research shows that clinically significant anxiety symptoms manifest in preschool-aged children, and correlates of anxiety symptoms are observable in infancy. Yet, predicting who is at risk for developing anxiety remains an enduring challenge. Predictive biomarkers of anxiety are needed before school age when anxiety symptoms typically consolidate into diagnostic profiles. Increasing evidence indicates that early neural measures implicated in anxiety and anxious temperament may be incorporated with traditional measures of behavioral risk (i.e., behavioral inhibition) to provide more robust classification of pediatric anxiety problems. This review examines the phenomenology of anxiety disorders in early life, highlighting developmental research that interrogates the putative neurocircuitry of pediatric anxiety. First, we discuss enduring challenges in identifying and predicting risk for pediatric anxiety. Second, we summarize emerging evidence for putative neural antecedents and networks underlying risk for pediatric anxiety in the fetal, neonatal, and infant periods that represent novel potential avenues for risk identification and prediction. We focus on evidence examining the importance of early amygdala and extended amygdala circuitry development to the emergence of anxiety. Finally, we discuss the utility of integrating developmental psychopathology and neuroscience to facilitate future research and clinical work.

Cognitive Control in Pediatric Obsessive-Compulsive and Anxiety Disorders: Brain-Behavioral Targets for Early Intervention

The DSM provides distinct criteria for obsessive-compulsive disorder (OCD) and various types of anxiety disorders, but phenomenological overlap, high rates of comorbidity, and early onset suggest common underlying mechanisms. This notion is further supported by use of the same treatments-cognitive behavioral therapy and serotonin reuptake inhibitor medication-for managing both OCD and non-OCD anxiety disorders in clinical settings. While early intervention with these gold standard treatments is recommended for pediatric OCD and anxiety disorders, young patients often remain symptomatic even after treatment. To guide the development of novel, mechanistically targeted treatments to better resolve OCD and anxiety symptoms, the identification of neural circuits underlying psychological constructs with relevance across disorders has been recommended. One construct that may be relevant for understanding pediatric OCD and anxiety disorders is cognitive control, given the difficulty that young patients experience in dismissing obsessions, compulsions, and worry despite recognition that these symptoms are excessive and unreasonable. In this review, we examine findings from a growing body of literature implicating brain-behavioral markers of cognitive control in pediatric OCD and anxiety disorders, including before and after treatment. We conclude by suggesting that interventions designed to enhance the functioning of the task control circuits underlying cognitive control may facilitate brain maturation to help affected youth overcome symptoms.

Shared and Anxiety-Specific Pediatric Psychopathology Dimensions Manifest Distributed Neural Correlates

BACKGROUND

Imaging research has not yet delivered reliable psychiatric biomarkers. One challenge, particularly among youth, is high comorbidity. This challenge might be met through canonical correlation analysis designed to model mutual dependencies between symptom dimensions and neural measures. We mapped the multivariate associations that intrinsic functional connectivity manifests with pediatric symptoms of anxiety, irritability, and attention-deficit/hyperactivity disorder (ADHD) as common, impactful, co-occurring problems. We evaluate the replicability of such latent dimensions in an independent sample.

METHODS

We obtained ratings of anxiety, irritability, and ADHD, and 10 minutes of resting-state functional magnetic resonance imaging data, from two independent cohorts. Both cohorts (discovery: n = 182; replication: n = 326) included treatment-seeking youth with anxiety disorders, with disruptive mood dysregulation disorder, with ADHD, or without psychopathology. Functional connectivity was modeled as partial correlations among 216 brain areas. Using canonical correlation analysis and independent component analysis jointly we sought maximally correlated, maximally interpretable latent dimensions of brain connectivity and clinical symptoms.

RESULTS

We identified seven canonical variates in the discovery and five in the replication cohort. Of these canonical variates, three exhibited similarities across datasets: two variates consistently captured shared aspects of irritability, ADHD, and anxiety, while the third was specific to anxiety. Across cohorts, canonical variates did not relate to specific resting-state networks but comprised edges interconnecting established networks within and across both hemispheres.

CONCLUSIONS

Findings revealed two replicable types of clinical variates, one related to multiple symptom dimensions and a second relatively specific to anxiety. Both types involved a multitude of broadly distributed, weak brain connections as opposed to strong connections encompassing known resting-state networks.

Anxiety disorders

Anxiety disorders form the most common group of mental disorders and generally start before or in early adulthood. Core features include excessive fear and anxiety or avoidance of perceived threats that are persistent and impairing. Anxiety disorders involve dysfunction in brain circuits that respond to danger. Risk for anxiety disorders is influenced by genetic factors, environmental factors, and their epigenetic relations. Anxiety disorders are often comorbid with one another and with other mental disorders, especially depression, as well as with somatic disorders. Such comorbidity generally signifies more severe symptoms, greater clinical burden, and greater treatment difficulty. Reducing the large burden of disease from anxiety disorders in individuals and worldwide can be best achieved by timely, accurate disease detection and adequate treatment administration, scaling up of treatments when needed. Evidence-based psychotherapy (particularly cognitive behavioural therapy) and psychoactive medications (particularly serotonergic compounds) are both effective, facilitating patients' choices in therapeutic decisions. Although promising, no enduring preventive measures are available, and, along with frequent therapy resistance, clinical needs remain unaddressed. Ongoing research efforts tackle these problems, and future efforts should seek individualised, more effective approaches for treatment with precision medicine.

