A literature review of heart rate variability in depressive and bipolar disorders

Bidirectionality of LF when the movie makes you sad: Effects of negative emotions on heart rate variability among patients with major depression

OBJECTIVES

Heart rate variability (HRV) reflects the capacity to adapt to internal and environmental changes. Decreased HRV may indicate inadequate adaptive capacity. This study aims to investigate the relationship between the heart and brain's adaptive abilities, both at rest and when negative emotions are stimulated in depression.

SUBJECTS AND METHODS

The study included 30 patients (20 female, 10 male) with major depression (mean age = 29.8 ± 7.8) and 30 healthy controls, all of whom had similar characteristics in terms of age and gender, selected through convenience sampling. The patients were drug-free at the time of the assessment. Holter recordings were obtained while subjects watched videos stimulating anger, fear, sadness, and a neutral video, and at rest, HRV parameters were calculated. To control for interindividual variability and account for paired sampling, linear mixed effects models were employed.

RESULTS

Watching the 'sadness video' led to an increase in low frequency band (LF) [LF change (Control vs depression); Difference:-620.80 df:107 t:-2.093 P:0.039] and LF/high frequency band ratio (LF/HF) [LF/HF change (control vs depression group); Difference:-1.718 df:105 t:-2.374 P:0.020] in the depression group. The video led to a decrease in LF and LF/HF in the controls. Although the differences between the conditions and interactions with the group were significant, the effects were independent of depression severity.

CONCLUSION

In depression, brain's regulatory effect on the heart differed from controls in the sadness condition, possibly due to increased arousal levels in subjects with depression and their inability to suppress sympathetic activity when a state of sadness is stimulated.

Heart Rate Variability as a Potential Predictor of Response to Intranasal Esketamine in Patients with Treatment-Resistant Depression: A Preliminary Report

Background: Esketamine has received approval as a nasal spray (ESK-NS) for treatment-resistant depression (TRD) and evidence from real-world investigations has confirmed the effectiveness of ESK-NS, albeit with interindividual differences in response. Heart rate variability (HRV), defined as the fluctuation in time interval between consecutive heartbeats, can be used to measure autonomic dysfunction in psychiatric disorders and its role has been investigated in diagnosis and prognosis of depression. Methods: This preliminary report aims to evaluate HRV parameters and their association with treatment outcome in 18 patients (55.6% males, 55.6 ± 9.39 years old) with TRD treated with a target dose of ESK-NS for one month (mean dose: 80.9 ± 9.05 mg). The Beck Depression Inventory (BDI) and a 3 min resting electrocardiogram were used to assess changes in depressive symptoms and HRV measurements before and after treatment. Results: Responders (n = 8, 44.5%; based on ≥30% BDI scores reduction) displayed lower HRV values than non-responders at baseline (p = 0.019), which increased at one month (p = 0.038). Receiver-Operating Characteristic (ROC) curves obtained from a logistic regression displayed a discriminative potential for baseline HRV in our sample (AUC = 0.844). Conclusions: These preliminary observations suggest a mutual interaction between esketamine and HRV, especially in relation to treatment response. Further studies are required to investigate electrophysiological profiles among predictors of response to ESK-NS and allow for personalized intervention strategies in TRD that still represent a public health concern.

Update: factors influencing heart rate variability-a narrative review

Objective

Heart rate variability (HRV) is an important non-invasive marker for the assessment of an organism's autonomic physiological regulatory pathways. Lower HRV has been shown to correlate with increased mortality. HRV is influenced by various factors or diseases. The aim of this narrative review is to describe the current state of knowledge on factors influencing HRV and their significance for interpretation.

Methods

The narrative review only included reviews, meta-analyses, and cohort studies which were published until 2021. HRV confounders were grouped into four categories (non-influenceable physiological factors, diseases, influenceable lifestyle factors and external factors).

Results

The review found that HRV was decreased not only in non-influenceable physiological factors (e.g., age, gender, ethnicity) but also in connection with various number of acute and chronic diseases (e.g., psychiatric diseases, myocardial infarction, heart failure), influenceable lifestyle factors (e.g., alcohol abuse, overweight, physical activity), and external factors (e.g., heat, noise, shift work, harmful- and hazardous substances).

Conclusion

In order to improve the quality of HRV studies and to ensure accurate interpretation, it is recommended that confounders be taken into account in future diagnostic measurements or measurements in the workplace (e.g., as part of health promotion measures) in order to counteract data bias.

Heart-Brain Axis: A Narrative Review of the Interaction between Depression and Arrhythmia

Arrhythmias and depression are recognized as diseases of the heart and brain, respectively, and both are major health threats that often co-occur with a bidirectional causal relationship. The autonomic nervous system (ANS) serves as a crucial component of the heart-brain axis (HBA) and the pathway of interoception. Cardiac activity can influence emotional states through ascending interoceptive pathways, while psychological stress can precipitate arrhythmias via the ANS. However, the HBA and interoception frameworks are often considered overly broad, and the precise mechanisms underlying the bidirectional relationship between depression and arrhythmias remain unclear. This narrative review aims to synthesize the existing literature, focusing on the pathological mechanisms of the ANS in depression and arrhythmia while integrating other potential mechanisms to detail heart-brain interactions. In the bidirectional communication between the heart and brain, we emphasize considering various internal factors such as genes, personality traits, stress, the endocrine system, inflammation, 5-hydroxytryptamine, and behavioral factors. Current research employs multidisciplinary knowledge to elucidate heart-brain relationships, and a deeper understanding of these interactions can help optimize clinical treatment strategies. From a broader perspective, this study emphasizes the importance of considering the body as a complex, interconnected system rather than treating organs in isolation. Investigating heart-brain interactions enhance our understanding of disease pathogenesis and advances medical science, ultimately improving human quality of life.

Assessment of symptom severity in psychotic disorder patients based on heart rate variability and accelerometer mobility data

BACKGROUND

Advancement in mental health care requires easily accessible, efficient diagnostic and treatment assessment tools. Viable biomarkers could enable objectification and automation of the diagnostic and treatment process, currently dependent on a psychiatric interview. Available wearable technology and computational methods make it possible to incorporate heart rate variability (HRV), an indicator of autonomic nervous system (ANS) activity, into potential diagnostic and treatment assessment frameworks as a biomarker of disease severity in mental disorders, including schizophrenia and bipolar disorder (BD).

METHOD

We used a commercially available electrocardiography (ECG) chest strap with a built-in accelerometer, i.e. Polar H10, to record R-R intervals and physical activity of 30 hospitalized schizophrenia or BD patients and 30 control participants through ca. 1.5-2 h time periods. We validated a novel approach to data acquisition based on a flexible, patient-friendly and cost-effective setting. We analyzed the relationship between HRV and the Positive and Negative Syndrome Scale (PANSS) test scores, as well as the HRV and mobility coefficient. We also proposed a method of rest period selection based on R-R intervals and mobility data. The source code for reproducing all experiments is available on GitHub, while the dataset is published on Zenodo.

RESULTS

Mean HRV values were lower in the patient compared to the control group and negatively correlated with the results of the PANSS general subcategory. For the control group, we also discovered the inversely proportional dependency between the mobility coefficient, based on accelerometer data, and HRV. This relationship was less pronounced for the treatment group.

CONCLUSIONS

HRV value itself, as well as the relationship between HRV and mobility, may be promising biomarkers in disease diagnostics. These findings can be used to develop a flexible monitoring system for symptom severity assessment.

An in vivo Dissection, and Analysis of Socio-Affective Symptoms related to Cerebellum-Midbrain Reward Circuitry in Humans

Emerging research in non-human animals implicates cerebellar projections to the ventral tegmental area (VTA) in appetitive behaviors, but these circuits have not been characterized in humans. Here, we mapped cerebello-VTA white-matter connectivity in humans using probabilistic tractography on diffusion imaging data from the Human Connectome Project. We uncovered the topographical organization of these connections by separately tracking from parcels of cerebellar lobule VI, crus I/II, vermis, paravermis, and cerebrocerebellum. Results revealed that connections from the cerebellum to the VTA predominantly originate in the right hemisphere, interposed nucleus, and paravermal cortex, and terminate mostly ipsilaterally. Paravermal crus I sends the most connections to the VTA compared to other lobules. We discovered a medial-to-lateral gradient of connectivity, such that the medial cerebellum has the highest connectivity with the VTA. Individual differences in microstructure were associated with measures of negative affect and social functioning. By splitting the tracts into quarters, we found that the socio-affective effects were driven by the third quarter of the tract, corresponding to the point at which the fibers leave the deep nuclei. Taken together, we produced detailed maps of cerebello-VTA structural connectivity for the first time in humans and established their relevance for trait differences in socio-affective regulation.

Guideline for the application of heart rate and heart rate variability in occupational medicine and occupational health science

This updated guideline replaces the "Guideline for the application of heart rate and heart rate variability in occupational medicine and occupational health science" first published in 2014. Based on the older version of the guideline, the authors have reviewed and evaluated the findings on the use of heart rate (HR) and heart rate variability (HRV) that have been published in the meantime and incorporated them into a new version of this guideline.This guideline was developed for application in clinical practice and research purposes in the fields of occupational medicine and occupational science to complement evaluation procedures with respect to exposure and risk assessment at the workplace by the use of objective physiological workload indicators. In addition, HRV is also suitable for assessing the state of health and for monitoring the progress of illnesses and preventive medical measures. It gives an overview of factors influencing the regulation of the HR and HRV at rest and during work. It further illustrates methods for measuring and analyzing these parameters under standardized laboratory and real workload conditions, areas of application as well as the quality control procedures to be followed during the recording and evaluation of HR and HRV.

