CRH, Stress, and Major Depression: A Psychobiological Interplay

Genetic Contributions to Attachment Stability Over Time: the Roles of CRHR1 Polymorphisms

Corticotropin-releasing hormone receptor 1 (CRHR1), a hormone receptor essential to the activation of HPA axis and the subsequent release of cortisol, plays critical roles in emotional and behavioral responses relevant to attachment. However, the specific roles of CRHR1 polymorphisms in attachment remain unclear. To further clarify these genetic effects, this research conducted a three-wave study to investigate whether the CRHR1 polymorphisms (i.e., rs110402 and rs242924) are associated with the stability and variability of attachment by using a sample of freshmen (N = 604; Mage = 18.57 years, SD = 1.90; 68.8% girls). The results showed that rs110402 and rs242924 were associated with the stability of closeness-dependence. The G alleles of the both polymorphisms were found not to be related to lower attachment stability. However, these polymorphisms were not associated with the variability of attachment. Overall, these findings provide evidence for the contribution of CRHR1 to attachment stability.

Selecting Antidepressants Based on Medical History and Stress Mechanism

Purpose At present, clinicians typically prescribe antidepressants based on the widely accepted "serotonin hypothesis." This study explores an alternative mechanism, the stress mechanism, for selecting antidepressants based on patients' medical history. Methods This study investigated clinicians' prescribing patterns for the 15 most common antidepressants, including amitriptyline, bupropion, citalopram, desvenlafaxine, doxepin, duloxetine, escitalopram, fluoxetine, mirtazapine, nortriptyline, paroxetine, ropinirole, sertraline, trazodone, and Venlafaxine. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to identify factors that affect the remission of depression symptoms after receiving an antidepressant. Results The study found that a wide range of factors influenced the propensity of clinicians to prescribe antidepressants, with the number of predictors ranging from 51 to 206 variables. The prevalence of prescribing an antidepressant ranged from 0.5% for doxepin to 24% for the combination of more than one antidepressant. The area under the receiver operating curves (AROC) ranged from 77.2% for venlafaxine to 90.5% for ropinirole, with an average AROC of 82% for predicting the propensity of medications. A variety of diagnoses and prior medications affected remission, in agreement that the central mechanism for the impact of medications on the brain is through stress reduction. For example, psychotherapy, whether done individually or in a group, whether done for a short or long time, and whether done with evaluation/assessment or not, had an impact on remission. Specifically, teenagers and octogenarians were less likely to benefit from bupropion, citalopram, escitalopram, fluoxetine, and sertraline compared to patients between 40 and 65 years old. The findings of this study suggest that considering a patient's medical history and individual characteristics is crucial for selecting the most effective antidepressant treatment. Conclusions Many studies have raised doubt about the serotonin hypothesis as the central mechanism for depression treatment. The identification of a wide range of predictors for prescribing antidepressants highlights the complexity of depression treatment and the need for individualized approaches that consider patients' comorbidities and previous treatments. The significant impact of comorbidities on the response to treatment makes it improbable that the mechanism of action of antidepressants is solely based on the serotonin hypothesis. It is hard to explain how comorbidities lead to the depletion of serotonin. These findings open up a variety of courses of action for the clinical treatment of depression, each addressing a different source of chronic stress in the brain. Overall, this study contributes to a better understanding of depression treatment and provides valuable insights for clinicians in selecting antidepressants based on patients' medical history.

Effects of Selective Serotonin Reuptake Inhibitor Treatment on Ovarian Reserves in Patients with Depression

Background and Objectives: The goal of this study was to investigate the effect of selective serotonin reuptake inhibitor treatment on the ovarian reserves of women of reproductive age with major depressive disorder. Materials and Methods: The current study is a prospective controlled trial including 48 women with major depressive disorder and 48 age-matched healthy controls. Ovarian reserve tests are performed prior to treatment and after six cycles of selective serotonin reuptake inhibitor treatment in the major depressive disorder group. Serum follicle-stimulating hormone, luteinizing hormone, estradiol, and anti-Müllerian hormone levels were evaluated from blood samples, and endometrial thickness, total antral follicle count, and volume of both ovaries were assessed using transvaginal ultrasonography. Results: When the first measurements were compared, menstrual duration and menstrual bleeding increased (p = 0.007 and 0.005, respectively) and luteinizing hormone decreased (p = 0.045) in the major depressive disorder group, while follicle-stimulating hormone, estradiol, anti-Müllerian hormone, endometrial thickness, total antral follicle count, and mean ovarian volume did not differ significantly between groups (p > 0.05). When the major depressive disorder group’s first and final measurements were compared, follicle-stimulating hormone, estradiol, and endometrial thickness increased (p = 0.05, 0.0001, and 0.005, respectively), luteinizing hormone remained constant (p = 0.541), and anti-Müllerian hormone and total antral follicle count decreased (p = 0.024 and 0.042, respectively). Conclusions: In this study, we observed that the ovarian reserve test results of patients diagnosed with major depression for the first time after 6 months of SSRI treatment were significantly different from the results of the pretreatment and control groups.

CRHR1 antagonist alleviates LPS-induced depression-like behaviour in mice

BACKGROUND

Maladaptation of the HPA (hypothalamic-pituitary-adrenal) axis plays an important role in depression-like behaviour, but the specific molecular mechanisms are unknown. Here, we determined the roles of CRHR1 (corticotrophin releasing hormone receptor 1) and nectin3 in LPS (lipopolysaccharide)-induced depression-like behaviour in mice.

METHODS

C57BL/6 male mice were intraperitoneally injected with LPS (0.83 g/kg), and the open field, novelty-suppressed feeding, forced swimming, and tail suspension tests were performed after intraperitoneal injections of saline or antalarmin (20 mg/kg). The hippocampal mRNA levels of CRHR1 and nectin3 were determined by quantitative reverse transcription-PCR. The hippocampal protein levels of CRHR1, nectin3, and calbindin were measured by western blotting. The CORT (corticosterone) levels in the blood were measured by ELISA kits.

RESULTS

Antalarmin alleviated LPS-induced depression-like behaviour in male mice. Furthermore, antalarmin significantly inhibited changes in CRHR1, nectin3 and calbindin levels in the hippocampus and reduced the increase in CORT levels in LPS-treated mice.

CONCLUSION

CRHR1antagonist showed antidepressant effects in LPS-induced depressive mice, and CRHR1/nectin3 signalling may play a crucial role in this process.

The Glutamatergic System in Treatment-Resistant Depression and Comparative Effectiveness of Ketamine and Esketamine: Role of Inflammation?