Neurocognitive and functional heterogeneity in depressed youth

Depression is a common psychiatric illness that often begins in youth, and is sometimes associated with cognitive deficits. However, there is significant variability in cognitive dysfunction, likely reflecting biological heterogeneity. We sought to identify neurocognitive subtypes and their neurofunctional signatures in a large cross-sectional sample of depressed youth. Participants were drawn from the Philadelphia Neurodevelopmental Cohort, including 712 youth with a lifetime history of a major depressive episode and 712 typically developing (TD) youth matched on age and sex. A subset (MDD n = 368, TD n = 200) also completed neuroimaging. Cognition was assessed with the Penn Computerized Neurocognitive Battery. A recently developed semi-supervised machine learning algorithm was used to delineate neurocognitive subtypes. Subtypes were evaluated for differences in both clinical psychopathology and brain activation during an n-back working memory fMRI task. We identified three neurocognitive subtypes in the depressed group. Subtype 1 was high-performing (high accuracy, moderate speed), Subtype 2 was cognitively impaired (low accuracy, slow speed), and Subtype 3 was impulsive (low accuracy, fast speed). While subtypes did not differ in clinical psychopathology, they diverged in their activation profiles in regions critical for executive function, which mirrored differences in cognition. Taken together, these data suggest disparate mechanisms of cognitive vulnerability and resilience in depressed youth, which may inform the identification of biomarkers for prognosis and treatment response.

The Hierarchical Taxonomy of Psychopathology (HiTOP): A Quantitative Nosology Based on Consensus of Evidence

Traditional diagnostic systems went beyond empirical evidence on the structure of mental health. Consequently, these diagnoses do not depict psychopathology accurately, and their validity in research and utility in clinicalpractice are therefore limited. The Hierarchical Taxonomy of Psychopathology (HiTOP) consortium proposed a model based on structural evidence. It addresses problems of diagnostic heterogeneity, comorbidity, and unreliability. We review the HiTOP model, supporting evidence, and conceptualization of psychopathology in this hierarchical dimensional framework. The system is not yet comprehensive, and we describe the processes for improving and expanding it. We summarize data on the ability of HiTOP to predict and explain etiology (genetic, environmental, and neurobiological), risk factors, outcomes, and treatment response. We describe progress in the development of HiTOP-based measures and in clinical implementation of the system. Finally, we review outstanding challenges and the research agenda. HiTOP is of practical utility already, and its ongoing development will produce a transformative map of psychopathology.

Irritability Is Associated With Decreased Cortical Surface Area and Anxiety With Decreased Gyrification During Brain Development

Background: Brain development is of utmost importance for the emergence of psychiatric disorders, as the most severe of them arise before 25 years old. However, little is known regarding how early transdiagnostic symptoms, in a dimensional framework, are associated with cortical development. Anxiety and irritability are central vulnerability traits for subsequent mood and anxiety disorders. In this study, we investigate how these dimensions are related to structural changes in the brain to understand how they may increase the transition risk to full-blown disorders. Methods: We used the opportunity of an open access developmental cohort, the Healthy Brain Network, to investigate associations between cortical surface markers and irritability and anxiety scores as measured by parents and self-reports. Results: We found that in 658 young people (with a mean age of 11.6) the parental report of irritability is associated with decreased surface area in the bilateral rostral prefrontal cortex and the precuneus. Furthermore, parental reports of anxiety were associated with decreased local gyrification index in the anterior cingulate cortex and dorsomedial prefrontal cortex. Conclusions: These results are consistent with current models of emotion regulation network maturation, showing decreased surface area or gyrification index in regions associated with impaired affective control in mood and anxiety disorders. Our results highlight how dimensional traits may increase vulnerability for these disorders.

Callous-Unemotional Traits Moderate the Relationship Between Irritability and Threatening Responding

Background: Irritability and callous-unemotional (CU; reduced guilt/empathy) traits vary dimensionally in the typically developing population but may be particularly marked in youth with conduct disorder (CD). While these dimensional traits are positively correlated, they have been associated with divergent forms of dysfunction, particularly with respect to threat processing (i.e., irritability with increased, and CU traits with decreased, threat responsiveness). This suggests that interactions between these two dimensions may be complex at the neurobiological level. However, this issue has received minimal empirical attention. Methods: The study included 105 adolescents (typically developing and cases with CD; N = 59). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding. Results: Significant irritability-by-CU traits-by-Direction-by-Emotion interactions were seen within right thalamus/PAG, left lingual gyrus and right fusiform gyrus; irritability was positively associated with the BOLD response for Looming Threatening vs. Receding Threatening trials, particularly for youth with low CU traits. In contrast, CU traits were negatively associated with the same differential BOLD response but particularly for youth showing higher levels of irritability. Similar findings were seen within left ventral anterior and posterior cingulate cortices, though the addition of the interaction with CU traits was only seen at slightly more lenient thresholds. Conclusions: The results support previous work linking irritability to increased, and CU traits to reduced, threat responsiveness. However, for adolescents with high irritability, if CU traits are also high, the underlying neuropathology appears to relate to reduced, rather than increased, threat responsiveness.

Emotion regulation in adolescents: Influences of internal representations of relationships - An ERP study

Emotion regulation (ER) strategies can decrease the intensity or modify the experience of emotions. Deficits in emotion regulation are implicated in a wide range of psychopathologies. It is argued that interpersonal, socio-cognitive, and developmental variables play an important role in ER. This is the first study to explore the contribution of individual differences in internal representations of relationships (IRR) to neural correlates of ER in a sample of adolescents. Event related potentials of 53 adolescents (12 to 17 years old) were collected while performing an ER task. IRR was assessed with the social cognition and object relations scale (SCORS-G; Westen, 1995) coding of narratives from interviews. Results show that individual differences in IRR significantly predicted the modulation of emotional responses by expressive suppression in adolescents, accounting for 48% of the variance of changes in occipital late positive potentials (LPP). Thus, it appears that IRR are implicated in an individual's ability to regulate emotions. The clinical implications of the findings are discussed.

Face Emotion Processing in Pediatric Irritability: Neural Mechanisms in a Sample Enriched for Irritability With Autism Spectrum Disorder

OBJECTIVE

Characterizing the pathophysiology of irritability symptoms from a dimensional perspective above and beyond diagnostic boundaries is key to developing mechanism-based interventions that can be applied broadly. Face emotion processing deficits are present in youths with elevated levels of irritability. The present study aimed to identify the neural mechanisms of face emotion processing in a sample enriched for irritability by including youths with high-functioning autism spectrum disorder (HF-ASD).

