Regulation of the hypothalamic-pituitary-adrenocortical system in patients with panic disorder

"Close your eyes and relax": the role of hypnosis in reducing anxiety, and its implications for the prevention of cardiovascular diseases

Anxiety is the most common form of mental health disorder, affecting millions of people worldwide. Psychosocial interventions such as mindfulness and cognitive behavioral therapy (CBT) have been suggested as an effective treatment in the management of general anxiety and anxiety disorders, with emerging evidence also suggesting the effectiveness of hypnosis. Moreover, anxiety has shown to be linked to the onset and development of several cardiovascular diseases (CVD), which are the leading cause of global death. In this paper, we review the current literature to examine the role that anxiety has on the onset and development of CVD and summarize the current knowledge on the role that hypnosis and hypnotherapy have in reducing anxiety, also explaining how this can impact the cardiovascular system and the prevention of CVD. Review of the evidence suggests that hypnosis and hypnotherapy are effective in treating anxiety and may positively affect the heart and the cardiovascular system, reducing sympathetic activation and increasing parasympathetic tone, potentially preventing the onset of CVD related to increased sympathetic activation. However, further studies are required to further understand how hypnosis and hypnotherapy affect the cardiovascular system through investigation of the neurophysiological components of the hypnotic state and of the mind-body relationship. Healthcare systems should embed mental health screening in patients at risk of developing CVD as part of the clinical pathway and consider the role that hypnosis and hypnotherapy may play in the management of CVD.

A New Player in the Game: Can Exergame Be of Support in the Management of Atrial Fibrillation?

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia, currently affecting 2-3% of the world's population. Traditional exercise and physical activity interventions have been successfully implemented in the management of AF, with the aim of improving patients' quality of life and their exercise capacity, as well as reducing their mortality rate. Currently, new technology-mediated approaches to exercise, defined as exergame, have been shown to be successful in the delivery of exercise home-based interventions in patients with cardiovascular diseases. However, data on the effects of exergame on AF are not yet available. In this paper, we summarise the current literature on the role of traditional exercise in AF and how it affects the pathophysiology of this condition. We also review the current literature on exergame and its employment in cardiac rehabilitation and suggest its potential role in the management of AF patients. A review of the evidence suggests that traditional exercise (of light-to-moderate intensity) is beneficial in patients with AF. Additionally, exergame seems to be a promising approach for delivering exercise interventions in patients with cardiovascular diseases. Exergame may be a promising tool to improve the quality of life and exercise capacity in patients with AF, with the additional advantage of being remotely delivered, and the potential to increase patients' engagement. Proper guidelines are required to prescribe exergame interventions, considering the principles of traditional exercise prescription and applying them to this new e-health approach. Further studies are needed to validate the use of exergame in patients with AF.

A human-relevant mixture of endocrine disrupting chemicals induces changes in hippocampal DNA methylation correlating with hyperactive behavior in male mice

Humans are ubiquitously exposed to endocrine disrupting chemicals (EDCs), substances that interfere with endogenous hormonal signaling. Exposure during early development is of particular concern due to the programming role of hormones during this period. A previous epidemiological study has shown association between prenatal co-exposure to 8 EDCs (Mixture N1) and language delay in children, suggesting an effect of this mixture on neurodevelopment. Furthermore, in utero exposure to Mixture N1 altered gene expression and behavior in adult mice. In this study, we investigated whether epigenetic mechanisms could underlie the long term effects of Mixture N1 on gene expression and behavior. To this end, we analyzed DNA methylation at regulatory regions of genes whose expression was affected by Mixture N1 in the hippocampus of in utero exposed mice using bisulfite-pyrosequencing. We show that Mixture N1 decreases DNA methylation in males at three genes that are part of the hypothalamus-pituitary-adrenal (HPA) axis: Nr3c1, Nr3c2, and Crhr1, coding for the glucocorticoid receptor, the mineralocorticoid receptor, and the corticotropin releasing hormone receptor 1, respectively. Furthermore, we show that the decrease in Nr3c1 methylation correlates with increased gene expression, and that Nr3c1, Nr3c2, and Crhr1 methylation correlates with hyperactivity and reduction in social behavior. These findings indicate that an EDC mixture corresponding to a human exposure scenario induces epigenetic changes, and thus programming effects, on the HPA axis that are reflected in the behavioral phenotypes of the adult male offspring.

Rearing in an Enriched Environment Ameliorates the ADHD-like Behaviors of Lister Hooded Rats While Suppressing Neuronal Activities in the Medial Prefrontal Cortex

In addition to genetic factors, environmental factors play a role in the pathogenesis of attention deficit/hyperactivity disorder (ADHD). This study used Lister hooded rats (LHRs) as ADHD model animals to evaluate the effects of environmental factors. Male LHR pups were kept in four rearing conditions from postnatal day 23 (4 rats in a standard cage; 12 rats in a large flat cage; and 4 or 12 rats in an enriched environment [EE]) until 9 weeks of age. EE rearing but not rearing in a large flat cage decreased the activity of LHRs in the open field test that was conducted for 7 consecutive days. In the drop test, most rats reared in an EE remained on a disk at a height, whereas most rats reared in a standard cage fell off. RNA sequencing revealed that the immediate-early gene expression in the medial prefrontal cortex of LHRs reared in an EE was reduced. cFos-expressing neurons were reduced in number in LHRs reared in an EE. These results suggest that growing in an EE improves ADHD-like behaviors and that said improvement is due to the suppression of neuronal activity in the mPFC.

Cortisol response under low intensity exercise during cognitive-behavioral therapy is associated with therapeutic outcome in panic disorder–an exploratory study

Objectives

Patients with Panic Disorder (PD) show an abnormal stress-induced functioning of the Hypothalamic-Pituitary-adrenal (HPA)-axis. Different protocols for stress induction are of rather low relevance for the psychotherapeutic treatment. In practice, interoceptive exposure is often realized as Low Intensity Exercise (LIE), as compared to an incremental cycle exercise test to exhaustion. Currently, it is not known, whether LIE displays an effective interoceptive stressor 1.) leading to a significant anxiety induction; 2.) a comparable HPA- and Sympathetic-Adreno-Medullar (SAM)-axis response in both patients and healthy controls; 3.) stress responses under LIE are associated with treatment outcomes.

