Gold Coast ADHD Clinic
Understanding Minds provides assessment and treatment of ADHD from our Gold Coast clinic and nationally and internationally via our videoconferencing facilities. We also provide expertise in assessment and treatment of conditions that commonly coexist with ADHD, such as anxiety and mood problems, behaviour problems, autism spectrum disorders, speech and language disorders, dyslexia and reading difficulties, learning difficulties, and sleep problems.
ADHD TIP SHEET
Attention-deficit/hyperactivity disorder (ADHD) is the term currently used to describe a developmental disorder seen in children and persisting into adulthood. The primary symptoms of hyperactivity, impulsivity, inattention and distractibility can be accompanied by associated problems in social and adaptive functioning, internalising symptoms, and oppositional and conduct disordered behaviour. Many children with ADHD also have a learning disability and almost all suffer from academic underachievement.
Primary Characteristics of ADHD
1. Impaired response inhibition. Many experts now believe that at the core of the disorder is a developmental delay in behavioural inhibition. Current neuropsychological theories of ADHD suggest that the ability to inhibit behaviour, to put a pause between an event and response, is an almost uniquely human trait. Behavioural inhibition is thought important for development of what neuropsychologists call the executive functions, which allow humans to guide and plan behaviour, and which are presumed to be deficient in ADHD.
Inhibitory deficits are often manifested as impairments in impulse control or the capacity to delay gratification. The individual has a hard time 'stopping and thinking' before acting and in waiting their turn during games or conversations. They have a hard time resisting distraction while working, therefore seeming 'inattentive', and they tend to be motivated by more immediate rewards rather than working towards larger, longer-term ones.
2. Excessive task-irrelevant activity (hyperactivity). They are often described as being fidgety, restless, "on the go", or as "having an outboard motor strapped to their backside." The excess movement is usually not required to complete a task (e.g., swinging their feet and legs, tapping things, rocking while seated, or squirming) and often serves to distract the child. Younger children with the disorder may show excessive running, climbing, and other gross motor activity. Activity levels tend to decline with age, however, a keen observer will still be able to find a higher level of restlessness, even if only in mood or intent, in teenagers and adults with ADHD.
3. Inattention. The symptoms of inattention relate to persistence of effort or sustaining vigilance/effort on tasks. Difficulties with persistence are most salient in structured situations, such as independent schoolwork, where the child has to complete dull, repetitive tasks. What underlies this problem is still open for debate. However, current thinking suggests the problem may be found in a diminished capacity to inhibit behavioural responses to competing (and more rewarding) activities. This may explain why many individuals who have ADHD seem able to attend to things in which they are interested – because the task (e.g., a computer game) is the most exciting thing in the room and no other stimulus can compete with it for attention.
4. Executive Functions. Executive functions (EF) are "top-down" functions, mediated by the prefrontal cortex, that are often referred to as the overseer or conductor of cognitive operations within the brain. A rather homely analogy that nicely encapsulates the interaction between EF and other cognitive and motor domains is as follows: to cook a meal one needs not only the ingredients, but also a recipe to follow. In this analogy, the EF are the recipe providing a structure and guide while the other cognitive and motor domains represent the ingredients. Just as a recipe is useless without the necessary ingredients, one cannot eat a cookbook full of recipes.
The EF that seem to be delayed in ADHD are:
1. Working memory. The deficits in working memory usually affect the ability to perform complex tasks; hence individuals with ADHD often have difficulty with reading comprehension even when oral language skills and word-reading are typical; they have trouble performing math problem-solving tasks even when they have the knowledge of math facts and operations to perform the required algorithms; they have difficulty learning new vocabulary and abstract academic concepts; they make place-finding errors and have difficulty maintaining a coherent set during performance of complex tasks; and, despite often have adequate short-term memory capacity they can have difficulty organising and coding information sufficiently which leads to errors in memory recall.
Working memory dysfunction often contributes to apparent deficits in hindsight and forethought. Individuals with ADHD may not learn as well from previous behaviour or consequences and they find it more difficult to plan and regulate future behaviour on the basis of previous successful or unsuccessful experiences. The ability to monitor task performance and to make changes in response to error or feedback can also be delayed. Put another way; individuals with ADHD seem to repeat the same mistakes.
Reduced working memory capacity may also affect the individual's sense of time. They have difficulty planning behaviour across time and using time to manage task performance. Children who fail to consider time and the future before acting show less goal directed behaviour, particularly for long term goals. They are also more likely to be motivated by smaller, shorter, more immediate goals.
Working memory dysfunction may also make the child with ADHD less able to utilise internally represented information such as rules, teacher/parents expectations, and social rules to guide behaviour.