METHOD

Youths (N = 120, age = 8.3-19.2 years) completed an implicit face emotion task during functional magnetic resonance imaging. We evaluated how irritability, measured dimensionally, above and beyond diagnostic group, relates to whole-brain neural activation and amygdala connectivity in response to face emotions.

RESULTS

Both neural activation and amygdala connectivity differed as a function of irritability level and face emotion in the prefrontal cortex. Youths with higher irritability levels had decreased activation in response to both fearful and happy faces in the left middle frontal gyrus and to happy faces in the left inferior frontal gyrus. Furthermore, increased irritability levels were associated with altered right amygdala connectivity to the left superior frontal gyrus when viewing fearful and sad faces.

CONCLUSION

The neural mechanisms of face emotion processing differ in youths with higher irritability compared to their less irritable peers. The findings suggest that these irritability mechanisms may be common to both typically developing and HF-ASD youths. Understanding the neural mechanisms of pediatric irritability symptoms that cut across diagnostic boundaries may be leveraged for future intervention development.

Association between irritability and suicidal ideation in three clinical trials of adults with major depressive disorder

Irritability in pediatric samples is associated with higher rates of subsequent suicide-related outcomes. No study, to date, has evaluated the longitudinal association between irritability and suicidal ideation (SI) in adults with major depressive disorder (MDD). This report evaluated whether irritability is associated with SI at the same visit (i.e., concurrently) and whether early changes in irritability with antidepressant treatment predict subsequent levels of SI. Participants of Combining Medications to Enhance Depression Outcomes (CO-MED, n = 665), Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC, n = 296), and Suicide Assessment Methodology Study (SAMS, n = 266) were included. Repeated-measures mixed model analyses evaluated concurrent association throughout the trial between irritability (five-item irritability domain of Concise Associated Symptom Tracking scale) and SI (three-item suicidal thoughts factor of Concise Health Risk Tracking scale) after controlling for overall depression (excluding suicidality-related item), and predicted subsequent levels of SI (repeated observations from week-2-to-week-8) based on early (baseline-to-week-2) changes in irritability after controlling for early changes in overall depression. Higher irritability was associated with higher SI concurrently; estimates (standard error) were 0.18 (0.02, p < 0.0001), 0.64 (0.02, p < 0.0001), and 0.26 (0.04, p < 0.0001) in CO-MED, EMBARC, and SAMS respectively. Greater baseline-to-week-2 reductions in irritability predicted lower levels of subsequent SI; estimates (standard errors) were -0.08 (0.03, p = 0.023), -0.50 (0.05, p < 0.0001), and -0.12 (0.05, p = 0.024) in CO-MED, EMBARC, and SAMS, respectively. Controlling for anxiety or insomnia produced similar results. In conclusion, irritability and SI were consistently linked in adults with MDD. These findings support careful assessment of irritability in suicide risk assessment.

Effects of Irritability of the Youth on Subjective Well-Being: Mediating Effect of Coping Styles

BACKGROUND

The global COVID-19 pandemic caused great impacts and influences to human psychology. As a result, youths who are kept at home for a long time easily develop irritability and problematic behaviors. However, relatively little attention has been paid to the relations among irritability, coping style, and subjective well-being of the youth.

METHODS

Overall, 1,033 youth respondents (aged 18-30 yr) from seven provinces in China were investigated in 2020 using the irritability, depression, and anxiety scale, coping style scale, and well-being index scale.

RESULTS

Among the dimensions of irritability of the youth, anxiety received the highest score, followed by introversion irritability, extroversion irritability, and depression. Irritability had significant regional differences. The total score of irritability among rural youth was significantly higher than that of urban youth (P<0.05). The irritability level of youths with parents' emotional status was harmonious and good relations with family members and peers was far lower than those of youths who have poor relations between parents, family members, and peers (P<0.05). The irritability level of youths with a lower monthly household income was higher (P<0.05). Irritability of the youth had significantly negative correlations with positive response and SWB, and it had a significantly positive correlative with negative response. Coping style can mediate the relationship between irritability and SWB of the youth to some extent.

CONCLUSION

Significant correlations exist among irritability, coping style, and SWB of the youth. Irritability can be used to predict SWB indirectly through positive response.

Emotional distractors and attentional control in anxious youth: eye tracking and fMRI data

Attentional control theory suggests that high cognitive demands impair the flexible deployment of attention control in anxious adults, particularly when paired with external threats. Extending this work to pediatric anxiety, we report two studies utilising eye tracking (Study 1) and functional magnetic resonance imaging (Study 2). Both studies use a visual search paradigm to examine anxiety-related differences in the impact of threat on attentional control at varying levels of task difficulty. In Study 1, youth ages 8-18 years (N = 109), completed the paradigm during eye tracking. Results indicated that youth with more severe anxiety took longer to fixate on and identify the target, specifically on difficult trials, compared to youth with less anxiety. However, no anxiety-related effects of emotional distraction (faces) emerged. In Study 2, a separate cohort of 8-18-year-olds (N = 72) completed a similar paradigm during fMRI. Behaviourally, youth with more severe anxiety were slower to respond on searches following non-threatening, compared to threatening, distractors, but this effect did not vary by task difficulty. The same interaction emerged in the neuroimaging analysis in the superior parietal lobule and precentral gyrus-more severe anxiety was associated with greater brain response following non-threatening distractors. Theoretical implications of these inconsistent findings are discussed.

Neural and behavioral correlates of inhibitory control in youths with varying levels of irritability

BACKGROUND

Irritability, a relatively lowered threshold for anger, is prevalent in typically and atypically developing youths. Inhibitory control, the ability to suppress behaviors counter to goals, is essential for regulating emotions, including anger. Understanding how irritability relates to behavioral and neural markers of inhibitory control may inform interventions.

