HPA axis activity in patients with panic disorder: review and synthesis of four studies

The role of nitric oxide and hormone signaling in chronic stress, anxiety, depression and post-traumatic stress disorder

This paper provides a summary of the role of nitric oxide (NO) and hormones in the development of chronic stress, anxiety, depression, and post-traumatic stress disorder (PTSD). These mental health conditions are prevalent globally and involve complex molecular interactions. Although there is a significant amount of research and therapeutic options available, the underlying mechanisms of these disorders are still not fully understood. The primary pathophysiologic processes involved in chronic stress, anxiety, depression, and PTSD include dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, the intracellular influence of neuronal nitric oxide synthase (nNOS) on transcription factors, an inflammatory response with the formation of nitrergic oxidative species, and reduced serotonergic transmission in the dorsal raphe nucleus. Despite the extensive literature on this topic, there is a great need for further research to clarify the complexities inherent in these pathways, with the primary aim of improving psychiatric care.

Increased reactivity of the paraventricular nucleus of the hypothalamus and decreased threat responding in male rats following psilocin administration

Psychedelics have experienced renewed interest following positive clinical effects, however the neurobiological mechanisms underlying effects remain unclear. The paraventricular nucleus of the hypothalamus (PVN) plays an integral role in stress response, autonomic function, social behavior, and other affective processes. We investigated the effect of psilocin, the psychoactive metabolite of psilocybin, on PVN reactivity in Sprague Dawley rats. Psilocin increased stimulus-independent PVN activity as measured by c-Fos expression in male and female rats. Psilocin increased PVN reactivity to an aversive air-puff stimulus in males but not females. Reactivity was restored at 2- and 7-days post-injection with no group differences. Additionally, prior psilocin injection did not affect PVN reactivity following acute restraint stress. Experimental groups sub-classified by baseline threat responding indicate that increased male PVN reactivity is driven by active threat responders. These findings identify the PVN as a significant site of psychedelic drug action with implications for threat responding behavior.

Molecular and Cellular Mechanisms of Intramuscular Fat Development and Growth in Cattle

Intramuscular fat, also referred to as marbling fat, is the white fat deposited within skeletal muscle tissue. The content of intramuscular fat in the skeletal muscle, particularly the longissimus dorsi muscle, of cattle is a critical determinant of beef quality and value. In this review, we summarize the process of intramuscular fat development and growth, the factors that affect this process, and the molecular and epigenetic mechanisms that mediate this process in cattle. Compared to other species, cattle have a remarkable ability to accumulate intramuscular fat, partly attributed to the abundance of sources of fatty acids for synthesizing triglycerides. Compared to other adipose depots such as subcutaneous fat, intramuscular fat develops later and grows more slowly. The commitment and differentiation of adipose precursor cells into adipocytes as well as the maturation of adipocytes are crucial steps in intramuscular fat development and growth in cattle. Each of these steps is controlled by various factors, underscoring the complexity of the regulatory network governing adipogenesis in the skeletal muscle. These factors include genetics, epigenetics, nutrition (including maternal nutrition), rumen microbiome, vitamins, hormones, weaning age, slaughter age, slaughter weight, and stress. Many of these factors seem to affect intramuscular fat deposition through the transcriptional or epigenetic regulation of genes directly involved in the development and growth of intramuscular fat. A better understanding of the molecular and cellular mechanisms by which intramuscular fat develops and grows in cattle will help us develop more effective strategies to optimize intramuscular fat deposition in cattle, thereby maximizing the quality and value of beef meat.

Revisiting benzodiazepines (GABA Enhancers):A transdiagnostic and precision medicine approach

Since the mid 1980's, there has been an increased focus on the side effects of benzodiazepines (GABA enhancers), and as a result there has been a decrease in their use. We have systematically reviewed recent studies of GABA enhancers in psychiatry, and highlight evidence of their utility which may impact their negative conceptualization in clinical practice. We propose a new perspective on the appropriate use of these medications and describeclinical reasoning underpinning the use of benzodiazepine (GABA enhancers) based on their effect on specific receptors. A translational approach, involving a more comprehensive characterization of GABA receptors and their neuroscience-based mechanisms allows for a more precise use of this medication class. By adopting a precision person-centered approach, instead of a categorical approach, supports the prescribing of GABA enhancers when a cross-cutting transdiagnostic assessment shows anxiety symptoms associated with clinical impairment.

Parental Social Isolation during Adolescence Alters Gut Microbiome in Rat Male Offspring

Previous work from our laboratory demonstrated that parental stress, induced by social isolation starting at puberty, leads to behavioral, endocrine, and biochemical changes in the male, but not female, offspring (ISO-O) of Sprague-Dawley rats. Here, we report alterations in the gut microbiota composition of ISO-O vs. grouped-housed offspring (GH-O), although all animals received the same diet and were housed in the same conditions. Analysis of bacterial communities by next-generation sequencing (NGS) of 16S rRNA gene revealed alterations at family and order levels within the main phyla of Bacteroides, Proteobacteria, and Firmicutes, including an almost total deficit in Limosilactobacillus reuteri (formerly Lactobacillus reuteri) and a significant increase in Ligilactobacillus murinus (formerly Lactobacillus murinus). In addition, we found an increase in the relative abundance of Rhodospirillales and Clostridiales in the families of Lachnospiraceae and Ruminococcaceae, and Bacteroidales in the family of Prevotellaceae. Furthermore, we examined plasma levels of the proinflammatory cytokines interleukin-1-beta and tumor necrosis factor-alpha, which did not differ between the two groups, while corticosterone concentrations were significantly increased in ISO-O rats. Our findings suggest that adverse environmental conditions experienced by parents may have an impact on the likelihood of disease development in the subsequent generations.

Copeptin response to panic provocation with CO2 in healthy adults

Repeated panic attacks are the core symptom of panic disorder and severely stressful for patients. Additional to the psychological response, the physiological symptoms are an important aspect of the experienced panic. However, data on the extent of hypothalamic-pituitary-adrenal (HPA)-axis activation during panic attacks is inconsistent. Therefore, in the present study, we aimed at investigating the stress-axis activity in more detail by including Copeptin (CoP) as a stable surrogate parameter for the vasopressinergic hypothalamic activity during experimentally induced panic attacks in healthy adults (N = 21). During a placebo-controlled panic challenge with 35% CO2 compared to normal air inhalation, we measured CoP and the peripheral effector hormones Adrenocorticotropic Releasing Hormone (ACTH) and cortisol in plasma along with the psychological response to panic anxiety. We analyzed hormonal secretion patterns, their correlations and individual panic ratings over time and explored differences between female and male participants. We found a significant CO2-induced increase of CoP plasma levels and psychological panic symptoms after CO2-administration, while no positive correlations of CoP levels with the peripheral HPA-axis hormones and with panic symptoms were present. No differences between female and male participants concerning their psychological response nor their baseline CoP levels, the release of CoP or its increase during the experiment were found. CoP could be a sensitive indicator for an organism's physiologic acute hypothalamic response during stress and panic attacks.

