Differential actions of antidepressant treatments on cardiac autonomic alterations in depression: A prospective comparison

Neuro-cardiac-guided transcranial magnetic stimulation: Unveiling the modulatory effects of low-frequency and high-frequency stimulation on heart rate

Transcranial magnetic stimulation (TMS) is pivotal in the field of major depressive disorder treatment. Due to its unsatisfied response rate, an increasing number of researchers have turned their attention towards optimizing TMS site localization. Since the influence of TMS in reducing heart rate (HR) offers insights into its regulatory impact on the autonomic nervous system, a novel approach, called neurocardiac-guided TMS (NCG-TMS), has been proposed to pinpoint the brain region eliciting the maximal individual reduction in HR as a personalized optimal stimulation target. The present study intends to systematically explore the effects of stimulation frequency, left and right hemispheres, stimulation positions, and individual differences on HR modulation using the NCG-TMS method. In experiment 1, low-frequency TMS was administered to 30 subjects, and it was found that low-frequency NCG-TMS significantly downregulated HR, with more significant effects in the right hemisphere than in the left hemisphere and the prefrontal cortex than in other brain areas. In experiment 2, high-frequency NCG-TMS stimulation was administered to 30 subjects, showing that high-frequency NCG-TMS also downregulated HR and had the greatest modulatory effect in the right prefrontal region. Simultaneously, both experiments revealed sizeable individual variability in the optimal stimulation site, which in turn validated the feasibility of the NCG-TMS method. In conclusion, the present experiments independently replicated the effect of NCG-TMS, provided an effect of high-/low-frequency TMS stimulation to downregulate HR, and identified a right lateralization of the HR modulation effect.

Research on treatment-related aspects of depression from India in the preceding decade (2014-2023): An updated systematic review

Background

The National Mental Health Survey reports a prevalence of 2.7% for depressive disorders in India. The services for depression patients may be organized differently in India as compared to Western countries. It is important to consider studies conducted in India to determine effective interventions for depression catered specifically to the needs of the Indian population. We intended to systematically review the articles studying the usefulness of various treatment modalities in the management of depression in the Indian context.

Materials and Methods

We searched PubMed, Google Scholar, and ScienceDirect to identify studies published in peer-reviewed English language journals. All articles from India evaluating the clinical efficacy of anti-depressants, electro-convulsive therapy, repetitive transcranial magnetic stimulation, and psychological interventions for the management of depression were evaluated. Data were extracted using standard procedures.

Results

A total of 36 studies were included in the review. Out of those, 15 were studies on drug efficacy, five on neuro-modulation, nine on psycho-social interventions, four on adverse effects, and three on miscellaneous studies. Innovations were seen in the field of neuro-modulation and psycho-social intervention. Trials on drug efficacy and adverse drug reactions require larger sample sizes, more studies on newer agents, and more robust study designs.

Conclusion

More research is needed to understand the effectiveness and potential negative effects of depression treatments in India. Studies on ketamine have been inconclusive, and existing research on pharmacological agents is limited. Neuro-modulation studies show promise, but larger-scale studies are needed. Innovative psychological interventions tailored to the Indian population include community-based and digital technology-driven care.

Resting-state EEG as a potential indicator to predict sleep quality in depressive patients

OBJECTIVES

To investigate the changes in sleep quality, heart rate variability (HRV) and resting-state electroencephalogram (rsEEG) in patients with major depressive disorder (MDD), and to explore whether HRV and rsEEG may be served as more convenient tools to assess sleep quality in MDD patients.

METHOD

We included a total of 91 subjects (46 healthy controls and 45 MDD patients) and compared their sleep quality, HRV and power spectra of rsEEG. Correlation analyses were conducted to discuss the relationship between HRV and seven factors of PSQI. Multiple linear regression model was used to examine whether absolute band power could predict sleep quality in MDD patients.

RESULTS

We found higher PSQI scores and lower levels of HRV in depressive individuals compared with healthy controls. In MDD patients, sleep latency was negatively correlated with RMSSD and HF. Delta, theta, and alpha band power of rsEEG were higher in MDD patients. Regression analyses showed delta band power of TP8, as well as theta, alpha band power of AF3 predicts PSQI score of MDD patients.