The glutamatergic system is the primary excitatory pathway within the CNS and is responsible for cognition, memory, learning, emotion, and mood. Because of its significant importance in widespread nervous system function, it is tightly regulated through multiple mechanisms, such as glutamate recycling, microglial interactions, and inflammatory pathways. Imbalance within the glutamatergic system has been implicated in a wide range of pathological conditions including neurodegenerative conditions, neuromuscular conditions, and mood disorders including depression. Major depressive disorder (MDD) is the most common mood disorder worldwide, has a high prevalence rate, and afflicts approximately 280 million people. While there are numerous treatments for the disease, 30-40% of patients are unresponsive to treatment and deemed treatment resistant; approximately another third experience only partial improvement (World Health Organization, Depression fact sheet [Internet], 2020). Esketamine, the S-enantiomer of ketamine, was approved by the Food and Drug Administration for treatment-resistant depression (TRD) in 2019 and has offered new hope to patients. It is the first treatment targeting the glutamatergic system through a complex mechanism. Numerous studies have implicated imbalance in the glutamatergic system in depression and treatment resistance. Esketamine and ketamine principally work through inhibition of the NMDA receptor, though more recent studies have implicated numerous other mechanisms mediating the antidepressant efficacy of these agents. These mechanisms include increase in brain-derived neurotrophic factor (BDNF), activation of mammalian target of the rapamycin complex (mTORC), and reduction in inflammation. Esketamine and ketamine have been shown to decrease inflammation in numerous ways principally through reducing pro-inflammatory cytokines (e.g., TNF-α, IL-6) (Loix et al., Acta Anaesthesiol Belg 62(1):47-58, 2011; Chen et al., Psychiatry Res 269:207-11, 2018; Kopra et al., J Psychopharmacol 35(8):934-45, 2021). This anti-inflammatory effect has also been shown to be involved in the antidepressive properties of both ketamine and esketamine (Chen et al., Psychiatry Res 269:207-11, 2018; Kopra et al., J Psychopharmacol 35(8):934-45, 2021).

Prevalence and predictors of depressive symptoms among married Egyptian women: a multicenter primary healthcare study

BACKGROUND

Depression affects about 3.8% of the world's population. Although marriage may contribute to subjective well-being, some marital variables could increase women's risk for depression. This study aimed to determine the prevalence of depressive symptoms and their correlates among married females attending primary healthcare facilities.

METHODS

A cross-sectional study was conducted on a purposive sample of 371 married women at the primary healthcare centers, Assiut Governorate, Upper Egypt. In this study, an interviewer-administered questionnaire was used for data collection. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9) and marital satisfaction using the ENRICH Marital Satisfaction Scale (EMS). Standardized measurements of weight and height were performed.

RESULTS

According to the PHQ-9 diagnostic criteria, the prevalence of depressive symptoms among the studied married females was 30.2%. The significant predictors of depressive symptoms were advanced husbands' ages, living with an extended family, exposure to spousal verbal violence, high body weight, and low marital satisfaction levels.

CONCLUSIONS

Approximately one-third of married Egyptian women experienced depressive symptoms. In addition to high body weight, some social and marital factors contributed to the increase in women's vulnerability to depressive symptoms. Egyptian primary healthcare physicians should be trained to identify females with depressive symptoms and refer them to specialists if need be. To combat depression in women, it may be helpful to construct qualified marital counseling centers. This may improve marital satisfaction, decrease the negative consequences of spousal violence, and ensure the value of independence for new families.

Gene polymorphisms and serum levels of BDNF and CRH in vitiligo patients

Background

Vitiligo is one of the most common hypomelanoses, in which the destruction of functioning melanocytes causes depigmentation of the skin, hair and mucous membranes. The genes encrypting brain-derived neurotrophic factor (BDNF) and corticotropin releasing hormone (CRH) might be the conceivable contributors to the development of vitiligo. This study was aimed at investigation of the serum levels of BDNF and CRH as well as their selected single nucleotide polymorphisms (SNPs) in vitiligo patients in comparison with the healthy controls.

Methods

The cross-sectional study was carried out between October 2020 and June 2021 in 93 vitiligo patients (age range from 23 to 48 years) and 132 healthy controls (age range from 24 to 52 years). The psychological status of study participants was evaluated using the Generalized Anxiety Disorder-7 (GAD-7) scale. Serum levels of BDNF and CRH were measured with the help of a commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kit. Genotyping for the rs11030094 polymorphism of the BDNF gene and for the rs242924 polymorphism of the corticotropin releasing hormone receptor 1 (CRH-R1) gene was performed by a real-time polymerase chain reaction (PCR).

Results

There was a significant relationship between the CRH-R1 rs242924 and BDNF rs11030094 polymorphisms and vitiligo. Moreover, serum levels of neurotransmitters differed significantly between vitiligo and control groups and were associated with the CRH-R1 rs242924 and BDNF rs11030094 SNPs.

Conclusions

Our findings demonstrated the association between CRH-R1 rs242924 and BDNF rs11030094 polymorphisms and vitiligo. Further studies need to be carried out in vitiligo patients to confirm the results observed.

Depression and Its Effect on the Menstrual Cycle

A strong association is noted between depression and early perimenopause as well as menopause. The association was found to be the greatest in women with natural menopause at the age less than 40 years. Excessive corticotropin-releasing hormone (CRH) levels in depression lead to inhibition of the hypothalamic-pituitary-gonadal (HPG) axis and increased cortisol levels which further inhibits the action of gonadotropin-releasing hormone (GnRH) neurons, gonadotrophs, and gonads. The resulting changes in luteinizing hormone (LH) amplitude, follicle-stimulating hormone (FSH) levels, and LH pulse frequency were noted in patients with depression.

Besides depression, earlier surgical menopause is associated with cognitive decline. In addition, it is seen that menopausal changes predisposed females to an increased risk of depression. The association between dysmenorrhea and depression was found to be bidirectional and congruent in most studies. Patients with dysmenorrhea and coexisting depression had enhanced pain perception along with a poor response to pain relief measures. Even the treatment of underlying depression has been shown to cause menorrhagia. On the other hand, amenorrhea has also been reported as a side effect of sertraline and electroconvulsive therapy. Menstrual disorders contribute to a significant number of outpatient gynecological visits per year in the United States. Co-existing or history of depression can either be the cause of or interfere in the treatment of these disorders. Furthermore, the treatment of depression can be the etiology of various menstrual abnormalities, while menstrual disorders themselves could be the cause of depression. The increasing prevalence of depression, women’s health, multiple female-specific subtypes, and the preexisting burden of menstrual disorders necessitates more detailed studies on the effects of depression on the menstrual cycle. 

The expression of mimecan in adrenal tissue plays a role in an organism's responses to stress

Mimecan encodes a secretory protein that is secreted into the human serum as two mature proteins with molecular masses of 25 and 12 kDa. We found 12-kDa mimecan to be a novel satiety hormone mediated by the upregulation of the expression of interleukin (IL)-1β and IL-6 in the hypothalamus. Mimecan was found to be expressed in human pituitary corticotroph cells and was up-regulated by glucocorticoids, while the secretion of adrenocorticotropic hormone (ACTH) in pituitary corticotroph AtT-20 cells was induced by mimecan. However, the effects of mimecan in adrenal tissue on the hypothalamic–pituitary–adrenal (HPA) axis functions remain unknown. We demonstrated that the expression of mimecan in adrenal tissues is significantly downregulated by hypoglycemia and scalded stress. It was down-regulated by ACTH, but upregulated by glucocorticoids through in vivo and in vitro studies. We further found that 12-kDa mimecan fused protein increased the corticosterone secretion of adrenal cells in vivo and in vitro. Interestingly, compared to litter-mate mice, the diurnal rhythm of corticosterone secretion was disrupted under basal conditions, and the response to restraint stress was stronger in mimecan knockout mice. These findings suggest that mimecan stimulates corticosterone secretion in the adrenal tissues under basal conditions; however, the down-regulated expression of mimecan by increased ACTH secretion after stress in adrenal tissues might play a role in maintaining the homeostasis of an organism’s responses to stress.

