Attention Research Update
February 2001
"Helping parents, professionals and educators
stay informed about new research on ADHD"
David
Rabiner, Ph.D. Senior Research
Scientist, Duke University
Neurofeedback - also known as EEG Biofeedback - is an approach for treating ADHD that has been studied and practiced for a number of years. In neurofeedback treatment, individuals are provided with real-time feedback about their brainwave activity and taught to use that information to modulate certain aspects of their minds. As a treatment for ADHD, neurofeedback is based on findings that measurements of brain activity in many individuals with ADHD indicate reduced activity in the prefrontal region and frontal lobes (cortical slowing). Neurofeedback treatment is designed to train individuals to increase the production of brainwave patterns that reduce or eliminate this cortical slowing, and thus reduce or eliminate many associated ADHD symptoms.
Within the medical and scientific communities, a diverse range of viewpoints exists on the utility of neurofeedback treatment for ADHD. At one extreme, there are prominent researchers who argue that, although neurofeedback treatment is consistent with current theories about the biological underpinnings of ADHD, there is a lack of scientific data documenting the efficacy of this approach. On the other hand, some neurofeedback researchers and practitioners argue that published studies clearly establish the effectiveness of this treatment.
As is often the case in such debates, a careful review of the available literature suggests that a more reasonable position falls somewhere in between these views. Two controlled studies and numerous, carefully conducted case studies have reported positive results. Based on this body of prior work, neurofeedback treatment has been considered a "promising" approach for which additional study was clearly warranted. This is the conclusion of Dr. Eugene Arnold in the most comprehensive review of alternative treatment approaches for ADHD published to date, and most ADHD experts would agree that additional controlled studies are required to unequivocally establish the efficacy of neurofeedback treatment for ADHD.
A recently conducted investigation -- "The Effects of Stimulant Therapy, EEG Biofeedback & Parenting Style on the primary symptoms of ADHD" (Monastra et. al.) --represents a significant step in this direction. Preliminary reports of this research were presented at the CHADD (Children and Adults with Attention Deficit-Hyperactivity Disorder) national conference in 1999 and the annual convention of the American Psychological Association (APA) in 2000. A manuscript describing this study is currently under editorial review.
As with many studies of neurofeedback treatment, this investigation was conducted in an actual clinical setting -- as opposed to an academic research setting. Participants were 100 children (83 boys and 17 girls) with an average age of 10 (range 6-19). Each child was diagnosed with ADHD and treated at the Family Psychology Clinic, a private outpatient psychological clinic in upstate New York. The ADHD diagnosis was established using a structured interview and standardized parent and teacher behavior rating scales.
After each child/teen was diagnosed, his or her parents were informed of a comprehensive treatment approach that included stimulant medication, parent counseling, school consultation to establish and monitor a program of academic support, and neurofeedback. Approximately half of the participants (n=51) opted to include neurofeedback as part of their child's treatment.
Because this study was conducted in a clinic setting where parents paid for treatment (as opposed to an academic research setting where treatment is often provided at no charge), it was not possible to randomly assign children to receive neurofeedback as part of their treatment package. One limitation associated with non-random assignment is the possibility that children in the two groups, or their families, may have differed in a systematic way prior to the beginning of treatment. If this were found, it would be difficult to attribute any differences found at the end of treatment to differences in the treatment they received. Fortunately, however, this does not seem to have been true.
Information presented indicates that the two groups (i.e. children whose treatment included neurofeedback and those who did not) did not differ in age, gender composition, IQ, or socioeconomic status. In addition, the representation of the different ADHD subtypes (i.e. inattentive and combined) was virtually identical. Finally, pre-treatment parent and teacher ratings of ADHD symptoms, scores on the TOVA (a computerized test of sustained attention that is often used in ADHD evaluations and to monitor the effects of medication treatment), and results of a QEEG scan were also equivalent. (Note: A QEEG scan is a technique used to identify the pattern of cortical under-activity characteristic of ADHD. Recent research indicates this technique shows considerable promise as an objective procedure to assist in the diagnosis of ADHD.
Treatment
Participants received treatment over the course of 12 months. The different treatment components are described below.