From operational diagnostic to dimensional-continuum concepts of psychotic and non-psychotic illness: Embracing catatonia across psychopathology and intrinsic movement disorder in neural network dysfunction

Psychiatry is currently negotiating several challenges that are typified by (but are not unique to) schizophrenia: do periodic refinements in operational diagnostic algorithms (a) resolve intricacies and subtleties within and between psychotic and non-psychotic disorders that are authentic and impactful, or (b) constitute arbitrary and porous boundaries that should be complemented, or even replaced, by dimensional-continuum concepts of abnormality and dysfunction. Critically, these issues relate not only to apparent boundaries between diagnoses but also to those between 'health' and 'illness'. This article considers catatonia within evolving dimensional-continuum approaches to the description of impairment and dysfunction among psychotic and non-psychotic disorders. It begins by considering the definition and assessment of catatonia vis-à-vis other disorders, followed by its long-standing conjunction with schizophrenia, relationship with antipsychotic drug treatment, transdiagnostic perspectives and relationships, and pathobiological processes. These appear to involve dysfunction across elements in overlapping neural networks that result in a confluence of psychopathology and intrinsic hypo- and hyperkinetic motor dysfunction. It has been argued that while current diagnostic approaches can have utility in defining groups of cases that are closely related, contemporary evidence indicates categorical diagnoses to be arbitrary divisions of what is essentially a continuous landscape. Psychotic and non-psychotic diagnoses, including catatonia, may reflect arbitrary areas around points of intersection between orthogonal dimensions of psychopathology and intrinsic movement disorder in a poly-dimensional space that characterises this continuous landscape of mental health and dysfunction.

Cardiovascular variations in patients with major depressive disorder versus bipolar disorder

BACKGROUND

Differentiating depression in major depressive disorder and bipolar disorder is challenging in clinical practice. Therefore, reliable biomarkers are urgently needed to differentiate between these diseases. This study's main objective was to assess whether cardiac autonomic function can distinguish patients with unipolar depression (UD), bipolar depression (BD), and bipolar mania (BM).

METHODS

We recruited 791 patients with mood disorders, including 191 with UD, 286 with BD, and 314 with BM, who had been drug free for at least 2 weeks. Cardiovascular status was measured using heart rate variability (HRV) and pulse wave velocity (PWV) indicators via finger photoplethysmography during a 5-min rest period.

RESULTS

Patients with BD showed lower HRV but higher heart rates than those with UD and BM. The PWV indicators were lower in the UD group than in the bipolar disorder group. The covariates of age, sex, and body mass index affected the cardiovascular characteristics. After adjusting for covariates, the HRV and PWV variations among the three groups remained significant. Comparisons between the UD and BD groups showed that the variable with the largest effect size was the frequency-domain indices of HRV, very low and high frequency, followed by heart rate. The area under the receiver operating characteristic curve (AUC) for each cardiovascular variable ranged from 0.661 to 0.714. The High-frequency index reached the highest AUC.

LIMITATIONS

Cross-sectional design and the magnitude of heterogeneity across participants with mood disorders limited our findings.

CONCLUSION

Patients with BD, but not BM, had a greater extent of cardiac imbalance than those with UD. Thus, HRV may serve as a psychophysiological biomarker for the differential diagnosis of UD and BD.

Neurobiological mechanisms of ECT and TMS treatment in depression: study protocol of a multimodal magnetic resonance investigation

BACKGROUND

Noninvasive neurostimulation treatments are increasingly being used to treat major depression, which is a common cause of disability worldwide. While electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS) are both effective in treating depressive episodes, their mechanisms of action are, however, not completely understood. ECT is given under general anesthesia, where an electrical pulse is administered through electrodes placed on the patient's head to trigger a seizure. ECT is used for the most severe cases of depression and is usually not prescribed before other options have failed. With TMS, brain stimulation is achieved through rapidly changing magnetic fields that induce electric currents underneath a ferromagnetic coil. Its efficacy in depressive episodes has been well documented. This project aims to identify the neurobiological underpinnings of both the effects and side effects of the neurostimulation techniques ECT and TMS.

METHODS

The study will utilize a pre-post case control longitudinal design. The sample will consist of 150 subjects: 100 patients (bipolar and major depressive disorder) who are treated with either ECT (N = 50) or TMS (N = 50) and matched healthy controls (N = 50) not receiving any treatment. All participants will undergo multimodal magnetic resonance imaging (MRI) as well as neuropsychological and clinical assessments at multiple time points before, during and after treatment. Arterial spin labeling MRI at baseline will be used to test whether brain perfusion can predict outcomes. Signs of brain disruption, potentiation and rewiring will be explored with resting-state functional MRI, magnetic resonance spectroscopy and multishell diffusion weighted imaging (DWI). Clinical outcome will be measured by clinician assessed and patient reported outcome measures. Memory-related side effects will be investigated, and specific tests of spatial navigation to test hippocampal function will be administered both before and after treatment. Blood samples will be stored in a biobank for future analyses. The observation time is 6 months. Data will be explored in light of the recently proposed disrupt, potentiate and rewire (DPR) hypothesis.

DISCUSSION

The study will contribute data and novel analyses important for our understanding of neurostimulation as well as for the development of enhanced and more personalized treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05135897.

Heart rate variability (HRV) as a way to understand associations between the autonomic nervous system (ANS) and affective states: A critical review of the literature

Evidence suggests affective disorders such as depression and bipolar disorder are characterised by dysregulated autonomic nervous system (ANS) activity. These findings suggest ANS dysregulation may be involved in the pathogenesis of affective disorders. Different affective states are characterised by different ANS activity patterns (i.e., an increase or decrease in sympathetic or parasympathetic activity). To understand how ANS abnormalities are involved in the development of affective disorders, it is important to understand how affective states correlate with ANS activity before their onset. Using heart rate variability (HRV) as a tool to measure ANS activity, this review aimed to look at associations between affective states and HRV in non-clinical populations (i.e., in those without medical and psychiatric disorders). Searches on PubMed and Google Scholar were completed using the following search terms: heart rate variability, autonomic nervous system, sympathetic nervous system, parasympathetic nervous system, affective state, mood and emotion in all possible combinations. All but one of the studies examined (N = 13), demonstrated significant associations between affect and HRV. Findings suggest negative affect, encompassing both diffused longer-term experiences (i.e., mood) as well as more focused short-term experiences (i.e., emotions), may be associated with a reduction in parasympathetic activity as measured through HRV parameters known to quantify parasympathetic activity (e.g., high frequency (HF)-HRV). HRV measures typically linked to reduction in parasympathetic activity appear to be linked to negative affective states in non-clinical populations. However, given the complex and possibly non-linear relationship between HRV and parasympathetic activity, further studies need to clarify specificity of these findings. Future studies should investigate the potential utility of HRV measures as biomarkers for monitoring changes in affective states and for early detection of onset and relapse of depression in patients with affective disorders.

Reduced heart rate variability during mania in a repeated naturalistic observational study

Background

Bipolar disorder (BD) is a chronic recurrent mood disorder associated with autonomic nervous system (ANS) dysfunction, indexed by heart rate variability (HRV). Changes in HRV between mood states are sparsely studied longitudinally. We aimed to compare HRV of hospitalized manic individuals with their own euthymic selves in a naturalistic observational study.

Methods

34 individuals were included, of which 16 were lost to follow-up. Ultimately 15 patients provided reliable heart rate data in both a manic and euthymic state, using photoplethysmography (PPG) sensor wristbands overnight. We calculated HRV measures Root Mean Square of Successive Differences (RMSSD), High-frequency (HF: 0.15-0.40 Hz), Low-frequency (LF: 0.40-0.15 Hz), Very low-frequency (VLF: 0.0033-0.04 Hz), Total power and Sample Entropy in 5-min night-time resting samples. We compared HRV measures by mood state within individuals using paired t-tests and linear regression to control for age and sex.

Results

HRV was lower in the manic state when compared to the euthymic state for all HRV metrics (p ≤ 0.02), with large to medium effect sizes (g = 1.24 to 0.65). HRV changes were not significantly affected by age or sex.

Conclusion

This longitudinal study provides evidence of lower HRV in manic states compared to euthymia, indicating an association between ANS dysregulation and changes in bipolar mood state. This corroborates previous cross-sectional studies, although the association may be less clear or reversed in hypomanic states. Further investigation in larger longitudinal samples is warranted.

