Neurophysiological and neurocognitive mechanisms underlying the effects of yoga-based practices: towards a comprehensive theoretical framework

Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity

Contemplative practices, such as meditation and yoga, are increasingly popular among the general public and as topics of research. Beneficial effects associated with these practices have been found on physical health, mental health and cognitive performance. However, studies and theories that clarify the underlying mechanisms are lacking or scarce. This theoretical review aims to address and compensate this scarcity. We will show that various contemplative activities have in common that breathing is regulated or attentively guided. This respiratory discipline in turn could parsimoniously explain the physical and mental benefits of contemplative activities through changes in autonomic balance. We propose a neurophysiological model that explains how these specific respiration styles could operate, by phasically and tonically stimulating the vagal nerve: respiratory vagal nerve stimulation (rVNS). The vagal nerve, as a proponent of the parasympathetic nervous system (PNS), is the prime candidate in explaining the effects of contemplative practices on health, mental health and cognition. We will discuss implications and limitations of our model.

5-HTTLPR and MTHFR 677C>T polymorphisms and response to yoga-based lifestyle intervention in major depressive disorder: A randomized active-controlled trial

BACKGROUND

There is growing evidence suggesting that both genetic and environmental factors modulate treatment outcome in, a highly heterogeneous, major depressive disorder (MDD). 5-HTTLPR variant of the serotonin transporter gene (SLC6A4) and MTHFR 677C>T polymorphisms have been linked to the pathogenesis of MDD, and antidepressant treatment response. The evidence is lacking on the clinical utility of yoga in patients with MDD who have 5-HTTLPR and MTHFR 677C>T polymorphisms and less likely to respond to medications (SSRIs).

AIMS

We aimed to examine the impact of YBLI in those who have susceptible 5-HTTLPR and MTHFR 677C>T polymorphisms and are less likely to drug therapy with SSRIs.

SETTINGS AND DESIGN

In a 12 week randomized active-controlled trial, MDD patients (n = 178) were randomized to receive YBLI or drug therapy.

METHODS

Genotyping was conducted using PCR-based methods. The clinical remission was defined as BDI-II score ≤ 9.

STATISTICAL ANALYSIS USED

An intent-to-treat analysis was performed, and the association of genotype with treatment remission consisted of the logistic regression model. A P value of <0.05 was considered statistically significant.

RESULTS

Multivariate logistic regression models for remission including either 5-HTTLPR or MTHFR 677C>T genotypes showed statistically significant odds of remission in YOGA arm vs. DRUG arm. Neither 5-HTTLPR nor MTHFR 677C>T genotype showed any influence on remission to YBLI (P = 0.73 and P = 0.64, respectively). Further analysis showed childhood adversity interact with 5-HTTLPR and MTHFR 677C>T polymorphisms to decrease treatment response in DRUG treatment arm, but not in YOGA arm.

CONCLUSIONS

YBLI provides MDD remission in those who have susceptible 5-HTTLPR and MTHFR 677C>T polymorphisms and are resistant to SSRIs treatment. YBLI may be therapeutic for MDD independent of heterogeneity in its etiopathogenesis.

How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing

Background: The psycho-physiological changes in brain-body interaction observed in most of meditative and relaxing practices rely on voluntary slowing down of breath frequency. However, the identification of mechanisms linking breath control to its psychophysiological effects is still under debate. This systematic review is aimed at unveiling psychophysiological mechanisms underlying slow breathing techniques (<10 breaths/minute) and their effects on healthy subjects.

