Sympathetic Neural Control in Humans with Anxiety-Related Disorders

Comorbid anxiety is associated with more changes in the Management of Postural Orthostatic Tachycardia Syndrome

OBJECTIVE

Postural Orthostatic Tachycardia Syndrome (POTS) is not an anxiety disorder, but it shares similar symptomatology. The impact of this comorbidity on management is unknown. This information may lead to better strategies to improve the care of this subgroup.

METHOD

The electronic medical records of 322 patients seen at our institution between 2018 and 2022 with confirmed POTS diagnoses were analyzed. Demographics, anxiety comorbidities, questionnaire responses, and treatment course changes were collected. Negative binomial regression models examined if the presence of an anxiety disorder was associated with the number of POTS treatment course changes offset by observation time.

RESULTS

When adjusted for sex, age, baseline GAD-7 score, and baseline PROMIS global mental health score, those with a diagnosis of an anxiety disorder had2.6 times the incident rate of treatment changes for POTS management (IRR = 2.66 (95% CI: 1.43-4.95)).

CONCLUSION

Individuals carrying the diagnosis of an anxiety disorder had an increase in the incident rate of treatment changes for POTS therapy. This finding may be due to the underlying pathophysiology and treatment of anxiety disorders, the effect of bias, and difficulty with symptom differentiation. More work needs to be done to determine how to best care for POTS patients with comorbid anxiety.

The role of non-ordinary states of consciousness occasioned by mind-body practices in mental health illness

BACKGROUND

Research with hallucinogens suggests that non-ordinary states of consciousness (NOSCs), particularly mystical-type experiences, predict improvements in various affective disorders and substance use disorders (SUDs). Little is known, however, about the therapeutic potential of NOSCs induced by mind-body practices such as meditation, yoga and breathwork.

METHODS

We conducted a literature review in online databases (PubMed, Scopus, Google Scholar) and preprint databases (SSRN, bioRxiv) to identify studies of NOSCs induced by mind-body practices and their effects in affective disorders and SUDs.

RESULTS

A wide variety of mind-body practices involving physical movement (i.e., shamanic drumming, yoga) and hyper-focused immersive mental experiences (i.e., meditation, breathwork) have been reported in the literature. Preliminary evidence, mostly from qualitative studies and open label studies, suggest that mind-body practices produce NOSCs. Such experiences have been associated with short-term reduced levels of anxiety and depression, increased motivation to quit addictive behaviors, and enhanced self-awareness and spiritual well-being.

LIMITATIONS

Findings are limited by the scarcity of literature in this field. Further rigorous and methodologically sound empirical research is needed, including comparative studies of NOSCs occasioned by different methods.

CONCLUSIONS

Mind-body practices may represent a promising approach for treating mental health disorders. The NOSCs induced by such practices may lead to beneficial shifts in perceptions, values, beliefs, and behaviors. Given the challenges with hallucinogen-based therapies, mind-body practices may represent a more accessible and acceptable way of eliciting potentially helpful NOSCs in clinical practice.

Blood pressure and muscle sympathetic nerve activity are associated with trait anxiety in humans

Chronic anxiety is prevalent and associated with an increased risk of cardiovascular disease. Prior studies that have reported a relationship between muscle sympathetic nerve activity (MSNA) and anxiety have focused on participants with anxiety disorders and/or metabolic syndrome. The present study leverages a large cohort of healthy adults devoid of cardiometabolic disorders to examine the hypothesis that trait anxiety severity is positively associated with resting MSNA and blood pressure. Resting blood pressure (BP) (sphygmomanometer and finger plethysmography), MSNA (microneurography), and heart rate (HR; electrocardiogram) were collected in 88 healthy participants (52 males, 36 females, 25 ± 1 yr, 25 ± 1 kg/m2). Multiple linear regression was performed to assess the independent relationship between trait anxiety, MSNA, resting BP, and HR while controlling for age and sex. Trait anxiety was significantly correlated with systolic arterial pressure (SAP; r = 0.251, P = 0.018), diastolic arterial pressure (DAP; r = 0.291, P = 0.006), mean arterial pressure (MAP; r = 0.328, P = 0.002), MSNA burst frequency (BF; r = 0.237, P = 0.026), and MSNA burst incidence (BI; r = 0.225, P = 0.035). When controlling for the effects of age and sex, trait anxiety was independently associated with SAP (β = 0.206, P = 0.028), DAP (β = 0.317, P = 0.002), MAP (β = 0.325, P = 0.001), MSNA BF (β = 0.227, P = 0.030), and MSNA BI (β = 0.214, P = 0.038). Trait anxiety is associated with increased blood pressure and MSNA, demonstrating an important relationship between anxiety and autonomic blood pressure regulation.NEW & NOTEWORTHY Anxiety is associated with development of cardiovascular disease. Although the sympathetic nervous system is a likely mediator of this relationship, populations with chronic anxiety have shown little, if any, alteration in resting levels of directly recorded muscle sympathetic nerve activity (MSNA). The present study is the first to reveal an independent relationship between trait anxiety, resting blood pressure, and MSNA in a large cohort of healthy males and females devoid of cardiometabolic comorbidities.

