How Strong is the Research Support for Neurofeedback Treatment?
- also known as EEG Biofeedback - is an approach for treating ADHD in which
individuals are provided real-time feedback on their brainwave activity and
taught to alter their typical EEG pattern to one that is consistent with a
focused and attentive state. According to neurofeedback proponents,
when this occurs, improved attention and reduced hyperactive/impulsive behavior
- Controversy Surrounding
Neurofeedback Research -
Neurofeedback treatment for ADHD has been a source of substantial controversy
in the field for many years and remains so today. Although there are
a number of published studies in which positive results have been reported,
many prominent ADHD researchers feel that given significant limitations to
the design and implementation of these studies, neurofeedback should be considered
a promising, but unproven treatment.
This position is summarized in the CHADD fact sheet on alternative and
complementary interventions, which includes the following statement about
"It is important to emphasize, however,
that although several studies of neurofeedback have yielded promising results,
this treatment has not yet been tested in the rigorous manner that is required
to make a clear conclusion about its effectiveness for ADHD. The aforementioned
studies can not be considered to have produced persuasive scientific evidence
concerning the effectiveness of EEG biofeedback for ADHD.
Controlled randomized trials are required
before conclusions can be reached. Until then, buyers should beware of the
limitations in the published science. Parents are advised to proceed cautiously
as it can be expensive - a typical course of neurofeedback treatment may require
40 or more sessions - and because other ADHD treatments (i.e., multi-modal
treatment) currently enjoy substantially greater research support."
Before reviewing some recent neurofeedback studies, it would be useful
to consider what an 'ideal' treatment study entails. This will provide a
context against which recent neurofeedback studies can be evaluated.
Ideally, treatment studies are designed so that if positive results are
obtained, all possible explanations for those results besides the treatment
itself have been eliminated. This requires 2 basic elements: random
assignment and an appropriate control group.
Imagine that you are testing a new medication treatment for ADHD with 50
children who have been carefully diagnosed. In a random assignment study,
whether each child is assigned to the treatment or control condition is determined
by chance - you could flip a coin and give the medicine to the 'heads' and
nothing to the 'tails'. This insures that any differences that might
exist between children who get the medication and those who don't are purely
chance differences. At the end of the study, if those who received the medicine
are doing better, you could feel confident that this is likely due to the
medicine itself, and not to differences that may have been there before the
treatment even started.
What if you didn't use random assignment, but let each child's parents
choose whether their child is in the treatment or control group? In
this case, it is possible that children in the 2 groups differed in important
ways before the treatment began. If children who received the medication
were doing better at the end of the study, it might be because of differences
that were there to start with.
For example, parents who chose the medicine might have been more willing
to pursue other ways to help their child than those who didn't. The
fact that children who received the medication were doing better at the
end of the study might thus have nothing to do with the medicine itself,
but reflect other things their parents were doing to help them. No
matter how hard you might try to rule out these other possible explanations
- and I'm sure you can think of many others - you could never do this with
certainty. Thus, I might reasonably doubt that your new medication
is really effective.
about control groups?
Even with the random assignment example above, however, your study would
still have an important problem. Because children in the control group
received nothing, everyone knows who is being treated and who isn't. If you
ask parents how their child is doing 4 weeks later, this could very possibly
bias their reports. Parents whose child received medication may report
their child is doing better simply because they expect the medicine to help.
Parents of children in the control condition may be biased against seeing
improvement because they know their child was not treated.
Thus, if parents of treated children reported more improvement than parents
of control children, I could still reasonably question whether the new medication
was truly helpful. Even if reports from teachers yielded similar findings,
I would argue that teachers might have learned when children were getting
medication. While this may be a low probability event, you couldn't completely
rule it out. If I was a real skeptic about your new medication, your
study would not be all that convincing.
The way around this is to create a situation where no one knows - not the
parents, child, teachers, researchers, or anyone else - whether the child
is receiving medication. With medication studies, this is relatively
simple to do: children in the control condition are given a placebo pill that
looks just like the real medication but that has no active ingredients.
Because no one knows who is getting medication and who isn't, possible biases
in parents' and teachers' reports at the end of the study are eliminated.
This way, if children in the medication condition are doing better at the
end of the study than children getting placebo, it is harder to doubt the
benefits of your medication. In fact, there would be no reasonable basis
for such doubt, especially if you repeated the study and found the same results.
With this as a background, let's take a brief look at 3 recent neurofeedback
studies and see how they fare on the critical dimensions of incorporating
random assignment and an 'ideal' control group.
- Study 1 -
In an interesting study by Vince Monastra and his colleagues [Monastra
et al. (2002). The Effects of Stimulant Therapy, EEG Biofeedback and Parenting
Style on the primary symptoms of ADHD. Applied Psychophysiology and Biofeedback,
27, 249.] one hundred 6-19 year-olds with ADHD were treated over 12 months.
Some parents chose a treatment plan that included medication, behavior therapy,
and school consultation. Other parents chose to add neurofeedback to
their child's treatment.
After 12 months, children whose treatment included neurofeedback back were
doing better than the other children according to both parents and teachers.
