Major depression and cardiac autonomic control

Impact of depression and antidepressant treatment on heart rate variability: a review and meta-analysis

BACKGROUND

Depression is associated with an increase in the likelihood of cardiac events; however, studies investigating the relationship between depression and heart rate variability (HRV) have generally focused on patients with cardiovascular disease (CVD). The objective of the current report is to examine with meta-analysis the impact of depression and antidepressant treatment on HRV in depressed patients without CVD.

METHODS

Studies comparing 1) HRV in patients with major depressive disorder and healthy control subjects and 2) the HRV of patients with major depressive disorder before and after treatment were considered for meta-analysis.

RESULTS

Meta-analyses were based on 18 articles that met inclusion criteria, comprising a total of 673 depressed participants and 407 healthy comparison participants. Participants with depression had lower HRV (time frequency: Hedges' g = -.301, p < .001; high frequency: Hedges' g = -.293, p < .001; nonlinear: Hedges' g = -1.955, p = .05; Valsalva ratio: Hedges' g = -.712, p < .001) than healthy control subjects, and depression severity was negatively correlated with HRV (r = -.354, p < .001). Tricyclic medication decreased HRV, although serotonin reuptake inhibitors, mirtazapine, and nefazodone had no significant impact on HRV despite patient response to treatment.

CONCLUSIONS

Depression without CVD is associated with reduced HRV, which decreases with increasing depression severity, most apparent with nonlinear measures of HRV. Critically, a variety of antidepressant treatments do not resolve these decreases despite resolution of symptoms, highlighting that antidepressant medications might not have HRV-mediated cardioprotective effects and the need to identify individuals at risk among patients in remission.

Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorder

Aim:

The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV.

Methods:

Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5–18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9–17.7). HRV was registered in the sitting position during 4 min with no interventions.

Results:

Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen’s d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN.

Conclusions:

Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference.

Gender differences in the relationship between depression and cardiac autonomic function among community elderly

OBJECTIVE

The mechanism underlying the differential effect of depression on morbidity and mortality in men and women remains unknown. This survey was designed to examine gender effects on the relationship between depressive symptoms and cardiac autonomic function among community dwelling elderly.

METHODS

Six hundred and six randomly selected community-dwelling elderly men and women > or = 65 years of age were enrolled. Depressive symptoms were assessed with the Hospital Anxiety and Depression Scale. Cardiac autonomic function was evaluated by measuring heart rate variability (HRV) parameters. Frequency-domain indices of HRV were obtained.

RESULTS

Among the subjects, 58.4% were male with a mean age of 77.9 years. Stratified analyses by gender revealed a dose-response association between depressive symptoms and lower cardiac vagal control among elderly males (p = 0.003). Male subjects with mild depressive symptoms (depression scores: 5-6) showed prominent cardiac sympathetic predominance compared with the reference group (depression scores: < 5) (p = 0.005). In contrast, these findings did not exist among elderly females.

CONCLUSIONS

The association of depressive symptoms with poor cardiac vagal control and sympathetic predominance was more robust among elderly males than females. This finding may help explain gender differences in the association of depression with morbidity and mortality.

Chronic fatigue in adolescence--autonomic dysregulation and mental health: an exploratory study

AIM

The present study investigates associations between autonomic cardiovascular dysregulation, psychosocial load and mental health in adolescents presenting with chronic fatigue.

METHOD

Twenty-two adolescents, mean age 15.7 years (12.7-19.1), underwent a clinical mental health examination as part of a broad medical investigation which included autonomic tests. Adolescents and their parents were also interviewed with regard to psychosocial stress factors, family health and previous illnesses. A count of psychosocial load was made for each adolescent based on the interview.

RESULTS

Of 22 fatigued adolescents in the present sample, 14 had psychiatric diagnoses. There was no significant difference in psychosocial load for the fatigued adolescents classified with normal autonomic regulation compared to those with deviant or borderline autonomic regulation. The present psychiatric diagnosis did not differ between the two groups. In a subsample, there was a significant negative association between depressive symptoms and abnormal blood pressure responses during orthostatic challenge.

CONCLUSION

No significant psychiatric or psychosocial differences between fatigued adolescents with or without autonomic dysregulation were found in this study. The trends towards higher psychosocial load and greater burden of depressive symptoms in fatigued adolescents with normal autonomic regulation warrant further studies.

