New Study
Supports Neurofeedback Treatment for ADHD
Neurofeedback - also known as EEG Biofeedback - is an approach for treating
ADHD in which individuals are provided real-time feedback on their brainwave
patterns and taught to alter their typical EEG pattern to one that is consistent
with a focused, attentive state. This is typically done by collecting
EEG data from individuals as they focus on stimuli presented on a computer
screen. Their ability to control the stimuli, for example, keeping
the smile on a smiley face, is contingent on maintaining the particular EEG
state being trained. According to neurofeedback proponents, learning
how to do this during training generalizes to real world situations and this
results in improved attention and reduced hyperactive/impulsive behavior.
Neurofeedback
treatment for ADHD has been controversial in the field for many years and
remains so today. Although a number of published studies have reported
positive results many prominent ADHD researchers believe that problems with
the design of these studies preclude concluding that neurofeedback is an effective
treatment. These limitations have included the absence of random assignment,
the lack of appropriate control groups, raters who are not 'blind' to children's
treatment status, and small samples. For additional background, you can find
a recent review I wrote on existing research support for neurofeedback treatment
of ADHD - along with links to extensive reviews of several recently published
studies - at www.helpforadd.com/2007/september.htm
- Results from a New Study of Neurofeedback -
Recently,
a study of neurofeedback treatment for ADHD was published that addresses
several limitations that have undermined prior research [Gevensleben, et al.,
(2009). Is neurofeedback an efficacious treatment for ADHD? A randomized controlled
clinical trial. Journal of Child Psychology and Psychiatry.]
The study
was conducted in Germany and began with 102 children aged 8 to 12. All
had been carefully diagnosed with ADHD and approximately over 90% had never
received medication treatment. About 80% were boys. Children were randomly
assigned to one of two treatment conditions: 36 sessions of neurofeedback
training or 36 sessions of computerized attention training. The computerized
attention training task was intended to serve as the control intervention.
Training was conducted in two 50-minute blocks per session, with a short
break in-between; children in both groups participated in two to three such
training sessions per week.
- Description of Training -
Neurofeedback Training -
As noted
above, neurofeedback entails providing children with real-time feedback on
their EEG state so that they become able to learn how to create and maintain
a state that is consistent with focused attention. This is done by linking
their ability to control what appears on the computer screen to their ability
to produce and maintain the EEG state being trained. Technical details
of the training protocols are not summarized here but were based on research
findings suggesting the specific EEG differences between children with and
without ADHD that training should address. For example, one part of
training focused on teaching children to elevate their production of higher
frequency beta waves and to supress the production of lower frequency theta
waves. This is based on prior findings that individuals with ADHD tend
to have an elevated ratio of theta to beta activity relative (see www.helpforadd.com/2008/november.htm for an
interesting study of this issue).
Computerized
Attention Training - This treatment
was based on a program called 'Skillies', described as award-winning German
learning software that provides systematic exercises in visual and auditory
perception, vigilance, sustained attention, and reactivity. It was considered
the 'control' condition to which the results of neurofeedback training was
compared.
Performing
well on the program requires children to sustain their attention to a variety
of game-like tasks that become increasingly challenging and that provide children
with frequent feedback about their performance. Children thus receive
extended practice in 'paying attention' for increasing periods to tasks that
become increasingly demanding and need to learn to sustain their attention
in order to do well. Unlike neurofeedback treatment,however, no direct
feedback on EEG state is provided.
- Experimental Controls -
As noted
above, children were randomly assigned to treatment condition, which is essential
when comparing different interventions. Efforts were also made to make
the intervention experience as similar as possible, except for the critical
difference as to whether children received direct training in modifiying their
EEG state. Thus, treatment for both groups entailed computer-game like
tasks that required children to sustain their attention. In both conditions,
children were encouraged to develop strategies to focus attention and to
practice these strategies at home and at school. They also received
similar amounts of attention and praise from the experimenters for doing so.
By equalizing as many aspects of the training experience as possible, the
researchers could attribute any outcome differences that were found to critical
differences in the programs themselves, i.e., whether feedback on EEG state
was provided, as opposed to some extraneous factor such as attention from
the experimenters, time spent on a demanding computer task, etc.
In addition to these important controls, efforts were made to keep parents
and teachers 'blind' to the type of training children received. Thus,
parents were only told that their child would receive either of two promising
computer-based treatments for ADHD. They also did not accompany their child
into the treatment room to observe and children's teachers were also not informed
about the child's treatment. Although a number of parents became aware
of which treatment their child received, and perhaps some teachers did as
well, it is not possible to keep everyone truly 'blind' in a study like this.
- Measuring Treatment Outcomes -
The main
outcome measure used were parent and teacher ratings of children's ADHD symptoms.