Predicting the diagnosis of various mental disorders in a mixed cohort using blood-based multi-protein model: a machine learning approach

The lack of objective diagnostic methods for mental disorders challenges the reliability of diagnosis. The study aimed to develop an easily accessible and useable objective method for diagnosing major depressive disorder (MDD), schizophrenia (SZ), bipolar disorder (BPD), and panic disorder (PD) using serum multi-protein. Serum levels of brain-derived neurotrophic factor (BDNF), VGF (non-acronymic), bicaudal C homolog 1 (BICC1), C-reactive protein (CRP), and cortisol, which are generally recognized to be involved in different pathogenesis of various mental disorders, were measured in patients with MDD (n = 50), SZ (n = 50), BPD (n = 55), and PD along with 50 healthy controls (HC). Linear discriminant analysis (LDA) was employed to construct a multi-classification model to classify these mental disorders. Both leave-one-out cross-validation (LOOCV) and fivefold cross-validation were applied to validate the accuracy and stability of the LDA model. All five serum proteins were included in the LDA model, and it was found to display a high overall accuracy of 96.9% when classifying MDD, SZ, BPD, PD, and HC groups. Multi-classification accuracy of the LDA model for LOOCV and fivefold cross-validation (within-study replication) reached 96.9 and 96.5%, respectively, demonstrating the feasibility of the blood-based multi-protein LDA model for classifying common mental disorders in a mixed cohort. The results suggest that combining multiple proteins associated with different pathogeneses of mental disorders using LDA may be a novel and relatively objective method for classifying mental disorders. Clinicians should consider combining multiple serum proteins to diagnose mental disorders objectively.

Mediating Effect of Work-Family Conflict on the Relationship Between Long Commuting Time and Workers' Anxiety and Insomnia

Background

Our study aimed to investigate the mediating role of work-family conflict (WFC) on the relationship between long commutes and workers' anxiety and insomnia.

Methods

Our study measured the two dimensions of WFC, time-related, and strain-related, which were considered multiple mediators. The mediating effect of WFC on anxiety and insomnia was investigated by decomposing the total effect into a direct effect (long commuting time → anxiety or insomnia) and an indirect effect (long commuting time → WFC → anxiety or insomnia). The combined indirect effect (joint indirect effect) of strain-related WFC and time-related WFC was estimated. The effects were presented as odds ratios and 95% confidence intervals (CIs).

Results

The direct effect of 120 min or longer of commuting time was 1.39 (95% CI: 1.17-1.65) times increase in the odds of anxiety and 1.64 (95% CI: 1.41-1.90) times increase in the odds of insomnia than those whose commuting time was less than 60 min. In the case of indirect effects, those whose commuting time was 120 min or longer had 1.13 times higher odds of anxiety (95% CI: 1.07-1.18) and 1.12 times higher odds of insomnia (95% CI: 1.07-1.17) via WFC. The joint indirect effects accounted for 26.4% and 18.5% of the total effect on anxiety and insomnia, respectively. The longer the commuting time, the stronger both direct and indirect effects.

Conclusions

Our findings highlight the mediating effect of WFC on the relationship between long commuting times and workers' anxiety and insomnia.

Biological and cognitive theories explaining panic disorder: A narrative review

The current narrative review summarizes and examines several theories of panic disorder (PD) including biological theories, encompassing neurochemical factors, metabolic and genetic theories, respiratory and hyperventilation theories and cognitive theory. Biological theories have informed the development of psychopharmacological treatments; however, they may be limited in their utility given the efficacy of psychological treatments. In particular, behavioral and, more recently, cognitive models have garnered support due to the efficacy of cognitive-behavior therapy (CBT) in treating PD. The role of combination treatments has been found to be superior in the treatment of PD in particular cases, lending support for the need for an integrated approach and model for PD given that the etiology of PD is complex and multifactorial.

Salivary cortisol levels and appraisals of daily hassles across dimensions of the tripartite model of anxiety and depression in emerging adults

The objective of this study was to investigate how cortisol levels and appraisals of daily hassles differ across tripartite dimensions of depression and anxiety in emerging adults. Data collected from a sample of undergraduate students at a large Midwestern university was used to investigate these aims. This included salivary cortisol data collected over four days, scores on a measure of the tripartite model of anxiety and depression, and scores on a measure of daily hassles administered everyday for two weeks. Generalized estimating equations and multilevel modeling techniques were used to analyze data. Elevated cortisol levels during the awakening period and the evening period, lower total levels across the day, steeper diurnal slopes, and elevated levels of negative affect and physiological hyperarousal predicted experiences of daily hassles. Tripartite dimensions were unrelated to cortisol indices. The present study demonstrates the utility of modeling multiple cortisol indices and provides evidence of differential associations between physiological and phenomenological indices of stress.

Neuroimmune mechanisms in fear and panic pathophysiology

Panic disorder (PD) is unique among anxiety disorders in that the emotional symptoms (e.g., fear and anxiety) associated with panic are strongly linked to body sensations indicative of threats to physiological homeostasis. For example, panic attacks often present with feelings of suffocation that evoke hyperventilation, breathlessness, or air hunger. Due to the somatic underpinnings of PD, a major focus has been placed on interoceptive signaling and it is recognized that dysfunctional body-to-brain communication pathways promote the initiation and maintenance of PD symptomatology. While body-to-brain signaling can occur via several pathways, immune and humoral pathways play an important role in communicating bodily physiological state to the brain. Accumulating evidence suggests that neuroimmune mediators play a role in fear and panic-associated disorders, although this has not been systematically investigated. Currently, our understanding of the role of immune mechanisms in the etiology and maintenance of PD remains limited. In the current review, we attempt to summarize findings that support a role of immune dysregulation in PD symptomology. We compile evidence from human studies and panic-relevant rodent paradigms that indicate a role of systemic and brain immune signaling in the regulation of fear and panic-relevant behavior and physiology. Specifically, we discuss how immune signaling can contribute to maladaptive body-to-brain communication and conditioned fear that are relevant to spontaneous and conditioned symptoms of PD and identify putative avenues warranting future investigation.

Heart Rate Variability: A Measure of Cardiovascular Health and Possible Therapeutic Target in Dysautonomic Mental and Neurological Disorders

Mental illness such as depression and anxiety as well as cerebrovascular disease are linked to impairment of neurocardiac function mediated by changes to the autonomic nervous system with increased sympathetic and decreased parasympathetic activity. Autonomic neurocardiac function can be evaluated by computing heart rate variability (HRV). Over the past decades, research has demonstrated the diagnostic value of HRV as independent predictor of cardiovascular mortality and as disease marker in progressive autonomic nervous system disorders such as Parkinson’s disease. Here we summarize our studies on HRV and its therapeutic modulation in the context of psychopharmacology as well as psychiatric and neurological disorders to honor the life of Professor Evgeny Vaschillo, the true pioneer of HRV research who sadly passed away on November 21st, 2020.

The circadian rhythm of blood pressure in patients with panic disorder and generalized anxiety disorder

BACKGROUND

Anxiety disorders affect blood pressure both during the day and at night. Little is known about the effect of individual anxiety disorders on the circadian rhythm of blood pressure.

OBJECTIVES

The purpose of this study is to compare the nocturnal drop in blood pressure in patients with panic disorder (PD), generalized anxiety disorder (GAD), and healthy individuals.

METHODS

The study was conducted on fifty consecutive outpatients with anxiety disorders and personality disorders who participated in intensive group psychotherapy. Diagnoses were made according to DSM-IV-TR criteria using the PSE-10 questionnaire. Out of 50 patients under study, 17 were diagnosed with PD and 21 with GAD. The control group consisted of 40 healthy people recruited in the course of other studies. The resulting three groups were compared in terms of circadian blood pressure using the ABPM method.