The influences of depression and venlafaxine use at therapeutic doses on atrial conduction

Patients with depression have increases risk of cardiac mortality. Overdose with venlafaxine has been accused of supraventricular tachycardia, atrial fibrillation and other cardiac effects. Discontinuous and inhomogeneous propagation of sinus impulses in atrium plays a major role in atrial fibrillation. We aimed to measure the effects of venlafaxine therapy on propagation of sinus impulses reflections in electrocardiography in depression. Eligible 19 participants were outpatients with depression. 75 mg/day dose of venlafaxine was administered to the patients. The patients were asked to complete both Beck Depression and Anxiety Inventories. 17 healthy participants enrolled in the study. The electrocardiography records were obtained while patients were drug naive and one week after treatment. The baseline durations of P(minimum) and P(maximum) in the patient group were significantly shorter than controls (p < 0,05). The differences between baseline and after venlafaxine therapy among electrocardiographical variables were statistically insignificant. There were no significant correlations between age, sex, body mass index, clinical inventories and electrocardiographical variables in both patients and controls. Autonomic dysregulation in myocardium is still inconclusive in depression. Venlafaxine at therapeutic dose of 75 mg/day does not seem to be associated with myocardial conduction dysregulation.

Trait negative affect: toward an integrated model of understanding psychological risk for impairment in cardiac autonomic function

OBJECTIVE

To assess depression, anxiety, and anger as well as the variance that these emotions share (conceptualized as negative affect) in relationship to high-frequency heart rate variability (HF-HRV), a specific indicator of parasympathetic cardiac autonomic function related to premature cardiovascular morbidity and mortality. Although individual trait negative emotions have been studied in relation to risk for coronary heart disease (CHD) as well as biological mechanisms leading to CHD end points (e.g., autonomic nervous system [ANS] dysfunction), the degree to which a general tendency to experience negative emotions may account for these relations is not known.

METHODS

The sample included 653 community volunteers (51.0% female; 15.8% Black) aged 30 to 54 years (mean +/- standard deviation = 43.8 +/- 7.1 years). Latent constructs of depression, anxiety, and anger were each measured by three scales from well-validated self-report questionnaires. Resting HF-HRV was derived from 5-minute segments of continuous electrocadiographs recorded during both unpaced and paced respiration conditions.

RESULTS

Structural equation models (SEM) of the individual trait emotions showed depression and anxiety related inversely to HF-HRV and anger unrelated to HF-HRV. SEM also showed negative affect related inversely to HF-HRV. All associations were present after covariate adjustment for traditional cardiovascular risk factors, including age, sex, race, education, body mass index, smoking status, and blood pressure.

CONCLUSIONS

Negative affect as a common pathway between depression, anxiety, and anger and impairments in cardiac autonomic function was supported, suggesting negative affect may be the unifying and potentially toxic element linking individual trait negative emotions to ANS dysregulation.

Alteration of cardiac autonomic functions in patients with major depression: a study using heart rate variability measures

BACKGROUND

Depression is associated with greater cardiac morbidity and mortality. One of the contributory factors for this may be altered cardiac autonomic activity in depression. However, cardiac autonomic involvement in depression remains controversial because of methodological issues. In this study, alteration of cardiac autonomic functions was studied in drug-naive patients with major depression without co-morbidity. Heart rate variability, a sensitive measure of neurocardiac autonomic regulation was used in addition to conventional methods of measuring cardiac autonomic functions.

METHODS

We recruited 40 patients suffering from major depression, diagnosed based on DSM-IV-TR criteria. Their cardiac autonomic functions were measured using both conventional and heart rate variability measures. These were compared with those of age- and gender-matched healthy controls.

RESULTS

Patients with major depression showed significantly lesser Valsalva ratio, maximum/minimum ratio and greater sympathovagal balance than healthy controls indicating decreased parasympathetic and increased sympathetic activity.

CONCLUSIONS

Depression is associated with alteration of cardiac autonomic tone towards decreased parasympathetic activity and an increased sympathetic activity. It is possible that a common neurobiological dysfunction contributes to both depression and cardiac autonomic changes in the illness.

RSA fluctuation in major depressive disorder

Cardiac vagal control, as measured by indices of respiratory sinus arrhythmia (RSA), has been investigated as a marker of impaired self-regulation in mental disorders, including depression. Past work in depressed samples has focused on deficits in resting RSA levels, with mixed results. This study tested the hypothesis that depression involves abnormal RSA fluctuation. RSA was measured in depressed and healthy control participants during rest and during two reactivity tasks, each followed by a recovery period. Relative to controls, depressed persons exhibited lower resting RSA levels as well as less RSA fluctuation, primarily evidenced by a lack of task-related vagal suppression. Group differences in RSA fluctuation were not accounted for by differences in physical health or respiration, whereas group differences in resting RSA level did not survive covariate analyses. Depression may involve multiple deficits in cardiac vagal control.

