Efficacy of bio- and neurofeedback for depression: a meta-analysis

Efficacy of bio- and neurofeedback for
depression: a meta-analysis

Background. For many years, biofeedback and neurofeedback have been implemented in the
treatment of depression. However, the effectiveness of these techniques on depressive symptomatology
is still controversial. Hence, we conducted a meta-analysis of studies extracted
from PubMed, Scopus, Web of Science and Embase.
Methods. Two different strings were considered for each of the two objectives of the study:
A first group comprising studies patients with major depressive disorder (MDD) and a second
group including studies targeting depressive symptomatology reduction in other mental or
medical conditions.
Results. In the first group of studies including patients with MDD, the within-group analyses
yielded an effect size of Hedges’ g = 0.717, while the between-group analysis an effect size of
Hedges’ g = 1.050. Moderator analyses indicate that treatment efficacy is only significant when
accounting for experimental design, in favor of randomized controlled trials (RCTs) in comparison
to non RCTs, whereas the type of neurofeedback, trial design, year of publication,
number of sessions, age, sex and quality of study did not influence treatment efficacy. In
the second group of studies, a small but significant effect between groups was found
(Hedges’ g = 0.303) in favor of bio- and neurofeedback against control groups. Moderator analyses
revealed that treatment efficacy was not moderated by any of the sociodemographic and
clinical variables.
Conclusions. Heart rate variability (HRV) biofeedback and neurofeedback are associated with
a reduction in self-reported depression. Despite the fact that the field has still a large room for
improvement in terms of research quality, the results presented in this study suggests that both
modalities may become relevant complementary strategies for the treatment of MDD and
depressive symptomatology in the coming years.