Executive functioning moderates neural mechanisms of irritability during reward processing in youth

Annual Research Review: What processes are dysregulated among emotionally dysregulated youth? - a systematic review

Proliferation of the term "emotion dysregulation" in child psychopathology parallels the growing interest in processes that influence negative emotional reactivity. While it commonly refers to a clinical phenotype where intense anger leads to behavioral dyscontrol, the term implies etiology because anything that is dysregulated requires an impaired regulatory mechanism. Many cognitive, affective, behavioral, neural, and social processes have been studied to improve understanding of emotion dysregulation. Nevertheless, the defective regulatory mechanism that might underlie it remains unclear. This systematic review of research on processes that affect emotion dysregulation endeavors to develop an integrative framework for the wide variety of factors investigated. It seeks to ascertain which, if any, constitutes an impaired regulatory mechanism. Based on this review, we propose a framework organizing emotion-relevant processes into categories pertaining to stimulus processing, response selection and control, emotion generation, closed- or open-loop feedback-based regulation, and experiential influences. Our review finds scant evidence for closed-loop (automatic) mechanisms to downregulate anger arousal rapidly. Open-loop (deliberate) regulatory strategies seem effective for low-to-moderate arousal. More extensive evidence supports roles for aspects of stimulus processing (sensory sensitivity, salience, appraisal, threat processing, and reward expectancy). Response control functions, such as inhibitory control, show robust associations with emotion dysregulation. Processes relating to emotion generation highlight aberrant features in autonomic, endocrine, reward functioning, and tonic mood states. A large literature on adverse childhood experiences and family interactions shows the unique and joint effects of interpersonal with child-level risks. We conclude that the defective closed-loop regulatory mechanisms that emotion dysregulation implies require further specification. Integrating research on emotion-relevant mechanisms along an axis from input factors through emotion generation to corrective feedback may promote research on (a) heterogeneity in pathogenesis, (b) interrelationships between these factors, and (c) the derivation of better-targeted treatments that address specific pathogenic processes of affected youth.

Neural Correlates of Irritability and Potential Moderating Effects of Inhibitory Control

Background

Irritability affects up to 20% of youth and is a primary reason for referral to pediatric mental health clinics. Irritability is thought to be associated with disruptions in processing of reward, threat, and cognitive control; however, empirical study of these associations at both the behavioral and neural level have yielded equivocal findings that may be driven by small sample sizes and differences in study design. Associations between irritability and brain connectivity between cognitive control and reward- or threat-processing circuits remain understudied. Furthermore, better inhibitory control has been linked to lower irritability and differential neural functioning among irritable youth, suggesting that good inhibitory control may serve as a protective factor.

Methods

We hypothesized that higher irritability scores would be associated with less positive (or negative) connectivity between cognitive control and threat-processing circuits and between cognitive control and reward-processing circuits in the Healthy Brain Network dataset (release 10.0; N = 4135). We also hypothesized that these associations would be moderated by inhibitory control such that weaker associations between irritability and connectivity would be detected in youths with better than with worse inhibitory control. Regression models were used to test whether associations between irritability and between-network connectivity were moderated by inhibitory control.

Results

Counter to our hypothesis, we detected higher irritability associated with reduced connectivity between threat- and reward-processing and cognitive control networks only in 5- to 9-year-old boys. Inhibitory control did not moderate associations of irritability with between-network connectivity.

Conclusions

Exploratory findings indicate that reduced between-network connectivity may underlie difficulty regulating negative emotions, leading to greater irritability.

Neural mechanisms of reward processing in preadolescent irritability: Insights from the ABCD study

Elevated youth irritability is characterized by increased proneness to frustration relative to peers when rewards are blocked, and is a transdiagnostic symptom that predicts multiple forms of psychopathology and poorer socioeconomic outcomes in adulthood. Although mechanistic models propose that irritability is the result of aberrant reward-related brain function, youth irritability as it relates to multiple components of reward processes, including reward anticipation, gain, and loss, has yet to be examined in large, population-based samples. Data from the Adolescent Brain and Cognitive Development (ABCD) baseline sample (N = 5923) was used to examine associations between youth irritability (measured by parent-report) and reward-related brain activation and connectivity in a large, preadolescent sample. Preadolescents (M age = 9.96 years, SD = 0.63) performed the Monetary Incentive Delay task during functional MRI acquisition. In the task, during the anticipation period, participants were informed of the upcoming trial type (win money, lose money, no money at stake) and waited to hit a target; during the feedback period, participants were informed of their success. Whole brain and region of interest (ROI) analyses evaluated task conditions in relation to irritability level. Preadolescents with higher compared to lower levels of irritability demonstrated blunted prefrontal cortex activation in the anticipation period and exaggerated striatum-prefrontal connectivity differences among reward conditions during the feedback period. These effects persisted after adjusting for co-occurring anxiety, depression, and attention-deficit/hyperactivity disorder symptoms. These findings provide evidence for the role of reward salience in pathophysiological models of youth irritability, suggesting a mechanism that may contribute to exaggerated behavioral responses.