RESULTS

Mean nocturnal falls in systolic and diastolic blood pressure were the following: 2% and 3% (PD), 11% and 12% (GAD), 27% and 23% (control). Four people out of PD group had higher systolic and diastolic blood pressure at night than during the day. The ratios between non-dippers/dippers were: 0/15 (PD), 8/21 (38% - GAD) and 40/40 (100% - control).

CONCLUSIONS

The patients with PD were characterized by an almost flat course of circadian blood pressure. The patients with GAD had a lower mean nocturnal fall in blood pressure than the control group, but significantly higher than the patients with PD. The differences in the circadian course of blood pressure between PD and GAD are so large that the impact of these disorders should be investigated separately.

The psychophysiology of the sigh: II: The sigh from the psychological perspective

A sigh is a distinct respiratory behavior with specific psychophysiological roles. In two accompanying reviews we will discuss the physiological and psychological functions of the sigh. The present review will focus on the psychological functions of the sigh. We discuss the regulatory effects of a sigh, and argue how these effects may become maladaptive when sighs occur excessively. The adaptive role of a sigh is discussed in the context of regulation of psychophysiological states. We propose that sighs facilitate transitions from one psychophysiological state to the next, and this way contribute to psychophysiological flexibility, via a hypothesized resetting mechanism. We discuss how a sigh resets respiration, by controlling mechanical and metabolic properties of respiration associated with respiratory symptoms. Next, we elaborate on a sigh resetting emotional states by facilitating emotional transitions. We attempt to explain the adaptive and maladaptive functions of a sigh in the framework of stochastic resonance, in which we propose occasional, spontaneous sighs to be noise contributing to psychophysiological regulation, while excessive sighs result in psychophysiological dysregulation. In this context, we discuss how sighs can contribute to therapeutic interventions, either by increasing sighs to improve regulation in case of a lack of sighing, or by decreasing sighs to restore regulation in case of excessive sighing. Finally, a research agenda on the psychology of sighs is presented.

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.

Oxytocin: An Old Hormone, A Novel Psychotropic Drug And Possible Use In Treating Psychiatric Disorders

BACKGROUND

Oxytocin is a nonapeptide synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Historically, this molecule has been involved as a key factor in the formation of infant attachment, maternal behavior and pair bonding and, more generally, in linking social signals with cognition, behaviors and reward. In the last decades, the whole oxytocin system has gained a growing interest as it was proposed to be implicated in etiopathogenesis of several neurodevelopmental and neuropsychiatric disorders.

METHODS

With the main goal of an in-depth understanding of the oxytocin role in the regulation of different functions and complex behaviors as well as its intriguing implications in different neuropsychiatric disorders, we performed a critical review of the current state of art. We carried out this work through PubMed database up to June 2021 with the search terms: 1) "oxytocin and neuropsychiatric disorders"; 2) "oxytocin and neurodevelopmental disorders"; 3) "oxytocin and anorexia"; 4) "oxytocin and eating disorders"; 5) "oxytocin and obsessive-compulsive disorder"; 6) "oxytocin and schizophrenia"; 7) "oxytocin and depression"; 8) "oxytocin and bipolar disorder"; 9) "oxytocin and psychosis"; 10) "oxytocin and anxiety"; 11) "oxytocin and personality disorder"; 12) "oxytocin and PTSD".

RESULTS

Biological, genetic, and epigenetic studies highlighted quality and quantity modifications in the expression of oxytocin peptide or in oxytocin receptor isoforms. These alterations would seem to be correlated with a higher risk of presenting several neuropsychiatric disorders belonging to different psychopathological spectra. Collaterally, the exogenous oxytocin administration has shown to ameliorate many neuropsychiatric clinical conditions.

CONCLUSION

Finally, we briefly analyzed the potential pharmacological use of oxytocin in patient with severe symptomatic SARS-CoV-2 infection due to its anti-inflammatory, anti-oxidative and immunoregulatory properties.

Pituitary-adrenal axis hormones in early-onset versus late-onset panic disorder

OBJECTIVE

It has been hypothesised that early-onset panic disorder (PD) may constitute a biologically distinct subtype of PD, but the few relevant data are inconclusive. We systematically explored for potential psychopathological and hormonal differences between early-onset (age at onset ≤ 27 years) versus late-onset PD, in consecutively-referred, medication-free, acutely-ill PD outpatients, moreover without comorbid mental disorders except agoraphobia (N = 54; age = 32.3 ± 7.5 years; early-onset = 27; females = 38).

METHODS

Hormones assessed (plasma levels) included adrenocorticotropic hormone (ACTH), cortisol and dehydroepiandrosterone sulphate (DHEAS). Psychopathological measures included panic attacks' number during last three weeks, the Agoraphobic Cognitions and the Body Sensations Questionnaires and the Hamilton Anxiety Rating Scale.

RESULTS

Early-onset PD patients - compared to their late-onset counterparts - had longer duration of the disease. The two onset-groups demonstrated similar panic and anxiety symptoms and similar ratios of smokers/never-smokers. However, early-onset patients demonstrated significantly greater ACTH and DHEAS levels and higher (marginally significant) cortisol levels than the late-onset patients. Moreover, in the early-onset patients only, significant positive correlations emerged between ACTH levels and the severity of both panic and anxiety symptomatology.

CONCLUSIONS

These findings suggest that the two onset-groups demonstrate significant differences in the hypothalamic-pituitary-adrenal axis functioning, at least when acutely-ill.Key pointsEarly-onset panic disorder (EOPD) may differ biologically from late-onset PD (LOPD).EOPD was correlated with greater adrenocorticotropic hormone (ACTH) plasma levels.EOPD was correlated with greater dehydroepiandrosterone sulphate plasma levels.In EOPD only, ACTH levels were positively correlated with panic and anxiety symptoms.

Defense mechanism responses to COVID-19

The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense mechanisms used to deal with the pandemic. It then discusses different categories of defense mechanisms and their roles in managing the impacts of psychological distress. The aim of this review is to highlight the various psychological defense mechanisms individuals use to deal with the pandemic and to discuss how adjustment mechanisms can protect individuals from internal and external threats by shielding the integrity of the ego (the mind) and helping individuals maintain their self-schema.

Stress Hormones as Predictors of Response to Cognitive Behavior Therapy in Panic Disorder

OBJECTIVE

Data regarding the potential association between the outcome of psychotherapy of panic disorder (PD) and biological parameters are few. In 21 (16 females) consecutively referred, medication-free, acutely ill PD outpatients, without comorbidities, except agoraphobia, we systematically explored for potential neuroendocrine and clinical correlates of response to a brief cognitive behavior therapy (CBT).

METHODS

Cortisol and adrenocorticotropic hormone (ACTH) basal plasma levels were measured. Measures of psychopathology: (a) Symptom Checklist-90-Revised (SCL-90-R), (b) Clinical Global Impressions-Improvement (CGI-I) Scale, (c) Agoraphobic Cognitions Questionnaire (ACQ), and (d) Mobility Inventory (MI)-alone subscale.