Stimulant medication: All participants received treatment with Ritalin throughout the year. The average daily dose was 25 mg (10 mg in the morning, 10 mg at midday, and 5 mg in the late afternoon) for children in both groups.
Parent Counseling: Parents participated in a ten-session parenting class, followed by individual consultation on an "as needed" basis. The parenting class was designed to increase parents' understanding of ADHD and help them increase the use of systematic reinforcement strategies and positive parental attention. Information on nutrition, problem solving with teens, and the educational rights of children with ADHD was also presented. The average number of clinical contact hours (parenting classes and subsequent individual consultation) totaled 25 for parents in the neurofeedback group and 27 for the other parents.
School Consultation: At the conclusion of the diagnostic evaluation, parents were informed about procedures to obtain special educational services for their children under the appropriate federal regulations. In accordance with applicable laws, school districts evaluated each child and developed, revised, and implemented an individualized educational program (IEP) or a plan of academic support/accommodation ("504 Plan") for each with the assistance of the treating clinician. For each group, the mean number of on-site consultations during the treatment year was 3.
Neurofeedback: For children whose parents elected to include neurofeedback in their child's treatment, "attention training" sessions lasting 30 to 40 minutes were conducted on a weekly basis. Periodic QEEG scans were used to determine training effectiveness. Training continued until the patient no longer exhibited abnormal cortical slowing. The average number of sessions required to reach this criterion was 43.
As is evident from the above discussion, the overall treatment regimens for the two groups of children appear to have been virtually identical, except for the inclusion of neurofeedback treatment in one of the groups. Because the groups did not differ in systematic ways before treatment began, the researchers could evaluate whether including neurofeedback training made any appreciable difference in the children's outcomes.
Results
A comprehensive set of treatment outcome measures was collected on each child one year after treatment had begun. These measures included: 1) parent and teacher ratings of inattentive and hyperactive/impulsive behavior using the Attention Deficit Disorder Evaluation Scale (ADDES), a widely used standardized behavior rating scale; 2) the children's scores on the TOVA; and 3) the children's Attention Index score, based on a QEEG scan. Each measure was collected twice: once when participants were still on medication and a second time after they had been off medication for an entire week.
The authors predicted that children in both groups would show behavioral improvements and "normalized" TOVA results when medication treatment was still in place, and would not differ from each other in terms of overall results. They also predicted that the improvements for the neurofeedback group would be significantly better upon the second outcome assessment, when the children were no longer receiving medication. (This prediction was based on prior research suggesting that neurofeedback training can yield sustained reductions in ADHD symptoms while medication-induced improvements typically last only as long as the child is on medication.) Finally, researchers expected that only children who received neurofeedback would show normalized Attention Index scores on the QEEG.
Outcomes when children were still on medication
As predicted, TOVA scores at the first outcome assessment were well within the normal range for both groups. In contrast to expectations, parent and teacher ratings of ADHD symptoms remained in the clinical range for children who had not received neurofeedback. For participants whose treatment included neurofeedback, however, parent and teacher ratings of ADHD symptoms were all in the normal range and were significantly better than ratings for the other participants. These results are shown below. (Note: Scores below 7 are considered to indicate significant difficulty. The numbers reported represent the average score for each group.)
|
|
No neurofeedback
|
Neurofeedback included
|
|
Parent inattention
|
4.63
|
8.59
|
|
Parent hyperactivity
|
6.06
|
8.65
|
|
Teacher inattention
|
4.96
|
9.35
|
|
Teacher hyperactivity
|
5.96
|
9.63
|
Similar results were obtained on the outcome measures taken after the children had been without medication for an entire week. As before, children whose treatment had not included neurofeedback continued to show significant ADHD symptoms according to parent and teacher ratings. In addition, the TOVA results for these participants fell in the clinical range on 3 of the 4 subscales.
In contrast, parent and teacher ratings of the neurofeedback group all remained within the normal range, as did their TOVA results. Furthermore, the QEEG scan showed that the average Attention Index score for the neurofeedback group was also within the normal range, indicating that the cortical slowing characteristic of ADHD that was present at the beginning of treatment was no longer evident. As expected, the average Attention Index scores for participants not receiving neurofeedback continued to indicate significant cortical slowing.