Cardiac vagal control in depression: a critical analysis

Rapidly developing research has found abnormal cardiac vagal control (CVC) in several physical and mental health conditions. CVC findings in depression are mixed, and the degree to which CVC is compromised in depression is unclear. A meta-analysis of 13 rigorous cross-sectional studies reveals that a diagnosis of depression exerts a small-to-medium effect size on CVC, and explains only about 2% of the overall variance in CVC. More robust data may emerge from alternative approaches to the depression-CVC relationship, such as the use of CVC to predict the course of the disorder. Despite the vigor of recent work on CVC and depression, overall findings are suggestive rather than conclusive. Methodological desiderata and priorities for future research are discussed, including the need to clarify the etiological significance of CVC.

Tryptophan depletion affects heart rate variability and impulsivity in remitted depressed patients with a history of suicidal ideation

BACKGROUND

Depression is a major risk factor for cardiovascular disease. An important risk factor for cardiovascular disease, low heart rate variability, often has been found in depressed patients and has been associated with impulsivity. The present study investigated whether experimental lowering of serotonin would decrease heart rate variability and increase impulsivity in remitted depressed patients, in particular in those patients with disturbed impulse control.

METHODS

Nineteen patients in remission from depression received high-dose and low-dose acute tryptophan depletion in a randomized, counterbalanced, double-blind crossover design. Heart rate variability and impulsivity were assessed during each acute tryptophan depletion session and during a baseline session. Suicidal ideation during past depression was used as an index for individual differences in impulse control.

RESULTS

High-dose acute tryptophan depletion led to a larger increase in depressive symptoms than did low-dose acute tryptophan depletion. High-dose acute tryptophan depletion decreased heart rate variability and increased impulsivity and anxiety, but only in patients with a history of suicidal ideation. Symptom effects of high-dose acute tryptophan depletion correlated with low heart rate variability at baseline.

CONCLUSIONS

Depressed patients who have problems with controlling impulsivity might be more at risk for developing cardiovascular disease, possibly related to increased vulnerability to impaired 5-hydroxytryptamine function.

Psychophysiological and cortisol responses to psychological stress in depressed and nondepressed older men and women with elevated cardiovascular disease risk

OBJECTIVE

The objective of this study was to compare psychophysiological and cortisol reactions to psychological stress in older depressed and nondepressed patients at risk for cardiovascular disease (CVD).

METHODS

Forty-eight depressed participants and 20 controls with elevated cardiovascular risk factors underwent a psychological stress test during which cardiovascular variables were measured. Salivary cortisol was collected after each test segment. Traditional (e.g., lipids) and atypical (e.g., C-reactive protein) CVD risk factors were also obtained.

RESULTS

At baseline, the groups did not differ on lipid levels, flow-mediated vasodilation, body mass index, or asymmetric dimethylarginine. However, the depressed patients had significantly higher C-reactive protein levels. Contrary to our hypothesis, there were no differences in baseline cortisol levels or diurnal cortisol slopes, but depressed patients showed significantly lower cortisol levels during the stress test (p = .03) and less cortisol response to stress. Compared with nondepressed subjects, depressed subjects also showed lower levels of respiratory sinus arrhythmia (RSA(TF)) during the stress test (p = .02).

CONCLUSIONS

In this sample, older depressed subjects with elevated risk for CVD exhibited a hypocortisol response to acute stress. This impaired cortisol response might contribute to chronic inflammation (as reflected in the elevated C-reactive proteins in depressed patients) and in other ways increase CVD risk. The reduced RSA(TF) activity may also increase CVD risk in depressed patients through impaired autonomic nervous system response to cardiophysiological demands.

Heart rate variability biofeedback as a behavioral neurocardiac intervention to enhance vagal heart rate control

BACKGROUND

Patients with coronary heart disease (CHD) who experience depressed mood or psychological stress exhibit decreased vagal control of heart rate (HR), as assessed by spectral analysis of HR variability (HRV). Myocardial infarction and sudden cardiac death are independently associated with depression and stress, as well as impaired vagal HR control. This study examined whether a behavioral neurocardiac intervention to reduce stress or depression can augment cardiovagal modulation in CHD patients. We hypothesized that (1) cognitive-behavioral training with HRV biofeedback would augment vagal recovery from acute stress, and (2) vagal regulation of HR would be inversely associated with stress and depression after treatment.