Methods: A systematic search of MEDLINE and SCOPUS databases, using keywords related to both breathing techniques and to their psychophysiological outcomes, focusing on cardio-respiratory and central nervous system, has been conducted. From a pool of 2,461 abstracts only 15 articles met eligibility criteria and were included in the review. The present systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: The main effects of slow breathing techniques cover autonomic and central nervous systems activities as well as the psychological status. Slow breathing techniques promote autonomic changes increasing Heart Rate Variability and Respiratory Sinus Arrhythmia paralleled by Central Nervous System (CNS) activity modifications. EEG studies show an increase in alpha and a decrease in theta power. Anatomically, the only available fMRI study highlights increased activity in cortical (e.g., prefrontal, motor, and parietal cortices) and subcortical (e.g., pons, thalamus, sub-parabrachial nucleus, periaqueductal gray, and hypothalamus) structures. Psychological/behavioral outputs related to the abovementioned changes are increased comfort, relaxation, pleasantness, vigor and alertness, and reduced symptoms of arousal, anxiety, depression, anger, and confusion.

Conclusions: Slow breathing techniques act enhancing autonomic, cerebral and psychological flexibility in a scenario of mutual interactions: we found evidence of links between parasympathetic activity (increased HRV and LF power), CNS activities (increased EEG alpha power and decreased EEG theta power) related to emotional control and psychological well-being in healthy subjects. Our hypothesis considers two different mechanisms for explaining psychophysiological changes induced by voluntary control of slow breathing: one is related to a voluntary regulation of internal bodily states (enteroception), the other is associated to the role of mechanoceptors within the nasal vault in translating slow breathing in a modulation of olfactory bulb activity, which in turn tunes the activity of the entire cortical mantle.

The effect of movement-focused and breath-focused yoga practice on stress parameters and sustained attention: A randomized controlled pilot study

Yoga-based practices (YBP) typically involve a combination of movement sequences, conscious regulation of the breath, and techniques to engage attention. However, little is known about whether effects of YBP result from the synergistic combination of these components, or whether a subset may yield similar effects. In this study we compared the effect of a movement-focused practice and a breath-focused practice on stress parameters (perceived stress and salivary cortisol) and sustained attention (response inhibition) in yoga naïve university students. While participants of both programs showed a reduction in perceived stress and salivary cortisol, only the breath-focused group showed improvements in sustained attention. In addition, improvement in sustained attention was correlated with reduction in perceived stress but not with reduction in salivary cortisol. We discuss these findings in the context of a theoretical framework outlining bottom-up neurophysiological and top-down neurocognitive mechanisms hypothesized to be engaged by YBP.

Integrating Pediatric Hypnosis with Complementary Modalities: Clinical Perspectives on Personalized Treatment

While pediatric integrative medicine (PIM) emphasizes an "evidence-based practice using multiple therapeutic modalities"; paradoxically, literature reviews examining the prevalence and/or efficacy of such mind⁻body approaches often address PIM modalities separately. Such contributions are relevant, yet documentation of how to deliver combined complementary approaches in children and youth are scarce. Nevertheless, integrative practitioners in clinical practice routinely mix approaches to meet the individual needs of each patient. Best practices are flexible, and include blending and augmenting services within the same session, and/or connecting modalities sequentially for an incremental effect, and/or referring to outside resources for additional interventions. Resonating with integrative medicine's definition, this article's goal is to demonstrate paradigms that "bring together complementary approaches in a coordinated way within clinical practice" by linking clinical hypnosis, the trail-blazer modality in PIM's history, with mindfulness, biofeedback, acupuncture, and yoga. Following the consideration of the overlap of guided imagery with hypnosis and an abridged literature report, this clinical perspective considers the selection of modalities within a collaborative relationship with the child/teen and parents, emphasizing goodness-of-fit with patients' contexts, e.g., symptoms, resources, interests, goals, and developmental stage. Case vignettes illustrate practical strategies for mixing approaches.