Patients and methods

N = 20 patients with PD and n = 20 healthy controls were exposed to ten minutes of LIE on an exercise bike. LIE was applied as part of the interoceptive exposure, during an intensive Cognitive-Behavioral Therapy (CBT) in a day clinic. Heart rate was monitored and salivary cortisol samples collected. Before and after the LIE, state anxiety/ arousal were assessed. In order to evaluate psychopathology, the Panic and Agoraphobia Scale, Mobility Inventory, Agoraphobic Cognitions Questionnaire and Body Sensations Questionnaire were applied, before (T1) and after five weeks (T2) of an intensive CBT.

Results

LIE led to a significant and similar heart rate increase in both groups. Cortisol decreased over time in both groups, especially in male patients. A higher psychopathology before, and after CBT, was associated with a significantly lower cortisol response under LIE.

Conclusions

In the present study, LIE led to a divergent stress response: while there was a significant heart rate increase, cortisol decreased over time, particularly in male patients. A lower reactivity of the HPA-axis seems to be associated with a lower treatment outcome, which may affect extinction based learning. The findings suggest, that interoceptive stimuli should be designed carefully in order to be potent stressors.

Associations of DNA methylation of HPA axis-related genes and neuroendocrine abnormalities in panic disorder

OBJECTIVE

The purpose of this study was to investigate the role of aberrant DNA methylation of hypothalamic-pituitary-adrenal (HPA) axis-related genes (CRHR1, CRHR2, CRH, FKBP5, HSP90AA1, NR3C1, and POMC) in panic disorder (PD) development. We investigated the correlation among gene methylation levels, adrenocorticotropic hormone (ACTH), cortisol, and PD severity in patients.

METHODS

We compared the methylation levels of HPA axis-related genes between 178 patients with PD and 184 healthy controls using MethylTarget. We then measured ACTH and cortisol levels using chemiluminescence. Disease severity was assessed using the Panic Disorder Severity Scale.

RESULTS

Compared with healthy controls, patients with PD displayed significantly higher levels of ACTH and cortisol, and significantly reduced methylation levels of CRHR1, FKBP5, HSP90AA1, and NR3C1 after correcting for multiple testing using the false discovery method. A significant positive correlation was observed between the methylation of CRHR1, CRHR2, and NR3C1 and ACTH levels in patients with PD, and methylation levels of CRHR1 and NR3C1 were significantly positively related to cortisol levels. In addition, a negative correlation was observed between PD severity and the methylation of CRH, CRHR1, CRHR2, and HSP90AA1.

CONCLUSION

Aberrant methylation of HPA axis-related genes may predict PD development and impact ACTH and cortisol levels.

Osmotic Stress Uncovers Correlations and Dissociations Between Larval Zebrafish Anxiety Endophenotypes

Larval zebrafish are often used to model anxiety disorders. However, since it is impossible to recapitulate the full complexity and heterogeneity of anxiety in this model, examining component endophenotypes is key to dissecting the mechanisms underlying anxiety. While individual anxiety endophenotypes have been examined in zebrafish, an understanding of the relationships between them is still lacking. Here, we investigate the effects of osmotic stress on a range of anxiety endophenotypes such as thigmotaxis, dark avoidance, light-dark transitions, sleep, night startle, and locomotion. We also report a novel assay for stress-induced anorexia that extends and improves on previously reported food intake quantification methods. We show that acute <30 min osmotic stress decreases feeding but has no effect on dark avoidance. Further, acute osmotic stress dose-dependently increases thigmotaxis and freezing in a light/dark choice condition, but not uniform light environmental context. Prolonged >2 h osmotic stress has similar suppressive effects on feeding while also significantly increasing dark avoidance and sleep, with weaker effects on thigmotaxis and freezing. Notably, the correlations between anxiety endophenotypes were dependent on both salt and dark exposure, with increased dissociations at higher stressor intensities. Our results demonstrate context-dependent effects of osmotic stress on diverse anxiety endophenotypes, and highlight the importance of examining multiple endophenotypes in order to gain a more complete understanding of anxiety mechanisms.

Larval Zebrafish as a Model for Mechanistic Discovery in Mental Health

Animal models are essential for the discovery of mechanisms and treatments for neuropsychiatric disorders. However, complex mental health disorders such as depression and anxiety are difficult to fully recapitulate in these models. Borrowing from the field of psychiatric genetics, we reiterate the framework of 'endophenotypes' - biological or behavioral markers with cellular, molecular or genetic underpinnings - to reduce complex disorders into measurable behaviors that can be compared across organisms. Zebrafish are popular disease models due to the conserved genetic, physiological and anatomical pathways between zebrafish and humans. Adult zebrafish, which display more sophisticated behaviors and cognition, have long been used to model psychiatric disorders. However, larvae (up to 1 month old) are more numerous and also optically transparent, and hence are particularly suited for high-throughput screening and brain-wide neural circuit imaging. A number of behavioral assays have been developed to quantify neuropsychiatric phenomena in larval zebrafish. Here, we will review these assays and the current knowledge regarding the underlying mechanisms of their behavioral readouts. We will also discuss the existing evidence linking larval zebrafish behavior to specific human behavioral traits and how the endophenotype framework can be applied. Importantly, many of the endophenotypes we review do not solely define a diseased state but could manifest as a spectrum across the general population. As such, we make the case for larval zebrafish as a promising model for extending our understanding of population mental health, and for identifying novel therapeutics and interventions with broad impact.

Hippocampal interneurons are direct targets for circulating glucocorticoids

The hippocampus has become a significant target of stress research in recent years because of its role in cognitive functioning, neuropathology, and regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Despite the pervasive impact of stress on psychiatric and neurological disease, many of the circuit- and cell-dependent mechanisms giving rise to the limbic regulation of the stress response remain unknown. Hippocampal excitatory neurons generally express high levels of glucocorticoid receptors (GRs) and are therefore positioned to respond directly to serum glucocorticoids. These neurons are, in turn, regulated by neighboring interneurons, subtypes of which have been shown to respond to stress exposure. However, GR expression among hippocampal interneurons is not well characterized. To determine whether key interneuron populations are direct targets for glucocorticoid action, we used two transgenic mouse lines to label parvalbumin-positive (PV+) and somatostatin-positive (SST+) interneurons. GR immunostaining of labeled interneurons was characterized within the dorsal and ventral dentate hilus, dentate cell body layer, and CA1 and CA3 stratum oriens and stratum pyramidale. While nearly all hippocampal SST+ interneurons expressed GR across all regions, GR labeling of PV+ interneurons showed considerable subregion variability. The percentage of PV+, GR+ cells was highest in the CA3 stratum pyramidale and lowest in the CA1 stratum oriens, with other regions showing intermediate levels of expression. Together, these findings indicate that, under baseline conditions, hippocampal SST+ interneurons are a ubiquitous glucocorticoid target, while only distinct populations of PV+ interneurons are direct targets. This anatomical diversity suggests functional differences in the regulation of stress-dependent hippocampal responses.