METHODS

This randomized controlled trial enrolled 46 CHD patients from 3 clinics of CHD risk reduction in Toronto and Vancouver, Canada. Subjects were randomized to five 1.5-hour sessions of HRV biofeedback or an active control condition. Outcome was assessed by absolute and normalized high-frequency spectral components (0.15-0.50 Hz) of HRV, and by the Perceived Stress Scale and Centre for Epidemiologic Studies in Depression scale.

RESULTS

Both groups reduced symptoms on the Perceived Stress Scale (P = .001) and Centre for Epidemiologic Studies in Depression scale (P = .004). Hierarchical linear regression determined that improved psychological adjustment was significantly associated with the high-frequency index of vagal HR modulation only in the HRV biofeedback group. Adjusted R 2 was as follows: HRV biofeedback group, 0.86 for stress (P = .02) and 0.81 for depression (P = .03); versus the active control group, 0.04 (P = .57) and 0.13 (P = .95), respectively.

CONCLUSION

A novel behavioral neurocardiac intervention, HRV biofeedback, can augment vagal HR regulation while facilitating psychological adjustment to CHD.

Sudarshan Kriya yogic breathing in the treatment of stress, anxiety, and depression: part I-neurophysiologic model

Mind-body interventions are beneficial in stress-related mental and physical disorders. Current research is finding associations between emotional disorders and vagal tone as indicated by heart rate variability. A neurophysiologic model of yogic breathing proposes to integrate research on yoga with polyvagal theory, vagal stimulation, hyperventilation, and clinical observations. Yogic breathing is a unique method for balancing the autonomic nervous system and influencing psychologic and stress-related disorders. Many studies demonstrate effects of yogic breathing on brain function and physiologic parameters, but the mechanisms have not been clarified. Sudarshan Kriya yoga (SKY), a sequence of specific breathing techniques (ujjayi, bhastrika, and Sudarshan Kriya) can alleviate anxiety, depression, everyday stress, post-traumatic stress, and stress-related medical illnesses. Mechanisms contributing to a state of calm alertness include increased parasympathetic drive, calming of stress response systems, neuroendocrine release of hormones, and thalamic generators. This model has heuristic value, research implications, and clinical applications.

Vagal withdrawal to a sad film predicts subsequent recovery from depression

Cardiac vagal tone, as indexed by abnormalities in the level and/or reactivity of respiratory sinus arrhythmia (RSA), has been related to psychiatric impairment, including risk for depression. Longitudinal studies of depression have focused on RSA levels and have found mixed support for the hypothesis that low RSA levels predict a more pernicious course of depression. The current investigation focuses on the relation between RSA reactivity and the course of depression. We measured depressed persons' RSA reactivity to sadness-, fear-, and amusement-inducing emotion films and reassessed participants' diagnostic status 6 months later. Depressed persons who exhibited a higher degree of vagal withdrawal to the sad film were more likely to recover from depression. Implications for the study of RSA in depression are discussed.

Depression, the autonomic nervous system, and coronary heart disease

Depression is a risk factor for medical morbidity and mortality in patients with coronary heart disease (CHD). Dysregulation of the autonomic nervous system (ANS) may explain why depressed patients are at increased risk. Studies of medically well, depressed psychiatric patients have found elevated levels of plasma catecholamines and other markers of altered ANS function compared with controls. Studies of depressed patients with CHD have also uncovered evidence of ANS dysfunction, including elevated heart rate, low heart rate variability, exaggerated heart rate responses to physical stressors, high variability in ventricular repolarization, and low baroreceptor sensitivity. All of these indicators of ANS dysfunction have been associated with increased risks of mortality and cardiac morbidity in patients with CHD. Further research is needed to determine whether ANS dysfunction mediates the effects of depression on the course and outcome of CHD, and to develop clinical interventions that improve cardiovascular autonomic regulation while relieving depression in patients with CHD.

A genetic analysis of ambulatory cardiorespiratory coupling

This study assessed the heritability of ambulatory heart period, respiratory sinus arrhythmia (RSA), and respiration rate and tested the hypothesis that the well-established correlation between these variables is determined by common genetic factors. In 780 healthy twins and siblings, 24-h ambulatory recordings of ECG and thorax impedance were made. Genetic analyses showed considerable heritability for heart period (37%-48%), RSA (40%-55%), and respiration rate (27%-81%) at all daily periods. Significant genetic correlations were found throughout. Common genes explained large portions of the covariance between heart period and RSA and between respiration rate and RSA. During the afternoon and night, the covariance between respiration rate and RSA was completely determined by common genes. This overlap in genes can be exploited to increase the power of linkage studies to detect genetic variation influencing cardiovascular disease risk.