RESULTS

Nonresponders to CBT (CGI-I >2; N = 6) - as compared to the responders (CGI-I ≤2; N = 15) - demonstrated significantly higher cortisol and ACTH basal plasma concentrations. These differences were much stronger when only female patients (nonresponders = 4; responders = 12) were taken into consideration. Regarding psychopathology, nonresponders to CBT suffered from more severe agoraphobia (MI-alone) at baseline. On the contrary, more intense manifestations of anger (SCL-90-R) at baseline were associated with a better treatment outcome. Response to CBT was associated with significant reductions in all SCL-90-R subscales, more pronounced for "phobic anxiety" and "anxiety" subscales.

CONCLUSIONS

This study suggests that in acutely ill, medication-free PD patients, response to CBT may be associated with certain hormonal and clinical parameters at baseline.

Biological Markers in Anxiety Disorders

Anxiety disorders are one of the most commonly reported disorders in psychiatry, causing a high medical and socio-economic burden. Recently, there has been a soaring interest in the biological basis of anxiety disorders, which is reflected in an increasing number of articles related to the topic. Due to the ambiguity of the diagnosis and a large number of underdiagnosed patients, researchers are looking for laboratory tests that could facilitate the diagnosis of anxiety disorders in clinical practice and would allow for the earliest possible implementation of appropriate treatment. Such potential biomarkers may also be useable in monitoring the efficacy of pharmacological therapy for anxiety disorders. Therefore this article reviews the literature of potential biomarkers such as components of saliva, peripheral blood, cerebrospinal fluid (CSF), and neuroimaging studies. There are promising publications in the literature that can be useful. The most valuable and promising markers of saliva are cortisol, lysozyme, and α-amylase (sAA). In the blood, in turn, we can distinguish serotonin, brain-derived serum neurotrophic factor (BDNF), cortisol, and microRNA. Structural changes in the amygdala and hippocampus are promising neuroimaging markers, while in CSF, potential markers include oxytocin and 5-Hydroxyindoleacetic acid (5-HIAA). Unfortunately, research in the field of biomarkers is hampered by insufficient knowledge about the etiopathogenesis of anxiety disorders, the significant heterogeneity of anxiety disorders, frequent comorbidities, and low specificity of biomarkers. The development of appropriate biomarker panels and their assessment using new approaches may have the prospective to overcome the above-mentioned obstacles.

Evolutionary Significance of the Neuroendocrine Stress Axis on Vertebrate Immunity and the Influence of the Microbiome on Early-Life Stress Regulation and Health Outcomes

Stress is broadly defined as the non-specific biological response to changes in homeostatic demands and is mediated by the evolutionarily conserved neuroendocrine networks of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system. Activation of these networks results in transient release of glucocorticoids (cortisol) and catecholamines (epinephrine) into circulation, as well as activation of sympathetic fibers innervating end organs. These interventions thus regulate numerous physiological processes, including energy metabolism, cardiovascular physiology, and immunity, thereby adapting to cope with the perceived stressors. The developmental trajectory of the stress-axis is influenced by a number of factors, including the gut microbiome, which is the community of microbes that colonizes the gastrointestinal tract immediately following birth. The gut microbiome communicates with the brain through the production of metabolites and microbially derived signals, which are essential to human stress response network development. Ecological perturbations to the gut microbiome during early life may result in the alteration of signals implicated in developmental programming during this critical window, predisposing individuals to numerous diseases later in life. The vulnerability of stress response networks to maladaptive development has been exemplified through animal models determining a causal role for gut microbial ecosystems in HPA axis activity, stress reactivity, and brain development. In this review, we explore the evolutionary significance of the stress-axis system for health maintenance and review recent findings that connect early-life microbiome disturbances to alterations in the development of stress response networks.

Blood endocannabinoid levels in patients with panic disorder

BACKGROUND

The development and maintenance of anxiety disorders is not fully understood. There is consensus in the literature that in addition to genetic factors, social, psychological and neurobiological factors are of crucial importance. The present exploratory study investigates the influence of the endocannabinoids (EC) and related N-acylethanolamines (NA) on the maintenance of panic disorder (PD).

METHODS

A total of n = 36 PD and n = 26 healthy controls (HC) were included in the study. Baseline characteristics showed no differences between the two groups. The participants were exposed to the Trier Social Stress Test (TSST) for reliable laboratory stress induction. Blood samples were taken during the TSST by an intravenous catheter to examine the endocannabinoid (EC) stress response. Repeated measures ANOVA was conducted to test for main effects of time and group as well as the respective interaction.

RESULTS

Participants with PD consistently had significantly higher EC and NA blood levels than HC. The consistently high EC and NA levels barely showed any reactivity as indicated by a lack of statistical variance. In line with these findings no reaction to the psychosocial stressor TSST could be detected.

CONCLUSION

Our main results show significant differences in EC concentrations between participants with PD and HC. These findings suggest that an imbalance in the ECS contributes to the maintenance of PD. Increased endocannabinoid levels may have important implications for organic diseases such as cardiovascular disorders. The limitations of the study as well as implications for further investigations are discussed.

Neuroimmune Mechanisms and Sex/Gender-Dependent Effects in the Pathophysiology of Mental Disorders

Innate and adaptive immune mechanisms have emerged as critical regulators of CNS homeostasis and mental health. A plethora of immunologic factors have been reported to interact with emotion- and behavior-related neuronal circuits, modulating susceptibility and resilience to mental disorders. However, it remains unclear whether immune dysregulation is a cardinal causal factor or an outcome of the pathologies associated with mental disorders. Emerging variations in immune regulatory pathways based on sex differences provide an additional framework for discussion in these psychiatric disorders. In this review, we present the current literature pertaining to the effects that disrupted immune pathways have in mental disorder pathophysiology, including immune dysregulation in CNS and periphery, microglial activation, and disturbances of the blood-brain barrier. In addition, we present the suggested origins of such immune dysregulation and discuss the gender and sex influence of the neuroimmune substrates that contribute to mental disorders. The findings challenge the conventional view of these disorders and open the window to a diverse spectrum of innovative therapeutic targets that focus on the immune-specific pathophenotypes in neuronal circuits and behavior. SIGNIFICANCE STATEMENT: The involvement of gender-dependent inflammatory mechanisms on the development of mental pathologies is gaining momentum. This review addresses these novel factors and presents the accumulating evidence introducing microglia and proinflammatory elements as critical components and potential targets for the treatment of mental disorders.

Pharmacological Treatment of Anxiety Disorders: The Role of the HPA Axis

Stress in general, and early life stress in particular, has been associated with the development of anxiety and mood disorders. The molecular, biological and psychological links between stress exposure and the pathogenesis of anxiety and mood disorders have been extensively studied, resulting in the search of novel psychopharmacological strategies aimed at targets of the hypothalamic-pituitary-adrenal (HPA) axis. Hyperactivity of the HPA axis has been observed in certain subgroups of patients with anxiety and mood disorders. In addition, the effects of different anti-anxiety agents on various components of the HPA axis has been investigated, including benzodiazepines, tricyclic antidepressants (TCAs), and selective serotonin reuptake inhibitors (SSRIs). For example, benzodiazepines, including clonazepam and alprazolam, have been demonstrated to reduce the activity of corticotrophin releasing factor (CRF) neurons in the hypothalamus. TCAs and SSRIs are also effective anti-anxiety agents and these may act, in part, by modulating the HPA axis. In this regard, the SSRI escitalopram inhibits CRF release in the central nucleus of the amygdala, while increasing glucocorticoid receptor (GRs) density in the hippocampus and hypothalamus. The molecular effects of these anti-anxiety agents in the regulation of the HPA axis, taken together with their clinical efficacy, may provide further understanding about the role of the HPA axis in the pathophysiology of mood and anxiety disorders, paving the way for the development of novel therapeutic strategies.