Association between depressive symptoms and heart rate variability in older patients admitted for rehabilitation: a cross-sectional study

Heart rate variability (HRV) is associated with depressive symptoms, but this relationship in older inpatients undergoing rehabilitation remains unclear. This study investigated the relationship between HRV and depressive symptoms in older inpatients undergoing rehabilitation. Fifty patients aged ≥65 years were assessed for depressive symptoms using the Geriatric Depression Scale. HRV was assessed by frequency analysis. The relationship between depressive symptoms and HRV indices, age, sex, Short Physical Performance Battery (SPPB) score, Mini-Mental State Examination score was examined using simple linear regression. Next, the predictors from the simple linear regression analysis significant at the 0.15 level were inputted in a multiple regression model. Multiple regression analysis revealed that very low frequency HRV [ β = -2.13, 95% confidence interval (CI) -3.15 to -1.11, P  < 0.05] and SPPB score ( β = -0.30, 95% CI -0.52 to -0.08, P  < 0.05) were negatively associated with depressive symptoms: the lower the HRV and the more severe the mobility impairment, the higher the severity of the depressive symptoms. Very low frequency (VLF) HRV and physical performance, as measured by the SPPB score, were associated with depressive symptoms in older patients undergoing rehabilitation. VLF HRV may serve as a useful biomarker for detecting depressive symptoms in this population.

The within-person association of relative left frontal activity and vagally mediated heart rate variability not moderated by history of depression

Motivated by the Neurovisceral Integration Model (NVI) of cardiac vagal control, we investigated the relationship between relative left frontal activity (rLFA) and vagally mediated heart rate variability or respiratory sinus arrhythmia (RSA) in 287 participants, half of whom had a history of depression. We hypothesized that there would be a within-person association of rLFA and RSA such that when RSA is lower rLFA would also be lower (Hypothesis I). Moreover, it was hypothesized that this within-subject association would be moderated by a history of depression (Hypothesis II). Metrics of rLFA and RSA were derived from concurrent electroencephalogram and electrocardiogram recordings. The logarithmic difference in EEG alpha power between the homologous right and left electrodes (Ln (Right/Left)) in the frontal region was used to index rLFA. A Hilbert transform was applied to the mean-centered and bandpass-filtered (0.12-.40 Hz) inter-beat interval (IBI) time series to get a fine-grained measure (in the time domain) of RSA. A linear mixed ANOVA model with rLFA as the dependent variable and RSA as the main fixed effect found that participants had less rLFA during epochs when they had lower RSA, which was consistent with the prediction from Hypothesis I. Contrary to the prediction from Hypothesis II, the within-person association of RSA and rLFA was not moderated by a history of depression. However, the association between RSA and rLFA varied across the four pairs of frontal electrodes that we examined. Thus, more research is needed to determine the spatial extent of this association, e.g., examining the relationship between source-localized rLFA and RSA.

Effects of man-made electromagnetic fields on heart rate variability parameters of general public: a systematic review and meta-analysis of experimental studies

OBJECTIVES

The effects of man-made electromagnetic fields (EMFs) on the cardiovascular system have been investigated in many studies. In this regard, the cardiac autonomic nervous system (ANS) activity due to EMFs exposure, assessed by heart rate variability (HRV), was targeted in some studies. The studies investigating the relationship between EMFs and HRV have yielded conflicting results. We performed a systematic review and meta-analysis to assess the data's consistency and identify the association between EMFs and HRV measures.

CONTENT

Published literature from four electronic databases, including Web of Science, PubMed, Scopus, Embase, and Cochrane, were retrieved and screened. Initially, 1601 articles were retrieved. After the screening, 15 original studies were eligible to be included in the meta-analysis. The studies evaluated the association between EMFs and SDNN (standard deviation of NN intervals), SDANN (Standard deviation of the average NN intervals for each 5 min segment of a 24 h HRV recording), and PNN50 (percentage of successive RR intervals that differ by more than 50 ms).

SUMMARY

There was a decrease in SDNN (ES=-0.227 [-0.389, -0.065], p=0.006), SDANN (ES=-0.526 [-1.001, -0.05], p=0.03) and PNN50 (ES=-0.287 [-0.549, -0.024]). However, there was no significant difference in LF (ES=0.061 (-0.267, 0.39), p=0.714) and HF (ES=-0.134 (0.581, 0.312), p=0.556). In addition, a significant difference was not observed in LF/HF (ES=0.079 (-0.191, 0.348), p=0.566).

OUTLOOK

Our meta-analysis suggests that exposure to the environmental artificial EMFs could significantly correlate with SDNN, SDANN, and PNN50 indices. Therefore, lifestyle modification is essential in using the devices that emit EMs, such as cell phones, to decrease some signs and symptoms due to EMFs' effect on HRV.

Predictive biosignature of major depressive disorder derived from physiological measurements of outpatients using machine learning

Major Depressive Disorder (MDD) has heterogeneous manifestations, leading to difficulties in predicting the evolution of the disease and in patient's follow-up. We aimed to develop a machine learning algorithm that identifies a biosignature to provide a clinical score of depressive symptoms using individual physiological data. We performed a prospective, multicenter clinical trial where outpatients diagnosed with MDD were enrolled and wore a passive monitoring device constantly for 6 months. A total of 101 physiological measures related to physical activity, heart rate, heart rate variability, breathing rate, and sleep were acquired. For each patient, the algorithm was trained on daily physiological features over the first 3 months as well as corresponding standardized clinical evaluations performed at baseline and months 1, 2 and 3. The ability of the algorithm to predict the patient's clinical state was tested using the data from the remaining 3 months. The algorithm was composed of 3 interconnected steps: label detrending, feature selection, and a regression predicting the detrended labels from the selected features. Across our cohort, the algorithm predicted the daily mood status with 86% accuracy, outperforming the baseline prediction using MADRS alone. These findings suggest the existence of a predictive biosignature of depressive symptoms with at least 62 physiological features involved for each patient. Predicting clinical states through an objective biosignature could lead to a new categorization of MDD phenotypes.

When Heart Beats Differently in Depression: Review of Nonlinear Heart Rate Variability Measures

BACKGROUND

Disturbed heart dynamics in depression seriously increases mortality risk. Heart rate variability (HRV) is a rich source of information for studying this dynamics. This paper is a meta-analytic review with methodological commentary of the application of nonlinear analysis of HRV and its possibility to address cardiovascular diseases in depression.

OBJECTIVE

This paper aimed to appeal for the introduction of cardiological screening to patients with depression, because it is still far from established practice. The other (main) objective of the paper was to show that nonlinear methods in HRV analysis give better results than standard ones.

METHODS

We systematically searched on the web for papers on nonlinear analyses of HRV in depression, in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 framework recommendations. We scrutinized the chosen publications and performed random-effects meta-analysis, using the esci module in jamovi software where standardized effect sizes (ESs) are corrected to yield the proof of the practical utility of their results.

RESULTS

In all, 26 publications on the connection of nonlinear HRV measures and depression meeting our inclusion criteria were selected, examining a total of 1537 patients diagnosed with depression and 1041 healthy controls (N=2578). The overall ES (unbiased) was 1.03 (95% CI 0.703-1.35; diamond ratio 3.60). We performed 3 more meta-analytic comparisons, demonstrating the overall effectiveness of 3 groups of nonlinear analysis: detrended fluctuation analysis (overall ES 0.364, 95% CI 0.237-0.491), entropy-based measures (overall ES 1.05, 95% CI 0.572-1.52), and all other nonlinear measures (overall ES 0.702, 95% CI 0.422-0.982). The effectiveness of the applied methods of electrocardiogram analysis was compared and discussed in the light of detection and prevention of depression-related cardiovascular risk.

CONCLUSIONS

We compared the ESs of nonlinear and conventional time and spectral methods (found in the literature) and demonstrated that those of the former are larger, which recommends their use for the early screening of cardiovascular abnormalities in patients with depression to prevent possible deleterious events.

Associations between sleep-related heart rate variability and both sleep and symptoms of depression and anxiety: A systematic review

There is a bidirectional relationship between poor sleep and both mood- and anxiety-related disorders, which are among leading global health concerns. Additionally, both disordered sleep and these psychiatric disorders appear to be independently associated with altered autonomic nervous system (ANS) function. We hypothesise that ANS dysregulation during sleep may explain part of the relationship between poor sleep and mood- and anxiety-related disorders. Heart rate variability (HRV) is a frequently used marker of ANS function and gives an indication of ANS input to the heart - in particular, of the relative contributions of sympathetic and parasympathetic activity. A systematic review of PubMed, Scopus and Web of Science yielded 41 studies dealing with sleep, mood- and anxiety-related disorders and sleep-related HRV. Hyperarousal during sleep, reflecting a predominance of sympathetic activation and indicative of ANS dysregulation, may be an important factor in the association between poor sleep and mood-related disorders. Longitudinal studies and mediation analyses are necessary to further understand the potential mediating role of ANS dysregulation on the relationship between poor sleep and mood- and anxiety-related disorders.

Vagally Mediated Heart Rate Variability Is Associated With Executive Function Changes in Patients With Treatment-Resistant Depression Following Magnetic Seizure Therapy

OBJECTIVES

Magnetic seizure therapy (MST) is a novel investigational brain stimulation modality for patients with treatment-resistant depression (TRD). MST is a potential alternative seizure-based treatment to electroconvulsive therapy (ECT), given that it may offer equivalent antidepressant efficacy, yet with a relative sparing of cognitive functioning. Heart rate variability (HRV) is a marker of central autonomic functioning. We aimed to explore the relationships among baseline HRV, age, clinical outcome, and executive function following MST, in patients with TRD.