Assessment of Virtual Mindfulness-Based Training for Health Care Professionals: Improved Self-Reported Respiration Rates, Perceived Stress, and Resilience

Background

Mindfulness in Motion (MIM) is a workplace resilience-building intervention that has shown reductions in perceived stress and burnout, as well as increased resilience and work engagement in health care workers.

Objective

To evaluate effects of MIM delivered in a synchronous virtual format on self-reported respiratory rates (RR), as well as perceived stress and resiliency of health care workers.

Methods

Breath counts were self-reported by 275 participants before and after 8 weekly MIM sessions. MIM was delivered virtually in a group format as a structured, evidence-based workplace intervention including a variety of mindfulness, relaxation, and resilience-building techniques. Participants counted their breaths for 30 seconds, which was then multiplied by 2 to report RR. Additionally, participants completed Perceived Stress Scale and Connor-Davidson Resiliency Scale.

Results

According to mixed effect analyses there were main effects of MIM Session (P < .001) and Weeks (P < .001), but no Session by Week interaction (P = .489) on RR. On average, RR prior to MIM sessions were reduced from 13.24 bpm (95% CI = 12.94, 13.55 bpm) to 9.69 bpm (95% CI = 9.39, 9.99 bpm). When comparing average Pre-MIM and Post-MIM RR throughout the MIM intervention, Week-2 (mean = 12.34; 95% CI = 11.89, 12.79 bpm) was not significantly different than Week-1 (mean = 12.78; 95% CI = 12.34, 13.23 bpm), but Week-3 through Week-8 demonstrated significantly lower average Pre-MIM and Post-MIM RR compared to Week-1 (average weekly difference range: 1.36 to 2.48 bpm, P < .05). Perceived stress was reduced from Week-1 (17.52 ± 6.25) to after Week-8 (13.52 ± 6.04; P < .001), while perceived resiliency was increased from Week-1 (11.30 ± 5.14) to after Week-8 (19.29 ± 2.58); P < .001).

Conclusion

Thus far, completion of MIM sessions has shown acute and long-term effects on self-reported RR, but more research is required to determine the extent of improved parasympathetic (relaxed) states. Collectively, this work has shown value for mind-body stress mitigation and resiliency-building in high stress acute health care environments.

Sympathetic neural reactivity to the Trier social stress test

Sympathetic responsiveness to laboratory mental stress is highly variable, making interpretations of its role in stress reactivity challenging. The present study assessed muscle sympathetic nerve activity (MSNA, microneurography) responsiveness to the Trier social stress test (TSST), which employs an anticipatory stress phase, followed by a public speaking and mental arithmetic task. We hypothesized that sympathetic reactivity to the anticipatory phase would offer a more uniform response between individuals due to elimination of confounds (i.e. respiratory changes, muscle movement, etc.) observed during more common stress tasks. Participants included 26 healthy adults (11 men, 15 women, age: 25 ± 6 years, body mass index: 24 ± 3 kg/m² ). Continuous heart rate (electrocardiogram) and beat-to-beat blood pressure (finger plethysmography) were recorded from all participants, while MSNA recordings were obtained in 20 participants. MSNA burst frequency was significantly reduced during anticipatory stress. During the speech, although burst frequency was unchanged, total MSNA was significantly increased. Changes in diastolic arterial pressure were predictive of changes in MSNA during anticipatory (β = -0.680, P = 0.001), but not the speech (P = 0.318) or mental maths (P = 0.051) phases. Lastly, sympathetic reactivity to anticipatory stress was predictive of subsequent reactivity to both speech (β = 0.740, P = 0.0002) and maths (β = 0.663, P = 0.001). In conclusion, anticipatory social stress may offer a more versatile means of assessing sympathetic reactivity to mental stress in the absence of confounds and appears to predict reactivity to subsequent mental stress paradigms. KEY POINTS: Cardiovascular reactivity to laboratory mental stress is predictive of future health outcomes. However, reactivity of the sympathetic nervous system to mental stress is highly variable. The current study assessed peripheral muscle sympathetic nerve activity in response to the Trier social stress test, a psychosocial stressor that includes anticipatory stress, public speaking and mental arithmetic. Our findings demonstrate that sympathetic neural activity is consistently reduced during anticipatory stress. Conversely, the classically observed inter-individual variability of sympathetic responsiveness was observed during speech and maths tasks. Additionally, sympathetic reactivity to the anticipatory period accurately predicted how an individual would respond to both speech and maths tasks, outlining the utility of anticipatory stress in future research surrounding stress reactivity. Utilization of the Trier social stress test in autonomic physiology may offer an alternative assessment of sympathetic responsiveness to stress with more consistent inter-individual responsiveness and may be a useful tool for further investigation of stress reactivity.