Neurofeedback - 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,
this often results in improved attention and reduced hyperactive/impulsive
Several years ago I summarized the scientific support for neurofeedback
treatment - see http://www.helpforadd.com/2007/september.htm
- and noted that although positive findings had been reported in multiple
published studies, limitations of these studies led many researchers to regard
neurofeedback as a promising, but unproven treatment.
The American Psychological Association has established a 5-level system
for grading the evidence in support of mental health treatments. An
abbreviated summary of this grading system, and the level of research support
associated with each level, are as follows:
Level 1 Not Empirically Supported
Supported only through anecdotal evidence or non-peer reviewed case-studies.
Level 2 Possibly Efficacious
Shown to have a significant impact in at least one study, but the study
lacked a randomized assignment between controls.
Level 3 Probably Efficacious
Shown to produce positive effects in more than one clinical, observational
wait list or within-subject or between-subject study.
Level 4 Efficacious
Shown to be more effective than a no-treatment or placebo control group;
the study must contain valid and clearly specified outcome measures, and it
must be replicable by at least two independent researchers demonstrating the
same degree of efficacy.
Level 5 Efficacious and Specific
Shown to be statistically superior to credible placebo therapies or to actual
treatments, and it must be shown as such in two or more independent studies.
Using the grading system above, and based on studies published through 2005,
the conclusion reached by the Professional Advisory Board of CHADD was that
evidence supporting neurofeedback treatment for ADHD warranted a Level 2,
or 'Possibly Efficacious'. You can read CHADD's summary statement at http://www.help4adhd.org/en/treatment/complementary/WWK6A
and I believe you will find this to be of interest.
Based on a research base that includes more recently published studies,
however, the conclusions reached by Arn et. al., (2009) were far more positive.
These researchers conducted a meta-analysis of 15 studies, 4 of which were
reported to be randomized controlled trials. Their conclusion was that
"Neurofeedback treatment for ADHD can be considered 'Efficacious and Specific'
(Level 5) with a large effect size for inattention and impulsivity and a medium
effect size for hyperactivity." This is a very different conclusion
from the CHADD review and it is understandable that parents, educators, and
professionals would be confused about the strength of the evidence base for
New Review Provides Some Clarification
The Journal of Attention Disorders recently published an updated review
of neurofeedback treatment for ADHD that helps clarify its scientific support
[Lofthouse et. al., (2011). A review of neurofeedback treatment for ADHD.
Journal of Attention Disorders, published online 16 November 2011. DOI: 10.1177/1087054711427530].
The authors include scientists who have conducted research trials of neurofeedback
and also been part of the Multimodal Treatment Study of ADHD (MTA Study),
the largest ADHD treatment study ever conducted. They are thus well
equipped, in my view, to provide a thorough and objective review of a complicated
The research base for their review was 14 studies of neurofeedback treatment
for children with ADHD in which participants were randomized to neurofeedback
treatment or a control condition. Eleven of these studies were conducted
between 2005 and 2010; this speaks to the strong acceleration of neurofeedback
research, which is a welcome development.
Their review was limited to those that randomly assigned children to treatment
or control conditions which is an essential element of rigorous treatment
studies. For each study, the authors provide a detailed critique it's strengths
and limitations. As a detailed review of the individual study critiques
is beyond what I can do here, below I summarize the authors' conclusions on
the state of the science.
When averaged across the studies for which appropriate outcome data was
available, the overall mean effect size (ES) was .79 for inattention measures,
and .71 for hyperactivity/impulsivity measures. These are in a range
that would be considered 'large' for inattention and 'moderate' for hyperactivity/impulsivity
and are below what is typically reported for stimulant medication. Five
of the studies showed neurophysiological changes that were specific to neurofeedback
treatment. Overall, these results are consistent with beneficial effects
of neurofeedback treatment for ADHD.
Summary of limitations
The authors identified 5 different limitations that undermine the conclusions
about neurofeedback treatment efficacy that can be made.
1. Minimal use of Triple Blinding
The ideal study would be one where children, parents and/or teachers who
rate children's behavior before and after treatment, and clinicians don't
know whether the child received active treatment. This eliminates -
or at least strongly reduces - the likelihood that apparent benefits associated
with neurofeedback can be explained by expectations that the child would benefit.
Only 4 of the 14 studies utilized triple blind procedures, however, and
in 6 of the studies none of these 3 sources was blind.
2. Nature of Control Group
The strongest neurofeedback treatment study would be one that used 'sham'
treatment for children randomized to the control group, i.e., participants
receive feedback that is not linked to the EEG state that is the focus of
actual training. The benefit of this is that - in theory - it keeps
children, parents, and clinicians blind to whether real treatment is being
provided, thus eliminating potential biases to the outcome ratings they provide.
For the 14 studies review, however, only 4 employed sham treatment.
And, of those 4, only 1 used what was felt to be a truly credible 'sham'.
In the absence of a credible 'sham' treatment, conducting a 'triple blind'
study is not possible.
The other studies either used 'wait list' controls or compared neurofeedback
treatment to a different type of cognitive training. The use of wait
list and alternative treatment control groups are prevalent in the treatment
literature, but are less able than a true 'sham' condition to unequivocally
establish that treatment gains associated with neurofeedback are attributable
to the feedback children receive on their EEG state.