MATERIALS AND METHODS

Eighty-eight TRD patients (55 females; 18-70 years) were enrolled and 48 patients completed a course of MST in an open-label study. Patients received MST treatments two to three times per week, using one of three stimulation frequencies (ie, 100 Hz, 50 Hz, or 25 Hz) at 100% stimulator output. Root mean square of the successive R-R differences (RMSSD), an index of HRV, was computed from a baseline electrocardiogram (ECG) recording. Clinical symptoms were assessed using the Hamilton Depression Rating Scale (HAM-D₂₄) and the Quick Inventory of Depressive Symptomatology (QIDS₁₆). Executive function was assessed using the Trail Making Test and the Mazes Test from the MATRICS battery.

RESULTS

Baseline RMSSD was correlated with baseline HAM-D₂₄ (r = -0.340, p = 0.001) and baseline Mazes Test (r = 0.417, p = 0.0007) but not with baseline Trail Making Test. Furthermore, baseline RMSSD was not correlated with changes on the HAM-D₂₄, QIDS₁₆, or total scores on the Trail Making Test. However, there was a significant correlation between baseline RMSSD and improvement on the Mazes Test following MST (r = 0.502, p = 0.0004).

CONCLUSIONS

Since this is an open-label trial, the influence of the placebo effect cannot be excluded. However, our results suggest that baseline RMSSD may be a state-biomarker of depression and executive function impairment. Additionally, while baseline vagally mediated resting cardiac activity did not predict the outcome of depression, it may mediate executive function improvements following MST.

Compassion Focused Group Therapy for People With a Diagnosis of Bipolar Affective Disorder: A Feasibility Study

Background

Compassion focused therapy (CFT) is an evolutionary informed, biopsychosocial approach to mental health problems and therapy. It suggests that evolved motives (e.g., for caring, cooperating, competing) are major sources for the organisation of psychophysiological processes which underpin mental health problems. Hence, evolved motives can be targets for psychotherapy. People with certain types of depression are psychophysiologically orientated towards social competition and concerned with social status and social rank. These can give rise to down rank-focused forms of social comparison, sense of inferiority, worthlessness, lowered confidence, submissive behaviour, shame proneness and self-criticism. People with bipolar disorders also experience elevated aspects of competitiveness and up rank status evaluation. These shift processing to a sense of superiority, elevated confidence, energised behaviour, positive affect and social dominance. This is the first study to explore the feasibility of a 12 module CFT group, tailored to helping people with a diagnosis of bipolar disorder understand the impact of evolved competitive, status-regulating motivation on their mental states and the value of cultivating caring and compassion motives and their psychophysiological regulators.

Methods

Six participants with a history of bipolar disorder took part in a CFT group consisting of 12 modules (over 25 sessions) as co-collaborators to explore their personal experiences of CFT and potential processes of change. Assessment of change was measured via self-report, heart rate variability (HRV) and focus groups over three time points.

Results

Although changes in self-report scales between participants and across time were uneven, four of the six participants consistently showed improvements across the majority of self-report measures. Heart rate variability measures revealed significant improvement over the course of the therapy. Qualitative data from three focus groups revealed participants found CFT gave them helpful insight into: how evolution has given rise to a number of difficult problems for emotion regulation (called tricky brain) which is not one's fault; an evolutionary understanding of the nature of bipolar disorders; development of a compassionate mind and practices of compassion focused visualisations, styles of thinking and behaviours; addressing issues of self-criticism; and building a sense of a compassionate identity as a means of coping with life difficulties. These impacted their emotional regulation and social relationships.

Conclusion

Although small, the study provides evidence of feasibility, acceptability and engagement with CFT. Focus group analysis revealed that participants were able to switch from competitive focused to compassion focused processing with consequent improvements in mental states and social behaviour. Participants indicated a journey over time from 'intellectually' understanding the process of building a compassionate mind to experiencing a more embodied sense of compassion that had significant impacts on their orientation to (and working with) the psychophysiological processes of bipolar disorder.

Heart rate variability biofeedback intero-nociceptive emotion exposure therapy for adverse childhood experiences

Background: Psychiatric patients with adverse childhood experiences (ACE) tend to have dysfunctions in the interoceptive part of their emotional experience. The integration of interoceptive emotional activity in the insular and cingulate cortices is linked to the regulation of sympathovagal balance. This makes heart rate variability (HRV) an ideal measure for providing feedback on emotion regulation in real-time.

Methods: A sample of one hundred (n=100) outpatients was evaluated. Participants underwent eight 30-minutes ACE exposure sessions during which patients were guided to experience bodily sensations related to ACE while their HRV was monitored using a commercial biofeedback device.

Results: Comparing the results of the first to last therapeutic session, a significant decrease in heart rate and an increase in HRV at the onset of the session were observed.

Conclusions: This study suggests a physiological impact of therapeutic interventions on autonomic balance and underlines the interest in HRV biofeedback as clinical practice.

Omega-3 fatty acids in bipolar patients with a low omega-3 index and reduced heart rate variability: the "BIPO-3" trial

Background

Research suggests that a low omega-3 index may contribute to the low heart rate variability and the increased risk of cardiovascular morbidity and mortality in bipolar disorders. However, so far, no intervention trial with EPA and DHA has been conducted in bipolar patients attempting to increase their heart rate variability.

Methods

119 patients with bipolar disorder according to DSM-IV were screened, with 55 euthymic bipolar patients—owing to inclusion criteria (e.g. low omega-3 index (< 6%), SDNN < 60 ms.)—being enrolled in a randomized, double-blind, 12-week parallel study design with omega-3 fatty acids (4 capsules of 530 mg EPA, 150 mg DHA) or corn oil as a placebo, in addition to usual treatment. Heart rate variability as well as the omega-3 index were measured at baseline and at the endpoint of the study.

Results

A total of 42 patients (omega-3: n = 23, corn oil: n = 19) successfully completed the study after 12 weeks. There was a significant increase in the omega-3 index (value at endpoint minus value at baseline) in the omega-3 group compared to the corn oil group (p < 0.0001). However, there was no significant difference in the change of the SDNN (value at endpoint minus value at baseline) between the treatment groups (p = 0.22). In addition, no correlation between changes in SDNN and change in the omega-3 index could be detected in the omega-3 group (correlation coefficient = 0.02, p = 0.94) or the corn oil group (correlation coefficient =  − 0.11, p = 0.91). Similarly, no significant differences between corn oil and omega-3 group regarding the change of LF (p = 0.19), HF (p = 0.34) and LF/HF ratio (p = 0.84) could be demonstrated.

Conclusions

In our randomized, controlled intervention trial in euthymic bipolar patients with a low omega-3 index and reduced heart rate variability no significant effect of omega-3 fatty acids on SDNN or frequency-domain measures HF, LF and LF/HF ratio could be detected. Possible reasons include, among others, the effect of psychotropic medication present in our trial and/or the genetics of bipolar disorder itself. Further research is needed to test these hypotheses.

Trial registration ClinicalTrials.gov, NCT00891826. Registered 01 May 2009–Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT00891826

Relationship between the proficiency level and anxiety-reducing effect in a one-time heart rate variability biofeedback: A randomized controlled trial

INTRODUCTION

Previous studies have reported that the proficiency level of heart rate variability biofeedback (HRVBF) contributes significantly to the anxiety-reducing effects in continuous HRVBF interventions. Meanwhile, anxiety-reducing effects have been confirmed in one-time HRVBF interventions as well as continuous HRVBF; however, no study has analyzed the relationship between the proficiency level of a one-time HRVBF and its anxiety-reducing effects. To pursuit the effectiveness of a one-time HRVBF intervention, it is necessary to clarify whether the proficiency level is an important predictor of anxiety-reducing effects from a dose-response relationship between these 2 variables. The purpose of this study was to examine the dose-response relationship between the proficiency level and anxiety-reducing effects of a one-time HRVBF.

METHODS

This study was a single-blinded, randomized, controlled trial with stratification based on trait anxiety of the State-Trait Anxiety Inventory-JYZ. In total, 45 healthy young males aged 20 to 30 years were allocated to the HRVBF or control group with simple breathing at rest. The intervention was performed for 15 minute in each group. The state anxiety score of the State-Trait Anxiety Inventory-JYZ was measured to evaluate the anxiety-reducing effect before and after training.

RESULTS

The results showed no significant linear relationship between the proficiency level and anxiety-reducing effect, and variations in the proficiency level were observed post-intervention in the HRVBF group. A significant anxiety-reducing effect was only observed in the HRVBF group (P = .001, effect size r = 0.62).

CONCLUSIONS

These results suggest that there is no close relationship between the proficiency level and anxiety-reducing effect in one-time HRVBF and that HRVBF is effective in reducing anxiety regardless of individual differences in the proficiency level. Therefore, a one-time HRVBF may be a useful breathing technique for reducing state anxiety without specific education and breathing techniques.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trial Registry (UMIN000041760).

