Research & Evidence

There is extensive evidence supporting biofeedback and neurofeedback for a range of conditions. In 2016 The Association for Applied Psychophysiology and Biofeedback (AAPB) published ‘Evidence-Based Practice in Biofeedback and Neurofeedback (3rd Ed.). This important document, the most comprehensive review of all the research, assessed the level of evidence for biofeedback and neurofeedback for numerous disorders and provided a ranking system, rating their level of efficacy, very similar to the rating schemes developed by the other organisations such as the American Psychological Association. Founded in 1969, AAPB is the foremost international association for the study of biofeedback and applied psychophysiology. AAPB is an interdisciplinary organisation representing the fields of psychology, psychiatry, medicine, dentistry, nursing, physical therapy, occupational therapy, social work, education, counselling and others.

Evidence-Based Practice in Biofeedback and Neurofeedback (3rd Ed.)

“Evidence-Based Practice in Biofeedback and Neurofeedback (3rd Ed.) is the most comprehensive review of research in the field of neurofeedback and biofeedback available to clinicians. The diversity of topics will extend the clinician’s knowledge. This serves as a vital resource to validate the use of these modalities. Perhaps the most important aspect of this review is the ranking of studies for each disorder based upon the methodological quality of the research. I recommend this book, not only to every clinician, but to all researchers interested in doing biofeedback and neurofeedback research. This will allow researchers to explore the extent of research thus far done, and will open the door to new ideas that can be investigated in the future.”

Deborah R. Simkin, MD, DFAACAP, Diplomat ABIHM, BCN. Clinical Assistant Professor, Department of Psychiatry, University of Emory, School of Medicine.

“The completely revised Evidence-Based Practice in Biofeedback and Neurofeedback (3rd Ed.) provides the most comprehensive and up-to-date evidence-based and neuroscientifically supported information available in print anywhere. Every clinical condition has been thoroughly reviewed, rigorously revised and updated, and meticulously documented and referenced by respected experts in their field, ensuring that this will be a continuously accessed tool for clinicians, researchers, and academicians looking for the most accurate, evidence-based information covering a comprehensive listing of clinical conditions for which ever-accumulating experience and evidence exists. This reference integrates the rigorous guidelines adopted by the Boards of Directors of both the Association for Applied Psychophysiology and Biofeedback (AAPB) and the International Society of Neurofeedback and Research (ISNR). For those in the worldwide field of neuromodulation and neurotherapy, this is an immensely valuable tool and vital resource to ensure we increasingly attain to the highest standards of scientific investigation and clinical expertise.”

Robert P. Turner, MD, MSCR, QEEGD, BCN. Associate Professor of Clinical Paediatrics and Neurology, University of South Carolina School of Medicine and Palmetto Health, Richland Children’s Hospital.

Efficacy, Clinical Effectiveness and Evidence-Based Practice

“Efficacy” refers to the determination of a training or treatment effect derived from a systematic evaluation obtained in a controlled clinical trial. “Clinical Effectiveness” assess how well a treatment works in actual clinical settings with typical clinical populations. Evidence-based practice must take into account both clinical efficacy in controlled research settings and effectiveness in the real world of clinical practice.

Rating Criteria 

The AAPB Rating Criteria are:

Level 1 - Not empirically supported. 

Supported only by anecdotal reports and/or case studies in non-peer reviewed venues.

Level 2 - Possibly Efficacious.

At least one study of sufficient statistical power with well identified outcome measures, but lacking randomised assignment to a control condition internal to the study.

Level 3 - Probably Efficacious.

Multiple observational studies, clinical studies, wait list controlled studies, and within subject and intra-subject replication studies that demonstrate efficacy.

Level 4 - Efficacious.

A. In a comparison with a no-treatment control group, alternative treatment group, or sham (placebo) control utilising randomised assignment, the investigational treatment is shown to be statistically significantly superior to the control condition or the investigational treatment is equivalent to a treatment of established efficacy in a study with sufficient power to detect moderate differences, and…
B. The studies have been conducted with a population treated for a specific problem, for whom inclusion criteria are delineated in a reliable, operationally defined manner, and…
C. The study used valid and clearly specified outcome measures related to the problem being treated and
D. The data are subjected to appropriate data analysis, and…
E. The diagnostic and treatment variables and procedures are clearly defined in a manner that permits replication of the study by independent researchers, and…
F. The superiority or equivalence of the investigational treatment have been shown in at least two independent research settings.

Level 5 - Efficacious and Specific.

The investigational treatment has been shown to be statistically superior to credible sham therapy, pill, or alternative bona fide treatment in at least two independent research settings.

