Increased sympathetic response to standing in panic disorder

Hemodynamic characteristics of postural hyperventilation: POTS with hyperventilation versus panic versus voluntary hyperventilation

Upright hyperventilation occurs in ~25% of our patients with postural tachycardia syndrome (POTS). Poikilocapnic hyperventilation alone causes tachycardia. Here, we examined changes in respiration and hemodynamics comprising cardiac output (CO), systemic vascular resistance (SVR), and blood pressure (BP) measured during head-up tilt (HUT) in three groups: patients with POTS and hyperventilation (POTS-HV), patients with panic disorder who hyperventilate (Panic), and healthy controls performing voluntary upright hyperpnea (Voluntary-HV). Though all were comparably tachycardic during hyperventilation, POTS-HV manifested hyperpnea, decreased CO, increased SVR, and increased BP during HUT; Panic patients showed both hyperpnea and tachypnea, increased CO, and increased SVR as BP increased during HUT; and Voluntary-HV were hyperpneic by design and had increased CO, decreased SVR, and decreased BP during upright hyperventilation. Mechanisms of hyperventilation and hemodynamic changes differed among POTS-HV, Panic, and Voluntary-HV subjects. We hypothesize that the hyperventilation in POTS is caused by a mechanism involving peripheral chemoreflex sensitization by intermittent ischemic hypoxia. NEW & NOTEWORTHY Hyperventilation is common in postural tachycardia syndrome (POTS) and has distinctive cardiovascular characteristics when compared with hyperventilation in panic disorder or with voluntary hyperventilation. Hyperventilation in POTS is hyperpnea only, distinct from panic in which tachypnea also occurs. Cardiac output is decreased in POTS, whereas peripheral resistance and blood pressure (BP) are increased. This is distinct from voluntary hyperventilation where cardiac output is increased and resistance and BP are decreased and from panic where they are all increased.

Salivary alpha-amylase and cortisol responsiveness to stress in first episode, drug-naïve patients with panic disorder

Reported findings on reactivity to stress of the sympathetic-adreno-medullar (SAM) and hypothalamic-pituitary-adrenal (HPA) systems in panic disorder (PD) are very variable. This inconsistency may be explained by differences in treatment exposure, illness duration and emotion regulation strategies. The present study examined the reactivity to mental stress of the SAM and HPA axes in a sample of first episode, drug naïve patients with PD which avoids confounds of medications exposure and illness chronicity. Activation of the SAM axis was evaluated by dosage of salivary alpha-amylase (sAA) and heart rate. Activation of the HPA axis was tested by dosage of salivary cortisol. Psychological assessments were done by the Self-Rating Depression Scale, the Self-Rating Anxiety Scale, the State-Trait Anxiety Inventory, the Cope Orientation to Problems Experienced (COPE) Inventory and the 16 Personality Factor Questionnaire (16PF). Patients showed reduced sAA stress reactivity, higher baseline cortisol levels and a more rapid decrease in stress cortisol levels as compared with controls. A significant correlation was found between active coping strategies and cortisol levels (response to stress). The findings suggest that blunted SAM stress reactivity and a rapid decrease in stress cortisol levels reflect traits that may enhance vulnerability to psychopathology in patients with PD.

Panic Disorder Comorbidity with Medical Conditions and Treatment Implications

Panic disorder (PD) is unique among the anxiety disorders in that panic symptoms are primarily of a physical nature. Consequently, comorbidity with medical illness is significant. This review examines the association between PD and medical illness. We identify shared pathophysiological and psychological correlates and illustrate how physiological activation in panic sufferers underlies their symptom experience in the context of the fight-or-flight response and beyond a situation-specific response pattern. We then review evidence for bodily symptom perception accuracy in PD. Prevalence of comorbidity for PD and medical illness is presented, with a focus on respiratory and cardiovascular illness, irritable bowel syndrome, and diabetes, followed by an outline for potential pathways of a bidirectional association. We conclude by illustrating commonalities in mediating mechanistic pathways and moderating risk factors across medical illnesses, and we discuss implications for diagnosis and treatment of both types of conditions.