The Sum of Fears in Cancer Patients Inside the Context of the COVID-19

The pandemic resulting from COVID-19 has led to the collapse of the health system in dozens of countries. Parallel to clinical risk, the appearance or intensification of psychiatric symptoms has also been documented. The identification of groups at risk is essential for the establishment of preventive and therapeutic strategies. Cancer patients appear to be especially vulnerable both from a clinical and psychiatric perspective. Problems related to contamination and the cancer treatments themselves are intertwined, causing a sum of patients' fears to arise, which can cause mental effects. This study aims to review and investigate the impact of COVID-19 on the mental health of cancer patients and indicate possible support strategies.

Mathematical modeling of depressive disorders: Circadian driving, bistability and dynamical transitions

The hypothalamus-pituitary-adrenal (HPA) axis is a key neuroendocrine system implicated in stress response, major depression disorder, and post-traumatic stress disorder. We present a new, compact dynamical systems model for the response of the HPA axis to external stimuli, representing stressors or therapeutic intervention, in the presence of a circadian input. Our work builds upon previous HPA axis models where hormonal dynamics are separated into slow and fast components. Several simplifications allow us to derive an effective model of two equations, similar to a multiplicative-input FitzHugh-Nagumo system, where two stable states, a healthy and a diseased one, arise. We analyze the effective model in the context of state transitions driven by external shocks to the hypothalamus, but also modulated by circadian rhythms. Our analyses provide mechanistic insight into the effects of the circadian cycle on input driven transitions of the HPA axis and suggest a circadian influence on exposure or cognitive behavioral therapy in depression, or post-traumatic stress disorder treatment.

Neuroendocrine and Inflammatory Effects of Childhood Trauma Following Psychosocial and Inflammatory Stress in Women with Remitted Major Depressive Disorder

The dysregulation of the inflammatory and neuroendocrine systems seen in major depressive disorder (MDD) may persist after remission and this is associated with a higher risk of relapse. This vulnerable subgroup may be characterized by a history of childhood trauma. In a single-blind randomized placebo-controlled crossover study, 21 women with remitted recurrent MDD and 18 healthy controls were exposed to psychosocial stress (Trier social stress test) or inflammatory stress (typhoid vaccine), or both, to investigate the effects of childhood trauma on the neuroendocrine and inflammatory responses. Childhood trauma was assessed using the Childhood Trauma Questionnaire and participants were dichotomized into a traumatized and non-traumatized group. Serum adrenocorticotropic hormone (ACTH), cortisol, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were measured at regular intervals after each intervention. The effects of trauma, time, and intervention on these parameters were modeled by fitting linear mixed models. Childhood trauma in itself did not have a main effect on the outcome measurements. However, an interactional effect of trauma with stressor type was found in the remitted MDD group: trauma was associated with higher cortisol levels only after adding immunological to psychosocial stress, and with lower TNF-α levels in response to vaccination. This suggests the existence of a vulnerable trauma-associated MDD endophenotype.

Ketamine Administration Reverses Corticosterone-Induced Alterations in Excitatory and Inhibitory Transmission in the Rat Dorsal Raphe Nucleus

Ketamine, a N-methyl-D-aspartate (NMDA) receptor antagonist, exerts rapid antidepressant effects in human patients and ameliorates depressive-like behavioral effects of chronic stress in animal models. Chronic stress and elevated corticosterone levels have been shown to modify serotonin (5-HT) neurotransmission, and ketamine's antidepressant-like activity involves a 5-HT-dependent mechanism. However, it is not known if and how ketamine affects the electrophysiological characteristics of neurons and synaptic transmission within the dorsal raphe nucleus (DRN), the main source of 5-HT forebrain projections. Our study was aimed at investigating the effects of a single ketamine administration on excitatory and inhibitory transmission in the DRN of rats which had previously been administered corticosterone twice daily for 7 days. Spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) were then recorded from DRN projection cells in ex vivo slice preparations obtained 24 h after ketamine injection. Repeated corticosterone administration increased sEPSC frequency and decreased sIPSC frequency in DRN projection cells. There were no changes either in the amplitude of postsynaptic currents or in the excitability of these cells. In slices prepared from rats with ketamine administered after the end of corticosterone treatment, the frequencies of sEPSCs and sIPSCs were similar to those in control preparations. These data indicate that a single administration of ketamine reversed the effects of corticosterone on excitatory and inhibitory transmission in the DRN.

Cytokine secretion and the risk of depression development in patients with connective tissue diseases

Research in the past two decades has revolutionized our understanding of depressive illnesses. Proinflammatory cytokines have become a point of interest in the interconnecting areas of neuropsychiatric and autoimmune diseases. The cytokine hypothesis of depression suggests that pro-inflammatory cytokines play a primary role in the mediation of the pathophysiological characteristics of major depression, in which an inflammatory process may be induced by external and internal stressors, such as psychological and inflammatory diseases, respectively. The higher prevalence of depression, particularly in patients with chronic autoimmune connective tissue disorders (CTD), suggests that depression may present a dysfunctional adaptation of cytokine-induced sickness, which could manifest in times of an exacerbated activation of the innate immune system. Inflammation is thought to contribute to the development of clinical depression through its ability to induce sickness behaviors corresponding to the neurovegetative features of depression, through the dysregulation of the hypothalamic-pituitary-adrenal axis, alterations in neurotransmitter synthesis and reuptake, and through its involvement in the neuroprogression pathways. This review explores the complex interrelationships in which inflammatory responses alter neuroendocrine and neuropsychological regulation contributing to depressive symptoms in CTD. The prevalence and characteristics of depression, and its correlation to the levels of inflammatory cytokines and disease activity among different CTD will be reviewed.

Depression as a Neuroendocrine Disorder: Emerging Neuropsychopharmacological Approaches beyond Monoamines

Depression is currently recognized as a crucial problem in everyday clinical practice, in light of ever-increasing rates of prevalence, as well as disability, morbidity, and mortality related to this disorder. Currently available antidepressant drugs are notoriously problematic, with suboptimal remission rates and troubling side-effect profiles. Their mechanisms of action focus on the monoamine hypothesis for depression, which centers on the disruption of serotonergic, noradrenergic, and dopaminergic neurotransmission in the brain. Nevertheless, views on the pathophysiology of depression have evolved notably, and the comprehension of depression as a complex neuroendocrine disorder with important systemic implications has sparked interest in a myriad of novel neuropsychopharmacological approaches. Innovative pharmacological targets beyond monoamines include glutamatergic and GABAergic neurotransmission, brain-derived neurotrophic factor, various endocrine axes, as well as several neurosteroids, neuropeptides, opioids, endocannabinoids and endovanilloids. This review summarizes current knowledge on these pharmacological targets and their potential utility in the clinical management of depression.