2. Reduced self-regulation of emotion/motivation. Individuals with ADHD experience the same emotions as other individuals. However, they have more difficulty inhibiting the external expression of those emotions. In other words, they are less emotionally inhibited.
When they are not responding impulsively, individuals with ADHD often have difficulty initiating action. They often require assistance to prompt them to begin tasks. Once started, tasks often remain incomplete due to the combined effects of difficulty sustaining mental arousal, working memory deficits, and inhibitory deficits which lead to distraction.
Individuals with ADHD tend to have more difficulty than others in using internal mechanisms to motivate and drive behaviour. They tend to be more influenced by the potential of immediate and external rewards. In a classroom setting, an individual with ADHD is most likely to respond to or be distracted by the stimulus that is potentially the most rewarding. In the absence of an alternative external reward for completing a standard academic task (e.g., math problems) it is to be expected that the student will shift their attention to a more rewarding stimulus (e.g., the noise made by a peer).
3. Poor planning and problem solving. Effective performance of complex tasks requires considerable EF demands. Beyond inhibiting responses to irrelevant stimuli and inhibiting impulsive responses to the task itself, one has to first deconstruct the task and develop a coherent strategy for performance. This EF may operate in much the same way as a Managing Director of a business who might manage an incoming job from a client by breaking it down and allocating sections of work to different work teams, by setting deadlines for each piece of work, by recruiting new team members if sufficient skill is not available within the business, by checking and monitoring ongoing performance and making changes where necessary, and by finally bringing the job to completion by reconstituting the individual pieces.
Individuals with ADHD often display dysfunction in these complex problem solving skills. They tend to respond without planning and tend to have difficulty inhibiting and changing inefficient strategies during the course of the task. Not only does this EF deficit affect academic performance but it may adversely affect social problem solving. Because replication of complex motor sequences often requires the individual to deconstruct the sequence into individual movements, EF deficit may also underlie the co-occurrence of motor coordination weaknesses in ADHD.
Australian studies have placed prevalence rates at 5-9%. Studies from overseas have estimated prevalence at 3-7% of the childhood population and 2-5% of the adult population. The gender ratio is approximately 3:1 in favour of males.
ADHD has a strong hereditable component, averaging ~80%. In other words, 80 percent of the individual variation in ADHD symptoms is attributable to genetic factors. This rivals human characteristics such as height. Given the complexity of the disorder it is unlikely that there will ever be a single gene identified as responsible. Environmental factors important to the disorder (in a minority of cases) include pregnancy complications, alcohol and tobacco use in mother during pregnancy, prematurity, low birth weight, exposure to lead, and post-natal injury to frontal brain regions. Despite popular belief, research has not supported the idea that ADHD arises from excessive TV watching, poor parenting, food additives, or excessive sugar intake. Diet accounts for about 3% of the individual variation in ADHD and there is a low chance of obtaining positive benefits from dietary modifications.
There is no long-term cure for ADHD, however, a combination of interventions has been shown to successfully manage the disorder. The first step in treatment for children should always be education of the family and school staff about the nature of the disorder and its management. The first step for adults involves personal and family education and counselling about ADHD.
The current best-practice non-medical treatment involves behaviour therapy/modification in which parents and teachers are taught how to best manage and change behaviours of concern. Behaviour therapy includes:
Multi-site randomised control trials (RCTs) have shown that behaviour therapy works best in combination with medications (see below). However, these data are not always applicable to community settings because the children in the studies were very carefully selected so as to only include cases of severe, Combined-Type ADHD ('combined' refers to inattentive and hyperactive children) who had few co-morbid disorders such as defiant behaviour, learning difficulties, or anxiety. In normal practice many children represent mild cases, are sometimes the purely Inattentive Type, and often represent complex cases.
Because of the invasive nature of medication, best practice for most children involves the behaviour therapy discussed above as a first step. If the child does not respond sufficiently then a medication should be trialed in combination with the behaviour therapy. The added advantage of this approach as a first step is that positive response to medication can be achieved at lower dosages – a good thing considering side effects increase along with the amount of medication required. Medication and behaviour therapy should be combined as a first step in severe cases.
Stimulant medications, such as methylphenidate (Ritalin) and dexamphetamine, have been in use since 1937 and research indicates that they provide a safe and effective management tool. A new non-stimulant medication called atomoxetine (Strattera) has recently become available. Commonly reported side effects of stimulant medication include decreased appetite and low growth rates. Less commonly reported are difficulty falling asleep, headaches and stomach aches. Most of these can be managed by changes in dose or dose timing.
A range of alternative therapies such as psychotherapy, diet supplements and restricted diets, herbal medicines, reflexology, neurofeedback, vestibular and sensory-motor integration, play therapy, vision therapy, chiropractic treatment, and rapid auditory processing training have been promoted at substantial expense to families. There is little to no evidence for their effectiveness.