Distinct Hypothalamic Paraventricular Nucleus Inputs to the Cingulate Cortex and Paraventricular Thalamic Nucleus Modulate Anxiety and Arousal

Insomnia and anxiety are two common clinical diseases that threaten people’s physical and mental health. Insomnia and anxiety may share some similar underlying neural circuit mechanisms in the brain. In this study, we combine techniques including chemo-fMRI, optogenetics, and chemogenetics to reveal that the glutamatergic neurons of the paraventricular hypothalamic nucleus (PVN) regulate both anxiety and arousal through two different downstream neural circuits. Optogenetic activation of the PVN-cingulate cortex (Cg) neural circuit triggers anxiety-like behaviors in mice without affecting the wakefulness, while optogenetic activation of the PVN-paraventricular thalamic nucleus (PVT) neural circuit promotes wakefulness in mice without affecting anxiety-like behaviors. Our research reveals that PVN is a key brain area for controlling anxiety and arousal behaviors. We also provide a neurological explanation for anxiety disorder and insomnia which may offer guidance for treatments including drugs or transcranial magnetic stimulation for the patients.

Hormonal responsiveness in the Trier Social Stress Test and the dexamethasone-corticotropin releasing hormone test in healthy individuals

A number of different laboratory procedures investigate the hormonal response in a standardized pharmacological challenge test (dexamethasone-corticotropin releasing hormone; DEX-CRH) or in a psychosocial stress induction on the hypothalamic-pituitary-adrenocortical axis by the Trier Social Stress Test (TSST). However, the magnitude of the response related to the different stressors and the interaction of the responsiveness between the two tests is still unclear. Fifty-two participants underwent both the DEX-CRH test and the TSST on two separate days. The cortisol and the plasma adrenocorticotropic hormone (ACTH) release were assessed before and after the stress tests. For a specification of the cortisol response to both conditions, subgroups of high- and low-cortisol responders to the TSST and the DEX-CRH test were formed. The healthy participants showed a substantial increase in the ACTH and the cortisol concentration after the two tests. This increase was 3 times greater in the TSST than the DEX-CRH test. High responders in both tests demonstrated a higher factor of the cortisol reactivity ratio (TSST/DEX-CRH test). Psychosocial stress as induced by the TSST was associated with a significantly greater increase in cortisol compared to the DEX-CRH test, even though the ACTH response displayed no differences. Our findings indicate an interaction of the hormonal responsiveness between the two tests with regard to the cortisol patterns.

The hypothalamus in anxiety disorders

Of all mental disorders, anxiety disorders are currently the strongest contributors to the global burden of disease, with 7.3% of the general population affected worldwide. The hypothalamus is crucial hub of a network of neural structures modulating fear conditioning and extinction and, as such, highly relevant to the pathophysiology of these conditions. Three hypothalamic systems have emerged as particularly relevant in this context. First, the oxytocin system is highly likely to be involved anxiety disorders and in particular in the cognitive and behavioral deficits pertaining to social anxiety disorder. Second, peripheral markers of the hypothalamic-pituitary-adrenal axis appear altered in patients with panic disorder and generalized anxiety disorder, which may denote aberrant functioning of their central corticotropin-releasing hormone system. Furthermore, cortisol seems to augment the effects of exposure therapy in patients with specific phobia. Third, the integrity of the hypothalamic-pituitary-thyroid axis is likely compromised in panic disorder. Further, cross-disciplinary research efforts are required to shed more light on how, exactly, these hypothalamic systems interact with the neural structures involved in fear conditioning and extinction, which should ultimately open up new avenues for the prevention and treatment of anxiety disorders.

Neuroinflammation-Associated Alterations of the Brain as Potential Neural Biomarkers in Anxiety Disorders

Stress-induced changes in the immune system, which lead to neuroinflammation and consequent brain alterations, have been suggested as possible neurobiological substrates of anxiety disorders, with previous literature predominantly focusing on panic disorder, agoraphobia, and generalized anxiety disorder, among the anxiety disorders. Anxiety disorders have frequently been associated with chronic stress, with chronically stressful situations being reported to precipitate the onset of anxiety disorders. Also, chronic stress has been reported to lead to hypothalamic–pituitary–adrenal axis and autonomic nervous system disruption, which may in turn induce systemic proinflammatory conditions. Preliminary evidence suggests anxiety disorders are also associated with increased inflammation. Systemic inflammation can access the brain, and enhance pro-inflammatory cytokine levels that have been shown to precipitate direct and indirect neurotoxic effects. Prefrontal and limbic structures are widely reported to be influenced by neuroinflammatory conditions. In concordance with these findings, various imaging studies on panic disorder, agoraphobia, and generalized anxiety disorder have reported alterations in structure, function, and connectivity of prefrontal and limbic structures. Further research is needed on the use of inflammatory markers and brain imaging in the early diagnosis of anxiety disorders, along with the possible efficacy of anti-inflammatory interventions on the prevention and treatment of anxiety disorders.

Association of ACE Gene Insertion/Deletion Polymorphism with Suicidal Attempt in an Iranian Population

Deregulation of the renin-angiotensin system (RAS) plays an important role in suicide. Angiotensin converting enzyme (ACE) gene is a key component in this system. The relationship between insertion/deletion (I/D) polymorphism of ACE gene with suicide attempt (SA) is controversial. According to previous studies, allele D in this polymorphism has been considered as a potential risk factor for suicide. However, no study has been conducted in Iran to investigate this matter. This case-control study has focused on investigating the association of ACE I/D polymorphism (rs1799752) with SA in an Iranian population. The frequency of genotypes was 14% for II, 55% for ID, and 31% for DD in the case group (100 persons), and 18% for II, 74% for ID, and 8% for DD in control group (100 persons). Results show there was a significant difference in the distribution of ACE I/D polymorphism genotypes in men with SA compared to controls, as well as in women with SA compared to controls. Also, there was a significant association between DD genotype and the risk of SA compared to II genotype as reference. The severity of depression was significantly different between DD and II genotypes in SA group. According to the results, we suggest that the presence of DD genotype is possibly associated with an increased risk of SA. Maybe part of that is related to severity of depression in DD genotypes carriers of ACE I/D polymorphism.

Psychosocial Stress Reactivity as Predictor of Operative Outcome in Lumbar Disc Surgery

BACKGROUND

A large proportion of the population suffers from chronic back pain. For optimal treatment, the question arises which patients would benefit from conservative therapy and for whom lumbar disc surgery is most appropriate. It seems reasonable to analyze the impact of paraclinical parameters on the operation outcome to identify patients who would benefit less from surgery or need special pre-/postoperative medical care.