METHODS

Youths (N=52; mean age=13.78) completed a Flanker task on an iPad to measure behavioral correlates of inhibitory control; a subsample (n=19; mean age=13.21) additionally completed a similar task while undergoing fMRI acquisition to evaluate inhibitory control on a neural level. Irritability was measured using the Affective Reactivity Index. Associations between irritability and inhibitory control were evaluated behaviorally (via Pearson correlations), and neurally (via ANCOVAs with whole-brain activation and amygdala connectivity).

RESULTS

fMRI results indicated that higher levels of irritability were associated with aberrant activation (in middle frontal gyrus, amygdala/parahippocampal gyrus, anterior cingulate, lentiform nucleus/striatum) and left amygdala connectivity (with middle temporal gyrus, parahippocampal gyrus, posterior cingulate, fusiform gyrus, and thalamus). Behavioral results were mixed.

LIMITATIONS

Longitudinal studies are needed to characterize changes in neural circuitry and delineate whether the brain profiles precede or are a consequence of symptoms. Larger samples powered to examine multiple irritability-related symptom dimensions will be necessary to elucidate shared vs. disorder-specific irritability mechanisms.

CONCLUSIONS

Findings suggest that pediatric irritability may be related to neural processes involving inhibitory control. Further, findings underscore the importance of neuroimaging in investigating symptom dimensions such as irritability, as neuroimaging may be more sensitive in detecting underlying abnormalities compared to behavioral data alone.

Multi-method assessment of irritability and differential linkages to neurophysiological indicators of attention allocation to emotional faces in young children

Facilitated attention toward angry stimuli (attention bias) may contribute to anger proneness and temper outbursts exhibited by children with high irritability. However, most studies linking attention bias and irritability rely on behavioral measures with limited precision and no studies have explored these associations in young children. The present study explores irritability-related attention biases toward anger in young children (N = 128; ages 4-7 years) engaged in a dot-probe task with emotional faces, as assessed with event-related brain potential (ERP) indices of early selective attention and multi-method assessment of irritability. Irritability assessed via semi-structured clinical interview predicted larger anterior N1 amplitudes to all faces. In contrast, irritability assessed via a laboratory observation paradigm predicted reduced P1 amplitudes to angry relative to neutral faces. These findings suggest that altered early attentional processing occurs in young children with high irritability; however, the nature of these patterns may vary with methodological features of the irritability assessments. Future investigations using different assessment tools may provide greater clarity regarding the underlying neurocognitive correlates of irritability. Such studies may also contribute to the ongoing debates about how to best define and measure irritability across the developmental spectrum in a manner that is most informative for linkage to neural processes.

Attention shifting in the context of emotional faces: Disentangling neural mechanisms of irritability from anxiety

BACKGROUND

Irritability predicts concurrent and prospective psychiatric disorders across the lifespan. Anxiety commonly co-occurs with irritability, and such comorbidity complicates care. Understanding the mechanisms of comorbid traits is necessary to inform treatment decisions. This study aimed to disentangle neural mechanisms of irritability from anxiety in the context of attentional shifting toward and away from emotional faces in youths from treatment-seeking families.

METHODS

Youths (N = 45), mean age = 14.01 years (standard deviation = 1.89) completed a dot-probe task during functional magnetic resonance imaging acquisition. Whole-brain activation analyses evaluated the effect of irritability on neural reactivity in the context of varying attentional shifting toward and away from emotional faces, both depending on and above and beyond anxiety (i.e., with anxiety as [a] a moderator and [b] a covariate, respectively).

RESULTS

Higher irritability levels related to distinct task-related patterns of cuneus activation, depending on comorbid anxiety levels. Increased irritability also related to distinct task-related patterns of parietal, temporal, occipital, and cerebellar activation, controlling for anxiety. Overall, youths with higher levels of irritability evinced more pronounced fluctuations in neural reactivity across task conditions.

CONCLUSION

The present study contributes to a literature delineating the unique and shared neural mechanisms of overlapping symptom dimensions, which will be necessary to ultimately build a brain- and behavior-based nosology that forms the basis for more targeted and effective treatments.

Comorbid anxiety and irritability symptoms and their association with cognitive functioning in children with ADHD

Anxiety and irritability symptoms frequently co-occur in children with Attention-Deficit/Hyperactivity Disorder (ADHD). This study aims to investigate whether irritability and anxiety are uniquely associated with performance on measures of cognitive functioning in children with ADHD and whether these associations hold when accounting for confounding variables. Baseline data was used from a randomised controlled trial of cognitive behavioural therapy for anxiety in children with ADHD (N = 219, 8-13 years). Anxiety was assessed using the child- and parent-reported Spence Children's Anxiety Scale, while irritability was assessed using the parent-reported Affective Reactivity Index. Children completed the National Institutes of Health Toolbox - Cognition Battery. Higher symptoms of anxiety were uniquely associated with performance on the Dimensional Card Change Sort Test (β = -2.75, confidence interval (CI) [-4.97, -.52], p = .02) and the List Sort Working Memory Test (β = -2.57, CI [-4.43, -.70], p = .01), while higher symptoms of irritability were negatively associated with Picture Vocabulary Test (β = -2.00, CI [-3.83, -.16], p = .03). These associations did not survive correction for multiple comparisons. There was little evidence of an association between anxiety or irritability symptoms and cognitive functioning. Frequent co-occurrence of anxiety and irritability suggests clinicians working with children with ADHD should assess co-morbid symptom profiles to inform the provision of optimum care.

