Heart Rate Variability Biofeedback Stress Relief Program for Depression: A Replicated Single-Subject Design

Background: Depressive disorders often have a chronic course and the efficacy of evidence-based treatments may be overestimated. Objective: To examine the effectiveness of the Heart Rate Variability Stress Reduction Program (SRP) as a supplement to standard treatment in patients with depressive disorders. Methods: The SRP was individually administered in eight weekly sessions. Seven participants completed the full protocol and were enrolled in a single-subject ABA multiple baseline experimental design. To perform interrupted time-series analyses, daily measures were completed in a diary (depression, resilience, happiness, heart coherence and a personalized outcome measure). Results: Five out of seven patients improved in depressed mood and/or a personalized outcome measure. The effect of treatment was reversed in four patients during the withdrawal phase. One patient reliably improved on depression, whereas two patients recovered on autonomy and one on social optimism. No consistent relationship was found between the heart rate variability-related level of coherence and self-reported mood levels. Conclusions: The SRP is beneficial in some domains and for some patients. A prolonged treatment or continued home practice may be required for enduring effects. The intervention had more clinical impact on resilience-related outcome measures than on symptoms. The small sample size does not permit generalization of the results. We recommend future investigation of the underlying mechanisms of the SRP.