Summary and Implications
These results provide compelling evidence that incorporating neurofeedback into a comprehensive treatment approach for ADHD can yield important benefits. As discussed above, only the participants whose treatment included attention training via neurofeedback showed behavioral improvement upon follow up, and these benefits were evident even after medication was discontinued. These children were doing substantially better --according to both parents and teachers--than participants who had not received neurofeedback. In addition, the pattern of cortical slowing that is found in many individuals with ADHD, and which is specifically targeted by neurofeedback, was no longer evident. This suggests that the gains associated with neurofeedback training cannot be attributed to the placebo effect, but instead reflect meaningful changes in EEG activity.
This is a very impressive set of findings. As with any study, however, it is important to recognize it's inherent limitations. First, it is surprising that no significant gains in parent and teacher ratings were obtained for the non-neurofeedback group, even when medication treatment was still in place. Recently published results from the MTA study document substantial benefits from medication treatment alone, and in combination with behavioral interventions, over a 14-month period. Based on these results, as well as results from other studies, improved symptom ratings from parents and teachers would have been anticipated. Because the same treatments were delivered to participants who also received neurofeedback, this does not call into question the incremental gains associated with neurofeedback. However, it does raise the question of whether such incremental gains would have been detected if the benefits provided by the other intervention components were as expected.
Several other cautions need to be noted. Because random assignment to treatment conditions was not feasible, one cannot rule out the possibility that parents who opted to include neurofeedback in their child's treatment were a more highly motivated group of parents, and this is why their children did better. After all, this was a time-consuming and expensive addition. The fact that there was no differential attendance in parent counseling sessions between the two groups mitigates these concerns, however. In addition, the EEG changes revealed by the QEEG scan make it unlikely that enhanced parent motivation alone could explain the differential treatment results. This is because these better results were associated with documented changes in neurophysiological processes known to be associated with ADHD, and it seems implausible that parents' motivation, or other extraneous factors , could have produced such changes.
Finally, it is important to emphasize that neurofeedback was delivered as part of a comprehensive treatment plan that included three other components. There is thus no basis for determining whether neurofeedback alone would have yielded positive results. And, although gains were sustained beyond the active use of medication, it is unclear whether these gains would persist without ongoing intervention. These issues would be important to address in subsequent research.
These cautions notwithstanding, this is an important study that makes a significant contribution to establishing a role for attention training using neurofeedback in the treatment of ADHD. One hopes that subsequent studies building on this impressive piece of work, and which incorporate important controls such as random assignment that were not possible in this investigation, will soon be forthcoming.
In a prior issue of Attention Research Update, I reviewed the results of an interesting study in which children with ADHD received an intervention designed to teach them how to improve their ability to sustain attention. This was one of very few studies to test whether systematic procedures to directly train attention skills in children with ADHD (other than attention training via neurofeedback) could be successful. Results from this study appeared to be promising.
A second investigation of this topic was published in the November 99 issue of the Journal of Learning Disabilities (Semrud-Clikeman, M., An Intervention Approach For Children With Teacher- And Parent-Identified Attentional Difficulties. Journal of Learning Disabilities, 32, 581-590). Participants in this study were 33 children in grades 2 through 6 who were diagnosed with ADHD, and 21 matched comparison children. Teachers nominated children to participate in the study, based on their difficulty completing assignments and paying attention in class. (Note: Efforts were made to screen out children who had other diagnoses in addition to ADHD, so this was not a truly representative group of ADHD children.)
Parents were informed about a program to teach their child better attention skills. Those parents expressing interest in the program were contacted so that an ADHD evaluation for their child could be completed. Interestingly, of the 33 children identified with ADHD in this study, only 50% had been previously diagnosed and very few were receiving any treatment. Although this is not the focus of the study, these data highlight the unfortunate fact that many children who struggle with ADHD are never formally identified and receive little appropriate assistance.
Attention training was conducted in after-school groups of 4 to 5 children that met twice a week for 60 minutes each time over an 18-week period. The attention training system used was based on the Attention Process Training model (APT), developed for adults over a decade ago. This system is based on the idea that there are different components to attention: lower level components such as being able to focus and sustain attention over time and higher level components that involve the ability to allocate attention between different tasks.