CONCLUSIONS

The findings of our study show that some aspects of sleep problems had negative correlations with parasympathetic activity and the regression model supports that the band power of rsEEG may be used as a potential indicator to evaluate the sleep quality in MDD patients.

SIGNIFICANCE

Cortical hyperarousal may be one of the reasons leading to poor sleep quality of MDD patients. And resting-state EEG can be used as a potential indicator for clinical assessment of MDD patients' sleep quality.

Impact of antidepressant use on the autonomic nervous system: A meta-analysis and systematic review

Changes in cardiac autonomic nervous system (ANS) regulation observed in psychiatric disorders may be mitigated by antidepressants. We meta-analyzed and systematically reviewed studies examining antidepressants' effects on ANS outcomes, including heart rate variability (HRV). We conducted a PRISMA/MOOSE-compliant search of PubMed and Scopus until March 28th, 2022. We included randomized placebo-controlled trials (RCTs) and pre-post studies, regardless of diagnosis. We pooled results in random-effects meta-analyses, pooling homogeneous study designs and outcomes. We conducted sensitivity analyses and assessed quality of included studies. Thirty studies could be meta-analyzed. Selective serotonin reuptake inhibitors (SSRIs) were significantly associated with a reduction in the square root of the mean-squared difference between successive R-R intervals (RMSSD) (SMD= -0.48) and skin conductance response (SMD= -0.55) in RCTs and with a significant increase in RMSSD in pre-post studies (SMD=0.27). In pre-post studies, tricyclic antidepressants (TCAs) were associated with a significant decrease in several HRV outcomes while agomelatine was associated with a significant increase in high frequency power (SMD= 0.14). In conclusion, SSRIs reduce skin conductance response but have no or inconclusive effects on other ANS outcomes, depending on study design. TCAs reduce markers of parasympathetic function while agomelatine might have the opposite effect. Studies are needed to investigate the impact of SSRIs on the recovery of cardiac ANS regulation after acute myocardial infarction, and the effects of newer antidepressants.

Cardiovascular biomarkers of response to accelerated low frequency repetitive transcranial magnetic stimulation in major depression

BACKGROUND AND OBJECTIVE

Repetitive transcranial magnetic stimulation (rTMS) is an effective and safe treatment for major depressive disorder (MDD). rTMS is in need of a reliable biomarker of treatment response. High frequency (HF) dorsolateral prefrontal cortex (DLPFC) rTMS has been reported to induce significant changes in the cardiac activity of MDD patients. Low frequency DLPFC rTMS has many advantages over HF-DLPFC rTMS and thus this study aims to further investigate the effect of low frequency 1 Hz right hemisphere (R)-DLPFC rTMS on the cardiac activity of MDD patients, as well as the potential of using electrocardiogram (ECG) parameters as biomarkers of treatment outcome.

METHODS

Baseline ECG sessions were performed for 19 MDD patients. All patients then underwent 40 sessions of accelerated 1 Hz R-DLPFC rTMS one week after the baseline session.

RESULTS

Heart rate (HR) significantly decreased from the resting period to the first and third minute of the 1 Hz R-DLPFC rTMS period. Resting HR was found to have a significant negative association with treatment outcome. Prior to Bonferroni correction, HR during stimulation and the degree of rTMS-induced HR reduction were significantly negatively associated with treatment outcome. No significant changes were observed for the heart rate variability (HRV) parameters.

LIMITATIONS

Sample size (n = 19); the use of electroencephalography equipment for ECG; lack of respiration monitoring; relatively short recording duration for HRV parameters.

CONCLUSION

This novel study provides further preliminary evidence that ECG may be utilized as a biomarker of rTMS treatment response in MDD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04376697.

Cautionary Observations Concerning the Introduction of Psychophysiological Biomarkers into Neuropsychiatric Practice

The combination of statistical learning technologies with large databases of psychophysiological data has appropriately generated enthusiastic interest in future clinical applicability. It is argued here that this enthusiasm should be tempered with the understanding that significant obstacles must be overcome before the systematic introduction of psychophysiological measures into neuropsychiatric practice becomes possible. The objective of this study is to identify challenges to this effort. The nonspecificity of psychophysiological measures complicates their use in diagnosis. Low test-retest reliability complicates use in longitudinal assessment, and quantitative psychophysiological measures can normalize in response to placebo intervention. Ten cautionary observations are introduced and, in some instances, possible directions for remediation are suggested.