The 5-HT7 receptor antagonist SB 269970 ameliorates corticosterone-induced alterations in 5-HT7 receptor-mediated modulation of GABAergic transmission in the rat dorsal raphe nucleus

RATIONALE

Chronic stress and corticosterone have been shown to affect serotonin (5-HT) neurotransmission; however, the influence of stress on the activity of the dorsal raphe nucleus (DRN), the main source of 5-HT in the forebrain, is not well understood. In particular, it is unknown if and how stress modifies DRN 5-HT₇ receptors, which are involved in the modulation of the firing of local inhibitory interneurons responsible for regulating the activity of DRN projection cells.

OBJECTIVES

Our study aimed to investigate the effect of repeated corticosterone injections on the modulation of the inhibitory transmission within the DRN by 5-HT₇ receptors and whether it could be reversed by treatment with a 5-HT₇ receptor antagonist.

METHODS

Male Wistar rats received corticosterone injections repeated twice daily for 14 days. Spontaneous inhibitory postsynaptic currents (sIPSCs) were then recorded from DRN projection cells in ex vivo slice preparations obtained 24 h after the last injection.

RESULTS

Repeated corticosterone administration resulted in decreased frequency, but not amplitude, of sIPSCs in DRN projection cells. There were no changes in the excitability of these cells; however, corticosterone treatment suppressed the 5-HT₇ receptor-mediated increase in sIPSC frequency. Administration of the 5-HT₇ receptor antagonist SB 269970 for 7 days beginning on the eighth day of corticosterone treatment reversed the detrimental effects of corticosterone on 5-HT₇ receptor reactivity and GABAergic transmission in the DRN.

CONCLUSIONS

Elevated corticosterone level reduces DRN 5HT₇ receptor reactivity and decreases GABAergic transmission within the DRN, which can be reversed by the 5-HT₇ receptor antagonist SB 269970.

Traditional herbal formula Sini Powder extract produces antidepressant-like effects through stress-related mechanisms in rats

Sini Powder (SP), a traditional Chinese herbal formula, has long been used to treat depression in patients, although the underlying mechanisms remain to be elucidated. In the present study, we found that rats treated with SP extract for 7 days showed a significant increase in swimming time and reduction in immobility time in forced swimming test in a dose-dependent manner, without changes in locomotion. These effects could be attributed to SP's modulation of the hypothalamus-pituitary-adrenal axis, because a single pretreatment of SP extract could rescue increased serum corticosterone and plasma adrenocorticotropin levels induced by acute elevated platform stress. A single pretreatment of SP extract could also elevate the mRNA expression of hippocampal glucocorticoid receptors. In conclusion, our results suggest that SP extract may act as an anti-stress medication to produce antidepressant-like effects.

Neurobiological consequences of juvenile stress: A GABAergic perspective on risk and resilience

ALBRECHT, A., MÜLLER, I., ARDI, Z., ÇALIŞKAN, G., GRUBER, D., IVENS, S., SEGAL, M., BEHR, J., HEINEMANN, U., STORK, O., and RICHTER-LEVIN, G. Neurobiological consequences of juvenile stress: A GABAergic perspective on risk and resilience. NEUROSCI BIOBEHAV REV XXX-XXX, 2016.- Childhood adversity is among the most potent risk factors for developing mood and anxiety disorders later in life. Therefore, understanding how stress during childhood shapes and rewires the brain may optimize preventive and therapeutic strategies for these disorders. To this end, animal models of stress exposure in rodents during their post-weaning and pre-pubertal life phase have been developed. Such 'juvenile stress' has a long-lasting impact on mood and anxiety-like behavior and on stress coping in adulthood, accompanied by alterations of the GABAergic system within core regions for the stress processing such as the amygdala, prefrontal cortex and hippocampus. While many regionally diverse molecular and electrophysiological changes are observed, not all of them correlate with juvenile stress-induced behavioral disturbances. It rather seems that certain juvenile stress-induced alterations reflect the system's attempts to maintain homeostasis and thus promote stress resilience. Analysis tools such as individual behavioral profiling may allow the association of behavioral and neurobiological alterations more clearly and the dissection of alterations related to the pathology from those related to resilience.

HPA Axis Interactions with Behavioral Systems

Perhaps the most salient behaviors that individuals engage in involve the avoidance of aversive experiences and the pursuit of pleasurable experiences. Engagement in these behaviors is regulated to a significant extent by an individual's hormonal milieu. For example, glucocorticoid hormones are produced by the hypothalamic-pituitary-adrenocortical (HPA) axis, and influence most aspects of behavior. In turn, many behaviors can influence HPA axis activity. These bidirectional interactions not only coordinate an individual's physiological and behavioral states to each other, but can also tune them to environmental conditions thereby optimizing survival. The present review details the influence of the HPA axis on many types of behavior, including appetitively-motivated behaviors (e.g., food intake and drug use), aversively-motivated behaviors (e.g., anxiety-related and depressive-like) and cognitive behaviors (e.g., learning and memory). Conversely, the manuscript also describes how engaging in various behaviors influences HPA axis activity. Our current understanding of the neuronal and/or hormonal mechanisms that underlie these interactions is also summarized. © 2016 American Physiological Society. Compr Physiol 6:1897-1934, 2016.

Revisiting the health effects of psychological stress-its influence on susceptibility to ionizing radiation: a mini-review

Both psychological stress (PS) and ionizing radiation (IR) cause varied detrimental effects on humans. There has been no direct evidence so far showing PS alone could cause cancer; however, long-lasting PS may affect our overall health and ability to cope with cancer. Due to their living conditions and occupations, some people may encounter concurrent exposure to both PS and IR to a high extent. In addition to possible health effects resulting directly from exposure to IR on these people, fear of IR exposure is also a cause of PS. The question of whether PS would influence susceptibility to IR, radiocarcinogenesis in particular, is of great concern by both the academic world and the public. Recently, investigations using animal PS models demonstrated that PS could modulate susceptibility to IR, causing increased susceptibility to radiocarcinogenesis in Trp53-heterozygous mice, hematological toxicity in peripheral blood and elevated chromosome aberration (dicentrics) frequency in splenocytes of Trp53-wild-type mice. To actively reduce health risk from exposure to IR, further studies are needed to cumulate more evidence and provide insights into the mechanisms underlying the alterations in susceptibility due to PS modulation. This mini-review gives a general overview of the significance of PS effects on humans and experimental animals, with a special focus on summarizing the latest weight-of-evidence approaches to radiobiological studies on PS-induced alterations in susceptibility in experimental animal models. The susceptibility being investigated is mainly in the context of the impact of the modulatory effect of PS on radiocarcinogenesis; we seek to improve understanding of the combined effects of exposure to both PS and IR in order to facilitate, via active intervention, strategies for radiation risk reduction.

Hypothalamus-Pituitary-Adrenal Axis Hypersuppression Is Associated with Gastrointestinal Symptoms in Major Depression

Background/Aims

Gastrointestinal symptoms and hypothalamus-pituitary-adrenal (HPA) axis dysfunction are frequently observed in patients with major depression. The primary aim of the study was to investigate the relationship between HPA-axis function and self-perceived functional gastrointestinal symptoms in major depression.

Methods

Patients with major depression (n = 73) and controls representative of the general population (n = 146) underwent a weight-adjusted very low dose dexamethasone suppression test (DST). Patients and controls completed the gastrointestinal symptom rating scale-iritable bowel syndrome (GSRS-IBS) and the hospital anxiety depression scale. Medical records of the patients were screened over a ten year period for functional gastrointestinal disorder and pain conditions.

