Exploring the Dynamic, Multidimensional Risk Factors of ADHD
Bradley McEwen | PhD, MHSc( Hum Nutr), MPH, BHSc, AdvDipNat, DBM, DNutr, DSM, Fellow ATMS, Naturopath Nutritionist, and Mentor. Adjunct Senior Lecturer, Faculty of Health, Southern Cross University.
Abstract
Attention‐Deficit / Hyperactivity Disorder( ADHD) is not a fixed childhood disorder. It is a dynamic, lifelong, multifactorial condition. The hallmarks of ADHD are inattention, impulsivity, and hyperactivity. This article provides a brief overview of the prevalence and symptoms of ADHD and explores the various risk factors of ADHD, including genetics, thyroid dysfunction, physical trauma, asthma, microbiome, gut-brain axis, lead exposure, tobacco smoke, alcohol, and other risk factors linked with ADHD( such as preterm birth, family adversity, and exposure to organochlorines, polychlorinated biphenyls, mercury, and organophosphate pesticides).
Introduction
Attention-deficit hyperactivity disorder( ADHD) is not a new condition. 1 The signs and symptoms of ADHD have been described in medical literature since the 1770s. 1 ADHD is a common neurodevelopmental disorder that is widely observed across the globe. 2 ADHD is one of the most common childhood disorders 3 and represents one of the most common disorders in individuals observed from childhood through to adulthood. 2, 4, 5
The hallmarks of ADHD are inattention, 2, 4, 5 impulsivity, 2, 4, 5 and hyperactivity, 2, 4, 5 which significantly affect the cognitive, 2 behavioural, 2 and emotional 2 aspects of individuals. Inattention, hyperactivity, and impulsivity of ADHD can be described as actions that are premature and lacking in thought( impulsivity), excessive and restless movement( hyperactivity), and a disorganised approach that hinders sustained effort( inattention). 5 Inattention refers to difficulty maintaining focus on tasks and activities requiring organisational skills, often due to challenges in understanding and processing information. 4 Hyperactivity involves excessive movement or restlessness, such as fidgeting or inappropriate physical activity. 4 Impulsivity is characterised by actions or speech that occur without thought. 4 The characterisations of ADHD highlight difficulties and challenges with selfcontrol and self-regulation, along with a tendency to act without considering potential consequences. 4
There are numerous risk factors for ADHD, some of which include genetics, 6 thyroid dysfunction, 7 physical trauma, 8 asthma, 9 microbiome, 5 gut-brain axis, lead exposure, 10, 11 tobacco smoke, 12-14 alcohol consumption, 14, 15 preterm birth, 16 family adversity, 17 and exposure to organochlorines, 18 polychlorinated biphenyls, 10, 11 mercury, 10 and
10, 19 organophosphate pesticides.
The economic and wellbeing costs of ADHD in Australia are estimated to be $ 20 billion annually. 20 It is timely for Australia to move towards a more ethical, evidence-informed, and equitable approach to care for people with ADHD. 21 This article briefly covers the prevalence and symptoms of ADHD and explores the risk factors linked with it.
Prevalence and incidence of ADHD
ADHD affects 7.2 % of children worldwide, with symptoms that may persist for 40 % to 60 % of a child’ s life. 2 The prevalence among adults is around 2.6 %. 1, 2 ADHD is present in roughly 6-10 % of children and adolescents in Australia, as well as 2-6 % of the adult
204 | vol31 | no4 | AJNM