Advances in the Conceptualization, Assessment, and Treatment of Pediatric Irritability

Pediatric irritability is a functionally impairing transdiagnostic symptom underlying a substantial proportion of child mental health referrals. The past 20 years have witnessed a striking uptick in empirical work focused on pediatric irritability, with increasing recognition of its role across multiple internalizing and externalizing disorders. That said, it has only been in recent years that research has begun to make advances in understanding the natural course and neurobiological underpinnings of irritability across development; research directly informing effective clinical management of pediatric irritability has been limited. At this critical stage in the study of pediatric irritability, this special series brings together the latest work from leading experts across three interrelated domains: (a) progress in understanding the phenomenology and course of pediatric irritability; (b) advances in the assessment of pediatric irritability; and (c) innovations in the treatment of pediatric irritability. The papers in this special series collectively offer critical steps forward for better understanding pediatric irritability and improving proper assessment, classification, and clinical management.

Exploring Longitudinal Mechanisms of Irritability in Children: Implications for Cognitive-Behavioral Intervention

Severe irritability is a common and clinically important problem longitudinally associated with internalizing and externalizing problems in children. To better understand these mechanisms and to inform treatment research, we tested cognitive-behavioral processes as candidate mediators in the paths from irritability to later problems. Methods: A school sample (N = 238, 48% female, ages 8-10) was assessed at ~6-month intervals in fall (T1) and spring (T2) of third to fourth grade, and again the following fall (T3). Measures assessed irritability (T1/predictor); anger and sadness coping, intolerance of uncertainty, and rumination; (T1-T2/mediators); and anxiety, depressive symptoms, reactive aggression, and oppositionality (T1-T3/outcomes). Focused cross-lagged panel models, controlling for gender and grade, were specified to examine full (X_T1 ➔ M_T2 ➔ Y_T3) and half (X_T1 ➔ M_T2; M_T1 ➔ Y_T2) longitudinal mediation. Across one or more intervals, irritability predicted higher depressive symptoms, anxiety, reactive aggression, oppositionality, intolerance of uncertainty, and poor emotion coping. From T1 irritability to T2/T3 outcomes, mediation was found for poor sadness coping leading to reactive aggression and oppositionality; poor anger coping to anxiety, depressive symptoms, and oppositionality; and intolerance of uncertainty to anxiety. Results offer further evidence for internalizing and externalizing outcomes of youth irritability and new evidence suggesting underlying mechanisms. Irritability may confer risk for externalizing problems via poor sadness/anger coping, and for internalizing problems via poor anger coping and intolerance of uncertainty. Theoretical models and psychosocial treatment should consider addressing regulation of various unpleasant emotions as well as psychological flexibility and tolerating uncertainty.

Bi-Directional Relationships Between Psychological Symptoms and Environmental Factors in Early Adolescence

AIM

Bi-directional relationships between various environmental factors and psychological symptoms can be seen from childhood to adolescence; however, there has been little prospective cohort study, which investigated the relationships simultaneously. In this study, we first distinguished specific psychological symptoms from general psychopathology using bifactor modeling and then tested the relationships between psychological symptoms and environmental factors from childhood to early adolescence using a structural equation model (SEM).

METHODS

The analyses were based on Tokyo TEEN Cohort (TTC) data collected between October 2012 and March 2016. We obtained self-reported psychological symptoms and environmental factors from both parents and children (at their ages of 10 and 12). Participants were 3,171 children aged 10 [girls = 1,487 (46.9%), mean age, SD = 10.2, 0.28] and subsequently 12 (N = 3,007, follow-up rate 94.8%, mean age, SD = 12.2, 0.31) from three municipalities in Tokyo area.

RESULTS

The best-fit symptom models included four unique factors and general psychopathology as the common factor. Combining the good fit bifactor model and the SEM, positive relationships between symptoms and environmental factors at the same waves and some bi-directional relationships were found. Especially, general psychopathology at age 10 was associated with bullying at age 12 and parental depressive symptoms at age 10 with general psychopathology at age 12. However, some negative relationships such as bullying/bullied involvement and later psychological symptoms were also seen.

CONCLUSION

By using the newly introduced methodology, our results were partly consistent with previous literature. Further studies are needed to validate this methodology and accelerate the findings regarding the emergence of psychological symptoms and the impact of environmental factors from childhood to early adolescence.

Accelerated cortical thinning within structural brain networks is associated with irritability in youth

Irritability is an important dimension of psychopathology that spans multiple clinical diagnostic categories, yet its relationship to patterns of brain development remains sparsely explored. Here, we examined how transdiagnostic symptoms of irritability relate to the development of structural brain networks. All participants (n = 137, 83 females) completed structural brain imaging with 3 Tesla MRI at two timepoints (mean age at follow-up: 21.1 years, mean inter-scan interval: 5.2 years). Irritability at follow-up was assessed using the Affective Reactivity Index, and cortical thickness was quantified using Advanced Normalization Tools software. Structural covariance networks were delineated using non-negative matrix factorization, a multivariate analysis technique. Both cross-sectional and longitudinal associations with irritability at follow-up were evaluated using generalized additive models with penalized splines. The False Discovery Rate (q < 0.05) was used to correct for multiple comparisons. Cross-sectional analysis of follow-up data revealed that 11 of the 24 covariance networks were associated with irritability, with higher levels of irritability being associated with thinner cortex. Longitudinal analyses further revealed that accelerated cortical thinning within nine networks was related to irritability at follow-up. Effects were particularly prominent in brain regions implicated in emotion regulation, including the orbitofrontal, lateral temporal, and medial temporal cortex. Collectively, these findings suggest that irritability is associated with widespread reductions in cortical thickness and accelerated cortical thinning, particularly within the frontal and temporal cortex. Aberrant structural maturation of regions important for emotional regulation may in part underlie symptoms of irritability.

Overlapping dimensional phenotypes of impulsivity and compulsivity explain co-occurrence of addictive and related behaviors

OBJECTIVE

Impulsivity and compulsivity have been implicated as important transdiagnostic dimensional phenotypes with potential relevance to addiction. We aimed to develop a model that conceptualizes these constructs as overlapping dimensional phenotypes and test whether different components of this model explain the co-occurrence of addictive and related behaviors.