Anxiety: An overlooked confounder in the characterisation of chronic stress-related conditions?

Although anxiety disorders are among the most prevalent of psychiatric disorders, childhood trauma-related studies seldom consider anxiety proneness as distinct aetiological contributor. We aimed to distinguish between trauma- and anxiety-associated physiological profiles. South African adolescent volunteers were categorised for trauma exposure (CTQ, mean score 39±11) and anxiety proneness (AP)(CASI, mean score 37±7, STAI-T, mean score 41±8). Circulating hormone and leukocyte glucocorticoid receptor levels, as well as leukocyte functional capacity, were assessed. AP was associated with lower DHEAs (P<0.05) and higher leukocyte GR expression (P<0.05). DHEAs was also negatively correlated with anxiety sensitivity (CASI, P<0.05). In conclusion, AP may have more predictive power than trauma in terms of health profile. Increased glucocorticoid sensitivity previously reported after trauma, may be a unique function of anxiety and not trauma exposure per se. DHEAs concentration was identified as potentially useful marker for monitoring progressive changes in HPA-axis sensitivity and correlated with psychological measures of anxiety.

The blockade of corticotropin-releasing factor 1 receptor attenuates anxiety-related symptoms and hypothalamus-pituitary-adrenal axis reactivity in mice with mild traumatic brain injury

Recent studies have shown that mild traumatic brain injury (mTBI) is associated with higher risk for anxiety-related disorders. Dysregulation in the hypothalamus-pituitary-adrenal (HPA) axis following mTBI has been proposed to be involved in the development of neurobehavioral abnormalities; however, the underlying mechanisms are largely unknown. The aim of this study was to determine whether the corticotropin-releasing-factor-1 (CRF-1) receptor is involved in the regulation of anxiety-related symptoms in a mouse model of mTBI. Animals with or without mTBI received intracerebroventricular injections of a CRF-1 receptor agonist (CRF; 0.01 nmol/mouse) or antagonist (antalarmin; 1 µg/mouse) for 5 days, and then the animals were subjected to anxiety tests (light-dark box and zero maze). The levels of adrenocorticotropic hormone and corticosterone, the most important markers of HPA axis, were also measured after behavioral tests. Our results indicated that mTBI-induced anxiety-related symptoms in mice through increased levels of adrenocorticotropic hormone and corticosterone, showing HPA axis hyperactivity. Interestingly, activation of CRF receptor by a subthreshold dose of CRF resulted in significant increases in anxiety-like behaviors and HPA axis response to stress, whereas blockade of CRF receptors by a subthreshold dose of antalarmin decreased anxiety-related symptoms and HPA axis response to stress in mTBI-induced mice. Collectively, these findings suggest that the CRF-1 receptor plays an important role in the regulation of anxiety-related behaviors following mTBI induction in mice and support the hypothesis that blockade of the CRF-1 receptor may be a promising therapeutic target for anxiety-related disorders in patients with TBI.

Exercise and Anxiety

Anxiety disorders are a group of highly prevalent mental health conditions that can have a debilitating impact on daily functioning and well-being. They can co-occur with other mental health disorders, such as depression. People with anxiety disorders are also at an elevated risk of cardiovascular disease and premature mortality. Physical activity appears to be protective against anxiety disorders in clinical and nonclinical populations. Exercise, a subset of physical activity, has been shown to significantly reduce the symptoms of anxiety. The mechanisms through which exercise produces these effects are likely to involve a combination of biological and psychological factors. Physical activity may also be useful in reducing the symptoms of comorbid mental health conditions and the risk of physical health complications over time. Promoting physical activity could be a method of preventing or treating anxiety disorders with a wide range of benefits. However, further research will be necessary to address important gaps in the literature before these approaches can be fully implemented in mental health services.

The Role of Early Life Stress in HPA Axis and Anxiety

Substantial evidence from various studies suggests a preeminent role for early adverse experiences in the development of psychopathology. The most recent studies reviewed here suggest that early life stressors are associated with an increased risk for anxiety disorders in adulthood. Early life stress predisposes individuals to develop a number of psychiatric syndromes, particularly affective disorders, including anxiety disorders, and is therefore a significant health problem.This review examines the emerging literature on the relationship between stress, hypothalamic-pituitary-adrenal (HPA) axis function, and generalized anxiety disorder (GAD), panic disorder, and phobias and the role of early life stress as an important risk factor for HPA axis dysfunction.The most consistent findings in the literature show increased activity of the HPA axis in depression associated with hypercortisolemia and reduced inhibitory feedback. In addition to melancholic depression, a spectrum of other conditions may be associated with increased and prolonged activation of the HPA axis, including panic, GAD, phobias and anxiety. Moreover, HPA axis changes appear to be state-dependent, tending to improve upon resolution of the anxiety syndrome. Interestingly, persistent HPA hyperactivity has been associated with higher rates of relapse. These studies suggest that an evaluation of the HPA axis during treatment may help identify patients who are at a higher risk for relapse. These findings suggest that this dysfunction of the HPA axis is partially attributable to an imbalance between glucocorticoid and mineralocorticoid receptors. Evidence has consistently demonstrated that glucocorticoid receptor function is impaired in anxiety disorders. 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. 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.

Increase in subjective well-being and psychological health after application of C8-silk lipoamino acid functionalized pigments included in a foundation

OBJECTIVE

The aim of this study was to evaluate the effects of two foundations before (D0) and after 5 days of application (D6) on psychophysiological parameters in order to compare C8-silk lipoamino acid functionalized pigments (FA) versus pure pigments (FP).

METHODS

Assessment of self-esteem, stress, mood and emotion using psychological tests and evaluation of salivary cortisol concentrations were realized on 40 healthy females using a crossover study design at D0 and D6. Four saliva samples were taken on the awakening (C1), 30 min after the awakening (during the foundation application (C2)), 1 h after the foundation application (C3) and at 1900 h (C4) at DO and D6. Area under the curve was calculated in order to obtain information about the total amount of a given substance excreted in a specific time period.

RESULTS

Five days of daily application of the foundation containing the pigments treated with the C8-silk lipoamino acids induced a significant increase (P < 0.001) in self-esteem and pleasant emotion (P < 0.05), and a significant decrease in general stress (P < 0.05). This was not the case after the FP application. Cortisol concentrations presented a pronounced diurnal rhythm whatever the foundation used. At DO, no significant differences were observed between the groups. At D6, cortisol concentrations measured 30 min and 1 h after the FA application were significantly lower (P < 0.05: C6.2, P < 0.05 C6.3, respectively) than those reported after FP application. AUC, a global stress response indicator, was significantly lower in FA group as compared to FP group after 5 days of application. Subjects found a decrease in tiredness signs and thought that FA has a good coverage.

CONCLUSION

Our results show that incorporation of C8-silk lipoamino acid as agent of pigment functionalization brings new benefits to a foundation. Adopting a psychophysiological approach, which is not invasive to the subjects, we show the measurement of cortisol at the same time that psychological indicators provide a scientific approach to examine the beneficial effects of a cosmetic product.