They also showed 'normal' EEG scans while the other children still had the
EEG pattern characteristic of ADHD. Even more impressive was that neurofeedback
treated children maintained these benefits after medication was discontinued
for a week. You can read a detailed review of this study at www.helpforadd.com/2003/january.htm
- Study 2 -
In a study by Fuchs et al (2003), parents of thirty-four 8-12-year-old
children with ADHD chose either stimulant medication or neurofeedback treatment
for their child. After 3 months, children in both groups showed significant
and comparable reductions in ADHD symptoms according to parents and teachers.
Laboratory tests of attention also showed equivalent improvement. A
comprehensive review of this study is available at www.helpforadd.com/2003/may.htm
- Study 3 -
In an especially interesting study, (Levesque, J., Beauregard, M., &
Mensour, B. 2006. Effect of neurofeedback training on the neural substrates
of selective attention in children with AD/HD: A functional magnetic resonance
imaging study. Neuroscience Letters, 394, 216-221.) twenty 8-12-year-old children
with ADHD were randomly assigned to receive neurofeedback treatment - 40
1-hours sessions - or to a wait-list control condition.
At the end of the study, treated children were doing significantly better
than control children according to parents. They also did better on
several objective, laboratory measures of attention. Especially noteworthy
was that fMRI scans used to measure brain activity during a complex cognitive
task showed significant change for treated children but no change for control
I suspect the answer to this question is obvious. While the first
2 studies yielded impressive results, neither included random assignment.
Thus, as discussed above, it is not possible to conclude that it is the neurofeedback
treatment specifically that made the difference. Instead, differences
that may have been present before treatment began and/or after treatment started
could be responsible. While this may be unlikely, it can't be entirely
The third study included random assignment so this is not a problem.
It should be noted, however, that with only twenty participants, treatment
and control groups are more likely to differ at the start of the study than
if a larger sample had been randomly assigned.
The bigger problem is that the control condition is not a very strong one
in that everyone knew who received neurofeedback treatment and who did not.
This may have biased parents' ratings, although it is difficult to argue that
it could have biased children's performance on the lab-based attention tests
or on the fMRI scan. Perhaps, however, it wasn't the specific feedback
on EEG states that neurofeedback provided, but simply the attention children
received during the 40 hours of training, that was the important factor.
Although unlikely in my opinion, this can't be definitely ruled out.
What would an 'ideal'
neurofeedback study look like?
This may be pretty clear by now as well. The most conclusive test
of neurofeedback treatment would include random assignment and a control
condition that closely matched the neurofeedback condition. For example,
children could receive video game coaching from a supportive adult for the
same time period. Or, even better, they could do exactly what children
getting the neurofeedback were doing but not receive direct feedback on their
EEG states. If positive treatment results were still found, it would
indicate that obtaining EEG feedback and learning to control one's EEG state
is why neurofeedback treatment works.
I've been told by people who know more about neurofeedback than I do that
such a study, while difficult to execute, is technically possible. I
am not aware of such a study having been published; if you are, please let
I should point out that there would be important ethical concerns with
such a study. Neurofeedback treatment typically occurs over a period
of months. Children who were receiving 'sham' neurofeedback would be
getting a treatment that no one expected to be helpful for a sustained time
A more reasonable alternative might thus be to provide children with a
treatment of known efficacy - such as medication - during the neurofeedback
trial. If this were given to children in the real and sham conditions
it would not create a confound because both groups would be receiving it.
After neurofeedback was completed, one could see whether children who got
the real treatment were doing better - i.e., did neurofeedback add anything
to medication - and whether these benefits persisted after medication was
What can we conclude
about neurofeedback until such a study is done?
It would be terrific if a study like the one outlined above were completed.
Unfortunately, however, I think it is a real possibility that we will never
see such a study. This would be a large and expensive undertaking and
obtaining funding for it would not be easy.
In the interim, my own view is that existing support for neurofeedback
should not be so readily discounted because of the study limitations discussed
above. Here's why I think this is the case.
The way treatment was 'assigned' in the first 2 studies summarized above
is very similar to what happens when parents seek treatment for their child.
That is, parents investigate different options and decide which one they want
for their child. This is what happened in these studies - some parents
chose neurofeedback for their child and some did not. When neurofeedback
was chosen, children were found to benefit on both 'subjective' parent reports
as well as on more 'objective' assessments.
This does not mean that neurofeedback would 'work' for children randomly
assigned to receive it. It also does not mean that reason neurofeedback
works by providing specific training in learning how to manage one's EEG state.
It is for these reasons that neurofeedback is understandably regarded as
an unproven treatment approach for ADHD at this time by many ADHD researchers.
However, these studies do provide a solid basis for suggesting that if
parents choose to pursue neurofeedback for their child, there is a reasonable
chance that their child will benefit even though we can't be sure that it
is the specific EEG training that is responsible for the benefits.
Thus, although the efficacy of neurofeedback has yet to be conclusively confirmed
in a randomized, placebo-controlled trial, it is important to place this limitation
in the context of the supportive research evidence that has been accumulated.
Providing this context can help families better understand the strengths
and limitations of the existing research on neurofeedback and enable them
to make a better informed decision about whether to consider this treatment
option for their child.
presented in Attention Research Update is for informational purposes only,
and is not a substitute for professional medical advice.