Attention Deficit Disorder

We have all read or heard about the increasing number of school children and young adults who appear to have problems with attention.  Such problems are typically displayed when otherwise bright and intelligent young people show problems in concentration, motivation and general discipline. In some cases these individuals also present erratic uncontrolled behavioural outbursts and excessive fidgeting.  Although, such behaviours are not the only definition of attention problems and hyperactivity they do, nevertheless, help contribute to the diagnosis of some aspect of Attention Deficit / Hyperactivity Disorders (ADHD) for both children and adults, (i.e. Combined, Predominately Inattentive, Predominately Hyperactive-Impulsive and Not Otherwise Specified).  Throughout the world there has been an increasing interest in this condition and more people are being assessed as having some aspect of the disorder effecting their school, business or social life.  As you can imagine many theories have been expanded to explain this phenomenon from diet, lack of opportunity, poor teaching and school experiences to clinical problems involving the central nervous system.  Whatever the causes, the problem remains a constant one, many individuals are failing to thrive in school or in the work place because in some way they lack the ability to focus, attend, successfully compete with their peers and achieve at tasks that involve some level of personal discipline.

Diagnosis 

There are many professionals ready to diagnose ADHD on a variety of factors.  Unfortunately, educationalists, psychologists and medical practitioners may often hold different views on the subtle manifestations of  ADHD and how it presents, regarding differing symptoms as evidence of the condition.  Therefore, there is often little agreement upon the diagnosis or treatment of the problem.  Thankfully, a few methods have been devised from years of detailed work assessing children's cognitive development.   This research found that a computer based statistical method which tests continuous performance provided one of the most reliable assessment tools to help professionals diagnose attention problems.  One of the leading, and most reliable of these tools involves using Continuous Performance Tests such as the IVA+Plus system and T.O.V.A which are routinely used for ADHD and general cognitive testing.

Of course, diagnosis without a treatment plan is of only little benefit.  Some 15 years of work with and research into disability has led to pioneering new treatment rationales to help disabled individuals achieve their true potential. Throughout this time our concern had been to ensure that individuals receive the correct information and advice on the many issues of disability, its treatment, and most importantly, the services disabled people need.  This expertise not only addresses brain injury as a clinical condition but has involved research into the phenomenological aspects of disability, that is, how disability is experienced as a living process.  Indeed, this approach assumes that the sociological dimensions of disability are as pertinent to treatment regimes as are clinical ones.  Therefore, assessment procedures should, where possible, involve both clinical methodologies such as Continuous Performance Tests (CPTs), EEG review, observational sessions and structured interviews with the individual and those with whom they interact on a daily basis.

The historical problem in diagnosing attention disorders persists despite new technologies and continues to remain a challenge for clinicians today.  Although the use of  a variety of differing CPTs has improved the ‘hit rate’ in ADHD diagnostics, nevertheless these analyses have utilised symptom complexes or types of behaviour that are common or statistically significant in those individuals who may have ADHD.  This means that the such tests can only indicate that the subject may have a problem and therefore other assessments are also required to confirm diagnosis.  Having said that, CPTs do provide one of the most reliable measures of attention variables that are fundamental to both the understanding and treatment of ADHD.

Referral for boys with ADHD is more common than that for girls but there could be social and cultural reasons for this as boys are typically more likely to express their frustration in antisocial ways that attract the attention of clinical services.  Girls with attention problems are often less disruptive and may not display the markers that frequently get boys noticed.  The facts are that ADHD occurs at a rate of between 3% -6% of the school age population (Silver 1999) and perhaps as much as 50% of those children with ADHD will continue to have problems as adults.

What Causes ADHD?

Although some factors are well recognised to be involved with ADHD we have yet to understand the complete clinical picture.  At the most simple level ADHD and the other attention disorders involve the brain and how it processes information.  The aetiology of this problem is likely to be diverse, arising from trauma at birth, accident or as a result of substance abuse. We also know that genetic factors may be involved, particularly where there are familial histories of attention problems. Miller & Bloom (1995), for example, suggest that chromosome 11 may be involved.  Other researchers have proposed that chemical imbalances and nutrition may act as causal agents.  We now know that all of the above can impact on brain functioning and lead to problems of attention, distractibility and hyperactivity.

Moreover, ADHD often overlaps with other disorders such as learning disabilities (LDs), conduct and anxiety disorders and oppositional defiant disorder (ODD).  However, the most common overlap appears to be with learning disorders of which there is an estimated 250 different kinds.  Indeed, Hynd et al (1991) suggests that there is as much as 70% of an overlap between  ADHD and its sub-types with the specific learning disabilities. 

Putting Causes and Treatments Together

By far the most common form of treatment has been pharmacological in nature.  Stimulant medication can produce dramatic results by altering the distribution of neurotransmitters in the brain, particularly dopamine and nor epinephrine.  An example of this type of treatment is the use of methylphenidate or Ritalin, however it is only effective when continuously taken, when the drug is stopped the symptoms return.  Recently an alternative has been proposed, one that attempts to address the deregulations of the nervous system and not simply treat the symptomology as does Ritalin.  Much of this new treatment has arisen from work involving the electroencephalograph or EEG that records the brain’s electrical potential.  Furthermore, specific electrical patterns have emerged from EEG recordings to suggest that ADHD individuals suffer from brain arousal problems at particular sites.  Such phenomena, involving the brain’s metabolism, has also been supported by a new brain imaging technique known as SPECT (single proton emission cerebral tomography).

SPECT utilises a low level radioactive tracer to measure cerebral blood flow which can visualise brain metabolism at sub cortical as well as at surface levels.  These investigations show that there is a hypoactivation of the prefrontal lobes and medial central cortex (Lubar et al 1999) in individuals with ADHD when subjected to cognitive tasks.

The brief description above indicates that cortical \ subcortical metabolism dysfunction has implications for central nervous system arousal patterns that are fundamental in brain processing mechanisms.  One approach to address this dysfunction involves a process called neurofeedback or EEG biofeedback.  This procedure involves recording the EEG signal from a particular site or sites that can then be acted upon by the individual via a computer game which rewards specific positive changes in EEG potential whilst inhibiting undesirable ones.  The game interface can be a simple ‘pacman’ or ‘space race’ game or a more abstract one depending upon age and interest of the individual.  The principle is simple, the games only give reward when the desired changes in EEG activity are recorded.  These thresholds of reward and inhibition are set by the therapist depending upon which particular EEG phenomena (arousal / under-arousal) may be associated with the presented problems.  Historically the central motor strip (Cz) was trained as this area demonstrated the highest ratios of beta \ theta activity which has been postulated to be one of the main EEG correlates of ADHD, (Lubar et al 1999).  Studies in America have shown other EEG montages to be effective in addressing attention problems by training the left and right temporal areas (C3 + C4) with rewards of 15-18 Hz (beta) and 12-15 Hz  (SMR) respectively whist inhibiting 8 – 11 Hz for the former and 4 –7 Hz for the latter.  However, protocols should always reflect that individual phenomena observed in the raw EEG record.  

Conclusion

In the past these procedures were considered largely experimental but in America today they have gained much in popularity and are often favoured over drug treatment.  The procedures of neurofeedback are safe as they do not directly effect the brain but rather changes in neural behaviour are learned through training involving operant conditioning techniques.  Such training is non invasive but does require individuals to commit themselves to the treatment regimes and the goals designated by the tpractitioner.  These latter considerations are critical in outcome success. Finally neurofeedback offers a safe and promising future for the treatment of attention disorders without recourse to drugs.

For more information on neurofeedback click on our Brain Cinema 'User's Guide' button.