Neuro-Cardiac-Guided TMS (NCG TMS): A replication and extension study

Neuro-Cardiac-Guided Transcranial Magnetic Stimulation (NCG-TMS) was studied for its potential to specifically target the frontal-vagal network. Previous research demonstrated that prefrontal stimulation led to significant heartrate slowing. We aimed to replicate these results in a larger sample and extend the findings to investigate dose-response relationships, reproducibility and stimulation frequency (10 Hz and intermittent theta burst (iTBS)). Data of forty-five healthy controls were analyzed, of which 28 received 10 Hz TMS (NCG-TMS) and 27 iTBS (NCG-iTBS; 10 received both protocols) at different stimulation sites according to the 10-20-EEG system. NCG-TMS yielded a relative heartrate deceleration at the F3/4 coil position replicating earlier studies. Both internal consistency and dose-response relationships were found. For NCG-iTBS adverse events were reported and topography for frontal-vagal activation was more lateralised relative to NCG-TMS. These results indicate that we were able to transsynaptically stimulate the frontal-vagal network and that excitability thresholds for the prefrontal cortex may differ relative to motor cortex.

The Heart-Brain Connection in Depression: Can it inform a personalised approach for repetitive transcranial magnetic stimulation (rTMS) treatment?

There is growing enthusiasm into the frontal-vagal network theory of major depressive disorder (MDD) and the potential role of a frontal-vagal network in the therapeutic mechanism of repetitive transcranial magnetic stimulation (rTMS) treatment for MDD. A review of the autonomic nervous system (ANS) in MDD and its role in antidepressant treatment for MDD is timely. The literature supports the well-established notion of ANS dysfunction in MDD and the benign effect of selective serotonin reuptake inhibitors, but not tricyclic antidepressants, on perturbed ANS function in MDD. Notwithstanding, there is some evidence that ANS measures have the capacity to inform response to antidepressant medication treatment. While there is a paucity of studies on the effects of rTMS on the ANS, critically, there is preliminary support that rTMS may alleviate ANS dysfunction in MDD and that ANS measures are associated with rTMS treatment response. These observations are consistent with the frontal-vagal theory of depression and the emerging literature on the use of ANS measures for personalising and optimising rTMS treatment of MDD.

The association of depression and anxiety with cardiac autonomic activity: The role of confounding effects of antidepressants

BACKGROUND

Depression and anxiety may unfavorably impact on cardiac autonomic dysregulation. However, it is unclear whether this relationship results from a causal effect or may be attributable to confounding factors. We tested the relationship between depression and anxiety with heart rate (HR) and heart rate variability (HRV) across a 9-year follow-up (FU) period and investigated possible confounding by antidepressant use and genetic pleiotropy.

METHODS

Data (no. of observations = 6,994, 65% female) were obtained from the longitudinal Netherlands Study of Depression and Anxiety, with repeated waves of data collection of HR, HRV, depression, anxiety, and antidepressant use. Summary statistics from meta-analyses of genome-wide association studies were used to derive polygenic risk scores of depression, HR, and HRV.

RESULTS

Across the 9-year FU, generalized estimating equations analyses showed that the relationship between cardiac autonomic dysregulation and depression/anxiety rendered nonsignificant after adjusting for antidepressant use. A robust association was found between antidepressant use (especially tricyclic antidepressants, selective serotonin, and noradrenalin reuptake inhibitors) and unfavorable cardiac autonomic activity across all waves. However, no evidence was found for a genetic correlation of depression with HR and HRV, indicating that confounding by genetic pleiotropy is minimal.

CONCLUSIONS

Our results indicate that the association between depression/anxiety and cardiac autonomic dysregulation does not result from a causal pathway or genetic pleiotropy, and these traits might therefore not be inevitably linked. Previously reported associations were likely confounded by the use of certain classes of antidepressants.