3. Insufficient identification, measurement, and control of concomitant
Children participating in these studies were frequently receiving other
treatments as well, either medication, psychotherapy, or educational interventions.
Because the presence and changes in concomitant treatments tended not to be
carefully monitored, however, positive change associated with neurofeedback
may have been caused, or at least influenced in some way, by unreported changes
in these other treatments.
4. General lack of post-treatment follow-up
Following children beyond the end of neurofeedback treatment is critical
for determining long-term efficacy and/or the need for booster sessions.
However, only 3 of the studies included a post-treatment follow up of neurofeedback.
And, in these studies, the procedures for assessing the sustainability of
treatment benefits were judged to be compromised. Thus, the authors
conclude that the duration of any gains associated with neurofeedback remains
This strikes me as a very important issue because one of the benefits that
has been claimed for neurofeedback is that the gains it proceuces are enduring.
At the moment, however, the data on which such claims can be made is
5. Limited attention to possible adverse side effects
Although neurofeedback is described as safe and without side effects, only
1 study actually monitored and reported adverse events that children and parents
related to treatment. Although no such effects were found, some have
argued that all truly effective treatments produce some side effects in some
percentage of individuals who receive them. Thus, rather than not attending
to this possibility in neurofeedback studies because the treatment is assumed
to be safe, the authors suggest that this is an area where greater scrutiny
An important issue not explicitly addressed by the authors concerns the
impact of neurofeedback on children's functioning beyond the benefits it
may yield in core ADHD symptoms. For example, academic performance
is an important domain where many children with ADHD struggle significantly.
To date, the benefits of existing evidence-based treatments, i.e.,
medication treatment and behavior therapy, on children's academic functioning
- especially over an extended period, have not been clearly demonstrated.
It would thus be very helpful to know whether and how neurofeedback
treatment leads to more positive academic outcomes.
Based on their review of the literature, the authors argue that "...due
to the lack of blinding and sham control conditions in randomized studies"
neurofeedback treatment for ADHD should not be considered 'Efficacious and
Specific' as was concluded in the 2009 review by Arn and his colleagues.
Instead, they believe that a grade of 3 on the APA evidence scale, which
corresponds to 'Probably Efficacious' is warranted. They note that a
large multisite triple-blind sham-controlled Randomized Controlled Trial is
needed to settle the issue.
Clearly, it is possible to review the same evidence and reach a different
conclusion. Some would argue that the authors are overly cautious in
the evidence grade they assign and that more is being required of neurofeedback
than of other ADHD treatments. For example, although the long-term benefits
of neurofeedback treatment may remain relatively unknown, evidence on the
long-terms benefits of medication treatment is also limited. My own
opinion is that according to the APA evidence standards, a grade of level
4, which corresponds to 'Efficacious', could reasonably be assigned. As
noted above, however, others reviewing this same evidence could certainly
reach other conclusions and the issues they raise in their review are important
ones for the field to address.
One could also argue that requiring a triple-blind trial with a credible
sham condition is unreasonable because this is a higher standard than that
employed most psychotherapy outcome research. In studies to establish
the efficacy of behavioral treatment for ADHD, for example, a triple blind
trial is not possible because clinicians know what treatment they are providing
and parents will know what treatment their child is receiving. Despite
this, behavior therapy is considered a strong evidence-based treatment for
In response to this objection, the authors argue that the highest standard
of scientific rigor should be required for any treatment offered to the public
for which triple blind studies are possible (they are not possible for behavior
therapy), and which are not precluded by strong ethical considerations.
They note that this is especially true for neurofeedback, as such a study
is possible and the treatment requires substantial time, effort, and expense.
My view is consistent with the authors in that I would very much like to
see the type of study they call for. Although I believe their rating
of 'Probably Efficacious' may be overly conservative based on the studies
they review, it should be stressed that having this conclusion published
in a scientific journal that does not focus on neurofeedback research represents
significant progress for the field. In fact, it was not too long ago
that a commonly held view was that there was little if any credible evidence
supporting this treatment.
Some Final Thoughts
It is important to recognize that what remains unclear is not whether children
with ADHD who receive carefully administered neurofeedback will generally
derive some benefit - the studies reviewed in this article establish that
- but, rather, why does benefit occurs. Here is what the authors say:
"...due to the lack of controls, it is unclear as to whether the large ESs
for impulsivity and inattention and the medium ES for hyperactivity are due
to the active component of EF and/or nonspecific treatment factors."
In other words, the research establishes that children who receive neurofeedback
treatment generally obtain benefits for core ADHD symptoms but is not fully
clear as to what explains those benefits. Is it the specific feedback
on EEG activity and learning to control that activity that produces the gains?
Or, do nonspecific factors associated with the treatment, e.g., expectancy
effects, clinician attention, praise for the effort involved, etc., actually
account for the gains?
This is the important scientific question that remains to be answered.
In the meantime, however, the research reviewed here indicates that if parents
obtain high quality neurofeedback treatment for their child there is a reasonable
basis for expecting that benefits will occur. The decision to do so should
be made with the knowledge that medication treatment and behavioral therapy
would be regarded as having stronger research support at this time.
To dismiss neurofeedback treatment simply as 'unproven', however, ignores
the considerable research on this approach that has been conducted. Helping
families better understand the strengths and limitations of this research
can enable them to make a better informed decision about whether to consider
this treatment option for their child.