25/01/2020
What is Attention Deficit Hyperactivity Disorder (ADHD)?
While everybody to some extent, and at certain times, occasionally has trouble sitting still, paying attention, or controlling impulsive behaviour , many others experience impulsivity, hyperactivity, and inattention at such mal-adaptively high levels that their daily lives at home, at school, at work, and in social settings are disrupted to a considerable and sometimes disabling extent. These people may have a common neurobiological disorder called Attention Deficit Hyperactivity Disorder (ADHD). There is also a less common and more severe form of ADHD called Hyperkinetic Disorder.
Although ADHD is a neurobiological disorder, it is defined at a behavioural level. That means that the symptoms are based upon observations about how people behave: ‘impulsivity’ signifies premature and thoughtless actions; ‘hyperactivity’ a restless and shifting excess of movement; and ‘inattention’ is a disorganised style preventing sustained effort. These symptoms are shown by individuals to different extents, and are influenced by context as well as by the constitution of the individual. People with ADHD may also be clumsy, unable to sleep, have temper tantrums and mood swings and find it hard to socialise and make friends.
Until recently, it was believed that children outgrew ADHD in adolescence, because sometimes hyperactivity seems to lessen in teen years. It is now known, however, that many symptoms continue into adulthood and hyperactivity may instead be experienced as internal restlessness. Undiagnosed ADHD in adults may have severe consequences including academic failure, substance abuse, criminal activity, failed relationships, troubled work relationships, and emotional difficulties such as anxiety and depression.
While most people diagnosed with ADHD can recall having problems during childhood, there have been some accounts recently of people experiencing “late-onset ADHD” in that as adults they meet the diagnostic criteria but did not during their childhood. This raises the possibility that symptoms of ADHD might emerge at different developmental stages. Researchers offer the following possible explanations for late-onset ADHD.
“The traditional explanation for this is that children with high intelligence quotients (IQs) or well developed executive function skills, who are well supported by structured home and school settings, might make use of so-called external scaffolding that facilitates compensatory behavioural mechanisms. Once such external scaffolding is removed, when leaving home and school for example, the full syndrome could emerge. Interestingly, this account of later-onset ADHD shows the interdependence of the association between symptoms and impairments of the disorder. An alternative hypothesis suggests that ADHD symptom expression depends on the efficiency of executive control processes. Poor maturation of cortical control during the adolescent years might lead to later emerging ADHD in some cases. Findings suggest that a late-onset ADHD-like syndrome might emerge, even in the absence of substantial childhood symptoms, perhaps reflecting an acquired syndrome with a different set of causal risk factors” (Asherson, Buitelaar, Faraone & Rohde, 2016).