Decreased Task-Related HRV Is Associated With Inhibitory Dysfunction Through Functional Inter-Region Connectivity of PFC in Major Depressive Disorder

The regulation of the autonomic nervous system (ANS) can improve cognitive function in major depressive disorders (MDD). Heart rate variability (HRV) derives from the dynamic control of the ANS and reflects the balance between the activities of the sympathetic and parasympathetic nervous systems by measuring tiny changes in adjacent heart beats. Task-related HRV may reflect the association between the flexibility of cognition and ANS function. The study was to investigate the neural mechanism of interactions between ANS and cognitive function in MDD with Magnetoencephalography (MEG) measurements. Participants included 20 MDD patients and 18 healthy controls (HCs). All participants were measured with a go/no-go task MEG. HRV indices, the standard deviation of the average normal-to-normal (NN) interval calculated over short periods (SDANN) and the square root of the mean squared differences of successive NN intervals (RMSSD), were derived from the raw MEG data. Results showed that MDD patients showed decreased SDANN and RMSSD. In MDD patients, both resting-state and task-related RMSSD were related to inhibitory and control dysfunction. In the go/no-go task, many areas in the prefrontal cortex (PFC) are responsible for an individual's inhibitory function. A brain MEG functional connectivity analysis revealed that there were significant differences in four brain regions within the prefrontal cortex (PFC) between MDD patients and HCs. Task-related RMSSD in HCs were related to the functional connectivity between the left middle frontal gyrus and the anterior cingulate cortex (ACC), while in MDD patients, these values were not related to the above functional connectivity but were related to the functional connectivity between the left middle frontal gyrus and insula. However, the resting-state RMSSD value was not related to these significant difference functional connectivity networks in all participants. It concludes that the decreased task-related HRV is associated with inhibitory dysfunction through functional inter-region connectivity in the PFC in MDD, and the task-related HRV can be used as an index of the association between MDD and autonomic dysregulation.

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.

Associations of immunometabolic risk factors with symptoms of depression and anxiety: The role of cardiac vagal activity

OBJECTIVES

This study examined 1) the cross-sectional relationships between symptoms of depression/anxiety and immunometabolic risk factors, and 2) whether these relationships might be explained in part by cardiac vagal activity.

METHODS

Data were drawn from the Adult Health and Behavior registries (n = 1785), comprised of community dwelling adults (52.8% women, aged 30-54). Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D) and the Beck Depression Inventory-II (BDI-II), and anxious symptoms with the Trait Anxiety scale of the State-Trait Anxiety Inventory (STAI-T). Immunometabolic risk factors included fasting levels of triglycerides, high-density lipoproteins, glucose, and insulin, as well as blood pressure, waist circumference, body mass index, C-reactive protein, and interleukin-6. Measures of cardiac autonomic activity were high- and low-frequency indicators of heart rate variability (HRV), standard deviation of normal-to-normal R-R intervals, and the mean of absolute and successive differences in R-R intervals.

RESULTS

Higher BDI-II scores, in contrast to CES-D and STAI-T scores, were associated with increased immunometabolic risk and decreased HRV, especially HRV likely reflecting cardiac vagal activity. Decreased HRV was also associated with increased immunometabolic risk. Structural equation models indicated that BDI-II scores may relate to immunometabolic risk via cardiac vagal activity (indirect effect: β = .012, p = .046) or to vagal activity via immunometabolic risk (indirect effect: β = -.015, p = .021).

CONCLUSIONS

Depressive symptoms, as measured by the BDI-II, but not anxious symptoms, were related to elevated levels of immunometabolic risk factors and low cardiac vagal activity. The latter may exhibit bidirectional influences on one another in a meditational framework. Future longitudinal, intervention, an nonhuman animal work is needed to elucidate the precise and mechanistic pathways linking depressive symptoms to immune, metabolic, and autonomic parameters of physiology that predispose to cardiovascular disease risk.

Association Between Depression, Anxiety, and Antidepressant Use With T-Wave Amplitude and QT-Interval

Objectives: Cardiac repolarization may be affected by psychiatric disorders and/or antidepressant use, but evidence for this is inconclusive. This study examined the relationship between depressive and anxiety disorder and use of antidepressants with T-wave amplitude (TWA) and QT-interval.

Methods: Data was obtained from the Netherlands Study of Depression and Anxiety (n = 1,383). Depression/anxiety was diagnosed with the DSM-IV based Composite International Diagnostic Interview. The use of tricyclic antidepressants (TCAs), selective serotonin and noradrenalin reuptake inhibitors (SNRIs), and selective serotonin reuptake inhibitors (SSRIs) was established. T-wave amplitude and QT-interval corrected for heart rate (QTc) were obtained from an ECG measured in a type II axis configuration.