Allergic rhinitis increases the risk of incident panic disorder among young individuals: A nationwide population-based cohort study in Taiwan

BACKGROUND

Studies have reported an association between allergy and panic disorder. However, few studies have explored the relationship between allergic rhinitis and panic disorder. Previous studies were limited by cross-sectional study designs, self-reported symptoms, absence of matched controls, and lack of consideration of the influence of steroid and comorbidities. This study aimed to explore the longitudinal association between allergic rhinitis and panic disorder in a large population-based cohort of young people.

METHODS

In this study, 79,917 new cases of allergic rhinitis between 1998 and 2012 in individuals younger than 20 years were identified from Taiwan's National Health Insurance Research Database. One control (nonallergic rhinitis) per case (allergic rhinitis) was randomly selected from the remaining sample, matching for age, sex, residence, and insurance premium. Both groups were followed until the end of 2013 for incidence of panic disorder. Cox regression analysis was performed, adjusting for sex, age, residence, insurance premium, systemic steroids, asthma, atopic dermatitis, allergic conjunctivitis, attention deficit hyperactivity disorder, depression, and Charlson index.

RESULTS

Allergic rhinitis was associated with a 2-fold increase in risk for panic disorder after adjustment for other variables. Additional independent risk factor of panic disorders were female sex, older age group, and depression.

LIMITATIONS

Lifestyle, substance use, smoking by the patient or family members, and psychosocial stressors were not evaluated.

CONCLUSIONS

Allergic rhinitis was associated with increased risk of panic disorder. Assessment and intervention of allergy rhinitis among young people with panic disorder are critical.

Comparison of Cortisol Stress Response in Patients with Panic Disorder, Cannabis-Induced Panic Disorder, and Healthy Controls

BACKGROUND/AIMS

Little research effort has so far been dedicated to the analysis of the hypothalamic-pituitary-adrenal axis of aetiologically differing subgroups of patients with panic disorder (PD). The current study aimed at a deeper understanding of the cortisol stress response in cannabis-induced PD (CIPD) patients.

METHODS

Matched groups of 7 PD patients (mean age ± SD: 32.95 ± 9.04 years), 7 CIPD patients (31.94 ± 8.40 years), and 7 healthy controls (HC) (31.13 ± 8.57 years) were included in the study. The Trier Social Stress Test (TSST) was used for stress induction. Salivary cortisol samples were collected and panic- and depression-related questionnaires were applied.

RESULTS

A stress response to the TSST was found in 28.6% of PD patients, in 51.1% of CIPD patients, and in 100% of HC subjects. Statistical analyses revealed a cortisol hyporesponsiveness in PD and CIPD patients. While cortisol values of PD patients and HC participants differed significantly, CIPD patients' cortisol courses balanced between those of PD patients and HC subjects.

CONCLUSIONS

Current findings show a distinctive pattern of the stress-induced cortisol reaction in CIPD patients, which is markedly different from the hormonal response in PD patients as well as HC subjects. Previous findings of cortisol hyporesponsiveness in PD patients compared to HC subjects were confirmed.

Coupling corticotropin-releasing-hormone and angiotensin converting enzyme 2 dampens stress responsiveness in male mice

This study used mice to evaluate whether coupling expression of corticotropin-releasing hormone (CRH) and angiotensin converting enzyme 2 (ACE2) creates central interactions that blunt endocrine and behavioral responses to psychogenic stress. Central administration of diminazene aceturate, an ACE2 activator, had no effect on restraint-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis; however, mice that ubiquitously overexpress ACE2 had reduced plasma corticosterone (CORT) and pituitary expression of POMC mRNA. The Cre-LoxP system was used to restrict ACE2 overexpression to CRH synthesizing cells and probe whether HPA axis suppression was the result of central ACE2 and CRH interactions. Within the paraventricular nucleus of the hypothalamus (PVN), mice with ACE2 overexpression directed to CRH had a ≈2.5 fold increase in ACE2 mRNA, which co-localized with CRH mRNA. Relative to controls, mice overexpressing ACE2 in CRH cells had a decreased CORT response to restraint as well as decreased CRH mRNA in the PVN and CEA and POMC mRNA in the pituitary. Administration of ACTH similarly increased plasma CORT, indicating that the blunted HPA axis activation that accompanies ACE2 overexpression in CRH cells is centrally mediated. Anxiety-like behavior was assessed to determine whether the decreased HPA axis activation was predictive of anxiolysis. Mice with ACE2 overexpression directed to CRH cells displayed decreased anxiety-like behavior in the elevated plus maze and open field when compared to that of controls. Collectively, these results suggest that exogenous ACE2 suppresses CRH synthesis, which alters the central processing of psychogenic stress, thereby blunting HPA axis activation and attenuating anxiety-like behavior.

Omega-3 fatty acids and anxiety: A systematic review of the possible mechanisms at play

Introduction: Anxiety is prevalent, costly, and associated with significant adverse outcomes. The importance of nutrition is underestimated in the management of mental health disorders. In particular, omega-3 fatty acids (ω-3 FAs) are a critical component for healthy development and have been shown to reduce anxiety symptoms. Objective: This paper reviews the current state of the research to identify potential mechanisms underlying the relationship between ω-3 FAs and anxiety reduction. Method: Studies were identified using PubMed, PsycINFO, and CINAHL databases. Results: Of the 197 full-text studies screened, six met criteria for inclusion. Four mechanisms were identified based on primary outcomes reported by each study, Inflammatory Response, Brain-Derived Neurotrophic Factor (BDNF), Cortisol, and Cardiovascular Activity. Conclusion: Five key recommendations are provided to guide future research examining ω-3 FAs and anxiety. They include: (1) standardization of dosage and duration of ω-3 supplementation, (2) more rigorous measurement of variables, (3) effective blinding of participants, (4) designing experiments that test mediation, and (5) increasing sample diversity.

Social Dominance Modulates Stress-induced Neural Activity in Medial Prefrontal Cortex Projections to the Basolateral Amygdala

Stress is a contributing factor in the etiology of several mood and anxiety disorders, and social defeat models are used to investigate the biological basis of stress-related psychopathologies. Male Syrian hamsters are highly aggressive and territorial, but after social defeat they exhibit a conditioned defeat (CD) response which is characterized by increased submissive behavior and a failure to defend their home territory against a smaller, non-aggressive intruder. Hamsters with dominant social status show increased c-Fos expression in the infralimbic (IL) cortex following social defeat and display a reduced CD response at testing compared to subordinates and controls. In this study, we tested the prediction that dominants would show increased defeat-induced neural activity in IL, but not prelimbic (PL) or ventral hippocampus (vHPC), neurons that send efferent projections to the basolateral amygdala (BLA) compared to subordinates. We performed dual immunohistochemistry for c-Fos and cholera toxin B (CTB) and found that dominants display a significantly greater proportion of double-labeled c-Fos + CTB cells in both the IL and PL. Furthermore, dominants display more c-Fos-positive cells in both the IL and PL, but not vHPC, compared to subordinates. These findings suggest that dominant hamsters selectively activate IL and PL, but not vHPC, projections to the amygdala during social defeat, which may be responsible for their reduced CD response. This project extends our understanding of the neural circuits underlying resistance to social stress, which is an important step toward delineating a circuit-based approach for the prevention and treatment of stress-related psychopathologies.

