Support for two increased vasopressinergic activities in depression at large and the differential effect of antidepressant treatment

Vasopressin Surrogate Marker Copeptin as a Potential Novel Endocrine Biomarker for Antidepressant Treatment Response in Major Depression: A Pilot Study

BACKGROUND

Major depressive disorder (MDD) constitutes the leading cause of disability worldwide. Although efficacious antidepressant pharmacotherapies exist for MDD, only about 40-60% of the patients respond to initial treatment. However, there is still a lack of robustly established and applicable biomarkers for antidepressant response in everyday clinical practice.

OBJECTIVE

This study targets the assessment of the vasopressin (AVP) surrogate marker Copeptin (CoP), as a potential peripheral hypothalamic-level biomarker of antidepressant treatment response in MDD.

METHODS

We measured baseline and dynamic levels of plasma CoP along with plasma ACTH and cortisol (CORT) in drug-naive outpatients with MDD before and after overnight manipulation of the hypothalamic-pituitary-adrenal (HPA) axis [i.e., stimulation (metyrapone) and suppression (dexamethasone)] on three consecutive days and their association with treatment response to 4 weeks of escitalopram treatment.

RESULTS

Our findings suggest significantly higher baseline and post-metyrapone plasma CoP levels in future non-responders, a statistically significant invert association between baseline CoP levels and probability of treatment response and a potential baseline plasma CoP cut-off level of above 2.9 pmol/L for future non-response screening. Baseline and dynamic plasma ACTH and CORT levels showed no association with treatment response.

CONCLUSIONS

This pilot study provide first evidence in humans that CoP may represent a novel, clinically easily applicable, endocrine biomarker of antidepressant response, based on a single-measurement, cut-off level. These findings, underline the role of the vasopressinergic system in the pathophysiology of MDD and may represent a significant new tool in the clinical and biological phenotyping of MDD enhancing individual-tailored therapies.

Vasopressinergic control of stress-related behavior: studies in Brattleboro rats

Vasopressin, a nonapeptide, signaling both as hormone in the blood and neuromodulator/neurotransmitter in the brain is considered to be causally involved in the pathological changes underlying anxiety and depression. In the present review we summarize experimental data obtained with Brattleboro rats as a model of congenital vasopressin-deficiency to test the hypothesis that central vasopressin signaling contributes to anxiety- and depression-like behavior. Male, female and lactating rats were studied. We focused on the paraventricular nucleus of the hypothalamus (PVN) and the septum, two brain areas in which vasopressin is proposed to control the endocrine and behavioral stress response, respectively. The presented data support the hypothesis that the behavioral changes seen in these rats are brought about by an altered vasopressin signaling at the brain level. Whereas vasopressin synthesized and released within the hypothalamus is primarily involved in endocrine regulation, vasopressin signaling in other brain areas may contribute to anxiety- and depression-like behavioral parameters. Further studies in this context might focus particularly on the interplay between extra-hypothalamic brain areas such as the septum and the medial amygdala.

Antidepressant-Like Effects of Fractions Prepared from Danzhi-Xiaoyao-San Decoction in Rats with Chronic Unpredictable Mild Stress: Effects on Hypothalamic-Pituitary-Adrenal Axis, Arginine Vasopressin, and Neurotransmitters

The aim of the present study was to investigate the antidepressant-like effects of two fractions, including petroleum ether soluble fraction (Fraction A, FA) and water-EtOH soluble fraction (Fraction B, FB) prepared from the Danzhi-xiaoyao-san (DZXYS) by using chronic unpredictable mild stress-induced depressive rat model. The results indicated that DZXYS could ameliorate the depression-like behavior in chronic stress model of rats. The inhibition of hyperactivity of HPA axis and the modulation of monoamine and amino acid neurotransmitters in the hippocampus may be the important mechanisms underlying the action of DZXYS antidepressant-like effect in chronically stressed rats.

Chronic all-trans retinoic acid administration induces CRF over-expression accompanied by AVP up-regulation and multiple CRF-controlling receptors disturbance in the hypothalamus of rats

Clinical reports suggest a potential link between excess retinoids and development of depression. Corticotropin-releasing factor (CRF) produced in the hypothalamic paraventricular nucleus (PVN) is considered the central driver of the hypothalamic-pituitary-adrenal (HPA) axis and plays a key role in the pathogenesis of depression. Although we had shown that chronic all-trans retinoic acid (ATRA) administration induced hypothalamic CRF over-expression and hyperactivity of HPA axis in rats, further insight into how ATRA modulate CRF expression is lacking. The activity of CRF neurons is under close control of vasopressinergic system and three-paired receptors (corticosteroid receptors, sex hormone receptors and CRF receptors). Here we show that ATRA-induced CRF over-expression is accompanied by arginine-vasopressin (AVP) up-regulation and apparent gene expression disturbances of CRF-controlling receptors. ATRA was applied to rats by daily intraperitoneal injection for 6 weeks. Chronic ATRA treatment induced significantly increased expression of CRF and AVP in the PVN. Moreover, the transcript levels of CRF receptor 1 (CRFR1), estrogen receptor-β (ERβ) and mineralocorticoid receptor (MR), three genes involved in the activation of CRF neurons, were significantly increased in the hypothalamus, and the expression ratio of GRα/MR was markedly decreased. Correlation analysis indicated that the alteration of multiple CRF-controlling receptors is highly correlated with depression-related behaviors of rats in the forced swimming test. These findings support that in addition to the 'classic' retinoic acid receptor α-mediated transcriptional control of CRF expression, disruption in CRF-modulating systems constitutes a novel pathway that underlies ATRA-induced HPA axis hyperactivity in vivo.

