Background and Objective: Mental illnesses are increasing worldwide with the internalising disorders (IDs; i.e. anxiety disorders, depressive disorders, post-traumatic stress disorder, obsessive-compulsive disorder) being the most prevalent. Current first-line therapies (e.g. pharmacotherapy) offer high failure rates and substantial side-effects.
Electroencephalogram neurofeedback (EEG-NFB) has been shown to be an effective and safe treatment for these conditions, however, there remains much doubt regarding the existence of specificity (i.e. clinical effects specific to the modulation of the EEG variable(s) of interest). We undertook a quantitative review in an attempt to determine if there is evidence for EEG-NFB specificity in the treatment of IDs. Methods: We considered all published and unpublished randomised, double-blind (i.e. trainees and raters), sham/placebo-controlled (i.e. feedback contingent on a random signal, the activity from a different person’s brain, or an unrelated signal from the trainees own brain) trials involving humans with at least one ID diagnosis without exclusion by language, locality, ethnicity, age, or sex. Outcomes of interest included self/parent/teacher reports and clinician ratings. Effect sizes were calculated for individual studies and combined in a meta- analysis. Results: Three trials met our criteria (2 published, 1 unpublished) encompassing a total of 102 participants. Effect sizes ranged from 0.12 to 0.59 with an overall small effect size (cohen’s d=0.36, 95% confidence interval=-0.04 to 0.75). Heterogeniety was low (Chi²=0.81, df=2, p=0.67; I² = 0%), however, there were serious concerns regarding the risk of bias and imprecision leading us to rate the overall certainty of the evidence as low. Conclusion: This quantitative review was undertaken to assess for evidence of EEG-NFB specificity in the treatment of IDs. Our analysis suggests that EEG-NFB does have specific effects in the treatment of IDs, however, the overall certainty of the evidence is low. More randomised, double-blind, sham-controlled trials are needed. Registration: This review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42020159702)
Presented by: Tyson Perez, Paul Glue , Dirk De Ridder, Divya Adhia & Jerin Mathew