Results

Patients with high GSRS-IBS scores (above median) exhibited HPA-axis hypersuppression more often than controls (defined by the lowest 10% cutoff of the post-DST cortisol values among controls, adjusted OR 7.25, CI 1.97–26.7) whereas patients with low GSRS-IBS scores did not differ from controls concerning their post-DST cortisol values. Patients who had consulted primary care for functional gastrointestinal disorder (P = 0.039), lumbago (P = 0.006) and chronic multifocal pain (P = 0.057) also exhibited an increased frequency of hypersuppression.

Conclusions

HPA-axis hypersuppression is associated with functional gastrointestinal symptoms in patients with major depression.

Sulforaphane produces antidepressant- and anxiolytic-like effects in adult mice

Increasing evidence suggests that depression is accompanied by dysregulation of neuroimmune system. Sulforaphane (SFN) is a natural compound with antioxidative, anti-inflammatory and neuroprotective activities. The present study aims to investigate the effects of SFN on depressive- and anxiety-like behaviors as well as potential neuroimmune mechanisms in mice. Repeated SFN administration (10mg/kg, i.p.) significantly decreased the immobility time in the forced swimming test (FST), tail suspension test (TST), and latency time to feeding in the novelty suppressed feeding test (NSF), and increased the time in the central zone in the open field test (OPT). Using the chronic mild stress (CMS) paradigm, we confirmed that repeated SFN (10mg/kg, i.p.) administration significantly increased sucrose preference in the sucrose preference test (SPT), and immobility time in the FST and TST of mice subjected to CMS. Also, SFN treatment significantly reversed anxiety-like behaviors (assessed by the OPT and NSF) of chronically stressed mice. Finally, ELISA analysis showed that SFN administration blocked the increase in the serum levels of corticosterone (CORT), adrenocorticotropic hormone (ACTH), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in chronically stressed mice. In summary, these findings demonstrated that SFN has antidepressant- and anxiolytic-like activities in stressed mice model of depression, which likely occurs by inhibiting the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory response to stress. These data support further exploration for developing SFN as a novel agent to treat depression and anxiety disorders.

History of sexual, emotional or physical abuse and psychiatric comorbidity in substance-dependent patients

Sexual, emotional or physical abuse history is a risk factor for mental disorders in addicted patients. However, the relationship between addiction and abuse lifespan is not well known. This study aims to compare clinical and psychopathological features of addicted patients according to the experience of abuse and to the number of different types of abuse suffered. Bivariate and multivariate analyses were conducted. 512 addicted patients seeking treatment were included, 45.9% reported abuse throughout life (38.9% emotional, 22.3% physical and 13.5% sexual abuse). It was found that female gender; depressive symptoms and borderline personality disorder were independently associated with history of any abuse throughout life. As well, it was found that 14% have been suffered from all three types of abuse (sexual, emotional and physical), 34.5% from two and 55.5% from one type. Female gender and borderline personality disorder were independently associated independently with a greater number of different types of abuse. Results suggest that history of abuse is frequent among substance-dependent patients and these experiences are more prevalent in women and are associated with more psychiatric comorbidity.

The Research of the Effect of the Olive Juice on Anxiety and Depression Behavior

In order to evaluate the effect of olive juice on the anxiety and depression behavior, the paper uses olive juice concentrate as experimental material, and uses mice as experimental subjects. Mice are randomly divided into negative, positive, high, medium and low-dose group, administered orally for 7 days. And observe the impact on the mice elevated plus maze test, the opening acts test and forced swim test. The experimental results show that under conditions of the sub-acute administration, olive juice can induce anti-anxiety behavior of mice, but also has the potential to improve depression of mice.

Early life influences on cognition, behavior, and emotion in humans: from birth to age 20

The long-lasting effects of fetal exposure to early life influences (ELI) such as maternal anxiety, stress, and micronutrient deficiencies as well as mediating and moderating factors are quite well established in animal studies, but remain unclear in humans. Here, we report about effects on cognition, behavior, and emotion in offspring aged 5-20 years old in two prospective longitudinal birth cohorts.

Childhood adversity, depression, age and gender effects on white matter microstructure: a DTI study

Previous diffusion tensor imaging (DTI) studies have shown that various factors can affect white matter (WM) tract diffusivity. The aim of the present study was to investigate the effects of childhood adversity (CA), age and gender on WM diffusivity in tracts that are thought to be involved in emotional regulation in individuals with major depressive disorder (MDD) and healthy controls (HC). DTI was obtained from 46 subjects with MDD and 46 HC subjects. Data were pre-processed and deterministic tractography was applied in the cingulum, uncinate fasciculus (UF), fornix, superior longitudinal fasciculus (SLF) and fronto-occipital fasciculus (FOF). In subjects with a history of CA, fractional anisotropy (FA) was greater in the rostral cingulum (RC) and dorsal cingulum, whereas radial diffusivity (RD) was smaller in the RC when compared with subjects with no history of CA. In the UF, FOF and parahippocampal cingulum, FA was greater in the left hemisphere in the subjects with CA when compared with those without CA. Age affected FA, longitudinal diffusivity and RD in the UF, fornix, FOF and SLF, reflecting axonal and myelin degeneration with increasing age. Depression or gender did not have any effects on the diffusivity measures. Due to the cross-sectional nature of the study, a recall bias for CA and possible effects of medical treatment on diffusivity measures could have played a role. CA and age could increase the likelihood to develop WM microstructural anomalies in the brain affective network. Moreover, subjects with CA could be more vulnerable to FA changes.

Cognitive functioning and cortisol suppression in recurrent major depression

Major Depressive Disorder (MDD) is often associated with high levels of stress and disturbances in the hypothalamic-pituitary-adrenal (HPA) system, yielding high levels of cortisol in addition to cognitive dysfunction. The aim of the present study was to examine the relation between cortisol levels after the dexamethasone suppression test and cognitive function in recurrent unipolar MDD patients. Twenty-four patients meeting the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.) criteria for a recurrent MDD diagnosis were included in the study. The control group was matched for age, sex, and education level. Cortisol was measured in saliva collected with Salivette sampling devices. Saliva samples were collected four times during a 24-hr period over two consecutive days: at awakening, after 45 min, after 7 hr, and at 11:00 p.m. One milligram of dexamethasone was given on Day 1 at 11:00 p.m. The neuropsychological test battery consisted of standardized tests measuring cognitive functioning within verbal and visual memory, as well as executive functioning. Cortisol levels did not differ between patients and controls on Day 1. Cortisol levels in patients were higher than in controls at awakening on Day 2 (D2S1), after dexamethasone administration the previous evening. All significant correlations between cognitive measures and cortisol at D2S1 were negative, indicating that low suppression after intake of dexamethasone is related to poor cognitive functioning. Significant relations were found in three of the cognitive tests measuring verbal memory, semantic fluency, and inhibition. The present findings indicate that dysregulation of the HPA-axis is related to poor verbal memory functioning. There was no firm evidence that abnormal cortisol levels were associated with inhibition difficulties.