In addition to ratings of core inattentive and hyperactive-impulsive symptoms,
ratings were collected on a variety of other behaviors, e.g., oppositional
behavior, conduct problems, emotional problems, and social problems.
These rating scales were obtained before and after treatment.
To rule out placebo effects as an explanation for any treatment differences
found, the researchers also asked parents about their attitudes towards treatment,
how motivated they thought their children were, and how satisified they were
with their child's treatment.
- Results -
Preliminary
analyses revealed no group differences in parents' attitudes towards, or
satisfaction with, their child's treatment. There were also no differences
found in how motivated parents felt their child was. These factors thus
should not have influenced parents' ratings of core symptoms.
Results of the parent and teacher behavior ratings indicated the following:
1. Parents of children treated with neurofeedback reported significantly
greater reductions in inattentive and hyperactive-impulsive symptoms than
parents of control children, i.e,. those who received computerized attention
training. The size of the group difference was in a range that would
be considered moderate, i.e., about .5 standard deviations.
2. Teachers of children treated with neurofeedback reported significantly
greater reductions in inattentive and hyperactive-impulsive symptoms than
teachers of control children. The size of the group difference was similar
in magnitude to that found for parents, about .5 standard deviations.
3. Apart from these differences in core ADHD symptoms, few group
differences were found. However, neurofeedback was associated with
greater reductions in parents' ratings of oppositional and aggressive behavior.
Teacher ratings for the two groups did not differ on any of the remaining
behavioral measures.
The results summarized above reflect average differences between the groups.
The authors also examined the percentage of children in each group that were
judged to derive significant benefit where this was defined as at least a
25% reduction in core ADHD symptoms. Fifty-one percent of children in
the neurofeedback group met this threshold compared to only 26% of children
in the attention training control group. This difference was statistically
significantl.
- Summary and Implications -
This was
a well-designed study of neurofeedback treatment for ADHD that used random
assignment, made an effort to have blind raters, and included an appropriate
control group. Results indicate that neurofeedback treatment yielded
significantly greater reductions in parent and teacher ratings of core ADHD
symptoms than the comparison treatment. Furthermore, the magnitude of
the reductions appear large enough to be clinically meaningful. Although the
impact of neurofeedback treatment on other aspects of children's functioning
was less pronounced, significant reductions in parents' ratings of oppositional
behavior were also found.
Overall, these findings add to the research support for neurofeedback as
a treatment for ADHD. However, despite the many strengths of this study,
there are concerns to note and reasons why some researchers will find a basis
for criticizing it. The main concerns - and my own take on them - include
the following:
1. Without getting too technical, some researchers will argue that the
statistical tests used in this study were not ideal and may have overestimated
the advantages of neurofeedback treatment. My sense from examining
the data presented is that the primary findings would hold up even if more
conservative statistical tests were employed. However, it would be
really nice to see that done.
2. Neurofeedback is supposed to work by teaching children to transform
their EEG state to one that is characteristic of children without ADHD.
However, there were no EEG measures taken in this study. Thus, there
is no way to know whether neurofeedback actually resulted in these hypothesized
changes in EEG. While this is certainly true, this has more to do with
documenting the mechanism by which neurofeedback led to reductions in ADHD
symptoms and has nothing to do with whether those reductions actually occurred.
I believe that some neurofeedback practitioners would argue that the absence
of direct EEG measurements may have also diminished the benefits provided
by neurofeedback treatment. The reason for this is that training was
not matched to the specific EEG parameters that needed to be altered for each
individual and that additional benefits would have accrued if this had been
done. Whether this is actually the case, however, would require additional
research to determine.
3. No measures of children's academic functioning were collected.
Because improving academic performance is a critical treatment target for
most children with ADHD, the absence of this data is an important study limitation.
There is no arguing with this and it is unfortunate that measures of academic
performance in the classroom were not collected.
4. No long-term follow up was conducted. There is thus no basis for
knowing whether neurofeedback treatment resulted in any enduring benefits.
While this is certainly a limitation, it should be noted that neither medication
treatment nor behavioral treatment have been shown to have enduring benefits
after treatment ends. However, one of the reputed advantages of neurofeedback
is that it can result in enduring gains. Thus, adding a long-term follow
up to this study would have been an important addition.
5. It is important to remember that when improvement was defined as at
least a 25% reduction in core ADHD symptoms, about 50% of children treated
with neurofeedback did not meet this threshold. Thus, many children
did not derive significant benefit from this treatment even though the benefits
averaged across all children were statistically significant.
This is not surprising as no treatment - including medication - will help
everyone. However, the rate of non-responders is less than what is typically
found in controlled studies of medication treatment and this is important
to remain aware of.
Despite these limitations and concerns, this study represents an important
addition to the research literature on neurofeedback treatment for ADHD.
In the context of other positive findings that have been reported for neurofeedback,
it provides additional basis for regarding this as an extremely promising
treatment approach for some children with ADHD.
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