The term ADHD stands for ‘Attention Deficit Hyperactivity Disorder’, however, this also encompasses ADD ‘Attention Deficit Disorder’, and the less common HKD ‘Hyperkinetic Disorder’.

ADHDis a neurodevelopmental disorder affecting 5% of children and adolescents and 4% of adult across ethnic, racial, gender, and socioeconomic lines in Europe and around the world (Clark, Carr-Fanning, & Norris, 2011).

ADHD is a medical label given to individuals who experience chronic and often debilitating difficulties due to symptoms of hyperactivity, impulsivity, and/or inattention. These symptoms co-occur in predictable clusters and are associated with similar trajectories and outcomes (Barkley, 2006). These symptoms are due to a developmental, and highly heritable, condition which results in atypical brain functioning (Barkley, 1998).

It is one of the best research conditions among children and young people (Brown, 2006), and as such, there is a huge amount known about the condition. As such, there is ample evidence from both the behavioural and biological sciences to support ADHD’s legitimacy as a diagnosis. Cumulative research evidence and clinical observations spanning more than two centuries, and published academic and medical papers numbering in the many many thousand, supports its legitimacy as a valid diagnosis (Barkley, 2006, 2010; Brown, 2006; Clark, Carr-Fanning, & Norris, 2011; Fitzgerald, Belgrove, Gill, 2007; Selkowitz, 2004). There is a general consensus by professionals in the clinical research and practice arena, that ADHD is a very real, prevalent, chronic, and pervasive condition (Barkley, 2006; Fitzgerlad, Belgrove, Gill, & 2007; Hinshw et al., 2011; Selkowitz, 2004; NICE, 2008).


ADHD is not the result of poor parenting, abuse, or neglect, nor is it due to a lack of motivation or willpower, selfishness or laziness, and it is definitely not caused by low intelligence. Albeit, these issues can also be present, they are not synonymous with ADHD.

Moreover, one of the key issues which never fails to have the critics up in arms is that ADHD-type behaviours occur in everyone. Thus, the ensuing cries that we have pathologised normal childhood behaviours, whatever ‘normal’ maybe.

It is true that there are times when everyone (man, woman, or child) can’t seem to pay attention and is easily distracted and irritated by the slightest change in noise or movement, but that is not sufficient evidence that a disorder does not exist. For example, there are times in all individuals’ lives when they feel a sense of despair, become lethargic and despondent, however, this does not mean that they are suffering from clinical depression, nor does it imply that depression doesn’t exist.

It is also undeniably true that most children will misbehave to some degree at some point in their lives. Indeed, some degree of oppositional behaviour in toddlers is considered healthy and necessary for their developing autonomy and self-identity. However, it is equally true that not all children suffer from significant impairments (symptoms) which cluster predictably together (Barkley, 2006); nor do these behaviours occur with the same intensity, duration, and chronisity as is observed in people with ADHD. More importantly, while disruptive behaviour might be a symptom of ADHD it is neither sufficient nor necessary for diagnosis.


  • How can you tell if someone has (ADHD)?
  • What does a person with ADHD look like?
  • How do you know that it is ADHD and not something else?

These are not easy questions to answer, and a number of ADHD profiles have been proffered over the years. They span a diverse continuum, from the daydreaming child who may take a little longer to process information, too the passionate and driven adult without a moment to spare.

Inattentive individuals may appear ‘tuned-out’, as if they are living in a fog or daydream, and may not seem to listen even when spoken to directly. In general, those with attentional deficits will get easily board, find it difficult to focus on one thing, and are easily distracted by sights and sound, even their own thought will be hard to ignore. They can often shift between activities quickly without finishing them, and not paying close attention to the details.

Some such individuals are perpetually disorganized and forgetful, losing things, fail to recall direction, and are chronically late for appointments, with homework, or meeting deadlines. Time, multi-step project, and personal belongings are often extremely difficult for them to manage. Problems focusing attention and organizing thoughts means they may have issues processing information with the same speed and accuracy as others (APA, 2001; Brown, 2006; Barkley, 2006; WHO, 1994).