Gene environment interaction studies in depression and suicidal behavior: An update

Increasing evidence supports the involvement of both heritable and environmental risk factors in major depression (MD) and suicidal behavior (SB). Studies investigating gene-environment interaction (G × E) may be useful for elucidating the role of biological mechanisms in the risk for mental disorders. In the present paper, we review the literature regarding the interaction between genes modulating brain functions and stressful life events in the etiology of MD and SB and discuss their potential added benefit compared to genetic studies only. Within the context of G × E investigation, thus far, only a few reliable results have been obtained, although some genes have consistently shown interactive effects with environmental risk in MD and, to a lesser extent, in SB. Further investigation is required to disentangle the direct and mediated effects that are common or specific to MD and SB. Since traditional G × E studies overall suffer from important methodological limitations, further effort is required to develop novel methodological strategies with an interdisciplinary approach.

Psychodynamic psychiatry in the general medical setting

For more than half a century analytically trained psychiatrists have been making observations about psychodynamic factors impacting on medical illness and treatment. Some of these reports have been subsequently supported by evidence-based research while others have been found to be clinically useful to varying degrees even if not substantiated by research. In this article we have presented some of the highlights of the application of psychodynamics to the treatment of physical illness in the general medical setting. It is not meant to be a comprehensive review but we hope it will demonstrate how psychodynamic thinking has permeated many aspects of care in the general medical setting. Topics considered include onset of disease (giving up complex, specificity, role of stress, anniversary reactions), reactions to illness (psychological defenses, fantasies, role of psychotherapy), specific conditions (pregnancy, cancer, human immunodeficiency virus, conversion and alexithymia, heart disease, death and dying), and the doctor-patient relationship.

The hypothalamic-pituitary-adrenal axis and serotonin abnormalities: a selective overview for the implications of suicide prevention

Suicidal behavior and mood disorders are one of the world's largest public health problems. The biological vulnerability for these problems includes genetic factors involved in the regulation of the serotonergic system and stress system. The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates the body's response to stress and has complex interactions with brain serotonergic, noradrenergic and dopaminergic systems. Corticotropin-releasing hormone and vasopressin act synergistically to stimulate the secretion of ACTH that stimulates the biosynthesis of corticosteroids such as cortisol from cholesterol. Cortisol is a major stress hormone and has effects on many tissues, including on mineralocorticoid receptors and glucocorticoid receptors in the brain. Glucocorticoids produce behavioral changes, and one important target of glucocorticoids is the hypothalamus, which is a major controlling center of the HPA axis. Stress plays a major role in the various pathophysiological processes associated with mood disorders and suicidal behavior. Serotonergic dysfunction is a well-established substrate for mood disorders and suicidal behavior. Corticosteroids may play an important role in the relationship between stress, mood changes and perhaps suicidal behavior by interacting with 5-HT1A receptors. Abnormalities in the HPA axis in response to increased levels of stress are found to be associated with a dysregulation in the serotonergic system, both in subjects with mood disorders and those who engage in suicidal behavior. HPA over-activity may be a good predictor of mood disorders and perhaps suicidal behavior via abnormalities in the serotonergic system.

Transient early-life forebrain corticotropin-releasing hormone elevation causes long-lasting anxiogenic and despair-like changes in mice

During development, early-life stress, such as abuse or trauma, induces long-lasting changes that are linked to adult anxiety and depressive behavior. It has been postulated that altered expression of corticotropin-releasing hormone (CRH) can at least partially account for the various effects of stress on behavior. In accord with this hypothesis, evidence from pharmacological and genetic studies has indicated the capacity of differing levels of CRH activity in different brain areas to produce behavioral changes. Furthermore, stress during early life or adulthood causes an increase in CRH release in a variety of neural sites. To evaluate the temporal and spatial specificity of the effect of early-life CRH exposure on adult behavior, the tetracycline-off system was used to produce mice with forebrain-restricted inducible expression of CRH. After transient elevation of CRH during development only, behavioral testing in adult mice revealed a persistent anxiogenic and despair-like phenotype. These behavioral changes were not associated with alterations in adult circadian or stress-induced corticosterone release but were associated with changes in CRH receptor type 1 expression. Furthermore, the despair-like changes were normalized with antidepressant treatment. Overall, these studies suggest that forebrain-restricted CRH signaling during development can permanently alter stress adaptation leading to increases in maladaptive behavior in adulthood.

Defining brain region-specific glucocorticoid action during stress by conditional gene disruption in mice

The ability of an organism to adapt during stress has a significant impact on long-term survival and health. Maladaptive responses to stress have been associated with susceptibility to the development of mood disorders, including major depressive disorder (MDD) and generalized anxiety disorder. Importantly, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, the endocrine stress response, has been linked to these diseases. Here, we review recent data on the region-specific role of glucocorticoid receptor (GR) signaling in the behavioral, molecular and endocrine response to stress. Using a conditional deletion approach, we have shown that disruption of GR function in the forebrain of mice induces alterations in despair-like behavior and HPA axis function, reminiscent of MDD. Furthermore, in an effort to explore the sub-regional specificity of GR activity, we have developed a model to disrupt GR in the central nucleus of the amygdala. In our initial efforts to characterize these mice, we have demonstrated a critical role for GR in the formation of fear memory.

Salivary cortisol and suicidal behavior--a follow-up study

INTRODUCTION

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA)-axis is a common finding in major depressive disorder. Similar studies on suicide attempters are less abundant, and the results are divergent. The main aim of the present study was to investigate HPA-axis parameters by the time of a suicide attempt and at follow-up in search for associations between HPA-axis function and suicidal behavior.

METHODS

Thirty-five suicide attempters and 16 non-suicidal controls were admitted to a psychiatric ward between the years of 1986 and 1992. Corticotrophin-releasing hormone (CRH) in cerebrospinal fluid and urinary cortisol were obtained for the suicide attempters. The patients were followed up approximately 12 years after the index admission. Cortisol was measured in saliva, and additional suicide attempts and current psychiatric symptoms were registered.

RESULTS

At follow-up, evening salivary cortisol was lower in suicide attempters compared to controls. Low cortisol levels at follow-up were associated with severe psychiatric symptoms. Among women, repeated suicide attempts were associated with low morning and lunch salivary cortisol, and in this subgroup we also found significant correlations between salivary cortisol at follow-up, and CRH as well as urinary cortisol at index.

CONCLUSION

We found evidence for an association between low HPA-axis activity and suicidal behavior. This could be due to long-lasting and severe psychiatric morbidity, which in turn has exhausted the HPA-axis of these patients. The potential role of hypocortisolism should be given more attention in studies on suicidal patients.

Combined dexamethasone/corticotropin-releasing factor test in chronic fatigue syndrome

BACKGROUND

Studies of hypothalamic-pituitary-adrenal (HPA) axis function in chronic fatigue syndrome (CFS) point to hypofunction, although there are negative reports. Suggested mechanisms include a reduced hypothalamic or supra-hypothalamic stimulus to the HPA axis and enhanced sensitivity to the negative feedback of glucocorticoids. The aim of the current study was to investigate HPA axis function in CFS with the dexamethasone/corticotropin-releasing factor (Dex/CRF) test, in analogy with research in affective disorders.

