Discovery

The Impacts of Trauma Exposure on Emotion Regulation and 2 Vagally Mediated Heart Rate Variability

Hypothesis

Editor's note

Reduced heart rate variability in trauma survivors signals a parasympathetic brake failure—meaning their nervous systems struggle to downshift from threat mode, which directly impairs emotion control and raises cardiac risk. This thesis-stage work bridges a critical gap by measuring vagal physiology alongside emotion dysregulation in PTSD, adding mechanistic clarity to an observation clinicians recognize but rarely quantify. Trauma psychiatrists, cardiologists managing PTSD comorbidity, and vagal intervention researchers should attend closely.

Source: openalex · Rebeka Catherine Tucker · CLOK (University of Central Lancashire) · 2027-01-01

URL: https://doi.org/10.17030/uclan.thesis.00059261

AI rationale (4/5, tier: emerging): Directly measures HRV and vagal tone in PTSD; links autonomic physiology to emotion regulation. Longitudinal design likely, but appears thesis-stage work.

Reduced parasympathetic activity is associated with emotion regulation difficulties and increased cardiovascular risk (CVR), both of which are prevalent in Post-Traumatic Stress Disorder (PTSD). Consequently, understanding the relationship between autonomic nervous system (ANS) functioning and emotion regulation in PTSD is critical for both psychological and physical health. The present thesis investigates the psychological and physiological processes linking PTSD, autonomic functioning, and emotion regulation difficulties. Chapter One provides an overall introduction to the thesis. The chapter first examines DSM-5 PTSD diagnostic criteria and symptom clusters, before evaluating psychophysiological explanations of PTSD. The chapter then introduces Heart Rate Variability (HRV) as an index of autonomic nervous system functioning and discusses psychophysiological theories to explain the association between HRV and emotion regulation. Finally, the concept of emotion regulation is explored in depth, highlighting how it manifests both physiologically and cognitively, and how it is affected in those with PTSD. Chapter One concludes by providing the rationale for the overarching aim of the thesis and the methodology adopted in subsequent chapters to address the aim. Chapter Two presents a comprehensive multilevel meta-analysis comparing short-term (5-minute) and long-term (24-hour) Vagally-Mediated HRV (vmHRV) in PTSD populations. The findings indicated that short-term recordings appear more sensitive to acute autonomic fluctuations but are susceptible to confounding variables. Conversely, long-term recordings provide more stable assessments of parasympathetic function but may overlook acute changes that occur in response to contextual demands. The results highlight the need for standardised vmHRV measurement protocols in PTSD studies and informed the methodology of the subsequent empirical studies presented in Chapter Five and Six. Chapter Three examined self-reported emotion regulation difficulties in individuals with and without PTSD. The findings revealed that whilst overall emotion regulation difficulties are associated with PTSD, specific facets of emotion regulation, such as impulse control and goal-directed behaviour, exhibit a stronger association with PTSD than other facets. The findings challenge the assumption of global emotion regulation deficits in PTSD and highlight the importance of recognising that not all facets are equally affected in PTSD. Consequently, the findings advocate for targeted PTSD treatments to address the specific emotion regulation difficulties experienced by an individual. Additionally, the findings informed the design of the remaining studies presented in the thesis, which aligned vmHRV with self-reported emotion regulation difficulties to identify which facets of emotion regulation are associated with autonomic functioning. Chapter Four employed a multivariate meta-analytic approach to examine the relationship between self-reported emotion regulation difficulties and vmHRV in trauma-exposed populations. The results demonstrated that vmHRV correlates more robustly with difficulties in specific facets of emotion regulation such as difficulties with goal directed behaviour and impulse control. These findings provided preliminary evidence that vmHRV may reflect specific facets of emotion regulation. Chapter Five empirically investigated the relationship between PTSD symptom severity, vmHRV, and self-reported emotion regulation difficulties. The findings indicated a threshold effect whereby diminished vmHRV was only observed in individuals with severe PTSD symptoms but not in those with moderate symptoms. Interestingly, the moderate PTSD symptom group reported greater regulation difficulties in some emotion regulation facets than the severe PTSD group, without corresponding autonomic dysregulation. The findings indicate a misalignment between the subjective emotional and physiological experiences of those with PTSD. Chapter Six examined vmHRV changes during implicit and explicit emotion regulation challenges across groups with moderate and severe PTSD symptoms and controls. Contrary to existing findings, no differences in vmHRV were observed between groups during the emotion regulation challenges. Although no group differences in vmHRV responsivity were observed, interpretations grounded in the Polyvagal and Neurovisceral Integration Theories suggest that, in those with PTSD, vmHRV may fail to capture the underlying mechanisms responsible for autonomic dysregulation and emotion regulation difficulties. The findings highlight the complexity of the relationship between autonomic functioning and emotion regulation in PTSD. Together, the findings from this thesis highlight the need for integrated subjective and objective measures of emotion regulation and autonomic functioning in those with PTSD. In turn, the integration of physiological indices and subjective experiences may facilitate the development of individualised treatments that improve both emotional and cardiovascular outcomes for those affected by PTSD.