Hormonal responses to striking combat sports competition: a systematic review and meta-analysis

Striking combat sports are challenging, commonly stressing the endocrinological system based on a mixture of body-contact actions and physiological efforts. The aims of this systematic review and meta-analysis were to discuss the hormonal responses related to striking combat sports competitions and to investigate the moderator and mediator variables of the hormonal response-competition/outcome relationship. Three electronic databases (i.e., PubMed, Google Scholar and ScienceDirect) were systematically searched (up to February 2016) followed by a manual search of retrieved papers. The data showed a moderate increase in cortisol (C) (ES = 0.79; 95% CI 0.31-1.28; p = 0.001), an extremely large increase in adrenaline (ES = 4.22; 95% CI 2.62-5.82; p < 0.001), and a very large increase in noradrenaline (ES = 3.40; 95% CI 1.03-5.76; p = 0.005) and human growth hormone (HGH) levels (ES = 3.69; 95% CI 1.96-5.42; p < 0.001) immediately following the combat events, compared to the control condition i.e., "pre-combat". Furthermore, amateur athletes had a larger increase in C levels compared to highly trained athletes (ES = 2.91 [very large] vs ES = 0.56 [small]), while evening events showed greater alterations in C levels compared to morning events (ES = 1.91 [large] vs ES = 0.48 [small]), without significant differences between them (p = 0.26 and p = 0.06, respectively). The present meta-analysis also showed a small, insignificant increase in testosterone (T) (ES = 0.47 [small]; 95% CI -0.45-0.99; p = 0.074) and a decrease in insulin-like growth factor 1 levels (ES = -0.20 [trivial]; 95% CI -0.78-0.37; p = 0.486) immediately following the combat events, compared to the control condition. The type of combat sports practised, participants' gender, and the nature of competition contests (i.e., official vs simulation) did not moderate the relationship between competition and hormonal response. Additionaly, sub-analysis results showed a significant difference between younger and older athletes (Q = 4.05, p = 0.044), suggesting that after combat, younger individuals (less than 17 years of age) had a small decrease in T levels (ES = -0.58), compared with the moderate increase observed in older individuals (ES = 0.76). In conclusion, irrespective of striking combat sports types, the results showed that both official and simulated bouts are a real stressor of the hormonal system of practitioners. Coaches and applied practitioners should adopt "pre-competitive cognitive/coping strategies" to improve the psychological state that mediates the hormonal changes-competition/outcome relationship of their athletes in order to mitigate athletes' stress.

Genetic, management, and nutritional factors affecting intramuscular fat deposition in beef cattle - A review

Intramuscular fat (IMF) content in skeletal muscle including the longissimus dorsi muscle (LM), also known as marbling fat, is one of the most important factors determining beef quality in several countries including Korea, Japan, Australia, and the United States. Genetics and breed, management, and nutrition affect IMF deposition. Japanese Black cattle breed has the highest IMF content in the world, and Korean cattle (also called Hanwoo) the second highest. Here, we review results of research on genetic factors (breed and sex differences and heritability) that affect IMF deposition. Cattle management factors are also important for IMF deposition. Castration of bulls increases IMF deposition in most cattle breeds. The effects of several management factors, including weaning age, castration, slaughter weight and age, and environmental conditions on IMF deposition are also reviewed. Nutritional factors, including fat metabolism, digestion and absorption of feed, glucose/starch availability, and vitamin A, D, and C levels are important for IMF deposition. Manipulating IMF deposition through developmental programming via metabolic imprinting is a recently proposed nutritional method to change potential IMF deposition during the fetal and neonatal periods in rodents and domestic animals. Application of fetal nutritional programming to increase IMF deposition of progeny in later life is reviewed. The coordination of several factors affects IMF deposition. Thus, a combination of several strategies may be needed to manipulate IMF deposition, depending on the consumer’s beef preference. In particular, stage-specific feeding programs with concentrate-based diets developed by Japan and Korea are described in this article.

A human exposure based mixture of persistent organic pollutants affects the stress response in female mice and their offspring

Persistent organic pollutants (POPs) are found in the food chain of both humans and animals and exert a wide spectrum of potentially adverse effects. The present experiment aimed to investigate whether a defined mixture of 29 POPs, based on the dietary intake of Scandinavians, could affect the stress response in female mice exposed through ingestion, and in their offspring. Female mice 129:C57BL/6F0 hybrids were exposed from weaning, throughout pregnancy, and up until necropsy, to either 5000 × or 100 000 × the estimated daily intake for Scandinavians. The offspring were fed a reference diet containing no POPs. Both the mothers and their offspring were tested for basal and stress responsive corticosterone levels, and in an open field test to measure locomotor activity and anxiety-like behaviours. We found mothers to have elevated basal corticosterone levels, as well as a prolonged stress response following POP exposure. In the offspring, there was no effect of POPs on the stress response in females, but the exposed males had an over-sensitised stress response. There was no effect on behaviour in either the mothers or the offspring. In conclusion, we found a human relevant POP mixture can lead to subtle dysregulation of the hypothalamus-pituitary-adrenal axis in mice. As HPA axis dysregulation is commonly associated with neurological disorders, further studies should explore the relevance of this outcome for humans.

Psychological pathways from racial discrimination to cortisol in African American males and females

The association between racial discrimination (discrimination) and stress-related alterations in the neuroendocrine response-namely, cortisol secretion-is well documented in African Americans (AAs). Dysregulation in production of cortisol has been implicated as a contributor to racial health disparities. Guided by Clark et al. (Am Psychol 54(10):805-816, 1999. doi: 10.1037/0003-066X.54.10.805 ) biopsychosocial model of racism and health, the present study examined the psychological pathways that link discrimination to total cortisol concentrations in AA males and females. In a sample of 312 AA emerging adults (45.5% males; ages 21-23), symptoms of anxiety, but not depression, mediated the relation between discrimination and total concentrations of cortisol. In addition, the results did not reveal sex differences in the direct and indirect pathways. These findings advance our understanding of racial health disparities by suggesting that the psychological consequences of discrimination can uniquely promote physiologic dysregulation in AAs.

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.

Cortisol stress response in post-traumatic stress disorder, panic disorder, and major depressive disorder patients

BACKGROUND

Previous research has focussed extensively on the distinction of HPA-axis functioning between patient groups and healthy volunteers, with relatively little emphasis on a direct comparison of patient groups. The current study's aim was to analyse differences in the cortisol stress response as a function of primary diagnosis of panic disorder (PD), post-traumatic stress disorder (PTSD), and major depressive disorder (MDD).

METHODS

A total of n=30 PD (mean age±SD: 36.07±12.56), n=23 PTSD (41.22±10.17), n=18 MDD patients (39.00±14.93) and n=47 healthy control (HC) individuals (35.51±13.15) participated in this study. All the study participants were female. The Trier Social Stress Test (TSST) was used for reliable laboratory stress induction. Blood sampling accompanied the TSST for cortisol and ACTH assessment. Panic-related, PTSD-specific questionnaires and the Beck Depression Inventory II were handed out for the characterisation of the study groups. Repeated measure ANCOVAs were conducted to test for main effects of time or group and for interaction effects. Regression analyses were conducted to take comorbid depression into account.