Proarrhythmia with Non-Antiarrhythmics

In 1987, at the American College of Cardiology national meeting, a group of physicians from Europe and the United States agreed to use the term 'arrhythmogenesis' to refer to an aggravation or provocation of arrhythmias resulting from any cause and specifically to use the word 'proarrhythmia' when such arrhythmogenesis is from drug therapy. Proarrhythmia is thus, defined as the potential of cardiac and non-cardiac drugs to induce or exacerbate arrhythmias. It is a relatively common finding in the hospitalized and outpatient settings. It was recognized since the early 1980's, but still was considered an extremely unusual event. In many instances, unfortunately the first manifestation of proarrhythmia is death. We have identified multiple conditions and non-cardiac medications that have been reported in association with this entity. Basic concepts of ion-channels of the heart are provided in this review, to help understanding the rational of the pathophysiology, which remains of paramount importance, as it gives insight to the diagnosis, that is mostly based on electrocardiographic findings. The careful detection of the presence of comordid diseases, makes it possible to prevent, recognize, avoid mistreatment and treat the condition. We present an overview of the cardiac cellular electrophysiology, mechanisms of cardiac arrhythmias and explain the substrates and targets of the pro-arrhythmic actions of non-cardiac drugs.

Anxiety and hostility are associated with reduced baroreflex sensitivity and increased beat-to-beat blood pressure variability

OBJECTIVE

The purpose of this study was to determine whether psychological factors are associated with heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) among healthy middle-aged men and women.

METHODS

A population-based sample of 71 men and 79 women (35-64 years of age) was studied. Five-minute supine recordings of ECG and beat-to-beat photoplethysmographic finger systolic arterial pressure and diastolic arterial pressure were obtained during paced breathing. Power spectra were computed using a fast Fourier transform for low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.40 Hz) powers. BRS was calculated by cross-spectral analysis of R-R interval and systolic arterial pressure variabilities. Psychological factors were evaluated by three self-report questionnaires: the Brief Symptom Inventory, the shortened version of the Spielberger State-Trait Anger Expression Inventory, and the Toronto Alexithymia Scale.

RESULTS

Psychological factors were not related to HRV. Anxiety was associated with decreased BRS (p = 0.001) and higher low-frequency (p = 0.002) power of systolic arterial pressure variability. These associations were independent of age, gender, other psychological factors, heart rate, and systolic and diastolic blood pressures. Hostility was an independent correlate of increased low-frequency power of diastolic arterial pressure (p = 0.001) and increased high-frequency power of systolic arterial pressure (p = 0.033) variability.

CONCLUSIONS

Anxiety and hostility are related to reduced BRS and increased low-frequency power of BPV. Reduced BRS reflects decreased parasympathetic outflow to the heart and may increase BPV through an increased sympathetic predominance.

Hopelessness is associated with decreased heart rate variability during championship chess games

OBJECTIVE

Clinical observations suggest that negative affects such as helplessness/hopelessness (HE/HO) may induce autonomic duration; affects were assessed for every move after reconstruction of the games. In all games compiled, 18 situation of intense confidence/optimism and 20 of intense helplessness/hopelessness were observed.

RESULTS

Intense affects of HE/HO were associated with decreasing HF-HRV (Fisher exact test, p =.003), increasing "nervousness" (p =.0005), decreasing "optimism" (p =.0005), and decreasing "calmness" (p =.0005).

CONCLUSIONS

Investigation of championship chess game players with an ELO strength > or = 2300 in a natural field setting revealed increasing HE/HO being associated with reduced HF-HRV suggestive of vagal withdrawal. Thus, our data may help link negative mood states, autonomic nervous system disturbances, and cardiac events.

Safety of antidepressant drugs in the patient with cardiac disease: a review of the literature

Patients with cardiac disease, specifically ischemic heart disease and heart failure, have a higher frequency of major depressive disorder than patients without cardiac disease. The pathophysiologic reason for this is not completely understood. Previous depression, other debilitating illnesses, and type A personality are risk factors for the development of depression in cardiac patients. Depression has been shown to lower the threshold for ventricular arrhythmias. Therefore, treatment of depression potentially may prolong life in these patients. Antidepressant options that have been evaluated include several of the tricyclic antidepressants, trazodone, bupropion, and several of the selective serotonin reuptake inhibitors. Individual antidepressant drugs vary in their pharmacologic activity and side-effect profiles. Although clinical data are limited, it is important to individualize therapy in order to minimize cardiac adverse effects. Clinicians are encouraged to evaluate patients with cardiac disease for major depressive disorder and to consider antidepressant drug therapy for these patients when appropriate.