Despite the fact that ADHD is, by its very name, a disorder of inattention, it is these characteristics which are often overlooked and tend to be misunderstood. Since inattention represents less of a problem for others (e.g., teachers or parents) these individuals can fall through the proverbial cracks in the system, and often go undiagnosed in children and young people (Du Paul & Stoner, 2004). This is serious problem, since unrecognized and untreated ADHD causes seriously and long standing issues, for the individual, others close to them, and society in general.

While most people are aware that individuals with ADHD have problems focusing, there is less recognition to the somewhat paradoxical side to these problems with attention, which has become known as hyper-focusingon tasks which are highly stimulating or rewarding.

Indeed, this is a source of frustration and disbelief for countless parents, teachers, and significant others who scoff at the idea of the individual being forgetful and disorganized due to issues related to inattention, resultant from ADHD. Indeed, they can usually cite any number of examples where the person has no problem organizing and attending to activities for long period, and so they insist that the problems arise from a lack of caring or laziness.

The problem is that rather than being a disorder of inattention, ADHD is better understood as attention inconsistency (Hallowell &Ratey, 2004), it is not lack of attention, its lack of control over what the brain concentrates on; essentially the person can’t select what to attend to and what to ignore (see discussion on executive functions). However, when they are doing something enjoyable, they can become hyper-focused, and their attention system will zone in intensely on one task or area (Brown, 2006). This is naturally extremely difficult for the outsider (e.g., non-ADHD parent) to understand; because they have observed the person with ADHD performing well, even exceptionally, in some areas or at certain times.

Hyperactivity is most noticeable by over-activity motor and/or verbal. These individuals are often said to be always ‘on the go’ or to act as if ‘driven by a motor’. They will leave their seat, fidget, or squirm at times when sitting quietly is required, such as during a class or for a meal. They can talk excessively, loudly, and very fast. Indeed, these people often have problems working or playing quietly, and they may even talk to themselves, oblivious of others in their environment (APA, 2001; Brown, 2006; Barkley, 2006; WHO, 1994).

Impulsive individuals often have problems waiting their turn in activities (e.g., games) or conversations, often interrupting or intruding on others. They shift quickly from one uncompleted task to the next, and tend to act first and think later which can often get them into trouble or place them in harm’s way(APA, 2001; Brown, 2006; Barkley, 2006; WHO, 1994).


ADHD is an extremely complex and multifaceted condition, best understood from a bio-psychosocial perspective (Cooper, 2001), meaning that it is medical in origin but is affected and influences the environment and social and emotional aspects of the person and situation. Behavioural symptoms, representing the criteria for diagnosis, include differential manifestations of inattention, hyperactivity, and impulsivity.

A diagnosis of ADHD is determined by behaviourally based descriptions, or symptoms (e.g., excessive talking), of problems meeting the demands of an environment (e.g., sit quietly).

These symptoms are due to a chemical imbalance in the brains neurotransmitters, in particular dopamine and noradrenalin (Fitzgerald et al., 2007). Since the brain is involved in everything we think, feel, and doa person can suffer numerous and long standing difficulties.

The demands of certain environments,such as school and work, often pose serious challenges, exacerbate symptoms, and do untold damage to a person’s self-esteem and well-being. Whereas, in another context with some other meaning attached, ADHD-type behaviours are assets and strengths. For example, a lot of energy and passion is hugely beneficially while taking part in a sports game, but that same enthusiasm will get you into trouble if you have to sit quietly in a classroom and pay attention to a stream of auditory information.

Different socio-cultural contexts place different demands on children’s behaviour and development, thus, how and when symptoms manifest and are exacerbated will vary in your country.

In addition, with age and experience individuals develop sophisticated coping mechanisms to deal with or mask their difficulties. For example, a young person who cannot focus in class may act out to divert attention away from the problems they have with learning. A young adult whose impulsivity makes socially appropriate behaviour a challenge, might withdraw from situations or occupations where they had to interact with strangers. These are not always negative, indeed, I have met many people who have struggled with disorganization in the past, causing them to become compulsively neat and tidy or ultra-organized in order to manage their lives.

Authors of the article: Kate Carr-Fanning and Conor Mc Guckin, the School of Education, Trinity College Dublin, 2012.


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