RESULTS

26.7% of the PD patients, 43.5% of the PTSD patients, 72.2% of the MDD patients and 80.6% of the HC participants showed a cortisol stress response upon the TSST. ANCOVA revealed a cortisol hypo-responsiveness both in PD and PTSD patients, while no significant group differences were seen in the ACTH concentrations. Additional analyses showed no impact of comorbid depressiveness on the cortisol stress response. MDD patients did not differ in the hormonal stress response neither compared to the HC participants nor to the PD and PTSD patients.

CONCLUSION

Our main findings provide evidence of a dissociation between the cortisol and ACTH concentrations in response to the TSST in PTSD and in PD patients, independent of comorbid depression. Our results further support overall research findings of a cortisol hypo-responsiveness in PD patients. A hypo-response pattern was also seen in the PTSD patients agreeing with previous finding on the cortisol stress reactivity following TSST stress induction in these patients. Patients with a primary MDD diagnosis showed descriptively higher cortisol concentrations compared to the anxiety patients, and lower cortisol concentrations as the healthy individuals. The limitations of the study and implications for future studies will be discussed.

Neuroendocrine Response to School Load in Prepubertal Children: Focus on Trait Anxiety

At the time of school-age, the most frequent stress stimuli are related to school environment and educational process. Anxiety may play a big role in coping with stressful situations associated with school load. To approach this issue, we performed a real-life study at school during the classwork. The sample consisted of 36 healthy children aged 10 years, which were divided to low and high trait anxiety group based on the median value of the anxiety score. The investigations were carried out in the classroom during a stress condition (final exams) and non-stress condition (without any exam). In the whole sample, the condition with exam was associated with higher cortisol and lower testosterone concentrations in saliva compared to the condition without exam. The activity of salivary alpha-amylase increased at the end of the exam. Anxious children showed higher concentrations of aldosterone and lower activity of alpha-amylase compared to children with low trait anxiety. Cortisol levels were higher in anxious children in the first morning samples before starting the lessons. Children with high and low trait anxiety did not differ in extraversion, neuroticism, as well as non-verbal intelligence and school success. Thus, the anxious children at school showed a more rapid decrease of anticipatory stress-induced cortisol concentrations, higher aldosterone levels, and lower alpha-amylase activities compared to non-anxious children. These changes, particularly high concentrations of aldosterone in children with high trait anxiety, may have an impact on their psychophysiological development.

Metabolomics reveals distinct neurochemical profiles associated with stress resilience

Acute social defeat represents a naturalistic form of conditioned fear and is an excellent model in which to investigate the biological basis of stress resilience. While there is growing interest in identifying biomarkers of stress resilience, until recently, it has not been feasible to associate levels of large numbers of neurochemicals and metabolites to stress-related phenotypes. The objective of the present study was to use an untargeted metabolomics approach to identify known and unknown neurochemicals in select brain regions that distinguish susceptible and resistant individuals in two rodent models of acute social defeat. In the first experiment, male mice were first phenotyped as resistant or susceptible. Then, mice were subjected to acute social defeat, and tissues were immediately collected from the ventromedial prefrontal cortex (vmPFC), basolateral/central amygdala (BLA/CeA), nucleus accumbens (NAc), and dorsal hippocampus (dHPC). Ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HRMS) was used for the detection of water-soluble neurochemicals. In the second experiment, male Syrian hamsters were paired in daily agonistic encounters for 2 weeks, during which they formed stable dominant-subordinate relationships. Then, 24 h after the last dominance encounter, animals were exposed to acute social defeat stress. Immediately after social defeat, tissue was collected from the vmPFC, BLA/CeA, NAc, and dHPC for analysis using UPLC-HRMS. Although no single biomarker characterized stress-related phenotypes in both species, commonalities were found. For instance, in both model systems, animals resistant to social defeat stress also show increased concentration of molecules to protect against oxidative stress in the NAc and vmPFC. Additionally, in both mice and hamsters, unidentified spectral features were preliminarily annotated as potential targets for future experiments. Overall, these findings suggest that a metabolomics approach can identify functional groups of neurochemicals that may serve as novel targets for the diagnosis, treatment, or prevention of stress-related mental illness.

Increased methylation of glucocorticoid receptor gene promoter 1F in peripheral blood of patients with generalized anxiety disorder

Previous findings on the dysfunction of hypothalamic-pituitary-adrenal (HPA) axis in generalized anxiety disorder (GAD) are controversial, and the molecular mechanisms underlying such dysfunction remain unclear. We analyzed the methylation status of the NR3C1 1_F promoter and the expression of glucocorticoid receptor-α isoform (GRα) in peripheral blood mononuclear cells (PMBCs), the basal cortisol level in serum, and a functional neuroendocrine marker for GR sensitivity in the PMBCs in 64 patients with current GAD and 85 healthy controls. We found that patients with GAD had significantly elevated levels of morning basal serum cortisol (P < 0.0001) and diminished GR sensitivity in the PBMCs (P < 0.0001) compared with healthy controls. The overall methylation levels across NR3C1 1_F promoter (P < 0.0001) and percent methylation at each of the 5 CpG sites including CpG12, 21, 30, 31, and 32 (P < 0.001) significantly increased. Accordingly, the mRNA levels of GRα significantly decreased (P < 0.0001) in the PBMCs in patients with GAD compared with healthy controls, with the effects specific in patients without childhood traumatic experience. Moreover, both serum basal cortisol levels and GR sensitivity in the PBMCs were negatively correlated with the overall methylation levels of the NR3C1 1_F promoter (P < 0.0001) and positively correlated with GRα mRNA levels (P = 0.007) in the PBMCs. In sum, our study revealed the increased activity of the HPA axis and diminished peripheral glucocorticoid responsiveness of GR underlying episodes of GAD. Furthermore, such dysfunction of the HPA axis is associated with both increased DNA methylation of NR3C1 1_F promoter and decreased GRα expression.

Drug-induced panic attacks: Analysis of cases registered in the French pharmacovigilance database

BACKGROUND

The potential role of drugs in the onset of panic attacks (PAs) is poorly understood.

AIM

The objective of our study was to characterize drug-induced PAs.

METHOD

We performed an analysis of PAs registered in the French pharmacovigilance database between 01/01/1985 and 05/11/2014.

RESULTS

Among the 163 recorded cases, 136 (83.4%) were directly related to drugs, mainly antidepressants (11.3%, mainly serotonin reuptake inhibitors), mefloquine (7.2%), isotretinoin (5.2%), rimonabant (3.6%) and corticosteroids (4.7%). PAs are labelled in the Summary of Product Characteristics (SmPC) for a minority (8.6%) of these drugs. In 31.4% of these cases, withdrawal of the suspected drug was performed more than a week after the onset of PAs. PAs could also be secondary to another adverse drug reaction (ADR; n = 14, 8.6%), mainly an allergy to antineoplastic or immunomodulating agents. In 13 cases (8.0%), PAs occurred during a drug-withdrawal syndrome, mainly after benzodiazepines or opioids. Most cases (73%) involved patients without any previous psychiatric disorder.

CONCLUSION

This is the first pharmacoepidemiological study about iatrogenic PAs. Beside antidepressants, the most often encountered drugs are not indicated for psychiatric diseases. This study also reveals that iatrogenic PAs mostly occur in patients without any psychiatric medical history and that PAs can be triggered by another ADR. Lastly, the many cases with delayed management underline the need to raise awareness of this relatively unknown ADR among physicians, especially since PAs are generally not labelled in SmPCs of the suspected drugs.

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.