🔬 Deep dive

Plain-language summary

This doctoral thesis investigates how experiencing trauma — particularly trauma severe enough to cause PTSD — disrupts the body's ability to regulate both emotions and heart function. The autonomic nervous system, which controls involuntary processes like heart rate, normally helps us manage stress; in PTSD this system appears chronically dysregulated. The author uses heart rate variability (HRV), specifically the vagally mediated component (vmHRV), as a physiological window into parasympathetic nervous system activity, because lower vmHRV is linked to poorer emotional control and higher cardiovascular risk. The thesis combines two meta-analyses (one on vmHRV measurement in PTSD populations, one on vmHRV and emotion regulation) with original empirical studies comparing trauma-exposed and non-exposed individuals. A key insight is that not all aspects of emotion regulation are equally impaired in PTSD — impulse control and goal-directed behaviour appear disproportionately affected compared to other facets. The work also finds that short-term (5-minute) vmHRV recordings are more sensitive to acute autonomic changes but more prone to confounding, whereas 24-hour recordings offer greater stability. Overall, the thesis argues for targeted, physiologically-informed PTSD treatments rather than assuming a blanket global deficit in emotion regulation.

Key findings

A multilevel meta-analysis (Chapter 2) found that short-term (5-minute) vmHRV recordings are more sensitive to acute autonomic fluctuations in PTSD populations but are more susceptible to confounding variables, while 24-hour recordings yield more stable parasympathetic indices but may miss context-driven acute changes.
Self-reported data (Chapter 3) showed that, although overall emotion regulation difficulties are elevated in PTSD, specific facets — particularly impulse control and goal-directed behaviour — show stronger associations with PTSD status than other facets, challenging the assumption of a uniform, global emotion-regulation deficit.
A multivariate meta-analytic examination (Chapter 4) confirmed that vmHRV correlates with self-reported emotion regulation difficulties in trauma-exposed populations, linking reduced parasympathetic tone to measurable dysregulation in emotional functioning; specific effect sizes were not fully reported in the available abstract excerpt.

Methods + cohort

This is a PhD thesis (University of Central Lancashire, submitted 2027) structured as a thesis by publication or integrated multi-study format across six chapters. The work includes at least two systematic meta-analyses — one multilevel meta-analysis comparing short-term vs. long-term vmHRV recordings in PTSD samples, and one multivariate meta-analysis examining vmHRV and emotion-regulation relationships in trauma-exposed populations — alongside at least two original empirical studies (Chapters 5 and 6) that align vmHRV measurement with self-reported emotion regulation instruments in PTSD and non-PTSD groups. Exact sample sizes and empirical study designs (e.g., cross-sectional vs. longitudinal, specific HRV recording protocols) are not fully specified in the available abstract; methods details are therefore best-effort estimates based on contextual description.

Limitations + open questions

Because this is a thesis with only the abstract publicly available, effect sizes, confidence intervals, and empirical sample characteristics cannot be verified, making quantitative comparison with other studies difficult. The reliance on self-report measures for emotion regulation introduces potential response bias, and the meta-analytic chapters may be limited by heterogeneity in HRV recording conditions and PTSD diagnostic criteria across included primary studies. Cross-sectional empirical designs, if used, would preclude causal inference about whether autonomic dysregulation precedes or follows emotion regulation difficulties. Future experiments should use standardised vmHRV protocols alongside ambulatory physiological monitoring and trauma-unexposed longitudinal controls to clarify directionality.

How this fits the corpus

This thesis sits at the intersection of autonomic physiology and psychological health, extending work represented by [§83], which also examines HRV and blood pressure mechanisms in relation to autonomic function, by shifting focus to a clinical PTSD population rather than healthy adults. It parallels [§82], which similarly deploys psychophysiological biomarkers and HRV-based risk stratification in a distinct clinical population (irritable bowel syndrome), illustrating how vagal tone measurement is emerging as a transdiagnostic tool across stress-related conditions. The thesis also parallels [§94], which investigates mind-body interventions targeting parasympathetic function in chronic pain (fibromyalgia), in that both works position autonomic regulation as a modifiable pathway linking psychological and physical outcomes. More broadly, the thesis complements [§93], which examines stress-related physiological dysregulation through inflammatory and allostatic load markers rather than ANS indices, suggesting these are parallel biological axes through which trauma and chronic stress damage health. Note: confidence in precise mechanistic overlap is moderate given that only the abstract is available for the index article.

Compare with

Repeated whole-body cryostimulation promotes a blood pressure reduction at rest in healthy adult men
Both studies use HRV as a primary index of autonomic/parasympathetic function, but [id=83] examines healthy men undergoing cryostimulation, providing a useful non-clinical contrast for understanding baseline vmHRV variability and confounding.
Distinct psychophysiological biomarkers and risk stratification models for irritable bowel syndrome with constipation (IBS-C) and diarrhea (IBS-D)
Directly comparable in methodology — both apply psychophysiological HRV biomarkers and autonomic profiling to a stress-related clinical population — allowing readers to assess how HRV-based risk stratification generalises across PTSD and IBS.
The Effect of Physiotherapy Integrated With Yoga and Mindfulness on Individuals With Fibromyalgia
Investigates mind-body interventions (yoga/mindfulness integrated with physiotherapy) that target the same parasympathetic regulatory pathway implicated in this thesis, offering evidence on whether vmHRV deficits in trauma populations are amenable to intervention.
Impact of Periodontal Inflammation on Allostatic Load
Examines allostatic load and inflammatory dysregulation as parallel physiological consequences of chronic stress, complementing the ANS/cardiovascular focus here and helping readers understand how autonomic and inflammatory pathways co-occur in stress-exposed populations.
Stress during the first 1,000 days of life in humans, when everything begins
Focuses on stress biology during the first 1,000 days of life, providing a developmental-origins lens that contextualises why early trauma exposure may produce the lasting ANS and emotion-regulation impairments characterised in this thesis.

AI-generated summary using claude-sonnet-4-6 on 2026-06-27. Information, not medical advice.

Published 2026-05-26 · Last kit-update 2026-05-26