Presentation and Evaluation of a Manual for Heart Rate Variability Biofeedback in Somatic Symptom Disorder

Background: There is initial evidence for the efficacy of heart rate variability biofeedback (HRV-BF) in depression, anxiety disorders, and functional somatic syndromes. In somatic symptom disorder (SSD), evidence is lacking. The aim of this study was to describe a newly developed HRV-BF brief intervention and to analyze HRV changes, and to examine the applicability and acceptance in SSD. Methods: We analyzed the data of the subsample of a pilot randomized controlled trial (22 subjects with SSD) who received HRV-BF over 4 sessions. We assessed HRV (SDNN: standard deviation of the NN interval, RMSSD: root mean square of successive differences between NN interval, LF: low frequency) and the subjective evaluation and acceptance of the intervention. Results: HRV analyses within therapy sessions showed that individuals learned to increase their HRV significantly during biofeedback sessions and were able to maintain it during self-regulation periods without feedback (SDNN, RMSSD, LF: 5.7 <= F-t <= 11.1). Moreover, HRV improved across sessions (SDNN). The majority of participants rated the intervention very positively (e.g., satisfaction, improvement in mood and physical well-being). Conclusions: HRV-BF can be learned within 4 sessions and shows positive effects in patients with SSD. Adding HRV-BF to existing treatments, e.g., psychotherapy, seems promising.