Yoga Therapy and Polyvagal Theory: The Convergence of Traditional Wisdom and Contemporary Neuroscience for Self-Regulation and Resilience

Yoga therapy is a newly emerging, self-regulating complementary and integrative healthcare (CIH) practice. It is growing in its professionalization, recognition and utilization with a demonstrated commitment to setting practice standards, educational and accreditation standards, and promoting research to support its efficacy for various populations and conditions. However, heterogeneity of practice, poor reporting standards, and lack of a broadly accepted understanding of the neurophysiological mechanisms involved in yoga therapy limits the structuring of testable hypotheses and clinical applications. Current proposed frameworks of yoga-based practices focus on the integration of bottom-up neurophysiological and top-down neurocognitive mechanisms. In addition, it has been proposed that phenomenology and first person ethical inquiry can provide a lens through which yoga therapy is viewed as a process that contributes towards eudaimonic well-being in the experience of pain, illness or disability. In this article we build on these frameworks, and propose a model of yoga therapy that converges with Polyvagal Theory (PVT). PVT links the evolution of the autonomic nervous system to the emergence of prosocial behaviors and posits that the neural platforms supporting social behavior are involved in maintaining health, growth and restoration. This explanatory model which connects neurophysiological patterns of autonomic regulation and expression of emotional and social behavior, is increasingly utilized as a framework for understanding human behavior, stress and illness. Specifically, we describe how PVT can be conceptualized as a neurophysiological counterpart to the yogic concept of the gunas, or qualities of nature. Similar to the neural platforms described in PVT, the gunas provide the foundation from which behavioral, emotional and physical attributes emerge. We describe how these two different yet analogous frameworks-one based in neurophysiology and the other in an ancient wisdom tradition-highlight yoga therapy's promotion of physical, mental and social wellbeing for self-regulation and resilience. This parallel between the neural platforms of PVT and the gunas of yoga is instrumental in creating a translational framework for yoga therapy to align with its philosophical foundations. Consequently, yoga therapy can operate as a distinct practice rather than fitting into an outside model for its utilization in research and clinical contexts.

Mind-Body Therapies for Late-Life Mental and Cognitive Health

PURPOSE OF REVIEW

A growing body of research supports the use of mind-body therapies (MBTs) as minimally invasive and effective approaches for the management of late-life mood and cognitive disorders.

RECENT FINDINGS

Recent randomized controlled trials and meta-analyses indicate that MBTs are effective for enhancing well-being, mood, sleep, and cognition in older adults. Evidence suggests that mindful movement (e.g., yoga, tai chi, walking meditation) may even outperform conventional physical exercise with regard to effects on quality of life, mood, and cognitive functioning. Practitioners may recommend MBTs as holistic, effective approaches for the management of common late-life mood and cognitive disorders. Continued research on MBTs will inform the development of even more effective/targeted interventions and contribute to greater acceptance and integration of these therapies into geriatric medicine and psychiatry.

The effects of yoga on stress and psychological health among employees: an 8- and 16-week intervention study

BACKGROUND

The stresses of modern work life necessitate effective coping strategies that are accessible and affordable to the general public. Yoga has been found to reduce stress in clinical samples, but studies are needed to examine standard gym yoga classes among functional individuals.

OBJECTIVES

This study investigated the effects of 8- and 16-week gym yoga on stress and psychological health.

DESIGN AND METHOD

Ninety individuals reporting moderate-to-high stress were randomly assigned to 16 consecutive weeks of yoga, or to a waitlist crossover group who did not practice yoga for 8 weeks then practiced yoga for 8 weeks. Stress and psychological health variables were assessed at baseline, 8 weeks, and 16 weeks.

RESULTS

Significant reductions in stress and all psychological health measures were found within the Yoga group over 16 weeks. When compared to the control group, yoga practitioners showed significant decreases in stress, anxiety, and general psychological health, and significant increases in well-being. The group who did not practice yoga showed significant decreases in stress, anxiety, depression, and insomnia after they crossed over and practiced yoga for 8 weeks.

CONCLUSIONS

Gym yoga appears to be effective for stress amelioration and promotion of psychological health among workers experiencing stress.

