Heart Rate Variability Biofeedback Improves Emotional and Physical Health and Performance: A Systematic Review and Meta Analysis.

We performed a systematic and meta analytic review of heart rate variability biofeedback (HRVB) for various symptoms and human functioning. We analyzed all problems addressed by HRVB and all outcome measures in all studies, whether or not relevant to the studied population, among randomly controlled studies. Targets included various biological and psychological problems and issues with athletic, cognitive, and artistic performance. Our initial review yielded 1868 papers, from which 58 met inclusion criteria. A significant small to moderate effect size was found favoring HRVB, which does not differ from that of other effective treatments. With a small number of studies for each, HRVB has the largest effect sizes for anxiety, depression, anger and athletic/artistic performance and the smallest effect sizes on PTSD, sleep and quality of life. We found no significant differences for number of treatment sessions or weeks between pretest and post-test, whether the outcome measure was targeted to the population, or year of publication. Effect sizes are larger in comparison to inactive than active control conditions although significant for both. HRVB improves symptoms and functioning in many areas, both in the normal and pathological ranges. It appears useful as a complementary treatment. Further research is needed to confirm its efficacy for particular applications.

Mind-body treatments of irritable bowel syndrome symptoms: An updated meta-analysis.

Irritable bowel syndrome (IBS) is a widespread chronic functional gastrointestinal (GI) disorder having bidirectional comorbidity with psychiatric disorders. This review focuses on psychological treatment of IBS, focusing on symptom severity rather than IBS diagnostic criteria. We chose this dimensional approach in order to assess mind-body effects as an alternative or complement to conventional medical treatment, which focuses on symptom relief. We calculated the effect sizes for various psychosocial-mind-body therapies (MBTs) for IBS symptoms in both children and adults. Therapies included meditation, relaxation, yoga, autogenic training, progressive relaxation, general training in stress coping, hypnotherapy, biofeedback, psycho-education, psychodynamic psychotherapy, and cognitive behavioral therapy. We performed a meta-regression analyses and mixed effects contrasts to find various outcome differences, and we analyzed their relative efficacy in both children and adults. We found 53 studies in 50 reports describing randomized controlled trials. Medium to high effect sizes were found across all methods compared with various controls, with possibly higher effects for children. We found no systematic differences among treatment methods. Meta-regression analyses showed no significant effect for the presence of psychophysiological training, meditation or explicit exposure procedures as treatment components, although most MBTs include exposure as a nonexplicit treatment characteristic, and many relaxation techniques have meditative characteristics. We conclude that there is considerable evidence that an array of mind-body and other psychological therapies can be effective complements to medical treatment for IBS symptom severity, with little evidence for relative superiority of any particular approach. We suggest that the various methods may operate through different mechanisms.