METHOD

Thirty-four well-characterized female CFS patients and 25 healthy control subjects participated in the low-dose Dex/CRF test. Current major depressive episode was an exclusion criterion. History of early-life stress (ELS) was assessed with the Structured Trauma Interview.

RESULTS

Salivary cortisol responses after 0.5 mg Dex were lower in CFS patients than in controls (before 100 microg CRF, p=0.038; after 100 microg CRF, p=0.015). A secondary analysis revealed an influence of early-life stress and of oestrogen intake. After removal of the 10 participants who were taking an oral oestrogen, patients without a history of ELS showed lower cortisol responses than patients with ELS and controls (before CRF, p=0.005; after CRF, p=0.008).

CONCLUSIONS

CFS is globally associated with reduced cortisol responses in the combined low-dose Dex/CRF test, but this effect is only clearly present in CFS patients without a history of ELS. This study provides further support for an enhanced glucocorticoid negative feedback and/or a reduced central HPA axis drive in CFS. Furthermore, it demonstrates that ELS is an important variable to consider in CFS research.

Antenatal maternal anxiety is related to HPA-axis dysregulation and self-reported depressive symptoms in adolescence: a prospective study on the fetal origins of depressed mood

Depressive symptomatology can proceed from altered hypothalamic-pituitary-adrenocortex (HPA)-axis function. Some authors stress the role that early life stress (ELS) may play in the pathophysiology of depressive symptoms. However, the involvement of the HPA-axis in linking prenatal ELS with depressive symptoms has not been tested in a prospective-longitudinal study extending until after puberty in humans. Therefore, we examined whether antenatal maternal anxiety is associated with disturbances in HPA-axis regulation and whether the HPA-axis dysregulation mediates the association between antenatal maternal anxiety and depressive symptoms in post-pubertal adolescents. As part of a prospective-longitudinal study, we investigated maternal anxiety at 12-22, 23-32, and 32-40 weeks of pregnancy (wp) with the State Trait Anxiety Inventory (STAI). In the 14-15-year-old offspring (n=58) HPA-axis function was measured through establishing a saliva cortisol day-time profile. Depressive symptoms were measured with the Children's Depression symptoms Inventory (CDI). Results of regression analyses showed that antenatal exposure to maternal anxiety at 12-22 wp was in both sexes associated with a high, flattened cortisol day-time profile (P=0.0463) which, in female adolescents only, was associated with depressive symptoms (P=0.0077). All effects remained after controlling for maternal smoking, birth weight, obstetrical optimality, maternal postnatal anxiety and puberty phase. Our prospective study demonstrates, for the first time, the involvement of the HPA-axis in the link between antenatal maternal anxiety/prenatal ELS and depressive symptoms for post-pubertal female adolescents.

Elevated plasma arginine vasopressin levels in veterans with posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with altered hypothalamic-pituitary-adrenal (HPA) axis functioning. Arginine vasopressin (AVP), in conjunction with corticotrophin releasing hormone, has shown to be an important modulator of the HPA axis. In order to evaluate the effect of trauma and PTSD on central AVP secretion we assessed plasma AVP levels in equally trauma exposed veterans with and without PTSD and a non-traumatized healthy control group.

METHODS

Assessment of plasma AVP in 29 male veterans with PTSD, 29 traumatized veterans without PTSD, matched for age, gender, year and region of deployment (trauma controls), and 26 age matched healthy controls.

RESULTS

Plasma AVP levels were higher in PTSD patients compared to both healthy controls (p = 0.004) and trauma controls (p < 0.001). In PTSD patients without a comorbid MDD a significant correlation was observed between plasma AVP levels and symptoms of avoidance measured with the Clinician Administered PTSD Scale (CAPS).

CONCLUSION

Elevated plasma AVP levels are specifically related to PTSD and not to exposure to traumatic stress during deployment. Our results indicate that AVP may play a role as an anxiogenic factor, but they do not support a role for AVP in the altered response to dexamethasone in PTSD.

Gastrointestinal symptoms are associated with hypothalamic-pituitary-adrenal axis suppression in healthy individuals

OBJECTIVE

The brain-gut axis has been proposed to influence symptoms in irritable bowel syndrome (IBS). In animal studies corticotropin-releasing hormone (CRH) challenge has been associated with decreased upper gastrointestinal motility and increased colonic motility. The purpose of this study was to investigate the association between gastrointestinal symptoms and the effect of CRH on the hypothalamic-pituitary-adrenal (HPA) axis using a weight-adjusted low-dose dexamethasone test in a group of healthy individuals (n = 157).

MATERIAL AND METHODS

Pre- and post-dexamethasone morning serum cortisol was analysed. All participants completed questionnaires regarding symptoms of IBS (GSRS-IBS (Gastrointestinal Symptom Rating Scale-IBS) and symptoms of anxiety and depression (HADS (Hospital Anxiety and Depression Scale)). After exclusions, 124 subjects were available for analysis (F/M: 60/64, mean age 55.8 years, SD 15.4, range 21-80 years).

RESULTS

A positive correlation was found between the GSRS-IBS score and HADS score (rs =0.36; p <0.001). There was no linear correlation between either pre- (rs = 0.145; p = 0.11) or post-dexamethasone cortisol levels (rs =0.087; p =0.337) and GSRS-IBS scores. By subgrouping the subjects at the lower and higher 25th percentiles of their post-dexamethasone morning cortisol levels, we found a trend towards a higher GSRS-IBS score (median 7.0 versus 5.0; p =0.069) (multivariate adjusted OR 2.6; CI 0.80-8.3) and a significantly higher diarrhoea score (median 2 versus 0; p = 0.021) (multivariate adjusted OR 5.7; CI 1.5-22), and a higher early satiety score (p=0.008) (multivariate adjusted OR 6.7; CI: 1.9-23) in the subjects with high post-dexamethasone cortisol levels (low HPA suppression) compared with the subjects with intermediate post-dexamethasone cortisol levels. Furthermore, individuals with low post-dexamethasone cortisol levels (high HPA suppression) showed a significant, higher score for diarrhoea (median 2.0 versus 0; p =0.010) (multivariate adjusted OR 6.1; CI 1.8-20) and early satiety (p=0.076) (multivariate adjusted OR 3.2; CI 1.0-10) compared with those with intermediate cortisol levels.

CONCLUSIONS

A trend toward a non-linear relationship between IBS-like symptoms and post-dexamethasone cortisol levels was observed in healthy individuals, with significantly more symptoms of diarrhoea and early satiety in individuals with high or low post-dexamethasone cortisol levels in comparison with those with intermediate post-dexamethasone cortisol levels.

