Efficacy Levels

Explanation of Efficacy Levels


Biofeedback and neurofeedback therapies have continued to develop over the last 40 years. Today there are myriad disorders for which they are used. Large research grants have funded studies on neurofeedback therapy for a variety of disorders. These studies consistently report positive results.


In 2001, a Task Force of the Association for Applied Psychophysiology and Biofeedback and the Society for Neuronal Regulation developed guidelines for the evaluation of the clinical efficacy of psychophysiological interventions. The board of directors of both organisations subsequently approved these guidelines.


A low efficacy rating does not indicate that neurofeedback is not effective for the disorder, only that an insufficient number of studies have been completed for conclusive results. 


Level 1: Not Empirically Supported

Supported only by anecdotal reports and/or case studies in non peer-reviewed venues. Not empirically supported.


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 intrasubject 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 has been shown in at least two independent research settings.


Level 5: Efficacious and Specific

Evidence for Level 5 efficacy meets all of the criteria for Level 4. In addition, the investigational treatment has been shown to be statistically superior to credible sham therapy, pill, or alternative bonafide treatment in at least two independent research settings.