MATERIALS AND METHODS

From March 2012 to July 2014, 32 patients were treated via microscopically supported interlaminar fenestration and discectomy at the Department of Neurosurgery, University Hospital Carl Gustav Carus Dresden. One day before the operation, a cortisol survey was made during the stress response of the Trier Social Stress Test. At the same time, a survey of relevant questionnaires was conducted by which the postoperative symptom experience was made operational and comparable with the evaluation of the same information thirty days afterwards.

RESULTS

It could be shown that there is a connection between cortisol reactivity and the pain burden following operations. Patients with a greater cortisol reaction under stress exposition partially experienced more intense postoperative pain than the patients with a lower cortisol reaction. However, this relationship could only be explained by single significant results, whereas further calculations could not produce any significance.

CONCLUSIONS

Cortisol reactivity seems to be associated with pain development. The inconsistent findings in empiricism as well as in this investigation are indicative of a complex association of postoperative pain and cortisol reactivity, which needs to be examined further.

Stress-induced pro- and anti-inflammatory cytokine concentrations in panic disorder patients

BACKGROUND

An attenuated responsivity of the hypothalamus-hypophysis-adrenal (HPA) axis upon challenge and an increased risk for cardiac events are relatively consistent findings in panic disorder (PD) patients. Due to cytokine-HPA interactions, an altered HPA-axis responsivity may be accompanied by altered cytokine concentrations. Immunological reactions under stress might be considered the missing link for explaining an increased cardiac risk. This study analyzed stress-induced cytokine levels in PD patients.

METHODS

A total of n = 32 PD patients and n = 32 healthy control individuals performed the Trier Social Test (TSST). Blood sample collection accompanied the TSST for the collection of cortisol and pro- (IL-6, TNF-α) and anti-inflammatory cytokines (IL-10). Established self-report questionnaires were handed out for the clinical characterization and the assessment of subjective levels of distress during testing. Repeated measures ANCOVA were conducted to evaluate main effects of time or group and time x group interaction effects. Additional ANCOVAS with disease severity as between-subjects factor (healthy, borderline, mild, moderate, severe) took global panic severity into account. Pearson correlation analyses were carried out to test for an association of panic specific symptoms and peak cytokine release.

RESULTS

The TSST resulted in a significantly increased secretion of cortisol, IL-6 and IL-10. The data analysis further revealed a significant time x group interaction effect for cortisol and IL-10. Compared to the healthy volunteers, the PD patients showed significantly higher baseline and challenged IL-10 concentrations but lower challenged cortisol concentrations. Mildly and moderately affected patients showed the highest levels of IL-10 compared to the healthy individuals. There were no differential secretion patterns of IL-6 and TNF-α between both groups in the course of the TSST. The peak IL-6 release was found to be significantly associated with global disease severity.

CONCLUSION

We found evidence for altered levels of cytokines with primarily anti-inflammatory properties in PD patients under baseline and a psychosocial stress condition. The results provide tentative evidence for a low-grade inflammatory process in PD patients, possibly representing a missing link factor between PD diagnosis and the increased risk for cardiac disease.

Stress hormone response to the DEX-CRH test and its relation to psychotherapy outcome in panic disorder patients with and without agoraphobia

This study tested whether the hormonal stress response to the DEX-CRH test may be predictive of the psychotherapy success for panic disorder (PD). Thirty-four patients diagnosed either with agoraphobia with PD or PD without agoraphobia were subjected to cognitive behavioural therapy (CBT). Patients (pre-therapy) and healthy volunteers were exposed to the DEX-CRH test. Blood samples were taken for cortisol and adrenocorticotropic hormone (ACTH) assessment. Established panic-specific questionnaires were handed out for the pre-therapy and post-therapy evaluation of disease severity (with reference to panic beliefs and agoraphobic cognitions, fear of bodily sensations, agoraphobic avoidance behaviour). Repeated measures ANCOVA were conducted for the analysis of the pre-therapy hormonal response, and Pearson's correlation analysis to test for associations with the psychotherapy outcome. Data analyses revealed large effect sizes for CBT in the clinical measures (η² ≥ 0.321), main effects of time for cortisol and ACTH with no differences between both groups, and significant associations between cortisol release and agoraphobic cognitions for the patients. PD diagnosis had no impact on the hormonal response. However, those patients with higher cortisol release showed less improvement after CBT (significantly for agoraphobic cognitions). Clinical implications of these findings are the prediction of the therapy success from a potential endocrine correlate whose persistency (if assessed repeatedly) during the treatment may predict (non-)response to the current treatment, possibly representing a decision support for a change in treatment to avoid the continuation of an inefficient treatment.

Post-dexamethasone serum copeptin corresponds to HPA axis responsiveness in human obesity

CONTEXT

Increased activities of the arginine-vasopressin (AVP) system and the hypothalamic-pituitary-adrenal (HPA) axis were shown to be associated with human obesity, but relationships between these systems in obesity remain unclear.

OBJECTIVES

To assess HPA axis responsiveness and its relation to serum concentrations of the AVP-surrogate copeptin in subjects with obesity (OB) in comparison to non-obesity controls (NOC).

METHODS

In a cross-sectional monocentric study, thirty-nine OB (f/m 25/14; age 36.5±10.0years; body mass index, BMI, 41.5±4.7kg/m²) were compared to twenty-two NOC (f/m 12/10; age 35.3±8.5years; BMI 23.1±2.4kg/m²), matched for age and sex. All individuals underwent the combined dexamethasone/CRH test.

MAIN OUTCOME MEASURES

Plasma ACTH and cortisol curve indicators derived from the dex/CRH test (post-CRH concentrations 30min after 100μg CRH; maximum concentration, MAX; area-under-the-curve, AUC; ACTH/cortisol ratios). Copeptin was assessed in 1500h samples of the dex/CRH test (after 1.5mg of oral dexamethasone, prior to CRH administration).

RESULTS

Copeptin serum concentrations were higher in OB (median [IQR]: OB 4.62 [2.60-5.88] vs. NOC 3.04 [2.52-4.29] pmol/l, P=0.04). Correspondingly, OB showed higher post-CRH cortisol concentrations (OB: 51.5 [25.9-159.3] vs. NOC: 28.6 [20.0-41.6] nmol/l, P=0.01) and a lower post-CRH ACTH/cortisol ratio (OB: 0.028 [0.016-0.053] vs. NOC: 0.048 [0.034-0.070] pmol/nmol, P<0.01). Serum copeptin was significantly associated with HPA responsiveness in OB (post-CRH ACTH: R=0.42, P<0.01), driven by OB men (post-CRH ACTH: R=0.76, P<0.01, post-CRH cortisol: R=0.64, P=0.02). All associations withstand adjustments for BMI and age.