No difference in symptoms of irritable bowel syndrome between healthy subjects and patients with recurrent depression in remission

There is bidirectional comorbidity between anxiety/depression and irritable bowel syndrome (IBS). To investigate the prevalence of IBS symptoms, and factors associated with gastrointestinal symptoms in patients with recurrent depressive disorder. Patients (n = 95) with recurrent type of major depression according to DSM-IV criteria and sex- and age-matched controls (n = 190) were sent questionnaires investigating symptoms of IBS [Gastrointestinal Symptom Rating Scale (GSRS)-IBS] and symptoms of anxiety and depression [Hospital Anxiety and Depression Scale (HADS)]. Medical records were checked over a 10-year period for chronic somatic symptoms or diseases. Seventy-three patients with unipolar disorder (mean age 63.6 years SD 13.8; range 23-86 years) and 156 controls (mean age 59.2 years SD 11.6, range 21-85 years) responded. Patients with recurrent depression had higher GSRS-IBS scores and showed a strong correlation between symptoms of IBS and anxiety-depression (r(s) = 0.54; P < 0.001). IBS symptoms were also associated with multiple pain symptoms, higher health-seeking behaviour and selective-serotonin-reuptake inhibitor intake. However, patients with recurrent depression (n = 46) in remission (HADS-Depression score <8) did not have more symptoms of IBS than controls (GSRS-IBS median score 6.0 vs 6.5; P = 0.46). There is a strong association between symptoms of IBS and symptoms of anxiety and depression, whereas depressive patients in remission do not have more IBS symptoms than controls.

Single nucleotide polymorphism analysis of corticotropin-releasing factor-binding protein gene in recurrent major depressive disorder

Corticotropin-releasing factor-binding protein (CRF-BP) regulates the availability of free CRF and is a functional candidate gene for affective disorders. Previous research showed an association between polymorphisms in the CRF-BP gene and recurrent major depression (MDD) in a Swedish sample. The purpose of the current study was to re-evaluate the previous findings in an extended Swedish sample and in an independent Belgian sample of patients with recurrent MDD and in control samples. In total, 317 patients and 696 control individuals were included. Five single nucleotide polymorphisms (SNPs) and a deletion polymorphism in the CRF-BP gene were genotyped and the haplotype block structure of the gene was assessed. In the extended Swedish population, there was a trend towards an association between two SNPs and MDD. The subsequent gender analysis showed significant associations of three SNPs (CRF-BPs2 T; CRF-BPs11 T and CRF-BPs12 C) and haplotype G_T_C_T_C with MDD in Swedish males. However, these findings did not withstand correction for multiple testing and there were no significant SNP or haplotype associations in the Belgian MDD sample. In conclusion, this study does not provide confirmatory evidence for a role of the CRF-BP gene in the vulnerability for MDD in general. The association between genetic CRF-BP variants and MDD may be sexually dimorphic, but this issue requires further investigation in a larger sample.

Significant increase in the aggressive behavior of transgenic mice overexpressing peripheral progastrin peptides: associated changes in CCK2 and serotonin receptors in the CNS

The gastrin precursor peptide, progastrin (PG), is secreted from enteroendocrine cells in the intestine and increased in patients with hypergastrinemia and colorectal cancers. In recent years, we and others have demonstrated an important role of PG peptides in colorectal carcinogenesis, and were surprised to note significant changes in the behaviors of transgenic mice overexpressing PGs. In the present studies, we examined emotional behaviors of transgenic mice overexpressing PG in the intestinal and peripheral circulation. Aggression, locomotor activity and anxiety-like behaviors of the homozygous transgenic (Tg/Tg) mice and the wild-type (WT) littermates were examined by intruder/resident test, open field and elevated plus maze, respectively. A significant increase in the aggression, locomotor activity, and anxiety-like behaviors was detected in the Tg/Tg vs WT mice. As CCK, CCK(2) receptors (CCK(2)R), and 5-HT(1A) receptors (5-HT(1A)R) in the CNS play an important role in these behaviors, possible changes in the expression of CCK and CCK(2)R and the density of CCK(2)R and 5-HT(1A)R were determined by either real-time RT-PCR or autoradiography of ligand binding assays. The results suggest that the expressions of CCK and CCK(2)R were increased in the hypothalamus, and the density of CCK(2)R were increased in the hypothalamus and amygdala of Tg/Tg vs WT mice. Similarly, the density of 5-HT(1A)R was increased in the hypothalamus. Our results suggest that an upregulation of the CCK response system and 5-HT(1A)R in the hypothalamus of Tg/Tg mice may mediate the alterations in the observed behaviors of these mice.

Glucocorticoid receptor transgenic mice as models for depression

In the era of mutant mice generated as molecular in vivo models for complex pathogenetic and therapeutic aspects of particular human diseases, glucocorticoid receptor transgenic mice represent an interesting and promising tool. Animals carrying mutations of this receptor show alterations in the hypothalamic-pituitary-adrenal (HPA)-system, which are comparable to those observed in depressed patients. Furthermore, similarities that may model the human disease have been described on the behavioral and pharmacological level, which increase the impact of such mutants. In this review we summarize different approaches used to alter or eliminate glucocorticoid receptor expression and function, and discuss their relevance as models for depression.

Leukocyte glucocorticoid receptor expression and immunoregulation in veterans with and without post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is associated with a dysregulation of the hypothalamus-pituitary-adrenal axis (HPA axis). In addition, there is evidence for altered glucocorticoid receptor (GR) expression and function in peripheral blood mononuclear cells. The aim of the present study was to differentiate between the effect of trauma exposure and PTSD on leukocyte GR expression and glucocorticoid immune regulation. Leukocyte GR binding characteristics and glucocorticoid sensitivity of immune activity, determined as the effect of dexamethasone (DEX) on in vitro cytokine release and T-cell proliferation, were compared between veterans with PTSD, traumatized veterans without PTSD and healthy controls. Leukocyte GR density was significantly lower in veterans with and without PTSD compared to healthy controls. DEX-induced inhibition of T-cell proliferation was significantly lower in PTSD compared to trauma and healthy controls. DEX-induced increase in lipopolysaccharide-stimulated interleukin-10 was less pronounced in traumatized veterans with and without PTSD compared to healthy controls. No group differences were observed in the effect of DEX on other cytokines or in baseline immune activity, except for lower tumor necrosis factor-alpha production in PTSD patients compared to healthy controls. The results suggest that trauma exposure is sufficient to induce changes in GR binding characteristics, whereas resistance of T-cell proliferation to DEX only occurs in PTSD. DEX resistance of in vitro immune activity was not a general phenomenon, but was restricted to specific immune functions.

Signs of attenuated depression-like behavior in vasopressin deficient Brattleboro rats

Vasopressin, a peptide hormone functioning also as a neurotransmitter, neuromodulator and regulator of the stress response is considered to be one of the factors related to the development and course of depression. In the present study, we have tested the hypothesis that congenital deficit of vasopressin in Brattleboro rats leads to attenuated depression-like behavior in tests modeling different symptoms of depression. In addition, hypothalamic-pituitary-adrenocortical axis activity was investigated. Vasopressin deficient rats showed signs of attenuated depression-like behavior in forced swimming and sucrose preference tests, while their behavior on elevated plus maze was unchanged. Vasopressin deficiency had no influence on basal levels of ACTH and corticosterone and had only mild impact on hormonal activation in response to forced swimming and plus-maze exposure. However, vasopressin deficient animals showed higher level of dexamethasone induced suppression of corticosterone response to restraint stress and higher basal levels of corticotropin-releasing hormone mRNA in the hypothalamic paraventricular nucleus. In conclusion, present data obtained in vasopressin deficient rats show that vasopressin is involved in the development of depression-like behavior, in particular of the coping style and anhedonia. Moreover, behavioral and endocrine responses were found to be dissociated. We suggest that brain vasopressinergic circuits distinct from those regulating the HPA axis are involved in generating depression-like behavior.