Results: Compared to controls, persons with depression or anxiety disorders did not show a significantly different TWA (p = 0.58; Cohen's d = 0.046) or QTc (p = 0.48; Cohen's d = −0.057). In spite of known sympathomimetic effects, TCA use (p = 0.26; Cohen's d = −0.162) and SNRI use (p = 0.70; Cohen's d = −0.055) were not significantly associated with a lower TWA. TCA use (p = 0.12; Cohen's d = 0.225) and SNRI use (p = 0.11; Cohen's d = 0.227) were also not significantly associated with a prolonged QTc.

Conclusion: We did not find evidence that either depressive/anxiety disorder or antidepressant use is associated with abnormalities in TWA or QTc. Earlier found sympathomimetic effects of TCAs and SNRIs are not evident in these measures of cardiac repolarization.

Heart rate variability and cordance in rapid eye movement sleep as biomarkers of depression and treatment response

OBJECTIVES

The relevance of rapid eye movement (REM) sleep in affective disorders originates from its well-known abnormalities in depressed patients, who display disinhibition of REM sleep reflected by increased frequency of rapid eye movements (REM density). In this study we examined whether heart rate variability (HRV) and prefrontal theta cordance, both derived from REM sleep, could represent biomarkers of antidepressant treatment response.

METHODS

In an open-label, case-control design, thirty-three in-patients (21 females) with a depressive episode were treated with various antidepressants for four weeks. Response to treatment was defined as a ≥50% reduction of HAM-D score at the end of the fourth week. Sleep EEG was recorded after the first and the fourth week of medication. HRV was derived from 3-min artifact-free electrocardiogram segments during REM sleep. Cordance was computed for prefrontal EEG channels in the theta frequency band during tonic REM sleep.

RESULTS

HRV during REM sleep was decreased in depressed patients at week four as compared to controls (high effect size; Cohen's d > 1), and showed a negative correlation with REM density in both, healthy subjects and patients at week four. Further, the fourteen responders had significantly higher prefrontal theta cordance as compared to the nineteen non-responders after the first week of antidepressant medication; in contrast, HRV at week one did not discriminate between responders and non-responders.

CONCLUSIONS

Our data suggest that HRV in REM sleep categorizes healthy subjects and depressed patients, whereas REM sleep-derived prefrontal cordance may predict the response to antidepressant treatment in depressed patients.

Intensified emotion perception in depression: Differences in physiological arousal and subjective perceptions

People suffering from depression perceive themselves and their surroundings as more negative than healthy ones. An explanation might be that depressed individuals experience negative information as more stressful than non-depressed subjects and, consequently, respond in an amplified manner on a subjective and physiological level. To test this proposition, we presented 41 patients with recurrent depressive episodes and 42 controls with stimuli from the International Affective Picture System split into three valence categories while different parameters of physiological arousal (e.g., heart rate variability) and subjective perceptions of valence and arousal were assessed. Furthermore, we examined social skills and emotional competence. Results regarding physiological arousal revealed an elevated skin temperature and a more accentuated respiratory frequency in depressed subjects. Furthermore, depressed subjects rated the stimuli as more negative and arousing, which was associated with reduced social and emotional competence. Variation in antidepressant medication, menstrual cycle and other factors that have an impact on HRV are a potential bias. Our findings suggest an intensified perception of negative emotion in depressed individuals as compared to controls that manifests itself in an increased physiological arousal as well as on a subjective level. This intensified emotion perception is further associated with deficits in social and emotional competence.

Evaluating Emotional and Biological Sensitivity to Maternal Behavior among Self-injuring and Depressed Adolescent Girls Using Nonlinear Dynamics

High sensitivity and reactivity to behaviors of family members characterizes several forms of psychopathology, including self-inflicted injury (SII). We examined mother-daughter behavioral and psychophysiological reactivity during a conflict discussion using nonlinear dynamics to assess asymmetrical associations within time-series data. Depressed, SII, and control adolescents and their mothers participated (n=76 dyads). We expected that (1) mothers' evocative behaviors would affect behavioral and psychophysiological reactivity among depressed and, especially, SII adolescents, (2) adolescents' behaviors would not evoke mothers' behavioral or physiological reactivity, and (3) control teens and mothers would be less reactive, with no dynamic associations in either direction. Convergent cross-mapping with dewdrop regression, which identifies directional associations, indicated that mothers' behaviors evoked behavioral responses among depressed and SII participants, but psychophysiological reactivity for SII teens only. There were no effects of adolescents' behavior on mothers' reactivity. Results are interpreted based upon sensitivity theories and directions for further research are outlined.