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

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

An Expanded Conceptual Framework for Understanding Irritability in Childhood: The Role of Cognitive Control Processes

Children prone to irritability experience significant functional impairments and internalising and externalising problems. Contemporary models have sought to elucidate the underlying mechanisms in irritability, such as aberrant threat and reward biases to improve interventions. However, the cognitive control processes that underlie threat (e.g., attention towards threats) and reward (e.g., attention towards reward-related cues) biases and the factors which influence the differential activation of positive and negative valence systems and thus leading to maladaptive activation of cognitive control processes (i.e., proactive and reactive control) are unclear. Thus, we aim to integrate extant theoretical and empirical research to elucidate the cognitive control processes underlying threat and reward processing that contribute to irritability in middle childhood and provide a guiding framework for future research and treatment. We propose an expanded conceptual framework of irritability that includes broad intraindividual and environmental vulnerability factors and propose proximal 'setting' factors that activate the negative valence and positive valence systems and proactive and reactive cognitive control processes which underpin the expression and progression of irritability. We consider the implications of this expanded conceptualisation of irritability and provide suggestions for future research.

Depression Severity Moderates Reward Learning Among Smokers With Current or Past Major Depressive Disorder in a Smoking Cessation Randomized Clinical Trial

INTRODUCTION

Behavioral and pharmacological smoking cessation treatments are hypothesized to increase patients' reward learning to reduce craving. Identifying changes in reward learning processes that support effective tobacco-dependence interventions among smokers who experience depression may guide patients toward efficient treatment strategies. The objective was to investigate the extent to which adult daily cigarette smokers with current or past major depressive disorder (MDD) learned to seek reward during 12 weeks of treatment combining behavioral activation and varenicline. We hypothesized that a decline in reward learning would be attenuated (least to most) in the following order: (1) behavioral activation integrated with ST (BASC) + varenicline, (2) BASC + placebo, (3) standard behavioral cessation treatment (ST) + varenicline, (4) ST + placebo.

METHODS

We ran a phase IV, placebo-controlled, randomized clinical trial with 300 participants receiving 12 weeks of one of four conditions across two urban medical centers. Depressive symptoms were measured using the Beck Depression Inventory-II (BDI). Reward learning was ascertained at weeks 1, 7, and 14 using the Probabilistic Reward Task (PRT), a laboratory task that uses an asymmetric reinforcement schedule to assess (a) learning to seek reward (response bias), (b) differentiate between stimuli, and (c) time to react to cues.

RESULTS

There was a significant interaction of BDI group × PRT response bias. Response bias declined from weeks 7 to 14 among participants with high baseline depression symptoms. The other two BDI groups showed no change in response bias.

CONCLUSIONS

Controlling for baseline depression, participants showed a decrease in response bias from weeks 1 to 14, and from weeks 7 to 14. Treatment condition and abstinence status were unassociated with change in reward learning.

IMPLICATIONS

Smokers who report greater depression severity show a decline in reward learning despite their participation in smoking cessation treatments, suggesting that depressed populations pose unique challenges with standard smoking cessation approaches.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02378714.

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

BACKGROUND

Irritability is common in multiple psychiatric disorders and is hallmark of disruptive mood dysregulation disorder. Child irritability is associated with higher risk of suicide and adulthood mental health problems. However, the psychological mechanisms of irritability are understudied. This study examined the relationship between anxiety sensitivity and irritability among youth, and further explored three possible mediated factors: selective attention for threat, delayed reward discounting, and insomnia.

METHODS

Participants were 1417 students (51.7% male; mean age 13.83 years, SD = 1.48) recruited from one high school in Hunan province, China. Self-report questionnaires were used to measure irritability (The Affective Reactivity Index and The Brief Irritability Test), anxiety sensitivity (The Childhood Anxiety Sensitivity Index), selective attention for threat (The Davos Assessment of Cognitive Biases Scale-attention for threat bias subscale), insomnia (The Youth Self-Rating Insomnia Scale), and delayed reward discounting (The 27-item Monetary Choice Questionnaire). Structural equation modal (SEM) was performed to examine mediated relations.

RESULTS

Anxiety sensitivity was modestly related to irritability and insomnia (r from 0.25 to 0.54) and slightly correlated with selective attention for threat (r from 0.12 to 0.28). However, there is no significant relationship of delayed rewards discounting with anxiety sensitivity and irritability. The results of SEM showed that selective attention for threat (indirect effect estimate = 0.04) and insomnia (indirect effect estimate = 0.20) partially mediate the relationship between anxiety sensitivity and irritability, which explained 34% variation.

CONCLUSIONS

Anxiety sensitivity is an important susceptibility factor for irritability. Selective attention for threat and insomnia are two mediated mechanisms to understand the relationship between anxiety sensitivity and irritability.

Future Directions in Youth Irritability Research

Research on irritability in children and adolescents has proliferated over the last 20 years. The evidence shows the clinical and developmental significance of irritable mood and behavior in youth, and it has led to significant changes in mental health classification, diagnosis, and services. At the same time, this research (including our own) has led to relatively little new in terms of practical, empirically based guidance to improve interventions and outcomes. In this article, we briefly summarize some of these developments and current evidence-based practices. We then put forth two key substantive challenges (the "whats") for future research to address: (a) the need for more effective treatments, especially evaluating and adapting evidence-based treatments that are already well-established for problems related to irritability (e.g., cognitive-behavioral therapies for internalizing and externalizing problems); and (b) the need for a better mechanistic understanding of irritability's phenomenology (e.g., phasic vs. tonic irritability, how frustration unfolds) and putative underlying mechanisms (e.g., cognitive control, threat and reward dysfunction). Lastly, we suggest three methodological approaches (the "hows") that may expedite progress in such areas: (a) ecological momentary assessment, (b) digital health applications, and (c) leveraging existing datasets. We hope this article will be useful for students and early-career researchers interested in tackling some of these important questions to better meet the needs of severely irritable youth.