Adult Neurogenesis and Psychiatric Disorders

Psychiatric disorders continue to be among the most challenging disorders to diagnose and treat because there is no single genetic or anatomical locus that is causative for the disease. Current treatments are often blunt tools used to ameliorate the most severe symptoms, at the risk of disrupting functional neural systems. There is a critical need to develop new therapeutic strategies that can target circumscribed functional or anatomical domains of pathology. Adult hippocampal neurogenesis may be one such domain. Here, we review the evidence suggesting that adult hippocampal neurogenesis plays a role in emotional regulation and forms of learning and memory that include temporal and spatial memory encoding and context discrimination, and that its dysregulation is associated with psychiatric disorders, such as affective disorders, schizophrenia, and drug addiction. Further, adult neurogenesis has proven to be an effective model to investigate basic processes of neuronal development and converging evidence suggests that aberrant neural development may be an etiological factor, even in late-onset diseases. Constitutive neurogenesis in the hippocampus of the mature brain reflects large-scale plasticity unique to this region and could be a potential hub for modulation of a subset of cognitive and affective behaviors that are affected by multiple psychiatric disorders.

Effect of combined cognitive-behavioural therapy and endurance training on cortisol and salivary alpha-amylase in panic disorder

Current data point to an alteration of both the hypothalamo-pituitary-adrenal (HPA)-system and the peripheral transmission of catecholamines in anxiety disorders. There is also some evidence for the effect of several components of cognitive-behavioural interventions such as coping and control and for an effect of exercise training on the neuroendocrine stress response in healthy subjects as well as patients suffering from distinct (mental) disorders. This double-blind, controlled study investigated the effect of cognitive-behavioural therapy (CBT) in combination with either high-level endurance training or low-level exercise on salivary cortisol (sC) and on levels of salivary alpha-amylase (sAA) in patients suffering from panic disorder (PD) with and without agoraphobia. In comparison to the low-level exercise condition, there were significantly lower sC-levels in the experimental group performing high-level endurance training at a 7-month follow-up. In contrast, there were no group differences in sAA levels during the study period. In this trial, we found evidence for a decelerated effect of endurance-training on HPA-system's functioning in PD. Further studies addressing the alteration of sAA levels in this population might investigate physical exercise different in intensity and duration.

Etiology, triggers and neurochemical circuits associated with unexpected, expected, and laboratory-induced panic attacks

Panic disorder (PD) is a severe anxiety disorder that is characterized by recurrent panic attacks (PA), which can be unexpected (uPA, i.e., no clear identifiable trigger) or expected (ePA). Panic typically involves an abrupt feeling of catastrophic fear or distress accompanied by physiological symptoms such as palpitations, racing heart, thermal sensations, and sweating. Recurrent uPA and ePA can also lead to agoraphobia, where subjects with PD avoid situations that were associated with PA. Here we will review recent developments in our understanding of PD, which includes discussions on: symptoms and signs associated with uPA and ePAs; Diagnosis of PD and the new DSM-V; biological etiology such as heritability and gene×environment and gene×hormonal development interactions; comparisons between laboratory and naturally occurring uPAs and ePAs; neurochemical systems that are associated with clinical PAs (e.g. gene associations; targets for triggering or treating PAs), adaptive fear and panic response concepts in the context of new NIH RDoc approach; and finally strengths and weaknesses of translational animal models of adaptive and pathological panic states.

Changes in cardiovascular function after venlafaxine but not pregabalin in healthy volunteers: a double-blind, placebo-controlled study of orthostatic challenge, blood pressure and heart rate

It is generally thought that venlafaxine raises blood pressure at higher doses; however, some studies have found no effect or a decrease in blood pressure. The aim of this study was to evaluate the cardiovascular (CV) effects of 3 weeks of dosing with venlafaxine, pregabalin and placebo on young healthy adults. Fifty-four participants, of mean age 23.1 years (sd 4.68), 29 male, were randomised into three parallel groups. Each group received one of the three drugs, dosed incrementally over a 3-week period to reach daily doses of 150 mg/day venlafaxine and 200 mg/day pregabalin. Blood pressure sphygmomanometer measurements, heart rate measurements, and orthostatic challenges recorded continuously beat-to-beat were performed weekly over this period and 5 days after treatment cessation. Results showed resting systolic blood pressure (SBP) and resting and standing diastolic blood pressure (DBP) and heart rate (HR) were significantly raised by venlafaxine compared with the pregabalin and placebo groups. SBP drop on standing was larger, the resulting overshoot was smaller, and recovery was slower on venlafaxine. HR recovery was significantly impaired by venlafaxine. CV changes were observed after only 1 week of dosing at 112.5 mg/day. These effects of venlafaxine are likely to be due to its action of noradrenergic reuptake inhibition.