Determining Psychoneuroimmunologic Markers of Yoga as an Intervention for Persons Diagnosed With PTSD: A Systematic Review

There is a growing body of research on yoga as a therapeutic intervention for psychological symptoms of post-traumatic stress disorder (PTSD) accompanied by speculations on underlying physiologic mechanisms. The purpose of this systematic review is to identify, qualitatively evaluate, and synthesize studies of yoga as an intervention for PTSD that measured physiologic outcomes in order to gain insights into potential mechanisms. The focus is on studies evaluating yoga as a therapeutic intervention for PTSD rather than for trauma exposure, PTSD prevention, or subclinical PTSD. Multiple databases were searched for publications from the past two decades using terms derived from the question, "In people with PTSD, what is the effect of yoga on objective outcomes?" Eligibility criteria included yoga-only modalities tested as an intervention for formally diagnosed PTSD with at least one physiologic outcome. Results of this review confirmed that, though much of the published literature proposes physiological mechanisms underlying yoga's effects on PTSD, very few studies ( n = 3) have actually evaluated physiological evidence. Additionally, several studies had methodological limitations. In light of the limited data supporting yoga's beneficial effects on autonomic nervous system dysregulation, we present a theoretical model of the psychoneuroimmunologic processes associated with PTSD and the effects yoga may have on these processes to guide future research. Gaps in the literature remain for mechanisms related to activation of the hypothalamic-pituitary-adrenal axis and inflammation. Additional rigorous mechanistic studies are needed to guide development of effective yoga interventions for PTSD to augment existing evidence-based PTSD treatments.

A Somatic Movement Approach to Fostering Emotional Resiliency through Laban Movement Analysis

Although movement has long been recognized as expressing emotion and as an agent of change for emotional state, there was a dearth of scientific evidence specifying which aspects of movement influence specific emotions. The recent identification of clusters of Laban movement components which elicit and enhance the basic emotions of anger, fear, sadness and happiness indicates which types of movements can affect these emotions (Shafir et al., 2016), but not how best to apply this knowledge. This perspective paper lays out a conceptual groundwork for how to effectively use these new findings to support emotional resiliency through voluntary choice of one's posture and movements. We suggest that three theoretical principles from Laban Movement Analysis (LMA) can guide the gradual change in movement components in one's daily movements to somatically support shift in affective state: (A) Introduce new movement components in developmental order; (B) Use LMA affinities-among-components to guide the expansion of expressive movement range and (C) Sequence change among components based on Laban's Space Harmony theory to support the gradual integration of that new range. The methods postulated in this article have potential to foster resiliency and provide resources for self-efficacy by expanding our capacity to adapt emotionally to challenges through modulating our movement responses.

A qualitative examination of physiotherapist led community-based yoga for individuals with Huntington's disease

PURPOSE

The purpose of this study is to examine community-based yoga, led by a physiotherapist, for individuals affected by Huntington's disease (HD).

METHODS

Qualitative case study methodology was used to examine the Hatha yoga led by a certified yoga instructor who was a neurologic physiotherapist. Data collection included participant observations, semi-structured interviews with the instructor, and structured participant surveys. Data were coded and thematically analyzed. Strategies for rigor included field engagement, triangulation, member checks, and reflexivity.

OUTCOMES

Five major themes emerged regarding the value and role of yoga for individuals affected by HD: [1] Emphasis on mindfulness, [2] Yoga is modifiable and accessible, [3] Precise communication, [4] Yoga fosters a sense of community, and [5] Poses tailored to HD-specific deficits.

CONCLUSIONS

Yoga led by a physiotherapist can be tailored to enable participation by those affected by HD, addresses HD-specific deficits, and promotes a sense of community to supplement traditional physiotherapy.

The Effect of Yoga on Menstrual Disorders: A Systematic Review

OBJECTIVE

To summarize and evaluate evidence for the effect of yoga on menstrual disorders.

METHODS

PubMed, CINAHL/MEDLINE, Web of Science, AMED, and Scopus were searched for English-language literature relevant to the review question. All primary research studies were included.