The training program utilized both visual and auditory attention tasks. The visual attention tasks required children to find a target stimulus embedded in an array of distracters. Tasks were relatively simple at first (i.e. the child was required to find one type of figure among widely spaced figures ranging from somewhat similar to widely dissimilar) and became increasingly difficult (i.e. the child had to find a selected number of figures from among many closely spaced figures as quickly as possible). For the auditory task, children were required to count the number of times particular targets could be heard on a cassette tape. The easier tasks required children to keep track of how often they were presented with a particular letter from among a group of dissimilar options. In the more difficult tasks, children had to count the instances of words beginning with particular sounds. These are the kinds of repetitive, uninteresting tasks that children with ADHD typically have great difficulty performing accurately.
During each session, children reviewed their performance (i.e. speed and accuracy) from prior sessions and were required to set goals for their performance that day. In addition, the group discussed strategies to help each child meet his or her goals. Children attempted the task using the strategy they had selected, and then evaluated the effectiveness of the strategy based on their performance. When this evaluation indicated the strategy was not effective, the group leader helped the child revise the initial strategy and he or she would try again. Thus, the basis on which better attention skills were trained included repetitive practice in attention tasks, reviewing prior performance and setting new performance goals, and developing, monitoring, and, if necessary, revising strategies to achieve one's performance goals. This active problem-solving approach is one that can be applied to a wide range of academic and behavioral objectives, not just the attention tasks that were the focus of this study.
Only 21 of the participants with ADHD received the intervention described above. The remaining children were unable to take part because of after-school scheduling conflicts. Prior to beginning the intervention, all 33 ADHD children and the 21 non-ADHD comparison subjects completed a test of visual and auditory attention that was different from those tasks used in the attention-training paradigm.
After the 18-week attention training intervention was completed, all children were given the visual and auditory attention tests a second time. To determine whether the attention-training program was successful, the authors compared the pre- and post-training performance of 3 groups: ADHD children who received the intervention (i.e. ADHD intervention group); ADHD children who did not receive the intervention (i.e. ADHD control group); and non-ADHD comparison children (non-ADHD control group).
RESULTS
As expected, pre-test results indicated that children in both ADHD groups performed more poorly on the visual and auditory attention tests than the non-ADHD comparison children. The ADHD groups did not differ from one another, however, suggesting that their attention skills were equivalently impaired prior to the training program. In addition, parent and teacher ratings of attention problems for children in these groups were equivalent prior to the start of training.
At the post-test assessment, the ADHD control group continued to show poorer performance on both attention tasks than the non-ADHD control group. Children who received the attention-training program scored as well as the non-ADHD subjects and significantly better than the children in the ADHD control group. In fact, on the auditory attention task, children in the ADHD intervention group had slightly higher average scores, although this difference was not statistically significant.
Post-test behavior ratings from parents and teachers were not obtained.
SUMMARY AND IMPLICATIONS
Results from this study indicate that children with ADHD can perform as well as non-ADHD children on visual and auditory attention tasks following training in sustained attention and problem-solving skills. This is the second study published in recent years suggesting the potential benefits of direct attention training for children with ADHD.
These are encouraging results, but there are limitations to this study that the author notes are important to consider. First, because the sample did not include any children with diagnoses in addition to ADHD, as is true for many children with ADHD, this was not truly representative of the overall ADHD population. Therefore, it cannot be determined whether similarly positive results would have been obtained for children with ADHD and co-occurring problems. Second, there were very few females included in the study, making it unclear whether the beneficial impact of the training program would generalize to girls as well.
The most important limitation is the absence of any post-test assessment of children's actual behavior and performance in the classroom. Although it is encouraging that children who received the training performed better on specific tests of attention, it is essential to know whether the training also had positive impact on classroom behavior and academic performance. It is certainly possible that it did, but it is also possible that there was no change in these more important outcomes. It would thus be very important to repeat this study to determine whether the attention-training paradigm used actually results in classroom gains.
(c) 2001 David Rabiner, Ph.D.
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