Salivary alpha-amylase and cortisol responsiveness following electrical stimulation stress in obsessive-compulsive disorder patients

Salivary α-amylase (sAA) serves as a marker of sympathoadrenal medullary system (SAM) activity. Salivary AA has not been extensively studied in obsessive-compulsive disorder (OCD) patients. In the current study, 45 OCD patients and 75 healthy volunteers were assessed with the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Profile of Mood State (POMS), and the State-Trait Anxiety Inventory (STAI). Measures of heart rate variability (HRV), sAA, and salivary cortisol were also obtained following the application of electrical stimulation stress. The Y-BOCS and POMS Tension-Anxiety, Depression-Dejection, Anger-Hostility, Fatigue, and Confusion scores were significantly increased in patients with OCD compared with healthy controls. In contrast, Vigor scores were significantly decreased in patients with OCD relative to scores in healthy controls. There was no difference in HRV between the patients and the controls. Salivary AA levels in female and male OCD patients were significantly elevated relative to controls both before and after electrical stimulation. In contrast, there were no differences in salivary cortisol levels between OCD patients and controls. The elevated secretion of sAA before and after stimulation may suggest an increased responsiveness to novel and uncontrollable situations in patients with OCD. An increase in sAA might be a characteristic change of OCD.

Is salivary alpha-amylase an indicator of autonomic nervous system dysregulations in mental disorders?--a review of preliminary findings and the interactions with cortisol

During recent years, a growing interest emerged in using salivary alpha-amylase (sAA) as a non-invasive, surrogate marker for sympathetic activity. Numerous studies applying stress protocols have demonstrated that sAA is highly sensitive to stress-related changes (in healthy subjects). Additionally, it was suggested that sAA might moreover serve as an index for pathological dysregulation of the autonomic nervous system (ANS) in patients showing psychopathology. Since then, a small but growing literature investigated sAA in patients with mental disorders. This review aims to give an overview of preliminary findings in this field of research. The results of n=15 studies are described in detail and implications for further research are discussed. Although the number of studies and the samples examined were rather small, changes in sAA, reflecting adrenergic dysregulation, could be demonstrated in psychopathology, especially in anxiety-related disorders. This field of research is still in its early stages. However, the studies included in this review revealed first evidence that the employment of sAA, as an indicator of ANS dysregulation in mental disorders, is promising.

Panic disorder and subthreshold panic in the light of comorbidity: a follow-up study

Especially in the presence of agoraphobia and comorbid conditions, panic disorder causes significant impairment in life quality. Although there are several studies about epidemiology and clinical features, subthreshold symptoms and courses of comorbidity have not been studied sufficiently in panic disorder. The current study assessed the courses of panic disorder and subthreshold panic symptoms in consideration of the major and subthreshold comorbid conditions. Patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-diagnosed panic disorder were assessed using the panic disorder follow-up questionnaire, Panic and Agoraphobia Scale, Hamilton Depression Rating Scale, and State-Trait Anxiety Inventory. Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders was used to determine comorbidity, and all participants were received to 1-year follow-up. Comorbidity assessment showed that the threshold comorbidity decreased, while the subthreshold comorbidity increased at 1-year follow-up. Panic disorder symptom severity was decreased, but subthreshold panic symptoms continued to be present within the course of the illness. Presence of agoraphobia and duration of disease were significantly related with higher Panic and Agoraphobia Scale scores in the second assessment, and these relationships were independent from the treatment process. Even if the comorbidity and the severity of panic decrease with treatment, subthreshold panic and comorbid symptoms may still resist in panic disorder.

A review of orthostatic blood pressure regulation and its association with mood and cognition

AIMS

This paper will review literature that examines the psychological and neuropsychological correlates of orthostatic blood pressure regulation.

RESULTS

The pattern of change in systolic blood pressure in response to the shift from supine to upright posture reflects the adequacy of orthostatic regulation. Orthostatic integrity involves the skeletal muscle pump, neurovascular compensation, neurohumoral effects and cerebral flow regulation. Various physiological states and disease conditions may disrupt these mechanisms. Clinical and subclinical orthostatic hypotension has been associated with impaired cognitive function, decreased effort, reduced motivation and increased hopelessness as well as dementia, diabetes mellitus, and Parkinson's disease. Furthermore, inadequate blood pressure regulation in response to orthostasis has been linked to increased depression and anxiety as well as to intergenerational behavioral sequalae.

CONCLUSIONS

Identifying possible causes and consequences of subclinical and clinical OH are critical in improving quality of life for both children and older adults.

Neurological soft signs in schizophrenia: a meta-analysis

BACKGROUND

Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups.

METHOD

A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms.

RESULTS

A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%-10% of their variance with NSS.

CONCLUSIONS

NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness.

Goal representations and motivational drive in schizophrenia: the role of prefrontal-striatal interactions

The past several years have seen a resurgence of interest in understanding the psychological and neural bases of what are often referred to as "negative symptoms" in schizophrenia. These aspects of schizophrenia include constructs such as asociality, avolition (a reduction in the motivation to initiate or persist in goal-directed behavior), and anhedonia (a reduction in the ability to experience pleasure). We believe that these dimensions of impairment in individuals with schizophrenia reflect difficulties using internal representations of emotional experiences, previous rewards, and motivational goals to drive current and future behavior in a way that would allow them to obtain desired outcomes, a deficit that has major clinical significance in terms of functional capacity. In this article, we review the major components of the systems that link experienced and anticipated rewards with motivated behavior that could potentially be impaired in schizophrenia. We conclude that the existing evidence suggests relatively intact hedonics in schizophrenia, but impairments in some aspects of reinforcement learning, reward prediction, and prediction error processing, consistent with an impairment in "wanting." As of yet, there is only indirect evidence of impairment in anterior cingulate and orbital frontal function that may support value and effort computations. However, there are intriguing hints that individuals with schizophrenia may not be able to use reward information to modulate cognitive control and dorsolateral prefrontal cortex function, suggesting a potentially important role for cortical-striatal interactions in mediating impairment in motivated and goal-directed behavior in schizophrenia.

Heart rate and blood pressure changes during autonomic nervous system challenge in panic disorder patients

OBJECTIVE

To test the hypothesis that panic disorder (PD) patients have a heightened or deregulated autonomic nervous system at rest and during autonomic challenge compared with healthy controls (HC); and to test a second hypothesis that severity of illness differentiates patients'; sympathovagal balance both at rest and during orthostatic challenge.

METHODS

Spectral analysis of heart rate (HR) and blood pressure was performed on 30 PD and 10 HC participants during an orthostatic challenge (head-up tilt).

RESULTS

PD patients presented higher HR (p < .001), lower heart rate variability (HRV) (p < .015), higher mean diastolic blood pressure (p < .006), higher low-frequency component of HR (p < .001), and a higher ratio of low-frequency to high-frequency component of HR (LF/HF) (p < .022) than HC at baseline. During tilt, PD patients responded with higher HR (p < .039), lower HRV (p < .043), increased mean diastolic blood pressure (p < .028), and a mild increase in LF/HF, whereas controls responded with a five-fold increase in LF/HF (p < .022). Patients with higher illness severity ratings (Clinical Global Impression Scale) showed higher HR (p < .002), lower HRV (p < .026), and a lower total power of systolic blood pressure (p < .02) compared with less ill patients.

CONCLUSION

These findings demonstrate a consistently higher or deregulated autonomic arousal in PD patients at rest and during orthostatic challenge compared with HC. These data also reveal a possible association between the level of anxiety illness severity and sympathovagal balance, which may imply greater cardiac risk.

Imaging genetic liability to schizophrenia: systematic review of FMRI studies of patients' nonpsychotic relatives

There is a growing literature on brain activity in the nonpsychotic first-degree relatives of patients with schizophrenia as measured using functional imaging. This systematic review examined 20 studies in 4 domains of cognition, including cognitive control (7 samples), working memory (5 samples), long-term memory (4 samples), and language (4 samples). While the literature was widely divergent, these studies did consistently find activation differences between patients' relatives and controls. The most consistent increases in activation within hemisphere were found in right ventral prefrontal cortex (PFC) and right parietal cortex. Abnormal activity, defined as significant increases or decreases in activation relative to controls irrespective of hemisphere, was found in about two-thirds of contrasts in the cerebellum, dorsal prefrontal, lateral temporal, and parietal cortices, and thalamus, with basal ganglia and ventral PFC showing abnormalities in approximately half of those contrasts. Anterior cingulate was generally spared in patients' relatives. The diversity of findings in studies of patients' relatives may derive from differences between the cognitive demands across studies. We identify avenues for building a more accurate and cumulative literature, including symmetrical inclusion criteria for relatives and controls, recording in-scanner responses, using both a priori and whole-brain tests, explicitly reporting threshold values, reporting main effects of task, reporting effect sizes, and quantifying the risk of false negatives. While functional imaging in the relatives of schizophrenia patients remains a promising methodology for understanding the impact of the unexpressed genetic liability to schizophrenia, no single region or mechanism of abnormalities has yet emerged.

Salivary alpha-amylase as a non-invasive biomarker for the sympathetic nervous system: current state of research

Development of new biomarkers is a constantly evolving field of research endeavor in psychoneuroendocrinology. Salivary biomarkers have received special attention since they are readily accessible and easily obtained. Salivary alpha-amylase (sAA) has been proposed as a sensitive biomarker for stress-related changes in the body that reflect the activity of the sympathetic nervous system (SNS), and a growing body of research is accumulating to support the validity and reliability of this parameter. However, questions remain to be answered before sAA can be accepted as an index of SNS activity. This review describes sAA as an emerging biomarker for stress and provides an overview of the current literature on stress-related alterations in sAA. It critically discusses how sAA might reflect changes in the autonomic nervous system. Finally, current and future fields for the application of sAA measurement are outlined.

What we know: findings that every theory of schizophrenia should explain

The article summarizes the process used to distill schizophrenia science into 22 facts. These facts consist of 6 basic facts, 3 etiological facts, 6 pharmacological and treatment facts, 5 pathology facts, and 2 behavioral facts that were critically reviewed by the scholarly community through a special initiative in cooperation with the Schizophrenia Research Forum. A subset of 10 of these facts was selected to form a common set of findings to be explained from the different theoretical perspectives included in this special section of Schizophrenia Bulletin. The rationale for this exercise is to distinguish more precisely the areas of agreement and disagreement between theories of schizophrenia and to highlight where more thought and data can make the greatest impact for understanding this disease.

The dopamine hypothesis of schizophrenia: version III--the final common pathway

The dopamine hypothesis of schizophrenia has been one of the most enduring ideas in psychiatry. Initially, the emphasis was on a role of hyperdopaminergia in the etiology of schizophrenia (version I), but it was subsequently reconceptualized to specify subcortical hyperdopaminergia with prefrontal hypodopaminergia (version II). However, these hypotheses focused too narrowly on dopamine itself, conflated psychosis and schizophrenia, and predated advances in the genetics, molecular biology, and imaging research in schizophrenia. Since version II, there have been over 6700 articles about dopamine and schizophrenia. We selectively review these data to provide an overview of the 5 critical streams of new evidence: neurochemical imaging studies, genetic evidence, findings on environmental risk factors, research into the extended phenotype, and animal studies. We synthesize this evidence into a new dopamine hypothesis of schizophrenia-version III: the final common pathway. This hypothesis seeks to be comprehensive in providing a framework that links risk factors, including pregnancy and obstetric complications, stress and trauma, drug use, and genes, to increased presynaptic striatal dopaminergic function. It explains how a complex array of pathological, positron emission tomography, magnetic resonance imaging, and other findings, such as frontotemporal structural and functional abnormalities and cognitive impairments, may converge neurochemically to cause psychosis through aberrant salience and lead to a diagnosis of schizophrenia. The hypothesis has one major implication for treatment approaches. Current treatments are acting downstream of the critical neurotransmitter abnormality. Future drug development and research into etiopathogenesis should focus on identifying and manipulating the upstream factors that converge on the dopaminergic funnel point.

Mechanisms of efficacy of CBT for Cambodian refugees with PTSD: improvement in emotion regulation and orthostatic blood pressure response

Based on the results of a randomized controlled trial, we examined a model of the mechanisms of efficacy of culturally adapted cognitive-behavior therapy (CBT) for Cambodian refugees with pharmacology-resistant posttraumatic stress disorder (PTSD) and comordid orthostatic panic attacks (PAs). Twelve patients were in the initial treatment condition, 12 in the delayed treatment condition. The patients randomized to CBT had much greater improvement than patients in the waitlist condition on all psychometric measures and on one physiological measure-the systolic blood pressure response to orthostasis (d = 1.31)-as evaluated by repeated-measures MANOVA and planned contrasts. After receiving CBT, the Delayed Treatment Group improved on all measures, including the systolic blood pressure response to orthostasis. The CBT treatment's reduction of PTSD severity was significantly mediated by improvement in orthostatic panic and emotion regulation ability. The current study supports our model of the generation of PTSD in the Cambodian population, and suggests a key role of decreased vagal tone in the generation of orthostatic panic and PTSD in this population. It also suggests that vagal tone is involved in emotion regulation, and that both vagal tone and emotion regulation improve across treatment.

The ventro-medial prefrontal cortex: a major link between the autonomic nervous system, regulation of emotion, and stress reactivity?

Recent progress in neuroscience revealed diverse regions of the CNS which moderate autonomic and affective responses. The ventro-medial prefrontal cortex (vmPFC) plays a key role in these regulations. There is evidence that vmPFC activity is associated with cardiovascular changes during a motor task that are mediated by parasympathetic activity. Moreover, vmPFC activity makes important contributions to regulations of affective and stressful situations.This review selectively summarizes literature in which vmPFC activation was studied in healthy subjects as well as in patients with affective disorders. The reviewed literature suggests that vmPFC activity plays a pivotal role in biopsychosocial processes of disease. Activity in the vmPFC might link affective disorders, stressful environmental conditions, and immune function.

Major depressive disorder and comorbid cardiac disease: is there a depressive subtype with greater cardiovascular morbidity? Results from the STAR*D study

The authors conducted exploratory analyses to determine whether specific symptoms of major depressive disorder (MDD) are associated with cardiac disease in 4,041 outpatients at baseline in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. MDD was diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; depressive symptoms were evaluated with the 30-item Inventory of Depressive Symptomatology, Clinician-Rated; and cardiac disease, with the Cumulative Illness Rating Scale. After adjustments for gender, age, ethnicity, education, and employment status, sympathetic arousal and early-morning insomnia were significantly associated with cardiac disease. Prospective studies are warranted to confirm these results.

Blood B-type natriuretic peptide level increases in patients who complain shortness of breath and chest pain in the course of panic attack

OBJECTIVE

Blood pro-B-type natriuretic peptide (pro-BNP) level increases in case of myocardial ischemia and myocardial volume or pressure overload. The aim of this study is to measure changes in blood pro-BNP level during the course of panic attack with symptoms of chest pain and/or dyspnea.

METHODS

Patients who were admitted to the emergency room with panic attack have been regarded as the study group. Blood pro-BNP level has been measured during follow-up of the patients upon admission and 2h later.

RESULTS

Systolic and diastolic blood pressure and pulse rate were significantly decreased (p<0.0001) during follow-up of the patients (ages between 18 and 43 years; mean 26+/-6.13 years). Paradoxically, blood pro-BNP level of patients was significantly increased during the same period (52.86+/-59.73 versus 50.97+/-57.42 U/L; p<0.0001).

CONCLUSION

Blood pro-BNP level has increased among patients who have complained chest pain and/or dyspnea as symptoms of panic attack. It is thought that chest pain and dyspnea in the course of panic attack may not be purely psychological.

Cardiovascular reactivity to mental stress is not affected by alpha2-adrenoreceptor activation or inhibition

RATIONALE

It has been postulated that cardiovascular reactivity to mental stress varies with tonic central sympathetic nervous system activity, but pharmacological evidence is missing.

OBJECTIVE

To test whether modulation of central sympathetic nervous system activity by alpha2-adrenergic agonism and antagonism affects cardiovascular reactivity to mental stress.

MATERIALS AND METHODS

On three five-stepped dose/concentration-response study days, 12 healthy male volunteers received intravenous infusions of dexmedetomidine (alpha2-agonist, target plasma concentrations: 0.04-0.32 ng/ml), yohimbine (alpha2-antagonist, doses: 0.016-0.125 mg/kg), and placebo, respectively. During each dose step, subjects performed a 5-Choice Reaction Time Task (CRTT) and a Paced Auditory Serial Addition Task (PASAT) to induce moderate mental stress. Prestress baseline, as well as stress-induced responses of heart rate, and noninvasive finger arterial blood pressure (Finapres) were assessed.

RESULTS

Prestress baseline heart rate and blood pressure decreased with increasing doses of dexmedetomidine and increased with increasing doses of yohimbine. However, dexmedetomidine and yohimbine did not affect stress-induced heart-rate and blood-pressure changes.

