Neurofeedback
Research
Neurofeedback Research
There is a large body of scientific research documenting the effectiveness of EEG neurofeedback for several areas of psychological or neurodevelopmental difficulty. These studies have been published in numerous scientific and professional journals in the US and abroad. Unfortunately, many healthcare professionals are not aware of the extent of research support.
Further support comes from recent fMFI research done at several universities. In these studies, participants were given visual feedback derived from real-time functional magnetic resonance imaging (fMRI), the most technologically advanced form of neuroimaging. Participants were asked to alter the level of activation in the brain areas being monitored by the fMRI. Results showed that participants could do so successfully in three different studies. Working with three different areas of the brain, it was demonstrated that individuals are able to learn to voluntarily control the level of activation in their brains (as indicated by blood oxygenation) when provided with immediate fMRI feedback about brain activation levels.
In addition, the well publicized success in several research labs in the US and abroad in training animal and human subjects to gain voluntary control of neural signals provides further empirical support for neurofeedback. For example, Brown University Neuroscience Professor John Donoghue has developed a system called The BrainGate Neural Interface, one type of brain-computer interface. With the BrainGate system, electrical signals transmitted from a sensor implanted in the brain can be translated into actions via computer. Using the BrainGate, a 25 year-old quadriplegic learned how to turn on lights, change television channels, and read email on a specially designed computer screen using only his brainwaves. This is neurofeedback in action.
This research represents an important convergence in findings and interest among disparate groups of scientists, researchers, and practitioners. Academic neuroscientists are now discovering with the advanced technology of the fMRI what has been known and practiced for over thirty years using a much more accessible form of neuroimaging – the EEG: we are able to voluntarily alter brain function when given feedback about it.
A comprehensive review of the research on EEG neurofeedback has been recently published in a special issue of Child and Adolescent Psychiatric Clinics of North America devoted to Emerging Interventions. In the introductory chapter, the volume editors assess the degree of scientific support for neurofeedback using standards developed by the child psychiatry professional organization (AACAP). They conclude that neurofeedback meets the same standard as that for stimulant medication:
“EEG biofeedback meets the AACAP criteria for clinical guideline (CG) for treatment of ADHD, seizure disorders, anxiety (OCD, GAD,PTSD, phobias), depression, reading disabilities, and addictive disorders. This suggests that EEG biofeedback should always be considered as an intervention for these disorders by the clinician. Clearly there is a stronger evidence of efficacy . . . for the use of EEG biofeedback for ADHD in children and adolescents. Due to this high level of empirical support, the use of EEG biofeedback for ADHD will meet the most stringent APA criterion of efficacious and specific.”
Five controlled studies of the use of neurofeedback for ADHD have been published, including one random controlled trial. A double blind, randomized, sham treatment study has just been completed, but is not yet published. Many open or clinical trials, with hundreds of participants, have been published as well. These studies uniformly show significant benefit for 70 to 80% of participants, with an effect size for neurofeedback equivalent to that of stimulants, as measured by computerized tests of attention and impulsivity (continuous performance tests) as well as standardized behavioral rating scales.
Several of the studies have shown improvements in brain function after EEG neurofeedback, including improvements in the EEG and in ERPs (evoked response potentials – a widely used indicator of brain function.) Most recently, results have been presented of a study using the most technologically advanced form of brain imaging – functional magnetic resonance imaging (fMRI) – in order to assess changes in brain function after EEG neurofeedback. This study showed that EEG neurofeedback with children with ADHD resulted in normalization of brain activation levels in the frontal circuits in the brain that are involved in attention. As shown in pre- and post- neurofeedback fMRI studies, blood oxygenation levels of 24 ADHD participants normalized with EEG neurofeedback training, with increased blood oxygenation in the prefrontal cortex bilaterally, and in the anterior portion of the cingulate gyrus. No such changes were seen in non-treatment controls.
Although much more follow up research needs to be done, several studies show the maintenance of gains years after neurofeedback training ended. There is also growing evidence of the specificity of effect in neurofeedback, such that the effect (behavioral and physiological) varies by specific location and frequencies trained.
In a recent paper Update on attention-deficit/hyperactivity disorder published in Current Opinion in pediatrics Katie Campbell Daley reviewed the research and practice standards on treatment of ADHD. Dr. Campbell serves on the staff of the Department of Medicine, Children’s Hospital Boston and in the Department of Pediatrics of the Harvard Medical School. She concluded:
“Overall, these findings support the use of multi-modal treatment, including medication, parent/school counseling, and EEG biofeedback, in the long term management of ADHD, with EEG biofeedback in particular providing a sustained effect even without stimulant treatment . . . parents interested in non-psychopharmacologic treatment can pursue the use of complementary and alternative therapy. The therapy most promising by recent clinical trials appears to be EEG biofeedback.”
Substantial validation research has also been completed on neurofeedback for epilepsy or seizure disorder. Several controlled studies have been completed, including three condition reversal studies. Several other open trials or case series have also been reported. A recent meta-analysis (combining results of numerous separate studies) indicated that 82% of patients demonstrated greater than 30% reduction in seizures, with an average greater than 50% reduction. This outcome is all the more significant in that most of the participants included in these studies did not improve with standard medical care. For many, neurofeedback was the only alternative to surgery. Recent clinical experience has shown significantly improved outcomes using neurofeedback which is individually targeted at abnormalities in the degree of co-activation of different brain sites, as guided by coherence findings in the QEEG.
Research on neurofeedback for anxiety is less well developed than for ADHD and epilepsy. Multiple small studies on generalized anxiety disorder, obsessive-compulsive disorder, phobic anxiety, and post traumatic stress disorder have been published, with several controlled trials. Overall results show significant reduction in anxiety with neurofeedback, although several of the studies involved many fewer sessions than is used in clinical settings. Clinical trials with QEEG guided neurofeedback appear to show stronger benefit. With depression, several case studies have been published providing preliminary evidence of efficacy with major depression. A published open case series also suggests that QEEG guided neurofeedback training may have a larger effect size.
In research with adults with substance use disorder (PSUD) multiple random controlled trials (RCT’s) as well as uncontrolled studies have shown protocol specific changes in the EEG, and improvements on measures of depression (self-rating), attention (Using computerized tests of attention) and stress (physiological). Several long term follow-up studies showed a significant reduction in the one year abstinence/recidivism rate for those treated with neurofeedback compared to controls. Given that neurofeedback is medication free and has been shown to be effective with ADHD, a condition frequently also found with PSUD, neurofeedback appears to have particular value for these (PSUD and ADHD) patients where the risk of medication abuse is high.
Reviews of the literature on treatment for traumatic brain injury (TBI) and reading disabilities (RD) indicate that very few of the commonly used interventions have shown efficacy in formal research, and that the effect size of these techniques is usually quite small. By contrast, preliminary research suggests that neurofeedback shows efficacy in the treatment of both of these conditions with a large effect size. Several open case series and controlled studies (including one RCT) have shown significant benefits for neurofeedback with TBE primarily in adults, with improvements on measures of attention, executive function, cognitive flexibility, problem solving, information processing, verbal fluency, and depression, as well as in the EEG. Cessation and reduction of medication has also been reported as well as return to productive work. For RD, no formal studies have been published to date, although several studies of the effect of neurofeedback on ADHD have provided suggestive preliminary evidence of improved cognitive function.
Although more research needs to be completed, especially further follow-up studies assessing the maintenance of gains over time, clearly there is at the present time substantial research support for this intervention.
For a Neurofeedback Bibliography please click HERE.
Click to read the Effects of an EEG Biofeedback Protocol on a Mixed Substance Abusing Population.