CONCLUSIONS

The association between increased copeptin with ACTH and cortisol release suggests a potential mechanistic interaction of the AVP system with HPA activation in human obesity. The relation of copeptin and HPA responsiveness should be further validated in situations with pronounced HPA activation, such as depression or multiple sclerosis.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Salivary alpha-amylase response following repeated psychosocial stress in patients with panic disorder

BACKGROUND

This study examined autonomic responses (salivary alpha-amylase, sAA; heart rate, HR) to repeated psychosocial stress as a candidate mechanism linking autonomic hyper-arousal and sensitization to the occurrence of panic disorder (PD).

METHODS

Thirty-three patients with PD and 34 healthy controls were exposed to the Trier Social Stress Test (TSST) twice on consecutive days.

RESULTS

sAA changes were comparable between PD and controls on both testing days with overall decreasing sAA responses (delta) on day two. In contrast, HR delta increased on day two in both groups. This sensitization was driven by female controls while male PD showed most pronounced HR changes to the first TSST.

CONCLUSIONS

Overall, a general autonomic hyper-arousal in PD could not be confirmed. In contrast, sAA responses slightly habituated to repeated stress. Whether sAA findings mirror assumed habituation effects of repeated stress exposure on normalizing autonomic reactivity remains to be investigated in longitudinal studies.

Cortisol awakening response in drug-naïve panic disorder

BACKGROUND

It is unclear whether hypothalamic-pituitary-adrenal axis is involved in the pathophysiology of panic disorder (PD). The findings remain inconsistent. Cortisol awakening response (CAR) is a noninvasive biomarker of stress system activity. We designed the study to assess CAR in drug-naïve PD patients.

MATERIALS AND METHODS

We assessed CAR in 14 psychotropic drug-naïve outpatients with PD and 14 healthy controls. The severity of PD was assessed with Panic and Agoraphobia Scale. The severity of anxiety and depression was screened with Hospital Anxiety and Depression Scale.

RESULTS

No significant difference in CAR between PD patients and control group was found. No correlations were observed between CAR and anxiety severity measures in PD patients and controls.

LIMITATIONS

The number of participating subjects was relatively small, and the study results apply to nonsuicidal drug-naïve PD patients without agoraphobia and with short-illness duration. There was a lack of control on subjects' compliance with the sampling instructions.

CONCLUSION

The study provides no support for elevated CAR levels in drug-naïve PD patients without agoraphobia.

Identification and characterization of HPA-axis reactivity endophenotypes in a cohort of female PTSD patients

Analysis of the function of the hypothalamic-pituitary-adrenal (HPA)-axis in patients suffering from posttraumatic stress disorder (PTSD) has hitherto produced inconsistent findings, inter alia in the Trier Social Stress Test (TSST). To address these inconsistencies, we compared a sample of 23 female PTSD patients with either early life trauma (ELT) or adult trauma (AT) or combined ELT and AT to 18 age-matched non-traumatized female healthy controls in the TSST which was preceded by intensive baseline assessments. During the TSST, we determined a variety of clinical, psychological, endocrine and cardiovascular parameters as well as expression levels of four HPA-axis related genes. Using a previously reported definition of HPA-axis responsive versus non-responsive phenotypes, we identified for the first time two clinically and biologically distinct HPA-axis reactivity subgroups of PTSD. One subgroup ("non-responders") showed a blunted HPA-axis response and distinct clinical and biological characteristics such as a higher prevalence of trauma-related dissociative symptoms and of combined AT and ELT as well as alterations in the expression kinetics of the genes encoding for the mineralocorticoid receptor (MR) and for FK506 binding protein 51 (FKBP51). Interestingly, this non-responder subgroup largely drove the relatively diminished HPA axis response of the total cohort of PTSD patients. These findings are limited by the facts that the majority of patients was medicated, by the lack of traumatized controls and by the relatively small sample size. The here for the first time identified and characterized HPA-axis reactivity endophenotypes offer an explanation for the inconsistent reports on HPA-axis function in PTSD and, moreover, suggest that most likely other factors than HPA-axis reactivity play a decisive role in determination of PTSD core symptom severity.

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

Arousal and the attentional network in panic disorder

Although a great deal of information about the neurobiology of panic disorder is now available, there is a need for an updated etiological model integrating recent findings on the neurobiology of the arousal system and its relationship with higher cortical functions in panic disorder. The current mini-review presents psychophysiological, molecular biological/genetic and functional neuroimaging evidence for dysfunction in major arousal systems of the brain. Such dysfunction may influence the development of panic disorder by precipitating autonomic bodily symptoms and at the same time increasing vigilance to these sensations by modulating cortical attentional networks. A multilevel model of arousal, attention and anxiety-including the norepinephrine, orexin, neuropeptide S and caffeine-related adenosine systems-may be useful in integrating a range of data available on the pathogenesis of panic disorder.

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.

Gender-specific association of variants in the AKR1C1 gene with dimensional anxiety in patients with panic disorder: additional evidence for the importance of neurosteroids in anxiety?

BACKGROUND

Neurosteroids are synthesized both in brain and peripheral steroidogenic tissue from cholesterol or steroidal precursors. Neurosteroids have been shown to be implicated in neural proliferation, differentiation, and activity. Preclinical and clinical studies also suggest a modulatory role of neurosteroids in anxiety-related phenotypes. However, little is known about the contribution of genetic variants in genes relevant for the neurosteroidogenesis to anxiety disorders.

METHODS

We performed an association analysis of single nucleotide polymorphisms (SNPs) in five genes related to the neurosteroidal pathway with emphasis on progesterone and allopregnanolone biosynthesis (steroid-5-alpha-reductase 1A (SRD5A1), aldo-keto reductase family 1 C1-C3 (AKR1C1-AKR1C3) and translocator protein 18 kDA (TSPO) with panic disorder (PD) and dimensional anxiety in two German PD samples (cases N = 522, controls N = 1,115).

RESULTS

Case-control analysis for PD and SNPs in the five selected genes was negative in the combined sample. However, we detected a significant association of anticipatory anxiety with two intronic SNPs (rs3930965, rs41314625) located in the gene AKR1C1 surviving correction for multiple testing in PD patients. Stratification analysis for gender revealed a female-specific effect of the associations of both SNPs.