Vagal rebound during resolution of tearful crying among depressed and nondepressed individuals

Respiratory sinus arrhythmia (RSA) is an index of the vagal control of heart rate that is associated with emotion regulatory capacity. To examine RSA in depressed and nondepressed participants in the context of an emotion-regulatory challenge, we presented a sad film to induce crying, a behavior associated with heightened parasympathetic activation. We predicted that nondepressed persons who cried would show elevations in RSA during the onset and the resolution of crying. By contrast, we predicted that depressed individuals who cried would fail to exhibit increased RSA over the course of their crying episodes. As hypothesized, nondepressed participants exhibited RSA increases that accompanied the resolution of tearful crying, consistent with a homeostatic function for crying, whereas depressed subjects who cried did not exhibit increased RSA. Results suggest that the physiological self-regulatory mechanisms invoked by crying are compromised in depression.

Respiratory sinus arrhythmia as a predictor of outcome in major depressive disorder

BACKGROUND

Respiratory sinus arrhythmia (RSA) is a noninvasive measure of parasympathetic tone that has been related to emotion regulatory capacity. While some previous work indicates that clinically depressed persons exhibit lower levels of RSA than do normal controls, there is nevertheless considerable between-subject variation in RSA among depressed persons. The current study evaluated the significance of variation in RSA among depressed persons by examining whether levels of RSA predicted concurrent symptomatology and the course of depressive illness.

METHODS

The RSA levels of 55 diagnosed depressed individuals were assessed during a paced breathing procedure at Time 1. Six months later (Time 2), participants were interviewed again to determine whether or not each had fully recovered from depression. Multinomial regression analyses were conducted to examine whether RSA predicted Time 2 clinical status.

RESULTS

Although RSA levels were not related to overall depression severity, they were associated with specific symptoms of depression: RSA was positively associated with the report of sadness and negatively associated with the report of suicidality. More strikingly, however, higher levels of RSA at Time 1 predicted non-recovery from depression at Time 2, even when statistically controlling for initial depression severity, age and medication use.

LIMITATIONS

Treatment and medication use were not controlled during the follow-up period and a group of nonpsychiatric controls was not included in this study.

CONCLUSIONS

A relatively high level of RSA among depressed individuals predicts a more pernicious course of illness than do lower RSA levels.

Atrial fibrillation, failed cardioversion, and electroconvulsive therapy

A case is described in which an elderly male with atrial fibrillation and major depression underwent a course of electroconvulsive therapy. Two of the first three treatments were associated with other arrhythmias, during and after the procedure. Prior to the fourth treatment cardioversion was unsuccessful. During the fourth episode of electroconvulsive therapy, the patient reverted to sinus rhythm and remained in this rhythm. Reversion of atrial fibrillation to sinus rhythm may be associated with embolization if atrial thrombus has formed. Factors predisposing to changes in rhythm with electroconvulsive therapy and the management of patients with atrial fibrillation having electroconvulsive therapy are discussed.

Association of anxiety with reduced baroreflex cardiac control in patients after acute myocardial infarction

BACKGROUND

Although depression has been associated with increased mortality in patients after acute myocardial infarction (AMI), little is known about the effects of depression on autonomic nervous system control of heart rate. This study evaluated whether depression is associated with impaired baroreflex sensitivity (BRS) in patients with AMI.

METHODS

Two hundred four hospitalized patients with AMI were evaluated 6 +/- 3 (mean +/- SD) days after AMI. BRS was assessed using cross-spectral analysis to measure baroreceptor-mediated R-R interval oscillations. Depression was determined using the Diagnostic Interview Schedule, and severity of depressive symptoms was measured with the Beck Depression Inventory. In order to adjust for possible differences in anxiety, we also measured state anxiety using the Spielberger State Anxiety Inventory.

RESULTS

Depression was not significantly related to BRS. However, anxiety was significantly related to low BRS in multivariate analysis, after the potentially confounding variables of age, blood pressure, and respiratory frequency were controlled for. Comparison of groups with high and low anxiety (on the basis of a median split of state anxiety scores) showed that BRS was reduced by approximately 20% in the patients with the higher anxiety scores (4.7 +/- 3.2 ms/mm Hg vs 5.7 +/- 3.3 ms/mm Hg, P <.05), after adjustment for differences in age, blood pressure, and respiratory frequency.

CONCLUSIONS

High levels of anxiety, but not depression, are associated with reduced vagal control in patients after AMI.

Assessing the suitability of cross-sectional and longitudinal cardiac rhythm tests with regard to identifying effects of occupational chronic lead exposure

The aim of this study was to examine whether signs of neurotoxic influence on the autonomic nervous system, after lengthy occupational lead exposure, could be revealed by appropriate cardiac rhythm analysis. A total of 109 male lead-exposed workers and 27 controls were examined in a cross-sectional study. In addition, 17 lead-exposed participants were investigated a second time in a follow-up study 4 years later. Heart rate variability was assessed in rest, strain, and recovery phases. In the cross-sectional study, lead-exposed persons showed a delayed restoration of cardiac rhythm parameters to the initial vegetative state after the strain phase. This effect significantly increased over a period of 4 more years of exposure in the 17 workers participating in the follow-up study. We found vagal depression caused by long-term lead exposure within the current threshold limit value range, which can be interpreted as an adverse effect.

Disinhibitory psychopathology in male adolescents: discriminating conduct disorder from attention-deficit/hyperactivity disorder through concurrent assessment of multiple autonomic states

T. P. Beauchaine recently proposed a model of autonomic nervous system functioning that predicts divergent patterns of psychophysiological responding across disorders of disinhibition. This model was tested by comparing groups of male adolescents with attention-deficit/hyperactivity disorder (ADHD) and attention-deficit/hyperactivity disorder plus conduct disorder (CD/ADHD) with controls while performing a repetitive motor task in which rewards were administered and removed across trials. Participants then watched a videotaped peer conflict. Electrodermal responding (EDR), cardiac pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA) were monitored. Compared with controls, the ADHD and CD/ADHD participants exhibited reduced EDR. The CD/ADHD group was differentiated from the ADHD and control groups on PEP and from the control group on RSA. Findings are discussed in terms of the motivational and regulational systems indexed. Implications for understanding rates of comorbidity between CD and ADHD are considered.

Thought Field Therapy clinical applications: utilization in an HMO in behavioral medicine and behavioral health services

Thought Field Therapy (TFT) is a self-administered treatment developed by psychologist Roger Callahan. TFT uses energy meridian treatment points and bilateral optical-cortical stimulation while focusing on the targeted symptoms or problem being addressed. The clinical applications of TFT summarized included anxiety, adjustment disorder with anxiety and depression, anxiety due to medical condition, anger, acute stress, bereavement, chronic pain, cravings, depression, fatigue, nausea, neurodermatitis, obsessive traits, panic disorder without agoraphobia, parent-child stress, phobia, posttraumatic stress disorder, relationship stress, trichotillomania, tremor, and work stress. This uncontrolled study reports on changes in self-reported Subjective Units of Distress (SUD; Wolpe, 1969) in 1,594 applications of TFT, treating 714 patients. Paired t-tests of pre- and posttreatment SUD were statistically significant in 31 categories reviewed. These within-session decreases of SUD are preliminary data that call for controlled studies to examine validity, reliability, and maintenance of effects over time. Illustrative case and heart rate variability data are presented.

Sex-related differences in nortriptyline-induced side-effects among depressed patients

1. Men and women may differ in their pharmacokinetic responses to tricyclic antidepressants (TCAs), in a number of autonomic indices, and in various adrenergic receptor mediated responses. Emerging evidence also suggests that women may have a lower rate of serotonin synthesis in brain and a greater sensitivity to the depressant effects of tryptophan depletion, relative to men. However, sex-related differences in TCA-induced side-effects, including increases in heart rate (HR), dry mouth, constipation, and difficulty urinating, has not been systematically investigated. 2. The authors examined potential sex-related differences in the pattern of side-effects during treatment with nortriptyline (NT), a TCA that is still widely used. Seventy-eight healthy outpatients who met Research Diagnostic Criteria and DSM-III-R criteria for major depression participated in a double-blind, randomized parallel trial of NT versus placebo. 3. Each subject was acutely challenged with either placebo or 50 mg NT prior to and after a 6-week treatment with NT. NT doses were adjusted weekly to maintain therapeutic plasma levels. Patients were assessed at multiple time points to detect the presence of NT-induced side-effects. 4. The initial, single (50 mg) dose of NT significantly increased supine HR. Six-week treatment with NT was found to significantly increase supine and sitting HRs, irrespective of sex. In rechallenge with the single NT dose, there were no significant effects on HR. 5. When sex-related differences were examined, HR increases were greater in men than women during weeks 4 through 6 of the NT treatment, although no sex-related differences were present in plasma NT levels or metabolites. In addition, there was a significant NT to placebo difference in self-rated dry mouth for women during all 6-weeks of treatment, whereas men showed a significant NT-placebo difference during weeks 3 and 5. 6. The results suggest the presence of sex-related differences in elevated supine HR response during the course of 6-week NT treatment. Depressed men may be more susceptible to NT-induced increases in supine HR than women.

Depressed mood is related to high-frequency heart rate variability during stressors

OBJECTIVE

The purpose of this study was to examine the relationships between depressed mood and parasympathetic control of the heart in healthy men and women at rest and during two stressors.

METHODS

Fifty-three healthy college students completed a laboratory stress protocol that included a baseline resting period, a challenging speech task, and a forehead cold pressor task. Depressed mood was assessed using the Beck Depression Inventory (BDI). Parasympathetic cardiac control was measured as the high-frequency (0.12-0.40 Hz) component (HF) of heart rate variability using power spectrum analysis. Blood pressure, respiration rate, and respiration amplitude were measured simultaneously.

RESULTS

Participants were categorized as having a high or low depressed mood on the basis of median splits of their BDI scores. Those in the high depressed mood group had significantly greater reductions in HF during the speech task and significantly smaller increases in HF during the forehead cold pressor task than those in the low depressed mood group. Women had significantly greater reductions in HF during the speech task and smaller increases in HF during the forehead cold pressor task than men. However, gender and depressed mood did not interact to predict changes in HF.

CONCLUSIONS

Depressed mood is related to the magnitude of decrease in parasympathetic cardiac control during stressors in healthy men and women. These findings extend those of previous studies, in which a similar phenomenon was observed among patients with cardiac disease. Because the participants in this study were healthy, the relationship between depressed mood and parasympathetic cardiac control does not seem to be secondary to cardiovascular disease.

Anxiety reduces baroreflex cardiac control in older adults with major depression

OBJECTIVE

Although depression and anxiety predict risk of cardiac mortality, the contributions of depression and anxiety to vagal cardiac control have not been systematically evaluated. The goal of this study was to examine the relationship between state anxiety and vagal control of heart rate in older adults with major depressive disorder (MDD). Older adults (50-70 years old) were selected for this study because of the greater cardiac risk associated with low vagal cardiac control across this age range.

METHODS

Fifty-six men and women with MDD were evaluated. MDD was diagnosed using the Diagnostic Interview Schedule, and severity of depression was measured using the Beck Depression Inventory and the Hamilton Rating Scale for depression. State anxiety was measured using the Spielberger State Anxiety Inventory. Power spectral analysis was used to measure two indices of vagal control: baroreflex control of heart rate (BRC(SPEC)) and respiratory sinus arrhythmia (RSA).

RESULTS

State anxiety was negatively correlated with levels of BRC(SPEC) (r = -0.32, p < .05), whereas depression severity was not related to either RSA or BRC(SPEC). Furthermore, BRC(SPEC) was reduced by approximately 33% in MDD patients with state anxiety scores (ST-ANX) in the highest quartile (ST-ANX > 41, N = 13), compared with patients with ST-ANX scores in the lowest quartile (ST-ANX < 25, N = 14; p < .05).

CONCLUSIONS

Anxiety, but not depression severity, is associated with reduced BRC(SPEC) in older men and women. Future studies are needed to determine whether comorbid anxiety contributes to the increased cardiovascular risk associated with MDD.

Increased heart rate in depressed subjects in spite of unchanged autonomic balance?

A clinical study was conducted to examine the effects of depression on cardiac autonomic control. Cardiac autonomic control was measured in 26 nonmedicated patients (19 females) suffering from Major Depression, melancholic type, and in 26 age- and sex-matched normal controls. We measured heart rate and high frequency heart rate variability (respiratory sinus arrhythmia), pulsewave velocity and blood pressure, during 10 min of supine rest under controlled conditions. Using a log transformed time domain measure of respiratory sinus arrhythmia (logRSA), we found an inverse linear dependence between cardiac vagal tone and age in the healthy subjects as well as the depressed patients. logRSA was 0.22+/-0.25 in the patients and 0.25+/-0.16 in the control group. While this difference was not significant (P > 0.1), the deviations from the regression line were significantly (P < 0.0005) greater in the patients (0.21+/-0.12) than in the control group (0.09+/-0.07), indicating a more heterogeneous vagal tone in the depressed patients. Heart rate was also significantly (P < 0.03) greater in the depressed patients (76.6+/-12.4) than in the control group (69.5+/-6.9). No between-group differences were found in pulsewave velocity or systolic blood pressure, but diastolic blood pressure was lower in depressed patients (73.5+/-8.7 vs. 80.8+/-9.1). We discuss the possibility that the increased heart rate seen in the absence of vagal tone changes may not be due to altered vagal or sympathetic tone, as measured in this study. Other factors, including altered autonomous heart rate, may be responsible for the higher heart rate in the depressed group.