Attention deficit/hyperactivity
disorder(ADHD) is a behavioural disorder that is characterized by an
inappropriate level of inattention, with or without impulsivity or
over activity. The estimated rate is 7% to 10% in boys and 3% in
girls aged four to 11 years of age(1). Inattentive behaviour can also
occur in children with depression and anxiety disorders. Both
conditions must be ruled out before a diagnosis of ADHD can be
confirmed.
Management of ADHD
The identification and treatment of
children with ADHD is essential in preventing or at least minimizing
the serious complications associated with the disorder. Stimulant
medications are especially effective, when used as part of a
treatment plan that includes academic and behavioural interventions
and supports. As a result of their effectiveness, relative safety and
enormous frequency of use, stimulant medications have become the gold
standard against which any treatment for ADHD is measured (2).
Despite the success of stimulants, alternative treatments are often
sought by parents of children with ADHD. Concerns around side effects
of medications lead parents to look for more natural or less invasive
approaches to treatment. A number of alternative and controversial
treatments for ADHD are available, including dietary management,
nutritional supplementation, vision therapy, hypnotherapy, guided
imagery, relaxation training and electroenchephalography(EEG)
neurofeedback (3)
Evaluating the validity of alternative treatments
Treatments should be evaluated by
evidence of how well an intervention works to prevent or improve the
disease or disability. The best evidence is from double blind,
randomized studies of groups of patients. These studies should
include a control group with patients who have the same set of
symptoms, but receive a different form of treatment from the group
being tested. For example, in a study of children receiving EEG
neurofeedback, the control group should include similar children with
ADHD of the same severity, who do not get actual neurofeedback
training. When evaluating the results of such a study, it is also
important to take into consideration confounding factors, placebo
effects and selection and information bias of the final report.
The mixing of effects causes
confounding factors. For example, with neurofeedback training,
extraneous factors such pre-testing training in relaxation skills may
in fact confound the results of the study. Another consideration is
the placebo effect. This is a physical or emotional change that
occurs during treatment, but is not the result of the treatment. For
example, just being part of the study may have an initial positive
effect on a participant. Finally, the collection of incorrect
information can bias a study. The most common error or bias of
information often occurs when clear criteria for diagnosis are not
used. In ADHD studies, it is important to distinguish whether
inattentive behavior is the result of depression, anxiety or learning
disabilities. The validity of a good study is dependent on the
avoidance of these three factors.
Neurofeedback
EEG studies have shown that children
with ADHD have increased theta(slow wave) activity and decreased
beta(fast wave) activity compared with normal controls(4). Children
who receive EEG neurofeedback training are able to decrease theta
activity. Theta activity is associated with daydreaming and other
distractions (5). The change in brain activity some believe is the
direct result of EEG neurofeedback training. This is the basis for
neurofeedback programs. However, it is unclear, how much of the
improvement is due to EEG neurofeedback and how much is due to other
factors.
Numerous studies have been
published on EEG neurofeedback. A review of all the scientific
articles using keywords 'attention deficit disorder',
'electroencephalography', 'biofeedback', and 'neurofeedback' from
MEDLINE(1966-May 2000) and PsycINFO(1984-April 2000) found that none
of the studies were valid based on generally accepted criteria for
evidence-based research. Only one study (6) included a control group.
In this study 18 children were randomly assigned to either a
treatment group, which received forty sessions of EEG training for 45
minute sessions or to a control group(those on the waiting list) who
received no treatment. However, though participants were blind to the
type of treatment they received, parents were aware of the treatment
selection for their children. Since parents completed the behavioural
rating scale, their knowledge of who was receiving treatment may have
effected their perception on the rating scales. Also, EEG data was
not evaluated before and after treatment. Improvements may have been
secondary to unidentified cointerventions. In the other studies, the
assignment of patients to treatment was not random, and, therefore,
subject to methodological flaws including confounding factors,
placebo effect, and bias.
Summary
Well-controlled scientific studies
have not been published either to support or refute the effectiveness
of EEG neurofeedback for children with ADHD. Until further research
is completed, the evidence will remain inconclusive.
References
Sgrok M., Roberts W., Grossman
S., Barozzine T., School board survey of attention
deficit/hyperactivity disorder: Prevalence of diagnosis and
stimulant medication therapy. Pediatric and Child Health 2000:5;
12-23 Baumgaertel A., Alternative and
controversial treatments for ADHD. Pediatric Clinic North America
1999:46; 977-92 Wolraich ML, Baumgaertel A., The
practical aspects of diagnosing and managing children with attention
deficit hyperactivity disorder. Clinical Pediatrics 1997:36; 497-504 Mann CA, Lubar JF, Zimmerman AW,
Miller CA, Muenchen RA., Quantitative analysis of EEG in boys with
attention-deficit hyperactivity disorder:Controlled study with
clinical implications. Pediatric Neurology 1992: 8; 30-6 Thompson L., Thompson M,
Neurofeedback combined with training in metacognitive strategies;
Effectiveness in students with ADD. Applied Psychophysiological
Biofeedback 1998:23; 243-63 Linden M, Habib T., Radojevic V.,
A controlled study of the effects of EEG biofeedback on cognitive
and behaviour of children with attention deficit disorder and
learning disabilities. Biofeedback Self Regulation:1966 21; 35-49
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