METHODS

A large sample of adults (N = 487) was recruited through Amazon's Mechanical Turk and completed self-report questionnaires measuring impulsivity, intolerance of uncertainty, obsessive beliefs, and the severity of 6 addictive and related behaviors. Hierarchical clustering was used to organize addictive behaviors into homogenous groups reflecting their co-occurrence. Structural equation modeling was used to evaluate fit of the hypothesized bifactor model of impulsivity and compulsivity and determine the proportion of variance explained in the co-occurrence of addictive and related behaviors by each component of the model.

RESULTS

Addictive and related behaviors clustered into 2 distinct groups: Impulse-Control Problems, consisting of harmful alcohol use, pathological gambling, and compulsive buying, and Obsessive-Compulsive-Related Problems, consisting of obsessive-compulsive symptoms, binge eating, and internet addiction. The hypothesized bifactor model of impulsivity and compulsivity provided the best empirical fit, with 3 uncorrelated factors corresponding to a general Disinhibition dimension, and specific Impulsivity and Compulsivity dimensions. These dimensional phenotypes uniquely and additively explained 39.9% and 68.7% of the total variance in Impulse-Control Problems and Obsessive-Compulsive-Related Problems.

CONCLUSION

A model of impulsivity and compulsivity that represents these constructs as overlapping dimensional phenotypes has important implications for understanding addictive and related behaviors in terms of shared etiology, comorbidity, and potential transdiagnostic treatments.

Irritability and brain volume in adolescents: cross-sectional and longitudinal associations

Irritability is garnering increasing attention in psychiatric research as a transdiagnostic marker of both internalizing and externalizing disorders. These disorders often emerge during adolescence, highlighting the need to examine changes in the brain and in psychological functioning during this developmental period. Adolescents were recruited for a longitudinal study examining the effects of early life stress on the development of psychopathology. The 151 adolescents (73 M/78 F, average age = 11.5 years, standard deviation = 1.1) were scanned with a T1-weighted MRI sequence and parents completed reports of adolescent irritability using the Affective Reactivity Index. Of these 151 adolescents, 94 (46 M/48 F) returned for a second session (average interval = 1.9 years, SD = 0.4). We used tensor-based morphometry to examine cross-sectional and longitudinal associations between irritability and regional brain volume. Irritability was associated with brain volume across a number of regions. More irritable individuals had larger hippocampi, insula, medial orbitofrontal cortex and cingulum/cingulate cortex and smaller putamen and internal capsule. Across the brain, more irritable individuals also had larger volume and less volume contraction in a number of areas that typically decrease in volume over the developmental period studied here, suggesting delayed maturation. These structural changes may increase adolescents' vulnerability for internalizing and externalizing disorders.

Brain structure changes induced by attention bias modification training

Attention bias modification (ABM) therapy aims to reduce anxiety by changing threat-related attention patterns using computerized training tasks. We examined changes in brain microstructure following ABM training. Thirty-two participants were randomly assigned to one of two training conditions: active ABM training shifting attention away from threat or attention control training involving no attention modification. Participants completed six lab visits, including five training sessions and three diffusion tensor imaging scans: immediately before and after the first training session, and at the end of the training series. Indices of local and global changes in microstructure and connectivity were measured. Significant longitudinal differences in fractional anisotropy (FA) between the active and control training regimens occurred in inferior temporal cortex. Changes in FA occurred across groups within ventromedial prefrontal cortex and middle occipital gyrus. These results indicate specific effects of active ABM on brain structure. Such changes could relate to clinical effects of ABM.

Exposure therapy for pediatric irritability: Theory and potential mechanisms

Pediatric irritability is prevalent and impairing, yet little is known about its pathophysiology and treatment. In this article, we build on our and others' previous work to posit core mechanisms of irritability operating across the brain, behavior, and environment. Specifically, we propose proximal processes that surround the symptomatology of irritability and are potential targets for an exposure-based cognitive-behavioral therapy (CBT) for irritability that our group has developed. The heart of this model focuses on neurocognitive processes: youth's encoding of nonreward and threat stimuli, which involves prediction error signaling in the brain, and cognitive control in the context of frustration. Alterations in these processes are theorized to be central to chronic, severe irritability. Environmental responses to youth's symptom expression are also examined. Exposure-based CBT for irritability utilizes controlled, in vivo exposure to nonreward and threat stimuli with the aim to engage cognitive control and target top-down regulation of frustration. This intervention integrates selected parent management training techniques to target symptom reinforcement processes. Continued pathophysiological and treatment studies of irritability will not only refine our emerging understanding of the phenotype, but also inform broader questions on the brain and behavioral mechanisms of CBT efficacy.

Toddler Temperament Mediates the Effect of Prenatal Maternal Stress on Childhood Anxiety Symptomatology: The QF2011 Queensland Flood Study

It is not known whether alterations to temperamental characteristics associated with prenatal maternal stress (PNMS) exposure account for the development of childhood anxiety symptomatology (internalizing behaviors and anxiety symptoms). The QF2011 Queensland flood study examined whether (1) toddler temperamental characteristics explained the association between PNMS exposure and childhood anxiety symptomatology; and (2) whether effects were dependent upon child sex or the timing of gestational exposure to PNMS. We investigated the effects of various aspects of flood-related stress in pregnancy (objective hardship, cognitive appraisal, subjective distress) on maternal report of 16-month toddler temperament (attentional control, shy-inhibition, negative reactivity), 4-year maternal-reported childhood anxiety symptomatology (internalizing and anxiety symptoms; N = 104), and teacher reports of internalizing behaviors (N = 77). Severity of maternal objective hardship during pregnancy and shy-inhibited behaviors were uniquely associated with 4-year child anxiety symptoms. Mediation analyses found that higher levels of 16-month negative reactivity accounted, in part, for the relationship between increased maternal objective flood-related hardship and greater internalizing behaviors (maternal but not teacher report). Neither child sex nor gestational timing of exposure moderated the hypothesized mediations. Our findings highlight several pathways through which varying aspects of disaster-related PNMS may influence early childhood anxiety symptomatology.