CONCLUSIONS

These results suggest a modulatory effect of AKR1C1 activity on anxiety levels, most likely through changes in progesterone and allopregnanolone levels within and outside the brain. In summary, this is the first evidence for the gender-specific implication of the AKR1C1 gene in the expression of anticipatory anxiety in PD. Further analyses to unravel the functional role of the SNPs detected here and replication analyses are needed to validate our results.

Multifunctional aspects of allopregnanolone in stress and related disorders

Allopregnanolone (3α-hydroxy-5α-pregnan-20-one) is a major cholesterol-derived neurosteroid in the central nervous system and is synthesized from progesterone by steroidogenic enzymes, 5α-reductase (the rate-limiting enzyme) and 3α-hydroxysteroid dehydrogenase. The pathophysiological role of allopregnanolone in neuropsychiatric disorders has been highlighted in several investigations. The changes in neuroactive steroid levels are detected in stress and stress-related disorders including anxiety, panic and depression. The changes in allopregnanolone in response to acute stressor tend to restore the homeostasis by dampening the hyper-activated HPA axis. However, long standing stressors leading to development of neuropsychiatric disorders including depression and anxiety are associated with decrease in the allopregnanolone levels. GABAA receptor complex has been considered as the primary target of allopregnanolone and majority of its inhibitory actions are mediated through GABA potentiation or direct activation of GABA currents. The role of progesterone receptors in producing the late actions of allopregnanolone particularly in lordosis facilitation has also been described. Moreover, recent studies have also described the involvement of other multiple targets including brain-derived neurotrophic factor (BDNF), glutamate, dopamine, opioids, oxytocin, and calcium channels. The present review discusses the various aspects of allopregnanolone in stress and stress-related disorders including anxiety, depression and panic.

Investigation of cortisol levels in patients with anxiety disorders: a structured review

Anxiety disorders are common and distressing medical conditions, which typically arise in adolescence or early adult life. They can persist for many years, reducing quality of life, limiting academic and occupational achievement, and being responsible for considerable economic pressures. Although a range of psychological and pharmacological treatments are available, their success is often limited, and many patients remain troubled by significant symptom-related disability for long periods. The detailed pathophysiology of each anxiety disorder is not established, and novel treatments that are based solely on current understanding of conventional neurotransmitter function are unlikely to be substantially more effective or better tolerated than current treatments. Investigations of hypothalamo-pituitary axis function across panic disorder, generalized anxiety disorder, specific phobias and social anxiety disorder have produced intriguing findings but not revealed a consistent pattern of endocrine disturbance, perhaps reflecting differences in methodology and the nature and size of the clinical samples. There is a persistent need for large, prospective studies using standardized methods for investigation and data analysis (164 words).

Translational approaches to anxiety: focus on genetics, fear extinction and brain imaging

Anxiety disorders are highly prevalent and debilitating psychiatric disorders. Owing to the complex aetiology of anxiety disorders, translational studies involving multiple approaches, including human and animal genetics, molecular, endocrinological and imaging studies, are needed to get a converging picture of function or dysfunction of anxiety-related circuits. An advantage of anxiety disorders is that the neural circuitry of fear is comparatively well understood, with striking analogies between animal and human models, and this article aims to provide a brief overview of current translational approaches to anxiety. Experimental models that involve similar tasks in animals and humans, such as fear conditioning and extinction, seem particularly promising and can be readily integrated with imaging, behavioural and physiological readouts. The cross-validation between animal and human genetics models is essential to examine the relevance of candidate genes, as well as their neural pathways, for anxiety disorders; a recent example of such cross-validation work is provided by preclinical and clinical work on TMEM132D, which has been identified as a candidate gene for panic disorder. Further integration of epigenetic data and gene × environment interaction are promising approaches, as highlighted by FKPB5 and PACAP, early life trauma and stress-related anxiety disorders. Finally, connecting genetic and epigenetic data with functionally relevant imaging readouts will allow a comparison of overlap and differences across species in mechanistic pathways from genes to brain functioning and behaviour.

The DEX/CRH test for major depression: a potentially useful diagnostic test

The dexamethasone/corticotropin-releasing hormone (DEX/CRH) test has been proposed as a potential diagnostic test for major depressive disorder (MDD). A previously proposed four-step approach assesses the stage of development for a biological finding into a clinically useful diagnostic test. Using this approach, we evaluated the progress of the DEX/CRH test using meta-analysis as a part of step 1. A literature review identified 15 studies of the DEX/CRH test in patients with MDD and healthy controls. Meta-analysis estimated the effect size, heterogeneity, and confidence intervals using random effects models. Studies consistent with any step of the four-step approach were identified, and their characteristics were presented. Eleven studies reported significantly higher cortisol levels with the DEX/CRH test in patients with MDD, compared with the healthy controls (step 1). Eight eligible studies were included in meta-analysis, and had an effect size of 1.34 (95% confidence interval: 0.70-1.97). Most studies were step-1 studies (comparison of patients and healthy controls), and no step-4 studies (multicenter trials) were found. This review emphasizes that despite appearing as a promising test, the DEX/CRH has not been adequately studied for the required stages of development into a clinically useful laboratory test. Particularly, additional step-3 and step-4 studies are necessary.

Exploring patterns in cortisol synchrony among anxious and nonanxious mother and child dyads: a preliminary study

Given that anxiety is highly familial, the current pilot study explored the association between anxiety diagnosis and diurnal cortisol rhythm in mother-child dyads with the hypothesis that a predisposition toward homogenous cortisol profiles may partially explain the familial linkage of anxiety. The role of family environment in stress response was also examined. Participants were 27 mother-child dyads. Results indicated that patterns of cortisol secretion between mother and child are synchronous. Maternal anxiety and aspects of family functioning significantly predicted child awakening cortisol pattern. Further, affective involvement and gender of the child significantly predicted mother-child diurnal cortisol secretion synchrony. These findings provide support for the degree of synchrony in patterns of physiological responsiveness between mother and child, as well as the importance of a child's affective environment in the prediction of a diagnosis of anxiety.