The Acute Effects of Aerobic Exercise on Nocturnal and Pre-Sleep Arousal in Patients with Unipolar Depression: Preplanned Secondary Analysis of a Randomized Controlled Trial

Unipolar depression is associated with insomnia and autonomic arousal. The aim of this study was to quantify the effect of a single bout of aerobic exercise on nocturnal heart rate variability and pre-sleep arousal in patients with depression. This study was designed as a two-arm, parallel-group, randomized, outcome assessor-blinded, controlled, superiority trial. Patients with a primary diagnosis of unipolar depression aged 18-65 years were included. The intervention consisted of a single 30 min moderate-intensity aerobic exercise bout. The control group sat and read for 30 min. The primary outcome of interest was RMSSD during the sleep period assessed with polysomnography. Secondary outcomes were additional heart rate variability outcomes during the sleep and pre-sleep period as well as subjective pre-sleep arousal. A total of 92 patients were randomized to either the exercise (N = 46) or the control (N = 46) group. Intent-to-treat analysis ANCOVA of follow-up sleep period RMSSD, adjusted for baseline levels and minimization factors, did not detect a significant effect of the allocation (β = 0.12, p = 0.94). There was no evidence for significant differences between both groups in any other heart rate variability measure nor in measures of cognitive or somatic pre-sleep arousal. As this is the first trial of its kind in this population, the findings need to be confirmed in further studies. Patients with depression should be encouraged to exercise regularly in order to profit from the known benefits on sleep and depressive symptoms, which are supported by extensive literature.

Heart Rate Variability and Pain Sensitivity in Chronic Low Back Pain Patients Exposed to Passive Viewing of Photographs of Daily Activities

OBJECTIVE

Investigation if emotional reactivity by measuring heart rate variability (HRV) and pressure pain sensitivity during a passive visualization task in participants with chronic low back pain (CLBP).

MATERIALS AND METHODS

This case-control study was composed of 47 participants with CLBP and 47 asymptomatic participants. Both groups were submitted to a passive visualization task using 27 pictures from PHODA (Photograph Series of Daily Activities). HRV frequency domains were measured before, during, and after the task. Pressure pain threshold and pain intensity were also measured before and after the task.

RESULTS

The adjusted mean difference was statistically significant for HRV frequency domains during the visualization task, including low frequency [-5.92; 95% confidence interval (CI)=-9.60 to -2.23], high frequency (-0.71; 95% CI=-1.02 to -0.39), and low-frequency/high-frequency ratio (8.82; 95% CI=5.19 to 12.45). Pressure pain threshold decreased after the task in the CLBP group in all body sites, and pain intensity increased (-0.8; 95% CI=-1.16 to -0.39).

DISCUSSION

Aversive environmental stimuli, such as visual cues, may generate defensive physiological reactions. HRV can provide a measure that reflects the perceptions of threat and safety in the environment. Participants with CLBP presented changes in sympathovagal balance during passive visualization of pictures of daily activities, higher pain sensitivity, and high pain intensity when they were exposed to a passive visualization task using pictures of daily living that may arouse fears of harm.

Imbalance Model of Heart Rate Variability and Pulse Wave Velocity in Psychotic and Nonpsychotic Disorders

OBJECTIVES

Patients with psychiatric disorders have an increased risk of cardiovascular pathologies. A bidirectional feedback model between the brain and heart exists widely in both psychotic and nonpsychotic disorders. The aim of this study was to compare heart rate variability (HRV) and pulse wave velocity (PWV) functions between patients with psychotic and nonpsychotic disorders and to investigate whether subgroups defined by HRV and PWV features improve the transdiagnostic psychopathology of psychiatric classification.

METHODS

In total, 3448 consecutive patients who visited psychiatric or psychological health services with psychotic (N = 1839) and nonpsychotic disorders (N = 1609) and were drug-free for at least 2 weeks were selected. HRV and PWV indicators were measured via finger photoplethysmography during a 5-minute period of rest. Canonical variates were generated through HRV and PWV indicators by canonical correlation analysis (CCA).

RESULTS

All HRV indicators but none of the PWV indicators were significantly reduced in the psychotic group relative to those in the nonpsychotic group. After adjusting for age, gender, and body mass index, many indices of HRV were significantly reduced in the psychotic group compared with those in the nonpsychotic group. CCA analysis revealed 2 subgroups defined by distinct and relatively homogeneous patterns along HRV and PWV dimensions and comprising 19.0% (subgroup 1, n = 655) and 80.9% (subgroup 2, n = 2781) of the sample, each with distinctive features of HRV and PWV functions.

CONCLUSIONS

HRV functions are significantly impaired among psychiatric patients, especially in those with psychosis. Our results highlight important subgroups of psychiatric patients that have distinct features of HRV and PWV which transcend current diagnostic boundaries.

Characteristics of cardiovascular autonomic dysfunction and association with quality of life in patients with systemic lupus erythematosus

OBJECTIVES

Cardiovascular autonomic neuropathy (CAN) may affect the clinical course of SLE leading to reduced quality of life. CAN is assessed by heart rate variability (HRV) measures and cardiovascular autonomic reflex tests (CARTs). In patients with SLE, we aimed to determine the characteristics of CAN and if CAN associates with health-related quality of life (HRQoL).

METHODS

Patients with SLE and healthy controls (HCs) were CAN tested with 5 min HRV and three CARTs to determine parameters reflecting parasympathetic and mixed sympathetic-parasympathetic function. Subjects were classified as having no, early or definitive CAN by having none, one or more than one abnormal CART, respectively. HRQoL as determined by the Short Form 12 (SF-12) was assessed in SLE.

RESULTS

Of 111 patients with SLE, 92 answered the SF-12 and 54 were matched with 54 HCs for characterisation of CAN. Definitive CAN was present in 24.1% (95% CI 15% to 37%) patients with SLE and 1.9% (95% CI 0.3% to 9.8%) HCs (OR 16.8, 95% CI 2.1 to 133.8, p=0.008). The corresponding prevalences of any CAN were 53.7% (95% CI 41% to 66%) and 22.6% (95% CI 13% to 35%). SLE patients with definitive CAN showed signs of mixed sympathetic-parasympathetic dysfunction, whereas patients without CAN primarily presented with impaired parasympathetic activity. Signs of parasympathetic as well as sympathetic-parasympathetic dysfunction were associated with low physical SF-12 component score (all: β>0.211, p<0.05). The mental SF-12 component score was not associated with any CAN indices.

CONCLUSIONS

CAN was a frequent finding in SLE and associated to self-report on impaired physical HRQoL. Even patients without CAN showed signs of impaired parasympathetic function compared with controls.

Development of a Novel Web Camera-Based Contact-Free Major Depressive Disorder Screening System Using Autonomic Nervous Responses Induced by a Mental Task and Its Clinical Application

Background

To increase the consultation rate of potential major depressive disorder (MDD) patients, we developed a contact-type fingertip photoplethysmography-based MDD screening system. With the outbreak of SARS-CoV-2, we developed an alternative to contact-type fingertip photoplethysmography: a novel web camera-based contact-free MDD screening system (WCF-MSS) for non-contact measurement of autonomic transient responses induced by a mental task.

Methods

The WCF-MSS measures time-series interbeat intervals (IBI) by monitoring color tone changes in the facial region of interest induced by arterial pulsation using a web camera (1920 × 1080 pixels, 30 frames/s). Artifacts caused by body movements and head shakes are reduced. The WCF-MSS evaluates autonomic nervous activation from time-series IBI by calculating LF (0.04-0.15 Hz) components of heart rate variability (HRV) corresponding to sympathetic and parasympathetic nervous activity and HF (0.15-0.4 Hz) components equivalent to parasympathetic activities. The clinical test procedure comprises a pre-rest period (Pre-R; 140 s), mental task period (MT; 100 s), and post-rest period (Post-R; 120 s). The WCF-MSS uses logistic regression analysis to discriminate MDD patients from healthy volunteers via an optimal combination of four explanatory variables determined by a minimum redundancy maximum relevance algorithm: HF during MT (HF _MT ), the percentage change of LF from pre-rest to MT (%ΔLF_(Pre-R⇒MT) ), the percentage change of HF from pre-rest to MT (%ΔHF_(Pre-R⇒MT) ), and the percentage change of HF from MT to post-rest (%ΔHF_{(MT⇒Post-R)} ). To clinically test the WCF-MSS, 26 MDD patients (16 males and 10 females, 20-58 years) were recruited from BESLI Clinic in Tokyo, and 27 healthy volunteers (15 males and 12 females, 18-60 years) were recruited from Tokyo Metropolitan University and RICOH Company, Ltd. Electrocardiography was used to calculate HRV variables as references.

Result

The WCF-MSS achieved 73% sensitivity and 85% specificity on 5-fold cross-validation. IBI correlated significantly with IBI from reference electrocardiography (r = 0.97, p < 0.0001). Logit scores and subjective self-rating depression scale scores correlated significantly (r = 0.43, p < 0.05).

Conclusion

The WCF-MSS seems a promising contact-free MDD screening apparatus. This method enables web camera built-in smartphones to be used as MDD screening systems.

Reduction of depressive symptoms during inpatient treatment is not associated with changes in heart rate variability

Vagally mediated heart rate variability (HRV) is a psychophysiological indicator of mental and physical health. Limited research suggests there is reduced vagal activity and resulting lower HRV in patients with Major Depressive Disorder (MDD); however little is actually known about the association between HRV and symptoms of depression and whether the association mirrors symptom improvement following psychotherapy. The aim of this study was to investigate the association between antidepressant therapy, symptom change and HRV in 50 inpatients (68% females; 17–68 years) with a diagnosis of MDD. Severity of depressive symptoms was assessed by self-report (Beck Depression Inventory II) and the Hamilton Rating Scale of Depression. Measures of vagally mediated HRV (root mean square of successive differences and high-frequency) were assessed at multiple measurement points before and after inpatient psychotherapeutic and psychiatric treatment. Results showed an expected negative correlation between HRV and depressive symptoms at intake. Depressive symptoms improved (d = 0.84) without corresponding change in HRV, demonstrating a de-coupling between this psychophysiological indicator and symptom severity. To our knowledge, this study is the first to examine an association between HRV and depressive symptoms before and after psychotherapy. The observed de-coupling of depression and HRV, and its methodological implications for future research are discussed.