Parsing neurodevelopmental features of irritability and anxiety: Replication and validation of a latent variable approach

Irritability and anxiety are two common clinical phenotypes that involve high-arousal negative affect states (anger and fear), and that frequently co-occur. Elucidating how these two forms of emotion dysregulation relate to perturbed neurodevelopment may benefit from alternate phenotyping strategies. One such strategy applies a bifactor latent variable approach that can parse shared versus unique mechanisms of these two phenotypes. Here, we aim to replicate and extend this approach and examine associations with neural structure in a large transdiagnostic sample of youth (N = 331; M = 13.57, SD = 2.69 years old; 45.92% male). FreeSurfer was used to extract cortical thickness, cortical surface area, and subcortical volume. The current findings replicated the bifactor model and demonstrate measurement invariance as a function of youth age and sex. There were no associations of youth's factor scores with cortical thickness, surface area, or subcortical volume. However, we found strong convergent and divergent validity between parent-reported irritability and anxiety factors with clinician-rated symptoms and impairment. A general negative affectivity factor was robustly associated with overall functional impairment across symptom domains. Together, these results support the utility of the bifactor model as an alternative phenotyping strategy for irritability and anxiety, which may aid in the development of targeted treatments.

Inhibitory control and emotion dysregulation: A framework for research on anxiety

While emotional dysregulation is a broad construct, the current paper adopts a narrow approach to facilitate translational neuroscience research on pediatric anxiety. The paper first presents data on an adapted version of the antisaccade task and then integrates these data into a research framework. Data on an adapted version of the antisaccade task were collected in 57 youth, including 35 seeking treatment for an anxiety disorder. Associations were examined between performance on the antisaccade task and (a) age, (b) performance on other cognitive-control tasks (i.e., the stop-signal delay and flanker tasks), and (c) level of anxiety symptoms. Better performance on the antisaccade task occurred in older relative to younger subjects and correlated with better performance on the flanker task. Across the 57 youth, higher levels of anxiety correlated with shorter latency for correct antisaccades. These data can be placed within a three-step framework for translational neuroscience research. In the first step, a narrow index of emotion dysregulation is targeted. In the second step, this narrow index is linked to other correlated indicators of the same underlying narrow latent construct. In the third and final step, associations are examined with clinical outcomes and response to treatment.

Socioeconomic hardship and delayed reward discounting: Associations with working memory and emotional reactivity

Prolonged exposure to socioeconomic hardship (SH) is associated with greater delayed reward discounting (DRD), a form of impulsive decision-making that reflects a reduced capacity to delay gratification and a significant correlate of diverse risk behaviors, but the neurobehavioral mechanisms linking SH and DRD are unknown. An emerging hypothesis suggests that cognitive and affective stress associated with poverty may tax neurocognitive functions, such as working memory (WM), and lead to impulsive DRD. Furthermore, research suggests that emotional reactivity (ER) is an important dispositional factor to consider in the link between executive functions and DRD. Thus, we longitudinally examined the indirect effect of SH on impulsive DRD via a network of brain regions associated with WM function in a sample of young adults, and whether that link was moderated by ER. Participants were 119 rural African Americans (aged 19–24 years) assessed behaviorally on four occasions, with fMRI at the last time point. Results showed that, among emerging adults with higher ER, SH severity was predictive of increased DRD via reduced response in brain regions activated during an n-back WM task. These findings reveal both the cognitive and affective mechanisms that underlie the relationship between SH and DRD.

Structural Brain Connectivity in Childhood Disruptive Behavior Problems: A Multidimensional Approach

BACKGROUND

Studies of white matter connectivity in children with disruptive behavior have yielded inconsistent results, possibly owing to the trait's heterogeneity, which comprises diverse symptoms like physical aggression, irritability, and delinquency. This study examined associations of global and specific white matter connectivity with childhood disruptive behavior problems, while accounting for their complex multidimensionality.

METHODS

In a large cross-sectional population-based study of 10-year-old preadolescents (n = 2567), we assessed four previously described empirically derived dimensions of disruptive behavior problems using the Child Behavior Checklist: physical aggression, irritability, disobedient behavior, and delinquent behavior. Global and specific white matter microstructure was assessed by diffusion tensor imaging.

RESULTS

Global fractional anisotropy and mean diffusivity were not associated with broad measures of disruptive behavior, e.g., Child Behavior Checklist externalizing problems scale. Global fractional anisotropy was negatively associated with delinquent behavior (β = -.123, p_{false discovery rate adjusted} = .028) and global mean diffusivity was positively associated with delinquent behavior (β = .205, p_{false discovery rate adjusted} < 0.001), suggesting reduced white matter microstructure in preadolescents with higher levels of delinquent behavior. Lower white matter microstructure in the inferior longitudinal fasciculus, superior longitudinal fasciculus, cingulum, and uncinate underlie these associations. Global white matter microstructure was not associated with physical aggression, irritability, or disobedient behavior.

CONCLUSIONS

Delinquent behavior, a severe manifestation of childhood disruptive behavior, was associated with lower white matter microstructure in tracts connecting frontal and temporal lobes. These brain regions are involved in decision making, reward processing, and emotion regulation. This study demonstrated that incorporating the multidimensional nature of childhood disruptive behavior traits shows promise in advancing the search for elucidating neurobiological correlates of disruptive behavior.