RESULTS

Fifteen studies described in 18 papers were included in the review. A range of yoga interventions were used. Some studies used a combination of Asana, Pranayama, and other yogic relaxation or meditation techniques. All included studies reported some change in their outcome measures, suggesting reduced symptoms of menstrual distress following a yoga intervention; however, the heterogeneity and intensity of the interventions and outcome measures meant that findings have limited generalizability and applicability in practice settings.

CONCLUSIONS

Further research on the relationship between yoga practice and menstrual disorders is warranted, but there must be both consistency in the methods, measures, and quality of studies and a shift toward research on yoga practices that are replicable outside of the clinical trial setting.

The feasibility and impact of a yoga pilot programme on the quality-of-life of adults with acquired brain injury

OBJECTIVE

This pilot study measured the feasibility and impact of an 8-week yoga programme on the quality-of-life of adults with acquired brain injury (ABI).

METHODS

Thirty-one adults with ABI were allocated to yoga (n = 16) or control (n = 15) groups. Participants completed the Quality of Life After Brain Injury (QOLIBRI) measure pre- and post-intervention; individuals in the yoga group also rated programme satisfaction. Mann-Whitney/Wilcoxon and the Wilcoxon Signed Rank tests were used to evaluate between- and within-group differences for the total and sub-scale QOLIBRI scores, respectively.

RESULTS

No significant differences emerged between groups on the QOLIBRI pre- or post-intervention. However, there were significant improvements on overall quality-of-life and on Emotions and Feeling sub-scales for the intervention group only. The overall QOLIBRI score improved from 1.93 (SD = 0.27) to 2.15 (SD = 0.34, p = 0.01). The mean Emotions sub-scale increased from 1.69 (SD = 0.40) to 2.01 (SD = 0.52, p = 0.01), and the mean Feeling sub-scale from 2.1 (SD = 0.34) to 2.42 (SD = 0.39, p = 0.01).

CONCLUSION

Adults with ABI experienced improvements in overall quality-of-life following an 8-week yoga programme. Specific improvements in self-perception and negative emotions also emerged. High attendance and satisfaction ratings support the feasibility of this type of intervention for people with brain injury.

Feasibility and Preliminary Efficacy of a Novel RDoC-Based Treatment Program for Adolescent Depression: "Training for Awareness Resilience and Action" (TARA)-A Pilot Study

BACKGROUND

The novel group treatment program Training for Awareness, Resilience, and Action (TARA) was developed to target specific mechanisms based on neuroscience findings in adolescent depression and framed within the National Institute of Mental Health Research Domain Criteria. TARA contains training of autonomic and emotional self-regulation, interoceptive awareness, relational skills, and value-based committed action.

METHODS

We performed a single-arm trial to test the feasibility and preliminary efficacy of TARA in reducing depression and anxiety levels and assessed whether the specific targeted domains of function reflected the hypothesized symptom change. Twenty-six adolescents (14-18 years old, 7 males and 19 females) participated in the 12-week group program. Assessment was performed before (T0), immediately after (T1), and 3 months after the end of TARA (T2).

RESULTS

Significant improvement was seen in depression symptoms (Reynolds Adolescent Depression Scale Second Edition) between T0-T1 (t-value = -3.56, p = 0.002, CI = -6.64, -1.77) and T0-T2 (t-value = -4.17, p < 0.001, CI = -11.20, -3.75) and anxiety symptoms (Multidimensional Anxiety Scale for Children) between T0-T1 (t-value = -2.26, p = 0.033, CI = -4.61, -0.21) and T0-T2 (t-value = -3.06, p = 0.006, 95% confidence interval = -9.02, -1.73). Significant improvements in psychological flexibility, sleep, and mindfulness skills were also found between T0 and T2.

LIMITATIONS

The sample size was small without a control condition. The pilot design did not allow for testing the hypothesized brain changes and effect of TARA on relevant systemic biomarkers.

CONCLUSION

TARA is feasible in a sample of clinically depressed and/or anxious adolescents and preliminary efficacy was demonstrated by reduced depression and anxiety symptoms. The specific symptom and behavioral outcomes corresponded well with the hypothesized mechanisms of change.