Underlying mechanisms of disruptive mood dysregulation disorder in children: A systematic review by means of research domain criteria

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.

Neuropsychological mechanisms of social difficulties in disruptive mood dysregulation disorder versus oppositional defiant disorder

Children with Disruptive Mood Dysregulation Disorder (DMDD) or Oppositional Defiant Disorder (ODD) are characterized by irritability and social difficulties. However, the mechanisms underlying these disorders could be different. This study explores differences in social cognition and executive function (EF) across DMDD and ODD and the influence of these factors and their interaction on social problems in both groups. Children with DMDD (n = 53, Mage = 9.3) or ODD (n = 39, Mage = 9.6) completed neuropsychological tasks measuring social cognition (Theory of Mind and Face-Emotion Recognition) and EF (cognitive flexibility, inhibition, and working memory). Parents reported social problems. More than one-third of the children with DMDD and almost two-thirds of those with ODD showed clear difficulties with Theory of Mind. Most children with DMDD (51-64%) or ODD (67-83%) showed difficulties with EF. In children with DMDD, worse EF (β = -.36) was associated with more social problems, whereas in children with ODD, better EF (β = .44) was associated with more social problems. In those with ODD, but not in those with DMDD, the interaction between social cognition and EF contributed to the explained variance of social problems (β = -1.97). Based on the observed interaction pattern, enhanced EF may lead to increased social problems among children with ODD who also exhibit social cognition difficulties. This study suggests the existence of distinct neuropsychological mechanisms underlying the social issues observed in children with DMDD versus those with ODD.

Disruptive Mood Dysregulation Disorder in a Norwegian Clinical Child Population

BACKGROUND

Disruptive Mood Dysregulation Disorder was included in DSM-5 to accommodate new research addressing aspects of emotional dysregulation in children suffering from disruptive behavior problems. Despite growing interest in Disruptive Mood Dysregulation Disorder, few studies have looked at prevalence rates in European clinical populations. The primary objective of this study was to examine the prevalence and characteristics associated with Disruptive Mood Dysregulation Disorder in a Norwegian clinical sample.

METHODS

The present study assessed children 6-12 years of age referred to a mental health clinic for evaluation and treatment (N = 218, Mage = 9.6, 60.4% boys) and compared those who did and did not meet Disruptive Mood Dysregulation Disorder diagnostic criteria. Diagnoses were determined using K-SADS-PL 2013. Associated difficulties at home and in school were measured by Achenbach Systems of Empirically Based Assessment battery.

RESULTS

In this clinical sample, 24% met the diagnostic criteria for Disruptive Mood Dysregulation Disorder. Children with Disruptive Mood Dysregulation Disorder were more likely than those without Disruptive Mood Dysregulation Disorder to be male (77% vs. 55%, p = .008), be living in poverty, have multiple mental health diagnoses (79% vs. 53%, p = .001), and have lower global functioning levels as measured by Children's Global Assessment Scale (range 0-100, M = 47, SD = 8.5 vs. M = 57, SD = 11.4, p=<.001). Finally, parents and teachers of children with Disruptive Mood Dysregulation Disorder reported lower overall competence and adaptive functioning, and higher total symptom load than children with other diagnoses.

CONCLUSION

Disruptive Mood Dysregulation Disorder is highly prevalent in a Norwegian clinical sample and displays a high symptom load. Our results are in accordance with similar studies. Consistent findings across the world may support Disruptive Mood Dysregulation Disorder as a valid diagnostic category.

Executive function in children with disruptive mood dysregulation disorder compared to attention-deficit/hyperactivity disorder and oppositional defiant disorder, and in children with different irritability levels

Addressing current challenges in research on disruptive mood dysregulation disorder (DMDD), this study aims to compare executive function in children with DMDD, children with attention-deficit/hyperactivity disorder (ADHD), and children with oppositional defiant disorder (ODD). We also explore associations between irritability, a key DMDD characteristic, and executive function in a clinical sample regardless of diagnosis. Our sample include children (6-12 years) referred to child psychiatric clinics. Measures of daily-life (parent-reported questionnaire) and performance-based (neuropsychological tasks) executive function were applied. Identifying diagnoses, clinicians administered a standardized semi-structured diagnostic interview with parents. Irritability was assessed by parent-report. First, we compared executive function in DMDD (without ADHD/ODD), ADHD (without DMDD/ODD), ODD (without DMDD/ADHD) and DMDD + ADHD (without ODD). Second, we analyzed associations between executive function and irritability using the total sample. In daily life, children with DMDD showed clinically elevated and significantly worse emotion control scores compared to children with ADHD, and clinically elevated scores on cognitive flexibility compared to norm scores. Children with DMDD had significantly less working memory problems than those with ADHD. No differences were found between DMDD and ODD. Increased irritability was positively associated with emotional dyscontrol and cognitive inflexibility. For performance-based executive function, no diagnostic differences or associations with irritability were observed. We discuss how, in daily life, children with high irritability-levels get overwhelmed by feelings without accompanying regulatory capacities.