Integrating Breathing Techniques Into Psychotherapy to Improve HRV: Which Approach Is Best?

Introduction

Approaches to improve heart rate variability and reduce stress such as breathing retraining are more frequently being integrated into psychotherapy but little research on their effectiveness has been done to date. Specifically, no studies to date have directly compared using a breathing pacer at 6 breaths per minute with compassion focused soothing rhythm breathing.

Current Study

In this randomized controlled experiment, 6 breaths per minute breathing using a pacer was compared with compassion focused soothing rhythm breathing, with a nature video being used as a control group condition.

Methods

Heart rate variability (HRV) measures were assessed via electrocardiogram (ECG) and respiration belt, and an automated blood pressure machine was used to measure systolic diastolic blood pressure, and heart rate (HR). A total of 96 participants were randomized into the three conditions. Following a 5-min baseline, participants engaged in either 6 breath per minute breathing, soothing rhythm breathing, or watched a nature video for 10 min. To induce a stressful state, participants then wrote for 5 min about a time they felt intensely self-critical. Participants then wrote for 5 min about a time they felt self-compassionate, and the experiment ended with a 10-min recovery period.

Results

Conditions did not significantly differ at baseline. Overall, HRV, as measured by standard deviation of NN intervals (SDNN), low frequency HRV (LF HRV), and LF/HF ratio, increased during the intervention period, decreased during self-critical writing, and then returned to baseline levels during the recovery period. High frequency HRV (HF HRV) was not impacted by any of the interventions. The participants in the 6 breath per minute pacer condition were unable to consistently breathe at that rate and averaged about 12 breaths per minute. Time by Condition analyses revealed that both the 6 breaths per minute pacer and soothing breathing rhythm conditions lead to significantly higher SDNN than the nature video condition during breathing practice but there were no significant differences between conditions in response to the self-critical and self-compassionate writing or recovery periods. The 6 breath per minute pacer condition demonstrated a higher LF HRV and LF/HF ratio than the soothing rhythm breathing condition, and both intervention conditions had a higher LF HRV and LF/HF ratio than the nature video.

Conclusions

Although the 6 breath per minute pacer condition participants were not able to breath consistently at the low pace, both the participants attempting to breathe at 6 breaths per minute as well as those in the soothing rhythm breathing condition effectively increased HR variability as measured by SDNN, and attempting to breathe at 6 breaths per minute led to the highest LF HRV and LF/HF ratio. Both breathing approaches impacted HRV more than watching a relaxing nature video and can potentially be used as key adjuncts in psychotherapy to aid in regulating physiological functioning, although it appears that consistent breathing practice would be needed.

Increased risk of ischemic heart disease in patients with bipolar disorder: A population-based study

OBJECTIVE

This study investigated the national prevalence and incidence of ischemic heart disease and associated factors among Taiwanese patients with bipolar disorder.

METHODS

We used a random sample of 766,427 subjects who were ≥18 years old from the National Health Research Institute database in 2005. Subjects with at least one primary diagnosis of bipolar disorder or ischemic heart disease were identified. We compared the prevalence and incidence of ischemic heart disease in bipolar patients and the general population in 2005 and the same cohort from 2006 to 2010. These associated factors with respect to ischemic heart disease among patients with bipolar disorder were also analyzed.

RESULTS

The prevalence of ischemic heart disease in patients with bipolar disorder was 1.69 times higher than in the general population (7.85% vs 4.67%; odds ratio 1.69; 95% confidence interval, 1.41-2.03) in 2005. The average annual incidence of ischemic heart disease in patients with bipolar disorder was also 1.60 times higher than in the general population (2.02% vs 1.24; risk ratio 1.60; 95% confidence interval, 1.36-1.90) from 2006 to 2010. The higher prevalence of ischemic heart disease among bipolar patients was associated with increased age, diabetes, hypertension, and antidepressant use.

CONCLUSIONS

Patients with bipolar disorder had a significantly higher prevalence and incidence of ischemic heart disease than the general population in both sexes, especially at younger ages. Among patients with bipolar disorder, older age, and hyperlipidemia were risk factors of ischemic heart disease.

Evolution of Heart Rate Variability and Heart Rate Turbulence in Patients with Depressive Illness Treated with Selective Serotonin Reuptake Inhibitors

Background and objectives: Major depressive disorder (MDD) and cardiovascular diseases (CVDs) represent serious and prevalent medical conditions. Autonomic nervous system (ANS) dysfunctions, expressed by parameters of heart rate variability (HRV) and heart rate turbulence (HRT), have been repeatedly associated with depression. The aim of our study was to identify potential HRV and HRT alterations in patients with MDD, before and after selective serotonin reuptake inhibitor (SSRI) therapy, and to observe any correlations between these parameters and the severity of depressive symptoms. Another aim was to evidence if there was a normalization or improvement of HRV and HRT parameters that paralleled the reduction of the intensity of depressive symptoms. Materials and Methods: We studied heart rate variability (HRV) and heart rate turbulence (HRT) in a sample of 78 patients, aged under 51 years, who were referred to our outpatient clinic between June 2017 and December 2019, for complaints in the context of a new onset major depressive disorder (MDD), before and after therapy with SSRIs. Results: By using 24 h Holter ECG monitoring, we evidenced alterations of HRV and HRT parameters, significantly correlated with the severity of depressive symptoms (p < 0.001), as assessed by the Montgomery-Åsberg Depression Rating Scale (MADRS). Our results indicated that these parameters improved following one and six months of SSRI therapy, when a partial or total remission of depressive symptoms was achieved (p < 0.001). Changes in HRV parameters were correlated with the reduction of the severity of depression. Conclusions: In our study group, we highlighted, through 24 h ECG Holter monitoring, frequent and clear HRV and HRT abnormalities that were statistically correlated with the severity of depressive symptoms. Furthermore, we were able to document a progressive improvement of these parameters, which corresponded with the improvement of depressive symptoms under SSRI therapy, when compared to the values measured before the commencement of antidepressant pharmacotherapy.

Heart Rate Variability (HRV) and Pulse Rate Variability (PRV) for the Assessment of Autonomic Responses

Introduction: Heart Rate Variability (HRV) and Pulse Rate Variability (PRV), are non-invasive techniques for monitoring changes in the cardiac cycle. Both techniques have been used for assessing the autonomic activity. Although highly correlated in healthy subjects, differences in HRV and PRV have been observed under various physiological conditions. The reasons for their disparities in assessing the degree of autonomic activity remains unknown.

Methods: To investigate the differences between HRV and PRV, a whole-body cold exposure (CE) study was conducted on 20 healthy volunteers (11 male and 9 female, 30.3 ± 10.4 years old), where PRV indices were measured from red photoplethysmography signals acquired from central (ear canal, ear lobe) and peripheral sites (finger and toe), and HRV indices from the ECG signal. PRV and HRV indices were used to assess the effects of CE upon the autonomic control in peripheral and core vasculature, and on the relationship between HRV and PRV. The hypotheses underlying the experiment were that PRV from central vasculature is less affected by CE than PRV from the peripheries, and that PRV from peripheral and central vasculature differ with HRV to a different extent, especially during CE.

Results: Most of the PRV time-domain and Poincaré plot indices increased during cold exposure. Frequency-domain parameters also showed differences except for relative-power frequency-domain parameters, which remained unchanged. HRV-derived parameters showed a similar behavior but were less affected than PRV. When PRV and HRV parameters were compared, time-domain, absolute-power frequency-domain, and non-linear indices showed differences among stages from most of the locations. Bland-Altman analysis showed that the relationship between HRV and PRV was affected by CE, and that it recovered faster in the core vasculature after CE.

Conclusion: PRV responds to cold exposure differently to HRV, especially in peripheral sites such as the finger and the toe, and may have different information not available in HRV due to its non-localized nature. Hence, multi-site PRV shows promise for assessing the autonomic activity on different body locations and under different circumstances, which could allow for further understanding of the localized responses of the autonomic nervous system.

Mindfulness-Based Student Training Leads to a Reduction in Physiological Evaluated Stress

Background and Objective

In today’s fast-paced modern lifestyle, chronic stress has become a serious issue with potential consequences for our physical and mental health. The concept of mindfulness and its derived Mindfulness-Based Stress Reduction (MBSR) program is considered to be an effective stress management technique for patients as well as for healthy persons. The effects of MBSR interventions on their participants have been subject of previous research, especially with regard to psychological or social science approaches using self-reports and questionnaires. In contrast, medical investigations in this field have been less frequent and often somehow limited, for example, addressing only absolute (discrete) mean values for heart rate or blood pressure.

Methods

In this study, we have evaluated a Mindfulness Based Student Training program (MBST) by applying methods of biosignal analysis to examine its impact on the training participants’ autonomic regulation. This intervention program included classical MBSR elements but was adapted to suit the normal daily needs of university students. We obtained the electrocardiogram, finger-pulse plethysmography, and respiration activity from students participating in either the intervention group (IGR, 38 subjects) or a passive control group (CON, 35 subjects) prior to and after 8 weeks of MBST intervention.

