A Systematic Review of a Polyvagal Perspective on Embodied Contemplative Practices as Promoters of Cardiorespiratory Coupling and Traumatic Stress Recovery for PTSD and OCD: Research Methodologies and State of the Art.

Andrea Poli,Angelo Gemignani,Mario Miccoli,Federico Soldani

doi:10.3390/ijerph182211778

Abstract

Baseline respiratory sinus arrhythmia (RSA) has been proposed as a transdiagnostic biomarker of stress vulnerability across psychopathologies, and a reliable association between PTSD, OCD and lower resting RSA was found. Contemplative practices have been linked to the activation of the vagus as well as to an increased RSA that, according to the polyvagal theory, reflects the activation of the ventral vagal complex (VVC) and may promote PTSD and OCD recovery. PubMed and Scopus databases were selected to conduct a search following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 guidelines, and A MeaSurement Tool to Assess systematic Reviews-2 (AMSTAR-2) was used to appraise the methodological quality for this systematic review. Six articles met the inclusion criteria (one cross-sectional study, one study with pre-post measurements, two cohort studies and two RCT studies). Mindfulness-related interventions promoted parasympathetic activity, an increased vagal tone and improvements in PTSD and OCD symptoms. According to the polyvagal theory, mindfulness-related and compassion-related meditations would be conceptualized as neural exercises expanding the capacity of the ventral vagal complex to regulate the present state and to promote resilience. Clinical and methodological issues are discussed.

Highlights

The polyvagal theory [1,2,3] proposes an evolutionary and neurophysiological framework that deals with the organization of autonomic systems and has been linked to functional gastrointestinal disorders and chronic diffuse pain [4] and to psychosocial pathology [5], both connected to chronic traumatic stress during development
One study was an Randomized Controlled Trials (RCTs) study [56] that aimed to evaluate the effect of two common components of meditation investigating HR, heart rate variability (HRV), awakening cortisol and post-traumatic stress disorder (PTSD) measures collected through the CAPS, while Williams et al [57] describe the protocol of an RCT to evaluate the effectiveness and mechanisms of three manualized
King et al [53] examined potential neural correlates of mindfulness-based exposure therapy (MBET), investigating 23 veterans with PTSD

Summary

Introduction

The polyvagal theory [1,2,3] proposes an evolutionary and neurophysiological framework that deals with the organization of autonomic systems and has been linked to functional gastrointestinal disorders and chronic diffuse pain [4] and to psychosocial pathology [5], both connected to chronic traumatic stress during development. Considering the evidence derived from neurophysiology, behavioral observations and comparative anatomy, the polyvagal theory proposes the existence of two separate vagal pathways belonging to the parasympathetic nervous system that give rise to the emergence of a dorsal vagal complex (DVC) and a ventral vagal complex (VVC). In accordance with the polyvagal theory [1,2], the function and the structural organization of the autonomic nervous system of the human being are embedded in its phylogenetic origin through a hierarchical organization.

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