Serotonergic neural links from the dorsal raphe nucleus modulate defensive behaviours organised by the dorsomedial hypothalamus and the elaboration of fear-induced antinociception via locus coeruleus pathways

Decrease of γ-aminobutyric acid (GABA)-mediated neurotransmission in the dorsomedial hypothalamus (DMH) evokes instinctive fear-like responses. The aim of the present study was to investigate the involvement of the serotonin (5-HT)- and norepinephrine-mediated pathways of the endogenous pain inhibitory system, including the dorsal raphe nucleus (DRN) and the locus coeruleus (LC), in the defensive responses and antinociceptive processes triggered by the blockade of GABAergic receptors in the DMH. The intra-hypothalamic microinjection of the GABA(A) receptor antagonist bicuculline (40 ng/200 nL) elicited elaborate defensive behaviours interspersed with exploratory responses. This escape behaviour was followed by significantly increased pain thresholds, a phenomenon known as fear-induced antinociception. Furthermore, at 5 and 14 days after DRN serotonin-containing neurons were damaged using the selective neurotoxin 5,7-dihydroxytryptamine (5,7-DHT), the frequency and duration of alertness and escape behaviour evoked by the GABA(A) receptor blockade in the DMH decreased, as well as fear-induced antinociception. Pre-treatment with the non-selective 5-HT receptor antagonist methysergide, the 5-HT(2A/2C) receptor antagonist ketanserin and the 5-HT(2A) receptor selective antagonist R-96544 in the LC also decreased fear-induced antinociception, without significant changes in the expression of defensive behaviours. These data suggest that the serotonergic neurons of the DRN are directly involved in the organisation of defensive responses as well as in the elaboration of the innate fear-induced antinociception. However, serotonin-mediated inputs from the NDR to the LC modulate only fear-induced antinociception and not the defensive behaviours evoked by GABA(A) receptor blockade in the DMH.

Childhood stressful events, HPA axis and anxiety disorders

Anxiety disorders are among the most common of all mental disorders and their pathogenesis is a major topic in psychiatry, both for prevention and treatment. Early stressful life events and alterations of hypothalamic pituitary adrenal (HPA) axis function seem to have a significant role in the onset of anxiety. Existing data appear to support the mediating effect of the HPA axis between childhood traumata and posttraumatic stress disorder. Findings on the HPA axis activity at baseline and after stimuli in panic disordered patients are inconclusive, even if stressful life events may have a triggering function in the development of this disorder. Data on the relationship between stress, HPA axis functioning and obsessive-compulsive disorder (OCD) are scarce and discordant, but an increased activity of the HPA axis is reported in OCD patients. Moreover, normal basal cortisol levels and hyper-responsiveness of the adrenal cortex during a psychosocial stressor are observed in social phobics. Finally, abnormal HPA axis activity has also been observed in generalized anxiety disordered patients. While several hypothesis have attempted to explain these findings over time, currently the most widely accepted theory is that early stressful life events may provoke alterations of the stress response and thus of the HPA axis, that can endure during adulthood, predisposing individuals to develop psychopathology. All theories are reviewed and the authors conclude that childhood life events and HPA abnormalities may be specifically and transnosographically related to all anxiety disorders, as well as, more broadly, to all psychiatric disorders.

The role of anxiety sensitivity in sleep disturbance in panic disorder

Previous research has demonstrated that individuals with panic disorder (PD) report significant sleep disturbances, although the mechanism of this disturbance is not clear. Patients with PD tend to report abnormally high levels of anxiety sensitivity (AS). Because higher AS involves increases in attention and fearfulness about anxiety and associated physical sensations, which in turn may cause excessive psychological and physiologic arousal, we hypothesized that amongst individuals with PD, higher AS would be associated with sleep disruption, particularly in the form of increased sleep latency. As expected, PD was associated with poorer sleep as measured by the Global Pittsburgh Sleep Quality Index (PSQI) compared to controls and AS was significantly associated with longer sleep latency. Our data suggest that sleep disturbance, and in particular sleep latency, in PD may be partly due to high levels of AS, which can be targeted with cognitive-behavioral therapeutic strategies.

Glucocorticoids as predictors of treatment response in depression

INTRODUCTION

Glucocorticoids and the stress hormone system have been implicated in the pathophysiology of depression and in the mechanism of action of antidepressant response. Many studies have investigated this system in an effort to predict response to antidepressant treatment. The purpose of this review is to evaluate the evidence for using glucocorticoid-related measures for personalized treatment of depression.

METHODS

We conducted a MEDLINE search from 1966 through 2010 and examined English-language studies reporting on the use of endocrine challenge tests and genetic polymorphisms in genes regulating the stress hormone system as predictors of antidepressant response.

RESULTS

While measures of glucocorticoid levels using endocrine tests, as well polymorphisms in genes regulating the stress hormone system, show associations with response to antidepressant treatment, these measures will need to be combined with other variables, including clinical information and other biological measures, to realize the goal of highly predictive and clinically relevant biomarkers.

DISCUSSION

The glucocorticoid system is potentially of great use in predicting antidepressant response. New combinations of biomarkers including these measures should be tested to develop clinically relevant predictors.

Dimensions of depression and anxiety and the hypothalamo-pituitary-adrenal axis

BACKGROUND

Results on the association between depression and the hypothalamo-pituitary-adrenal (HPA) axis have been inconsistent, possibly due to heterogeneity of the DSM-IV category of depression. Specific symptom-dimensions could be used as a more homogenous phenotype in HPA-axis research.

METHODS

Subjects (n = 1029) with a lifetime depression and/or anxiety disorder from the NESDA study (Netherlands Study of Depression and Anxiety) (mean age: 43.0 ± 12.7 years, 67.4% women) provided seven saliva samples to yield the cortisol awakening response (CAR), evening cortisol, and dexamethasone suppression data. The dimensions of the tripartite model (General Distress, Anhedonic Depression, and Anxious Arousal) were measured with the 30-item adapted Mood and Anxiety Symptoms Questionnaire (MASQ-D30) and analyzed in association with the cortisol measures with linear and nonlinear regression.

RESULTS

Median (interquartile range) scores of General Distress, Anhedonic Depression, and Anxious Arousal were 20 (14-27), 36 (28-44), and 15 (12-19), respectively, indicating large variability. Nonlinear associations with the shape of an inverted U were found between General Distress, Anhedonic Depression, and Anxious Arousal on one hand and total morning secretion and the dynamic of the CAR by contrast. Both high and low severity levels were associated with a lower CAR, compared with intermediate levels of severity. Most of the associations remained significant when adjusted for covariates and the presence of DSM-IV diagnoses.

CONCLUSIONS

Nonlinear associations were found between the CAR and the dimensions of the tripartite model. This could explain previous inconsistent findings regarding HPA-axis activity in depressed patients and illustrates the added value of symptom-dimensions for HPA-axis research.