Results

When comparing various indices from heart rate variability, pulse wave variability, and respiration in linear and nonlinear domains, significant changes in the autonomic regulation were observed for the IGR group after 8 weeks of MBST.

Conclusion

The results indicate a reduced stress level exclusively for the intervention participants, and therefore, we assume a health benefit from the MBST program.

Evaluating depression with multimodal wristband-type wearable device: screening and assessing patient severity utilizing machine-learning

OBJECTIVE

We aimed to develop a machine learning algorithm to screen for depression and assess severity based on data from wearable devices.

METHODS

We used a wearable device that calculates steps, energy expenditure, body movement, sleep time, heart rate, skin temperature, and ultraviolet light exposure. Depressed patients and healthy volunteers wore the device continuously for the study period. The modalities were compared hourly between patients and healthy volunteers. XGBoost was used to build machine learning models and 10-fold cross-validation was applied for the validation.

RESULTS

Forty-five depressed patients and 41 healthy controls participated, creating a combined 5,250 days' worth of data. Heart rate, steps, and sleep were significantly different between patients and healthy volunteers in some comparisons. Similar differences were also observed longitudinally when patients' symptoms improved. Based on seven days' data, the model identified symptomatic patients with 0.76 accuracy and predicted Hamilton Depression Rating Scale-17 scores with a 0.61 correlation coefficient. Skin temperature, sleep time-related features, and the correlation of those modalities were the most significant features in machine learning.

LIMITATIONS

The small number of subjects who participated in this study may have weakened the statistical significance of the study. There are differences in the demographic data among groups although we performed a correction for multiple comparisons. Validation in independent datasets was not performed, although 10-fold cross validation with the internal data was conducted.

CONCLUSION

The results indicated that utilizing wearable devices and machine learning may be useful in identifying depression as well as assessing severity.

A Longitudinal Examination of Heart-Rate and Heart Rate Variability as Risk Markers for Child Posttraumatic Stress Symptoms in an Acute Injury Sample

Heart rate (HR) alterations in the immediate aftermath of trauma-exposure have been proposed to be potentially useful markers for child and adolescent posttraumatic stress disorder (PTSD). However, it is not yet clear if this holds true for measures taken more distal to the trauma, and no studies have investigated the predictive validity of more sensitive HR variability (HRV) indices. We recruited 76 parent-child pairs (child age 6 to 13 years) after the child experienced a traumatic event leading to presentation at a hospital emergency department. At 1-month post trauma (T1), HR recordings were obtained at rest, and while children verbally recounted their traumatic experience, both alone and together with a parent. Child post-traumatic stress symptoms (PTSS) were assessed concurrently (T1), and at 3 (T2) and 6-month (T3) follow-ups. We found that for T1, elevated mean HR during trauma narratives, but not at baseline, was positively associated with PTSS, with some evidence that HRV-indices were negatively cross-sectionally associated with PTSS. Furthermore, T1 HR indices predicted PTSS at T2 and partially at T3, although these effects did not hold when T1 PTSS were added to the model. Findings suggest that, consistent with the adult literature, HR indices in children may be a concurrent marker of higher PTSS and may be predictive of longer term distress. The findings encourage further investigations that track child HR and HRV in relation to PTSS over time after trauma, in order to examine how biological profiles evolve in those with persistent symptoms.

Neurophysiological and Psychological Predictors of Social Functioning in Patients with Schizophrenia and Bipolar Disorder

OBJECTIVE

The aim of this study is to examine social functioning in patients with schizophrenia and bipolar disorder and explore the psychological and neurophysiological predictors of social functioning.

METHODS

Twenty-seven patients with schizophrenia and thirty patients with bipolar disorder, as well as twenty-five healthy controls, completed measures of social functioning (questionnaire of social functioning), neurocognition (Verbal fluency, Korean-Auditory Verbal Learning Test), and social cognition (basic empathy scale and Social Attribution Task-Multiple Choice), and the childhood trauma questionnaire (CTQ). For neurophysiological measurements, mismatch negativity and heart rate variability (HRV) were recorded from all participants. Multiple hierarchical regression was performed to explore the impact of factors on social functioning.

RESULTS

The results showed that CTQ-emotional neglect significantly predicted social functioning in schizophrenia group, while HRV-high frequency significantly predicted social functioning in bipolar disorder patients. Furthermore, emotional neglect and HRV-HF still predicted social functioning in all of the subjects after controlling for the diagnostic criteria.

CONCLUSION

Our results implicated that even though each group has different predictors of social functioning, early traumatic events and HRV could be important indicators of functional outcome irrespective of what group they are.

Cardiac dysautonomia in depression - heart rate variability biofeedback as a potential add-on therapy

Depressive disorders are among the most important health problems and are predicted to constitute the leading cause of disease burden by the year 2030. Aside significant impact on quality of life, psychosocial well-being and socioeconomic status of affected patients, depression is associated with impaired cardiovascular health and increased mortality. The link between affective and cardiovascular disease has largely been attributed to dysregulation of the autonomic nervous system resulting in a chronic shift toward increased sympathetic and decreased parasympathetic activity and, consecutively, cardiac dysautonomia. Among proposed surrogate parameters to capture and quantitatively analyze this shift, heart rate variability (HRV) and baroreflex sensitivity have emerged as reliable tools. Attenuation of these parameters is frequently seen in patients suffering from depression and is closely linked to cardiovascular morbidity and mortality. Therefore, diagnostic and therapeutic strategies were designed to assess and counteract cardiac dysautonomia. While psychopharmacological treatment can effectively improve affective symptoms of depression, its effect on cardiac dysautonomia is limited. HRV biofeedback is a non-invasive technique which is based on a metronomic breathing technique to increase parasympathetic tone. While some small studies observed beneficial effects of HRV biofeedback on dysautonomia in patients with depressive disorders, larger confirmatory trials are lacking. We reviewed the current literature on cardiac dysautonomia in patients suffering from depression with a focus on the underlying pathophysiology as well as diagnostic workup and treatment.

Biological and Clinical Markers in Panic Disorder

OBJECTIVE

Classifying mental disorders on the basis of objective makers might clarify their aetiology, help in making the diagnosis, identify "at risk" individuals, determine the severity of mental illness, and predict the course of the disorder. This study aims to review biological and clinical markers of panic disorder (PD).

METHODS

A computerized search was carried out in PubMed and Science Direct using the key words: "marker/biomarker/clinical marker/neurobiology/staging" combined using Boolean AND operator with "panic." In addition, the reference lists from existing reviews and from the articles retrieved were inspected. Only English language papers published in peer-reviewed journals were included.

RESULTS

Structural changes in the amygdala, hippocampus, cerebral blood level in the left occipital cortex, serotonin 5-TH and noradrenergic systems activation, aberrant respiratory regulation, hearth rate variability, blood cells and peripheral blood stem cells, hypothalamic-pituitary-adrenal axis dysregulation were identified as potential candidate biomarkers of PD. Staging was identified as clinical marker of PD. According to the staging model, PD is described as follows: prodromal phase (stage 1); acute phase (stage 2); panic attacks (stage 3); chronic phase (stage 4).

CONCLUSION

The clinical utility, sensitivity, specificity, and the predictive value of biomarkers for PD is still questionable. The staging model of PD might be a valid susceptibility, diagnostic, prognostic, and predictive marker of PD. A possible longitudinal model of biological and clinical markers of PD is proposed.

The impact of childhood trauma and psychophysiological reactivity on at-risk women's adjustment to parenthood

Adverse childhood experiences (ACEs) have an impact on women's adaptation to parenthood, but mechanisms are poorly understood. Autonomic nervous system reactivity was tested as a potential mediating mechanism in a sample of 193 at-risk primiparous women. ACEs were measured retrospectively during pregnancy. A baby cry-response task was administered during pregnancy while indicators of sympathetic reactivity (pre-ejection period; PEP) and parasympathetic reactivity (respiratory sinus arrhythmia; RSA) were recorded. Parenting self-efficacy, anxiety, and depressive symptoms were measured during pregnancy and 1 year after giving birth. Harsh discipline was measured 2 years after giving birth. Structural equation modeling was employed to test whether baseline PEP and RSA and reactivity mediated links between ACEs and postnatal outcomes, adjusted for prenatal variables. High ACEs predicted less RSA reactivity (p = .02), which subsequently predicted increases in depressive symptoms (p = .03). The indirect effect was not significant (p = .06). There was no indirect link between high ACEs and harsh parenting through PEP nor RSA (n = 98). The parasympathetic nervous system may be involved in negative affective responses in the transition to parenthood among women exposed to childhood trauma.

Randomized controlled trial of an 8-week intervention combining self-care and hypnosis for post-treatment cancer patients: study protocol

Background

Cancer has a lot of consequences on patients’ quality of life (such as cancer-related fatigue (CRF), sleep difficulties and emotional distress) and on patients’ partners and their relationship, such as distress and communication difficulties. These consequences are undertreated, and interventions based on hypnosis often focus on breast cancer patients only. This paper describes the study protocol of a longitudinal randomized controlled trial aiming to assess the efficacy of an 8-week intervention combining hypnosis and self-care to improve cancer patients’ CRF, sleep and emotional distress and to indirectly improve their partners’ distress.