CONCLUSIONS

Cardiovascular reactivity to mental stress is not related to pharmacologically manipulated tonic central sympathetic nervous system activity by alpha2-adrenergic agonists and antagonists. These results do not support the assumption that cardiovascular reactivity is an index of tonic central sympathetic nervous system activity.

Single-unit analysis of sympathetic nervous discharges in patients with panic disorder

Patients with panic disorder are at increased cardiac risk. While the mechanisms responsible remain unknown, activation of the sympathetic nervous system may be implicated. Using isotope dilution methodology, investigations of whole-body and regional sympathetic nervous activity have failed to show any differences between patients with panic disorder and healthy subjects. Using direct recording of single unit efferent sympathetic vasoconstrictor nerve activity by microneurography we examined sympathetic nervous function in patients with panic disorder more precisely than previously reported. The activity of multiunit and single unit vasoconstrictor sympathetic nerves was recorded at rest at the level of the peroneal nerve in 10 patients diagnosed with panic disorder and in nine matched healthy volunteers. Multiunit sympathetic activity was not different between the two groups (26+/-3 bursts min-1 in patients with panic disorder and 28+/-3 bursts min-1 in controls). The firing frequency of single unit vasoconstrictor neurones was also similar between the two groups (0.38+/-0.09 versus 0.22+/-0.03 Hz). However, the probability of firing during a sympathetic burst was higher in patients with panic disorder compared with healthy controls (45+/-5%versus 32+/-3%, P<0.05). When only the neural bursts during which the vasoconstrictor neurone was active were considered, we found that in patients with panic disorder the neurones tended to fire more often in a 'multiple spike' pattern than in the controls (i.e. the probability of the neurone firing twice was 25+/-3% in patients with panic disorder compared with 14+/-3% in controls). Quantification from single vasoconstrictor unit recording provides evidence of a disturbed sympathetic firing pattern in patients with panic disorder.

Emotion regulation in action: emotional reactivity in experiential avoidance

The present study examined the relationship between emotional reactivity (self-report and physiological reactivity) to pleasant, unpleasant, and neutral emotion-eliciting stimuli and experiential avoidance (EA). Sixty-two participants were separated into high and low experiential avoiders. Results indicated that high EA participants reported greater emotional experience to both unpleasant and pleasant stimuli compared to low EA participants. In contrast to their heightened reports of emotion, high EA participants displayed attenuated heart rate reactivity to the unpleasant stimuli relative to the low EA participants. These findings are interpreted as reflecting an emotion regulation attempt by high EA participants when confronted with unpleasant emotionally-evocative stimuli.

Autonomic Dysfunctions in Patients with Anxiety Throughout Therapy

Abstract Patterns of autonomic cardiovascular regulation were studied in patients with anxiety throughout the course of an intensive inpatient rehabilitation therapy at rest, and in response to an anxiety provocation, in order to measure reactivity changes. Patients had to meet the ICD-10 criteria: F40.0 (agoraphobia), F40.00 (agoraphobia without panic attacks), F40.01 (agoraphobia with panic attacks), or F41 (panic disorder). Thirty-eight patients (13 males, 25 females) were examined after recruitment (T1) and at the end of treatment (T2). Each laboratory session consisted of a resting baseline (5min) and two stress tests of 8min (presentation of word pairs with either neutral or with anxiety-related content). A continuous assessment of ECG, blood pressure, breathing pattern, and thoracic impedance allowed the calculation of heart rate variability (power spectra), baroreflex sensitivity, stroke volume, vascular compliance, and total peripheral resistance. In general, therapy had little impact on the parameters of autonomic cardiovascular regulation, neither on resting level nor on reactivity. Diminished baroreflex sensitivity values in our patients with anxiety were observed; in particular, 15% of the patients had values below 3ms/mmHg, which indicates an increased risk for cardiovascular mortality. Low baroreflex sensitivity in this group goes along with further changes within the cardiovascular system (higher heart rate, diminished heart rate variability, lower stroke volume, higher vascular compliance). This general effect describes altered sympathetic/parasympathetic balance and may be the consequence of illness-related changes in behavior. Our results suggest that a careful cardiovascular examination of patients with anxiety will detect patients with clinically significant cardiovascular alterations. This might lead to a more complex intervention in these patients including, for example, exercise training.