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

OBJECTIVE

Autonomic nervous system dysfunction has the potential to adversely impact general medical health and is known to exist in a number of psychiatric disorders. It reflects alterations in the function of several regions of the central nervous system. Measurement of heart rate variability provides a non-invasive tool for studying autonomic function. While the literature relating to the technical process of heart rate variability and aspects of depressive disorders has been reviewed in the past, research relating to both depressive and bipolar disorders has not been comprehensively reviewed. This paper critically considers the published research in heart rate variability in both depressive and bipolar affective disorders.

METHOD

A literature search using Medline, EMBASE, PsycINFO, ProQuest Psychology and references included in published literature was conducted using the following keywords: 'heart rate variability and autonomic, combined with depression, depressive disorder, bipolar, mania and sleep'.

RESULTS

The evidence demonstrates that, using heart rate variability measures, significant distortions of autonomic function are evident in both depressive and bipolar disorders and from most of their pharmacological treatments.

CONCLUSION

The autonomic dysfunction evident in both unipolar and bipolar affective disorders, and many psychotropic medications, has significant implications for our understanding of the neurophysiology of these disorders, their treatment and associated general health.

Autonomic nervous system dysfunction in psychiatric disorders and the impact of psychotropic medications: a systematic review and meta-analysis

BACKGROUND

Autonomic nervous system (ANS) dysfunction is a putative underlying mechanism for increased cardiovascular disease risk in individuals with psychiatric disorders. Previous studies suggest that this risk may be related to psychotropic medication use. In the present study we systematically reviewed and analyzed published studies of heart rate variability (HRV), measuring ANS output, to determine the effect of psychiatric illness and medication use.

METHODS

We searched for studies comparing HRV in physically healthy adults with a diagnosed psychiatric disorder to controls and comparing HRV pre- and post-treatment with a psychotropic medication.

RESULTS

In total, 140 case-control (mood, anxiety, psychosis, dependent disorders, k = 151) and 30 treatment (antidepressants, antipsychotics; k = 43) studies were included. We found that HRV was reduced in all patient groups compared to controls (Hedges g = -0.583) with a large effect for psychotic disorders (Hedges g = -0.948). Effect sizes remained highly significant for medication-free patients compared to controls across all disorders. Smaller and significant reductions in HRV were observed for specific antidepressants and antipsychotics.

LIMITATIONS

Study quality significantly moderated effect sizes in case-control analyses, underscoring the importance of assessing methodological quality when interpreting HRV findings.

CONCLUSION

Combined findings confirm substantial reductions in HRV across psychiatric disorders, and these effects remained significant even in medication-free individuals. Reductions in HRV may therefore represent a significant mechanism contributing to elevated cardiovascular risk in individuals with psychiatric disorders. The negative impact of specific medications on HRV suggest increased risk for cardiovascular disease in these groups, highlighting a need for treatment providers to consider modifiable cardiovascular risk factors to attenuate this risk.

Investigating the Effect of Mindfulness Training on Heart Rate Variability in Mental Health Outpatients: A Pilot Study

Depression is associated with increased cardiac morbidity and mortality in people with and without cardiac risk factors, and this relationship is, in part, mediated by heart rate variability (HRV). Increased heart rate and reduced HRV are common in depressed patients, which may explain their higher cardiac risk. This pilot study investigated whether mindfulness-based cognitive therapy (MBCT) promoted objective changes in (1) HRV, and (2) depressive symptoms and quality of life, in mental health outpatients. Twenty-seven adults meeting criteria for DSM-IV Axis I disorders completed an 8-week MBCT program. Data were collected on three occasions, 8 weeks apart; twice before and once after MBCT. Participants completed the Short Form-36 and the Center for Epidemiological Studies Depression Scale (CES-D) at each test period. Heart rate and HRV were measured during electrocardiographic monitoring before and after a cognitive stressor. At baseline, 78% of participants met criteria for depression (CES-D ≥16). Multivariate analyses revealed a significant treatment effect for SF-36 physical summary score and depression (as a dichotomous variable), but not for HRV. This pilot study highlights the immediate psychological and health benefits of MBCT. Low power may have influenced the lack of a finding of an association between HRV and MBCT. However, the feasibility of the study design has been established, and supports the need for larger and longer-term studies of the potential physiological benefits of MBCT for cardiac health.