A single dose of fluoxetine reduces neural limbic responses to anger in depressed adolescents

Depression in adolescence is frequently characterised by symptoms of irritability. Fluoxetine is the antidepressant with the most favourable benefit:risk ratio profile to treat adolescent depression, but the neural mechanisms underlying antidepressant drugs in the young brain are still poorly understood. Previous studies have characterised the neural effects of long-term fluoxetine treatment in depressed adolescents, but these are limited by concurrent mood changes and a lack of placebo control. There is also recent evidence suggesting that fluoxetine reduces the processing of anger in young healthy volunteers, which is consistent with its effect for the treatment of irritability in this age group, but this remains to be investigated in depressed adolescents. Here we assessed the effects of a single, first dose of 10 mg fluoxetine vs. placebo on neural response to anger cues using fMRI in a sample of adolescents with Major Depressive Disorder (MDD) who had been recently prescribed fluoxetine. As predicted, adolescents receiving fluoxetine showed reduced activity in response to angry facial expressions in the amygdala-hippocampal region relative to placebo. Activity in the dorsal anterior cingulate cortex (dACC) was also increased. No changes in symptoms were observed. These results demonstrate, for the first time in depressed adolescents, that fluoxetine has immediate neural effects on core components of the cortico-limbic circuitry prior to clinical changes in mood. The effect on anger is consistent with our previous work and could represent a key mechanism through which fluoxetine may act to alleviate irritability symptoms in adolescent depression.

Brain Mechanisms of Attention Orienting Following Frustration: Associations With Irritability and Age in Youths

OBJECTIVE

Childhood irritability is a common, impairing problem with changing age-related manifestations that predict long-term adverse outcomes. However, more investigation of overall and age-specific neural correlates is needed. Because youths with irritability exhibit exaggerated responses to frustrating stimuli, the authors used a frustration functional MRI (fMRI) paradigm to examine associations between irritability and neural activation and tested the moderating effect of age.

METHOD

The authors studied a transdiagnostic sample of 195 youths with varying levels of irritability (disruptive mood dysregulation disorder, N=52; anxiety disorder, N=42; attention deficit hyperactivity disorder, N=40; and healthy volunteers, N=61). Irritability was measured by parent and child reports on the Affective Reactivity Index. The fMRI paradigm was a cued-attention task differentiating neural activity in response to frustration (rigged feedback) from activity during attention orienting in the trial following frustration.

RESULTS

Whole-brain activation analyses revealed associations with irritability during attention orienting following frustration. Irritability was positively associated with frontal-striatal activation, specifically in the dorsolateral prefrontal cortex, inferior frontal gyrus, and caudate. Age moderated the association between irritability and activation in some frontal and posterior regions (the anterior cingulate cortex, medial frontal gyrus, cuneus, precuneus, and superior parietal lobule [F=19.04-28.51, df=1, 189, partial eta squared=0.09-0.13]). Specifically, higher irritability was more strongly related to increased activation in younger youths compared with older youths.

CONCLUSIONS

Following frustration, levels of irritability correlated with activity in neural systems mediating attention orienting, top-down regulation of emotions, and motor execution. Although most associations were independent of age, dysfunction in the anterior cingulate cortex and posterior regions was more pronounced in young children with irritability.

Deficits in emotion recognition are associated with depressive symptoms in youth with disruptive mood dysregulation disorder

BACKGROUND

Although severe irritability is a predictor of future depression according to recent meta-analytic evidence, other mechanisms for this developmental transition remain unclear. In this study, we test whether deficits in emotion recognition may partially explain this specific association in youth with severe irritability, defined as disruptive mood dysregulation disorder (DMDD).

METHODS

Participants aged 8-20 years (M = 13.3, SD = 2.8) included youth with DMDD, split by low depressive (DMDD/LD; n = 52) and high depressive (DMDD/HD; n = 25) symptoms, and healthy controls (HC; n = 39). A standardized computer task assessed emotion recognition of faces and voices of adults and children expressing happiness, fear, sadness, and anger. A Group (3) × Emotion (4) × Actor (2) × Modality (2) repeated measures analysis of covariance examined the number of errors and misidentification of emotions. Linear regression was then used to assess whether deficits in emotion recognition were predictive of depressive symptoms at a 1 year follow-up.

RESULTS

DMDD/HD youth were more likely to interpret happy stimuli as angry and fearful compared to DMDD/LD (happy as angry: p = 0.018; happy as fearful: p = 0.008) and HC (happy as angry: p = 0.014; happy as fearful: p = 0.024). In youth with DMDD, the misidentification of happy stimuli as fearful was associated with higher depressive symptoms at follow-up (β = 0.43, p = 0.017), independent of baseline depressive and irritability symptoms.

CONCLUSIONS

Deficits in emotion recognition are associated, cross-sectionally and longitudinally, with depressive symptoms in youth with severe irritability. Future studies should examine the neural correlates that contribute to these associations.

White Matter Correlates of Mild Traumatic Brain Injuries in Women Subjected to Intimate-Partner Violence: A Preliminary Study

A large proportion (range of 44-75%) of women who experience intimate-partner violence (IPV) have been shown to sustain repetitive mild traumatic brain injuries (mTBIs) from their abusers. Further, despite requests for research on TBI-related health outcomes, there are currently only a handful of studies addressing this issue and only one prior imaging study that has investigated the neural correlates of IPV-related TBIs. In response, we examined specific regions of white matter microstructure in 20 women with histories of IPV. Subjects were imaged on a 3-Tesla Siemens Magnetom TrioTim scanner using diffusion magnetic resonance imaging. We investigated the association between a score reflecting number and recency of IPV-related mTBIs and fractional anisotropy (FA) in the posterior and superior corona radiata as well as the posterior thalamic radiation, brain regions shown previously to be involved in mTBI. We also investigated the association between several cognitive measures, namely learning, memory, and cognitive flexibility, and FA in the white matter regions of interest. We report a negative correlation between the brain injury score and FA in regions of the posterior and superior corona radiata. We failed to find an association between our cognitive measures and FA in these regions, but the interpretation of these results remains inconclusive due to possible power issues. Overall, these data build upon the small but growing literature demonstrating potential consequences of mTBIs for women experiencing IPV, and further underscore the urgent need for larger and more comprehensive studies in this area.