Note: Lower efficacy ratings do not necessarily indicate that an intervention is not helpful. In some cases a lower rating has been applied because the relevant research has not yet been conducted. In other cases, a lower rating means that the application benefits some subjects and not others because of wide inter-subject variability. If people cannot tolerate medication-based treatments, or if people wish to avoid medication if possible, then “Possibly Efficacious” (Level 2) rated neurofeedback and biofeedback therapies may be reasonable alternatives.

Level of Evidence for Disorders

Whilst The AAPB Review assessed and rated 39 different disorders the list below is limited to some of the most common conditions:

ADHD - Efficacious and Specific: Level 5. 

Anxiety and Anxiety Disorders - Efficacious: Level 4

Chronic Pain - Efficacious: Level 4 (muscle-related orofacial pain, non-cardiac chest pain, posture-related pain problems); Probably Efficacious: Level 3 (muscle-related low back pain, phantom-limb pain, pelvic-floor pain syndromes)

Depression - Efficacious: Level 4.

Epilepsy - Efficacious: Level 4.

Headache - Efficacious: Level 4.

Post-Traumatic Stress Disorder (PTSD) - Efficacious: Level 4

ASD - Probably Efficacious: Level 3

Fibromyalgia - Probably Efficacious: Level 3.

Insomnia - Probably Efficacious: Level 3.

Performance Enhancement - Probably Efficacious: Level 3.

Traumatic Brain Injury (TBI) - Probably Efficacious: Level 3.

Trans-Cranial Direct Current Stimulation (tDCS)

There is increasing evidence supporting tDCS (trans-cranial direct current stimulation) for a range of conditions. In 2020 a group of international experts from hospitals and university medical schools, (including departments of clinical neuroscience, neurology, neurophysiology, neuropsychology, physiology, psychiatry and psychotherapy and translational neuroscience) collaborated to production‘Evidence-Based Guidelines and Secondary Meta-Analysis for the use of Trans-Cranial Direct Current Stimulation in Neurological and Psychiatric Disorders’. This expert review assessed the level of evidence for tDCS for numerous disorders and provided a ranking system, rating the level of effectiveness.

Rating Criteria

The Rating Criteria are:

Level A - Definitely Effective 

Requires at least two convincing Class I studies or one convincing Class I study and at least two consistent convincing Class II studies.

Level B - Probable Effective 

Requires at least two convincing Class II studies, or one convincing Class II study and at least two consistent convincing Class III studies.

Level C - Possibly Effective

Requires one convincing Class II study or at least two convincing Class III studies.

Level of Evidence for Disorders

Whilst the expert review assessed and rated over 15 different disorders the list below is limited to some of the most common conditions:

Depression - Definitely Effective: Level A.

Addiction (Alcohol) - Probably Effective: Level B.

Chronic Neuropathic Pain - Probably Effective: Level B.

Epilepsy - Probably Effective: Level B.

Fibromyalgia - Probably Effective: Level B.

Migraine - Probably Effective: Level B.

Stroke (Motor Function in Sub-Acute and Chronic Stroke) - Probably Effective: Level B.

Post-Operative Acute Pain - Probably Effective: Level B.

Schizophrenia (Auditory Hallucinations) - Probably Effective: Level B.

QEEG

“QEEG represents a critical tool to improve clinical diagnosis and treatment response evaluation.”

“QEEG is a modern type of EEG analysis that involves recording digital EEG signals which are processed, transformed, and analysed using complex mathematical algorithms. QEEG has brought new techniques of EEG signals feature extraction: analysis of specific frequency band and signal complexity, analysis of connectivity and network analysis. The clinical application of QEEG is extensive, including neuropsychiatric disorders, epilepsy, stroke, dementia, traumatic brain injury, mental health disorders and many others. The role of QEEG is not necessarily to pinpoint an immediate diagnosis but to provide additional insight in conjunction with other diagnostic evaluations in order to provide objective information necessary for obtaining a precise diagnosis, correct disease severity assessment, and specific treatment response evaluation.”

“QEEG is commonly used in the study of autism spectrum disorders, associating quantitative markers with changes in brain functions. It can also be applied for therapeutic purposes using neurofeedback.”

Livint Popa L, Dragos H, Pantelemon C, Verisezan Rosu O, Strilciuc S. The Role of Quantitative EEG in the Diagnosis of Neuropsychiatric Disorders. J Med Life. 2020;13(1):8-15. doi:10.25122/jml-2019-0085.

Soft-Wired, How the New Science of Brain Plasticity Can Change Your Life (2013) by Michael Merzenich.

The Brain That Changes Itself (2007) by Norman Doidge.

The Brain’s Way of Healing (2015) by Norman Doidge.