Methods

A power analysis required a total sample of 88 patients. To test the efficacy of the intervention, results of the experimental group receiving the intervention will be compared to those of the control group. Data will be collected by questionnaires, relaxation tasks, an attentional bias task, and everyday life assessments measured at four different times: 1.) before inclusion in the study (baseline); 2.) after the intervention; and 3.) at 4- and 12-month follow-up. Partners’ symptoms will also be evaluated with questionnaires at the same measurement times.

Discussion

There is a growing interest in alternative approaches (such as hypnosis) in addition to standard therapies in oncology settings. The results of this study should be useful for improving knowledge about long-term efficacy of hypnosis-based group interventions for CRF, sleep and distress among all types of cancer patients and their partners, and to better understand the mechanisms of emotional regulation in cancer patients through the attentional bias task.

Trial registration

ClinicalTrials.gov (NCT03144154). Retrospectively registered on the 1st of May, 2017.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5046-6) contains supplementary material, which is available to authorized users.

Enhancing Social Interaction in Depression (SIDE study): protocol of a randomised controlled trial on the effects of a Cognitively Based Compassion Training (CBCT) for couples

INTRODUCTION

Positive social interactions (PSIs) and stable relationships can exert substantial benefits on health. However, patients suffering from depression benefit less from these health-promoting effects. Moreover, relationship quality and even partners' health has been found to be negatively affected by depressive symptomatology, which may result in overall impairments in social functioning of a romantic couple. Psychobiological research indicates that these impairments may be accompanied by a maladaptive regulation of the patient's neuroendocrine response to external stressors. Concerning the improvement of social functioning, first studies showed promising results of "Cognitively Based Compassion Training (CBCT®)". However, randomised trials are still scarce. Previous programmes did not involve participation of the patient's romantic partner. Therefore, the present study aims to investigate whether a CBCT® programme adapted for couples (CBCT®-fC) can improve depressive symptoms, distress, social interaction skills and the neurobiological regulation of stress.

METHODS AND ANALYSIS

Couples with the female partner suffering from depression will be invited to participate in a pre-to-post intervention assessment on two consecutive days, respectively, involving a standardised PSI task, eye-tracking, ECG recordings, saliva-sampling, blood-sampling and questionnaire data. After baseline assessment, participating couples will be randomised to either a 10 week CBCT®-fC or to a treatment as usual control condition. The primary endpoint is the reduction of depressive symptoms measured by the Hamilton Depression Rating Scale. Secondary outcomes encompass self-rated depression (Beck Depression Inventory), attention towards the partners face during PSI (eye tracking), stress-related biomarkers (cortisol, α-amylase, interleukin (IL)-1ß/IL-6, heart rate variability), methylation of oxytocin-receptor-genes and serotonin-transporter-genes and self-ratings of psychological constructs such as relationship quality and empathy.

ETHICS AND DISSEMINATION

Ethical approval has been obtained by the Ethics Committee of the Medical Faculty Heidelberg. Results will be presented in international, peer-reviewed journals and on conferences in the field of clinical psychology and psychiatry.

TRIAL REGISTRATION NUMBER

NCT03080025.

Heart rate variability in patients with bipolar disorder: From mania to euthymia

Bipolar Disorder (BD) is characterized by the occurrence of mania alternating with euthymia. The aim of the present study was to investigate the impact of BD on the autonomic nervous system, as indicated by heart rate variability (HRV). The study was registered in the Clinical Trials Registration (NCT01272518). Nineteen hospitalized, male patients (age: 34.0 ± 12.3 years) with type I BD were assessed during mania and at discharge on euthymia. HRV data were collected during 20- minutes in supine position at rest, on spontaneous breathing, using the Polar RS 800 CX frequencymeter. HRV measures included variables in time, frequency and non-linear domains. Psychiatric conditions were evaluated by the Mini International Neuropsychiatric Interview (MINI) and the Bech-Rafaelsen mania scale (BRMS). Time domain measures of RMSSD (Cohen's d = 0.668) and pNN50 (Cohen's d = 0.688) increased from first to second assessments. The high-frequency component (HFms2) also increased (Cohen's d = 0.586), while the LF/HF ratio decreased (Cohen's d = 0.785). Non-linear domain measures including the SD1 component (Cohen's d = 0.668), and the SD1/SD2 ratio (Cohen's d = 1.2934) extracted from the Poincare plot analysis increased from first to second assessment. The variables Lmean (Cohen's d = 0.9627), Lmax (Cohen's d = 1.2164), REC% (Cohen's d = 1.0595) and EntShannon (Cohen's d = 1.0607) were higher in mania. By contrast, ApEn (Cohen's d = 0.995) and EntSample (Cohen's d = 1.189) were less during mania, all reflecting ANS improvement. Findings are interpreted in the context of recently published models relating to neurovisceral integration across the continuum of time, and the implications for the future health and wellbeing of patients are considered.

Associations between symptoms of depression and heart rate variability: An exploratory study

Major depressive disorder (MDD) is associated with decreased heart rate variability (HRV), a predictor of cardiovascular morbidity by many, but not all studies. This inconsistency could be due to the association of HRV with specific depressive symptoms. Here, we investigated the association of HRV parameters with components of depressive symptoms from 120 MDD patients, at baseline of a published trial comparing the effect of sertraline to transcranial direct current stimulation. We used Principal Component Analysis to extract components of the Hamilton Rating Scale for Depression (HAM-D-17), the Montgomery Asberg Depression Rating Scale (MADRS) and the Beck Inventory for Depressive Symptomatology (BDI). We constructed one equation of multiple linear regression for each HRV parameter as the dependent variable, and the components of depressive symptoms of the three scales as the independent ones, adjusted for age and gender. A component of HAM-D-17 predicted LF/HF (low frequency/high frequency) and a component of MADRS predicted LF (low frequency). "Guilt" and "loss of interest/pleasure in activities" were present in the components of both scales, and the MADRS component also included "psychomotor retardation". These results suggest that melancholic features might be relevant for the association between MDD and HRV. Considering multiple comparisons, these results are preliminary.

The Heart´s rhythm 'n' blues: Sex differences in circadian variation patterns of vagal activity vary by depressive symptoms in predominantly healthy employees

INTRODUCTION

Successful regulation of emotional states is positively associated to mental health, while difficulties in regulating emotions are negatively associated to overall mental health and in particular associated with anxiety or depression symptoms. A key structure associated to socio-emotional regulatory processes is the central autonomic network. Activity in this structure is associated to vagal activity can be indexed noninvasively and simply by measures of peripheral cardiac autonomic modulations such as heart rate variability. Vagal activity exhibits a circadian variation pattern, with a maximum during nighttime. Depression is known to affect chronobiology. Also, depressive symptoms are known to be associated with decreased resting state vagal activity, but studies investigating the association between circadian variation pattern of vagal activity and depressive symptoms are scarce. We aim to examine these patterns in association to symptom severity of depression using chronobiologic methods.

METHODS

Data from the Manheim Industrial Cohort Studies (MICS) were used. A total of 3,030 predominantly healthy working adults underwent, among others, ambulatory 24-h hear rate-recordings, detailed health examination and online questionnaires and were available for this analysis. The root mean sum of successive differences (RMSSD) was used as an indicator of vagally mediated heart rate variability. Three individual-level cosine function parameters (MESOR, amplitude, acrophase) were estimated to quantify circadian variation pattern. Multivariate linear regression models including important covariates such as age, sex, and lifestyle factors as well as an interaction effect of sex with depressive symptoms were used to estimate the association of circadian variation pattern of vagal activity with depressive symptoms simultaneously.

RESULTS

The analysis sample consisted of 20.2% females and an average age 41 with standard deviation of 11 years. Nonparametric bivariate analysis revealed significant MESOR and amplitude differences between the 90^th percentile split, but not on acrophase. Multivariate linear regression models estimated depressive symptoms to be negatively associated with the 24h mean (MESOR) and oscillation amplitude in men but positively associated in women. This pattern of findings indicates a blunted day-night rhythm of vagal activity in men with greater depressive symptoms as well as a moderation effect of sex in the association of CVP and depressive symptoms.

CONCLUSIONS

This is the first study investigating circadian variation pattern by mild depressive symptoms in a large, rather healthy occupational sample. Depressive symptoms were associated with decreased circadian variation pattern of vagal activity in men but with increased circadian variation pattern in women. The possible underlying mechanism(s) are discussed using the neurovisceral integration model. These findings may have implications for the knowledge on etiology, diagnosis, course, and treatment of depressive symptoms and thus may be of significant public health relevance.

Adding HRV biofeedback to psychotherapy increases heart rate variability and improves the treatment of major depressive disorder

Heart rate variability (HRV) is a significant marker of health outcomes with decreased HRV predicting increased disease risk. HRV is decreased in major depressive disorder (MDD) but existing treatments for depression do not return heart rate variability to normal levels even with successful treatment of depression. Heart rate variability biofeedback (HRVB) increases heart rate variability but no studies to date have examined whether combining HRVB with psychotherapy improves outcome in MDD treatment. The present study used a randomized controlled design to compare the effects of HRVB combined with psychotherapy on MDD relative to a psychotherapy treatment as usual group and to a non-depressed control group. The HRVB+psychotherapy group showed a larger increase in HRV and a larger decrease in depressive symptoms relative to the other groups over a six-week period, whereas the psychotherapy group only did not improve HRV. Results support the supplementation of psychotherapy with HRVB in the treatment of MDD.