Basal cortisol levels in relation to dimensions and DSM-IV categories of depression and anxiety

The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV classification may fail to adequately distinguish neuroendocrine factors involved in the etiology of depressive and anxiety disorders. Continuous phenotypic dimensions may correlate better with underlying neuroendocrine dysregulations. We compared the categorical DSM-IV diagnoses with a dimensional approach in the same group of outpatients with depressive (n=36), anxiety (n=18), and comorbid depressive and anxiety (n=19) disorders, who were free of psychotropic medication, and in 36 healthy controls. The Mood and Anxiety Symptom Questionnaire (MASQ) was used to measure the three dimensions of the tripartite model, i.e., anhedonic depression, anxious arousal, and general distress. The salivary cortisol awakening response (CAR) (0, 30, 45, and 60 min after awakening), and diurnal cortisol decline (11:00 h, 15:00 h, 19:00 h, and 23:00 h) were analyzed for linear and nonlinear associations. The CAR showed statistically significant nonlinear relationships with two MASQ dimensions, i.e., anhedonic depression and general distress, but no differences between DSM-IV categories. The diurnal cortisol decline was linearly related to the MASQ dimensions anhedonic depression and general distress and significantly higher AUC(diurnal) levels and a steeper slope were found in depressive patients compared to controls using DSM-IV categories. The present study shows that linear and nonlinear associations with salivary cortisol are detected when using phenotypic dimensions and may be complementary to phenotypic DSM-IV categories when doing neuroendocrine research.

Tolerability of the dexamethasone-corticotropin releasing hormone test in major depressive disorder

BACKGROUND

The dexamethasone-corticotropin releasing hormone (Dex-CRH) test may differentially predict which depressed patients will respond to antidepressant medication. However, a comprehensive analysis of the safety of this test in psychiatric patients has not previously been performed.

METHODS

We conducted a pooled analysis of depressed patients in four clinical studies. Observed and subjectively reported side-effects in 454 patients were collected for 90 minutes following CRH administration. Pre-test electrocardiograms were available in 250 patients to assess cardiac safety. Descriptive statistics were performed to evaluate these safety data.

RESULTS

Eight-six (18.9%) subjects experienced no side-effects from the procedure. The mean number of side-effects per subject was 1.4±1.0. The most frequent adverse events were: flushing (n=216, 47.6%), feeling of warmth (144, 31.7%), hyperpnea/tachypnea (108, 23.8%), palpitations (37, 8.1%), and tachycardia (28, 6.2%). Side-effects were consistently mild and brief in duration. There were no serious adverse events.

CONCLUSION

The Dex-CRH test produces a mild, predictable side-effect profile, characterized by flushing, feelings of warmth, hyperpnea/tachypnea, palpitations, and tachycardia. These results provide reassurance that the Dex-CRH test is well tolerated in psychiatric patients.

Synthesis and Biological Evaluation of New CRH Analogues

A series of 7 new human/rat Corticotropin Releasing Hormone (h/r-CRH) analogues were synthesized. The induced alterations include substitution of Phe at position 12 with D-Phe, Leu at positions 14 and 15 with Aib and Met at positions 21 and 38 with Cys(Et) and Cys(Pr). The analogues were tested regarding their binding affinity to the CRH-1 receptor and their activity which is represented by means of percentage of maximum response in comparison to the native molecule. The results indicated that the introduction of Aib, or Cys derivatives although altering the secondary structure of the molecule, did not hinder receptor recognition and binding.

Long-term anxiolytic and antidepressant-like behavioural effects of tiagabine, a selective GABA transporter-1 (GAT-1) inhibitor, coincide with a decrease in HPA system activity in C57BL/6 mice

Gamma-aminobutyric acid (GABA) system plays a pivotal role in the pathophysiology of anxiety and mood disorders. This study was aimed to assess the anxiolytic and antidepressant-like properties of tiagabine, an inhibitor of the GABA transporter-1 (GAT-1), after acute and chronic administration in C57BL/6JOlaHsD mice with paroxetine as a positive control. In first experiments, the acute administration of tiagabine (7.5 mg/kg, orally [PO]) and paroxetine (10 mg/kg PO) induced anxiolytic effects in the elevated plus maze test and the modified hole board test and an antidepressant-like effect in the forced swim test. Chronic application of tiagabine (7.5 mg/kg PO) and paroxetine (10 mg/kg PO) for 22 days revealed an anxiolytic and antidepressant-like efficacy of tiagabine only. In a further experiment, we analysed the impact of chronic tiagabine versus paroxetine treatment on the hypothalamic-pituitary-adrenocortical (HPA) system regulation. GAT-1 blockade induced a setpoint-shift of the stress hormone system toward lower levels as indicated by decreased plasma corticosterone concentrations and attenuated gene expression levels of corticotropin-releasing factor in the paraventricular nucleus of the hypothalamus and of hippocampal steroid receptors. This data indicate that both acute and long-term anxiolytic and antidepressant-like properties of brain GAT-1 inhibition coincide with a reduction in HPA system activity in mice.

Salivary cortisol levels in persons with and without different anxiety disorders

OBJECTIVE

To examine the association between several subtypes of anxiety disorders and various cortisol indicators in a large cohort study. Anxiety disorders have been suggested to be linked to hypothalamic-pituitary-adrenal (HPA) axis activity, although results are scarce and inconsistent. No earlier studies have examined consistency of HPA axis findings across several anxiety subtypes and whether associations are state or trait dependent.

METHODS

Data are derived from 1427 participants of the Netherlands Study of Depression and Anxiety. Three groups were compared: 342 control participants without psychiatric disorders; 311 persons with a remitted (no current) anxiety disorder (social phobia, generalized anxiety disorder, panic disorder); and 774 persons with a current anxiety disorder, as diagnosed using the Composite International Diagnostic Interview psychiatric interview. Cortisol levels were measured in seven saliva samples, determining the 1-hour cortisol awakening response, evening cortisol, and cortisol response after 0.5 mg of dexamethasone ingestion.

RESULTS

Current anxiety disorder was associated with higher awakening cortisol levels (p = .002). These findings were mainly present for patients with panic disorder with agoraphobia and anxious patients with comorbid depressive disorder. Remitted anxiety only showed a trend toward higher morning cortisol (p = .08). No associations were observed for anxiety status and evening cortisol level or cortisol suppression after dexamethasone.

CONCLUSIONS

This study showed a modest but significantly higher 1-hour cortisol awakening response among anxiety patients, which was driven by those with panic disorder with agoraphobia and those with comorbid depression.

GABA(A) receptor blockade in dorsomedial and ventromedial nuclei of the hypothalamus evokes panic-like elaborated defensive behaviour followed by innate fear-induced antinociception

Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour.