CONTEXT: It has been hypothesized that depression is associated with lower heart rate variability and decreased cardiac vagal control. This may play an important role in the risk of cardiovascular disease among depressed individuals.
OBJECTIVE: To determine whether heart rate variability was lower in depressed individuals than in healthy controls in a large adult sample.
DESIGN: Cross-sectional analyses from a large depression cohort study.
SETTING: The Netherlands Study of Depression and Anxiety.
PARTICIPANTS: Two thousand three hundred seventy-three individuals (mean age, 41.8 years; 66.8% female) who participated in the Netherlands Study of Depression and Anxiety. Included were 524 controls, 774 individuals with a diagnosis of major depressive disorder (MDD) earlier in life (remitted MDD), and 1075 individuals with current MDD based on the Composite International Diagnostic Interview. This sample was sufficiently powered to examine the confounding effects of lifestyle, comorbid anxiety, and antidepressants.
MAIN OUTCOME MEASURES: The standard deviation of normal-to-normal beats (SDNN) and cardiac vagal control, as indexed by respiratory sinus arrhythmia (RSA), were measured during 1(1/2) hours of ambulatory recording of electrocardiograms and thorax impedance. Multivariate analyses were conducted to compare SDNN and RSA across depression groups after adjustment for demographics, health, lifestyle, comorbid anxiety, and psychoactive medication.
RESULTS: Individuals with remitted and current MDD had a lower mean SDNN and RSA compared with controls (SDNN, 3.1-5.7 milliseconds shorter, P < or = .02; RSA, 5.1-7.1 milliseconds shorter, P < .001; effect size, 0.125-0.269). Comorbid anxiety and lifestyle did not reduce these associations. However, accounting for psychoactive medication removed the association with SDNN and strongly attenuated the association with RSA. Depressed individuals who were using selective serotonin reuptake inhibitors, tricyclic antidepressants, or other antidepressants had significantly shorter SDNNs and RSAs (effect size, 0.207-0.862) compared with controls and depressed individuals not taking medication. CONCLUSIONS: This study shows that depression is associated with significantly lowered heart rate variability. However, this association appears to be mainly driven by the effect of antidepressants.

Acute mental stress tests have helped to clarify the pathways through which psychosocial factors are linked to disease risk. This methodology is now being used to investigate potentially protective psychosocial factors. We investigated whether global self-esteem might buffer cardiovascular and inflammatory responses to acute stress. One hundred and one students completed the Rosenberg Self-Esteem Scale. Heart rate and heart rate variability (HRV) were recorded for 5min periods at baseline, during two mental stress tasks, (a speech and a color-word task) and 10, 25 and 40min into a recovery period. Plasma levels of tumor-necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1Ra) were assessed at baseline, immediately post-stress and after 45min recovery. Repeated measures analysis of variance demonstrated that heart rate levels were lower across all time points in those with high self-esteem, although heart rate reactivity to stress was not related to self-esteem. There were no differences in baseline HRV, TNF-α, IL-6 or IL-1Ra. Multiple linear regressions revealed that greater self-esteem was associated with a smaller reduction in heart rate variability during the speech task, but not the color-word task. Greater self-esteem was associated with smaller TNF-α and IL-1Ra responses immediately following acute stress and smaller IL-1Ra responses at 45min post-stress. In conclusion, global self-esteem is associated with lower heart rate and attenuated HRV and inflammatory responses to acute stress. These responses could be processes through which self-esteem protects against the development of disease.

This study was designed to investigate the question of whether psychophysiological changes during EMDR sessions are related to subjective and objective reduction of PTSD symptoms. During-session changes in autonomic tone in relation to session-to-session changes of subjective stress, trauma-related symptoms, and psychophysiological reactions during a traumatic reminder were investigated in 10 patients suffering from single-trauma PTSD. Treatment duration followed each patient’s individual needs and ranged between 1 and 4 sessions, resulting in a total of 24 EMDR treatment sessions from which psychophysiological data were completely recorded. Treatment with EMDR was followed by a significant reduction of trauma-related symptoms, elimination of the PTSD diagnosis in 8 of the 10 participants, as well as by significantly reduced psychophysiological reactivity to an individualized trauma script. Psychophysiological dearousal in sessions correlated significantly with decrease in script-related reactions in heart rate and parasympathetic tone, and with changes in subjective disturbance. Our results indicate that information processing during EMDR is followed by during-session decrease in psychophysiological activity, reduced subjective disturbance and reduced stress reactivity to traumatic memory.

EMDR combines stimuli that evoke divided attention – e.g. eye movements – with exposure to traumatic memories. Our objective was to investigate psycho-physiological correlates of EMDR during treatment sessions. A total of 55 treatment sessions from 10 patients with PTSD was monitored applying impedance cardiography. Onset of every stimulation/exposure period (n=811) was marked and effects within and across stimulation sets on heart rate (HR), heart rate variability (HRV), pre-ejection period (PEP) and respiration rate were examined. At stimulation onsets a sharp increase of HRV and a significant decrease of HR was noticed indicating de-arousal. During ongoing stimulation, PEP and HRV decreased significantly while respiration rate significantly increased, indicating stress-related arousal. However, across entire sessions a significant decrease of psycho-physiological activity was noticed, evidenced by progressively decreasing HR and increasing HRV. These findings suggest that EMDR is associated with patterns of autonomic activity associated with substantial psycho-physiological de-arousal over time.

According to recent theorizing in social psychology, social behavior is controlled not only by reflective, but also by impulsive systems. The latter are based on associative links that may influence behavior without intent. The current study examined how prejudiced implicit associations affect physiological and automatic behavioral responses. Our native Dutch participants were immersed in a virtual environment in which they encountered virtual persons (avatars) with either White or Moroccan facial features. In line with our predictions, participants maintained more distance and showed an increase in skin conductance level when approaching Moroccan avatars as opposed to White avatars. Participants’ implicit negative associations with Moroccans moderated both effects. Moreover, evidence was found that the relation between implicit prejudice and distance effects was fully mediated by skin conductance level effects. These data demonstrate how prejudiced implicit associations may unintentionally lead to impulsive discriminatory responses.

The present study investigated the impact of reinforcement valence and magnitude on response timing in children with ADHD. Children were required to estimate a 1-s interval, and both the median response time (response tendency) and the intrasubject-variability (response stability) were investigated. In addition, heart rate and skin conductance were measured to examine the autonomic responses to reinforcement. Feedback-only trials were compared to low response cost trials (response cost for incorrect responses), low reward trials (reward for correct responses), high response cost and high reward trials. In feedback-only trials, children with ADHD underestimated more severely the interval and responded more variably than controls. Children with ADHD, unlike controls, were unaffected by the reinforcement conditions in terms of time underestimations. The variability of responding, on the other hand, decreased under conditions of reinforcement to a larger extent in children with ADHD than controls. There were no indications that children with ADHD were abnormally affected by the valence or magnitude of reinforcement. Furthermore, skin conductance responses increased when feedback was coupled with reinforcement, an effect which was larger in children with ADHD than controls. This could be interpreted as demonstrating that children with ADHD suffer from a diminished awareness of the significance of feedback in the feedback-only condition. The current study suggests that children with ADHD suffer from motivation problems when reinforcement was not available, at least when variability in responding was measured. Underestimations of time may reflect more stable deficits in ADHD.

In this study the effects of stress-induced cortisol increases on long-term memory retrieval during and after acute psychosocial stress were examined. Seventy male students were exposed to either a psychosocial stress task or to a non-stressful control task. During and after this task, retrieval was tested for idiosyncratic emotionally negative and neutral word pair associations that were learned 1 day or 5 weeks earlier. Within the stress condition, retrieval of negative words, 5 weeks after learning, was impaired both during and after the stress task compared to the control group. Further, during the stress task, when sympathetic activity was enhanced, impaired retrieval of both neutral and emotional words was significantly related to enhanced cortisol response. In contrast, after the stress task, when cortisol levels were still increased but sympathetic activity was low again, no association was found between cortisol increase and retrieval of either neutral or emotional material. These results are in line with the previous animal research showing that when arousal is high, cortisol increase can impair memory retrieval.

Although positive emotion research has begun to flourish, the extremes of positive emotion remain understudied. The present research used a multimethod approach to examine positive emotional disturbance by comparing participants at high and low risk for episodes of mania, which involves elevations in positive emotionality. Ninety participants were recruited into a high or low mania risk group according to responses on the Hypomanic Personality Scale. Participants’ subjective, expressive, and physiological emotional responses were gathered while they watched two positive, two negative, and one neutral film clip. Results suggested that participants at high risk for mania reported elevated positive emotion and irritability and also exhibited elevated cardiac vagal tone across positive, negative, and neutral films. Discussion focuses on the implications these findings have for the diagnosis and prevention of bipolar disorder, as well as for the general study of positive emotion.

We examined the effect of training state on cardiac autonomic control in a naturalistic setting. Twenty-four vigorous exercisers were compared to age-and sex-matched sedentary controls. The regular exercisers were subjected to a 6-week training program after which they were randomized to 2 weeks of continued training or 2 weeks of detraining. Cardiac autonomic control was measured over a 24-h period by ambulatory recording, using the preejection period (PEP) and respiratory sinus arrhythmia (RSA). Nonexercising controls had a significantly higher ambulatory heart rate (HR) compared to the regular exercisers but comparable 24-h levels of PEP and RSA. In regular exercisers, 2 weeks of detraining did not significantly change the 24-h levels of HR, PEP, or RSA. We conclude that the bradycardia in healthy regular exercisers is the result of a lower intrinsic heart rate rather than a shift in cardiac autonomic balance from sympathetic to vagal control.

Patients with rheumatoid arthritis are at increased risk for myocardial infarction. It has been hypothesized that mental stress-induced cardiovascular reactions may play a role in the triggering of myocardial infarction. Cardiovascular activity was measured during rest, stress, and recovery in rheumatoid arthritis patients with high systemic inflammation (C-reactive protein>8mg/l), rheumatoid arthritis patients with low systemic inflammation (C-reactive protein≤8mg/l), and osteoarthritis patients. Systemic vascular resistance increased only in rheumatoid arthritis patients with high systemic inflammation. Heart rate and mean arterial pressure increased during the stress task in all groups. Thus, acute cardiovascular events in rheumatoid arthritis patients may be related to stress-induced increases in systemic vascular resistance, particularly in patients with high levels of systemic inflammation.