Heart rate variability biofeedback in the treatment of major depression

Major depressive disorder is the most common mood disorder and is one of the most burdensome and disabling diseases in the world. Prevailing approaches to treating depression have a number of significant limitations and drawbacks. Consequently, alternative and adjunctive treatments for depression are being increasingly explored. The role of autonomic nervous system functioning in the etiology of depression has been examined, and depression has been found to be associated with sympathetic predominance and parasympathetic impairment. This decreased parasympathetic modulation has been attributed to impaired activity of the vagus nerve, as indexed by attenuated heart rate variability (HRV) at the respiratory frequency. Areas of the brain that areinvolved in emotion regulation influence vagus nerve functioning. HRV biofeedback has been shown to be a modality through which individuals can learn to increase the amplitude of their HRV oscillations by breathing at specific rates. Through HRV biofeedback, the vagus nerve is thought to be stimulated in such a way that promotes autonomic balance and improved emotion regulation. Previous research suggests that HRV biofeedback may significantly reduce depression symptoms. The current study was a preliminary efficacy, randomized controlled trial that intended to follow-up an open label pilot study previously conducted by this lab, which found HRV biofeedback to be effective at significantly reducing depressive symptoms. The primary goal was to evaluate the efficacy of a HRV biofeedback protocol by comparing it to a sham control protocol with similar demand characteristics. The study also sought to evaluate the feasibility, tolerability and effectiveness of this placebo. Eleven participants were recruited from the UMDNJ-University Behavioral Health Care population and surrounding communities, and were randomized to a treatment group, receiving ten weeks of HRV biofeedback training and home practice, or a control group, receiving ten weeks of sham respiratory biofeedback training and home practice. Primary outcome measures were the HAMD and the BDI-II—assessed at baseline, week four, week seven, and week ten. Results indicated no significant differences in depression symptom improvement between groups, although significant main effects for time were observed for both groups (p<.05). Results did, however, support the utility, feasibility, and tolerability of the credible sham respiratory control protocol.