title: Exploring the link between inhibitory control and disruptive behaviour: Implications for research and practice.
Creators: name: Bonham, Mikaela D
Publisher: name: Griffith University
Year: 2022
Subjects: subject: inhibitory control
subject: Disruptive behaviour disorders
subject: Attention-Deficit/Hyperactivity Disorder (ADHD)

description: Disruptive behaviour disorders can affect between 1 and 11% of children. Without adequate intervention, children with disruptive behaviour and their families experience social, emotional, and occupational impacts (e.g., depression, self-harm, lower academic achievement, family stress). We have yet to clearly understand the causal factors that underlie disruptive behaviour. Inhibitory control problems are a common aetiological factor associated with Attention-Deficit/Hyperactivity Disorder (ADHD), a disorder that is commonly comorbid with disruptive behaviours. What remains unclear is whether inhibitory control problems are present in disruptive behaviour disorders, such as Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD), independent of ADHD symptomatology. Determining the role of inhibitory control in ODD/CD is challenging for two reasons: 1) high comorbidity between ODD/CD and ADHD, and 2) theoretical issues in how we conceptualise inhibitory control, which is part of executive functioning. This thesis presents three papers aiming to clarify some of these issues: 1) A systematic review and meta-analysis of 25 studies examined the presence of inhibitory control problems in children with ODD/CD compared to clinical and healthy controls. Results revealed that children with ODD/CD had more difficulties with inhibitory control problems than healthy controls. Children with ODD/CD also presented with similar inhibitory control problems and ADHD symptomatology to children with ADHD. Given that inhibitory control problems are similar across clinical groups, transdiagnostic formulations of disruptive behaviour in diagnosis and treatment were discussed. 2) Based on the findings of the review, the associations between disruptive behaviours (measured by conduct problems and aggression) and inhibitory control in a community sample of 148 school aged children were explored. Another aim of this study was to understand the relationship between inhibitory control and callous-unemotional traits (CU traits) on disruptive behaviour to further extend our understanding of risk factors. Results indicated that caregivers who rated their children as having more inhibitory control problems also rated their children as more aggressive and as having more conduct problems, even after controlling for ADHD symptoms. Further, inhibitory control exacerbated the effect of CU traits on conduct problems, but not aggression. The results of this study identified unique relationships between inhibitory control and CU traits on disruptive behaviour, laying the groundwork for future studies to explore their role in the aetiology of disruptive behaviours. 3) Across studies, the challenges inherent in the executive function literature appeared to limit our understanding of inhibitory control. These challenges were explored by a critical review of the executive dysfunction literature. Results highlighted that a divergence of theoretical frameworks has negatively impacted upon operationalisation, measurement, and translation of research results on executive function into clinical practice. The development of clinical guidelines for executive dysfunction was recommended as a next step in bridging the research-practice gap, with a focus on the inclusion of key stakeholders (i.e., health professionals and consumers) in the process. The results of this thesis have key implications for the conceptualisation of disruptive behaviours from a dimensional perspective, specifically that inhibitory control difficulties are likely to play a critical aetiological role in disruptive behaviour. Inhibitory control difficulties, which cut across disorders, may be an important consideration in complementary approaches to intervention and future iterations of diagnostic manuals. Further, this thesis highlights the need for consensus within the executive function research, to provide clarity on theoretical underpinnings and allow for more meaningful results which can inform better care for consumers.