Impaired baroreflex sensitivity in subjects with impaired glucose tolerance, but not isolated impaired fasting glucose

Impaired baroreflex sensitivity (BRS) is associated with adverse cardiovascular outcomes. There are currently no studies on BRS changes in subjects with different glycemic statuses, including normal glucose tolerance (NGT), isolated impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and newly diagnosed diabetes (NDD). The aim of this study was to investigate the effects of NDD, IGT and isolated IFG on BRS, based on a community-based data. A total of 768 subjects were classified as NGT (n = 498), isolated IFG (n = 61), IGT (n = 126) and NDD (n = 83). Spontaneous BRS was determined by the spectral α coefficient method, i.e., the square root of the ratio between the power of the RR interval and the power of systolic blood pressure in the LF frequency region (0.04-0.15 Hz) after the subjects had rested in a supine position for 5 min. Valsalva ratio was calculated as the longest RR interval after release of the Valsalva maneuver, divided by the shortest RR interval during the maneuver. As compared with NGT subjects, NDD (p = 0.039) and IGT (p = 0.041) subjects had a reduced spontaneous BRS in multivariate analysis based on analysis of covariance. NDD subjects exhibited a lower Valsalva ratio than NGT subjects (p = 0.043). However, there were no significant differences in spontaneous BRS and Valsalva ratio between subjects with isolated IFG and NGT. In conclusion, NDD and IGT subjects had an impaired BRS as compared to NGT subjects. However, reduced BRS was not apparent in subjects with isolated IFG.

Comparative Study of Heart Rate Variability in Patients with Schizophrenia, Bipolar Disorder, Post-traumatic Stress Disorder, or Major Depressive Disorder

Objective

Heart rate variability (HRV) changes as a function of psychiatric illness. This study aimed to evaluate HRV among patients with various psychiatric disorders.

Methods

The present study recruited patients with schizophrenia (n=35), bipolar disorder (n=41), post-traumatic stress disorder (PTSD; n=34), or major depressive disorder (n=34) as well as healthy controls (n=27). The time-domain analysis (the standard deviation of all RR intervals [SDNN] and the square root of the mean squared differences of successive normal sinus intervals [RMSSD]), the frequency-domain analysis (very low frequency, low frequency [LF], high frequency [HF], and total power [TP]), and a non-linear complexity measure the approximate entropy were computed.

Results

SDNN and HF were significantly reduced in patients with schizophrenia compared with healthy controls. SDNN, RMSSD, TP, LF, and HF were significantly reduced in bipolar patients compared with healthy controls. HF was significantly reduced in PTSD patients compared with healthy controls.

Conclusion

Our findings indicate that HRV is not sufficiently powerful to discriminate among various psychiatric illnesses. However, our results suggest that HRV, particularly HF, could be used as a tool for discriminating between psychiatric patients and healthy controls.

Mechanisms of contextual risk for adolescent self-injury: invalidation and conflict escalation in mother-child interactions

According to developmental theories of self-injury, both child characteristics and environmental contexts shape and maintain problematic behaviors. Although progress has been made toward identifying biological vulnerabilities to self-injury, mechanisms underlying psychosocial risk have received less attention. In the present study, we compared self-injuring adolescents (n = 17) with typical controls (n = 20) during a mother-child conflict discussion. Dyadic interactions were coded using both global and microanalytic systems, allowing for a highly detailed characterization of mother-child interactions. We also assessed resting state psychophysiological regulation, as indexed by respiratory sinus arrhythmia (RSA). Global coding revealed that maternal invalidation was associated with adolescent anger. Furthermore, maternal invalidation and coerciveness were both related to adolescent opposition/defiance. Results from the microanalytic system indicated that self-injuring dyads were more likely to escalate conflict, suggesting a potential mechanism through which emotion dysregulation is shaped and maintained over time. Finally, mother and teen aversiveness interacted to predict adolescent resting RSA. Low-aversive teens with highly aversive mothers had the highest RSA, whereas teens in high-high dyads showed the lowest RSA. These findings are consistent with theories that emotion invalidation and conflict escalation are possible contextual risk factors for self-injury.