Copeptin during rest and exercise in major depression

BACKGROUND

High vasopressin levels and a correlation between vasopressin and cortisol has been observed in patients with depression. The aim was to assess copeptin, the c-terminal of provasopressin, and the association between cortisol, adrenocorticotropic hormone (ACTH) and copeptin in patients with depression. Secondly, to examine the copeptin response to acute exercise and aerobic training.

METHODS

Copeptin, ACTH, and cortisol were measured in 111 patients with depression and 57 controls at rest. Copeptin was also measured during exercise. The depressed patients were subsequently randomized to an aerobic training intervention or an exercise control intervention.

RESULTS

The plasma level of copeptin in depressed subjects was 5.14 pg/ml (IQR 3.4-8.4) and 4.82 pg/ml (IQR 2.8-7.5) in healthy controls (p=.66). The association between copeptin and cortisol was.02 (95% CI -.44 to.48; p=.93) and the association between copeptin and ACTH was -.06 (95% CI -.17 to.05; p=.27). All associations were independent of depression status (p=.15). Aerobic exercise training did not influence copeptin levels at rest (p=.09) or the response to acute exercise (p=.574). Copeptin decreased at rest in response to aerobic training in participants with high compliance to the exercise intervention (p=.04).

LIMITATIONS

We did not measure plasma osmolality, which is a possible confounder in this study.

CONCLUSIONS

Copeptin levels are not elevated or associated to ACTH or cortisol in depressed patients. Aerobic exercise training decreased copeptin levels in high attenders only. This study does not support a role of copeptin or vasopressin in depression.

Increased plasma norepinephrine concentration in psychotic depression

OBJECTIVE

We previously found psychotic depression (PSDEP) to have positively correlating plasma norepinephrine (NE) and vasopressin (AVP) concentrations. Since central noradrenergic activity and plasma NE concentration are highly correlated, this suggests an increased noradrenergic activation of the hypothalamus-pituitary-adrenal axis. We hypothesize the increased release of NE in PSDEP to be an associated mechanism.

METHODS

To test this hypothesis we analyzed the relation between plasma NE and PSDEP in a comparison with non-psychotically depressed patients. Potentially confounding variables were, among others, melancholia and two better validated subcategories in the field of melancholia and endogenous depression, three global dimensions of psychopathology - Emotional Dysregulation, Retardation and Anxiety - smoking habit, and different types of psychotropic and particularly antidepressant treatment. The data from nine patients with PSDEP and 69 patients with non-PSDEP were reanalysed.

RESULTS

Analysis of covariance controlling for the effects of tricyclic antidepressant treatment (≥100 mg) and smoking habit showed that PSDEP had an increased concentration of plasma NE. The previously found correlation between plasma NE and AVP was still present after correcting for the effects of confounding variables.

CONCLUSIONS

The results suggest an increased activity of the sympathetic nervous system in PSDEP that may act as a specific mechanism for increased vasopressinergic activation. This supports the view of PSDEP as a distinct subcategory of major depression.

The neuroendocrinology of childhood trauma in personality disorder

BACKGROUND

Childhood trauma has been associated with elevated central corticotropin releasing hormone (CRH) drive in adults meeting general DSM-IV criteria for personality disorder. It is not clear how this may be related to pituitary or adrenal responsiveness in personality disorder. It was hypothesized that high levels of childhood trauma would be associated with blunted cortisol and adrenocorticotropin releasing hormone (ACTH) response to the combined dexamethasone(DEX)/CRH test in adults meeting general DSM-IV criteria for personality disorder.

METHOD

24 healthy, medication free adults with personality disorder (N=16) and a group of healthy controls (N=8) underwent semi-structured diagnostic interviews and completed the Childhood Trauma Questionnaire (CTQ). Across two separate study sessions separated by at least a week, cerebrospinal fluid (CSF) was sampled by lumbar puncture for measurement of CRH concentration (N=17), and peripheral blood cortisol and ACTH levels were measured after challenge with DEX/CRH (N=24).

RESULTS

As hypothesized, high CTQ score was associated with a blunted cortisol and ACTH response to DEX/CRH challenge. Indices of cortisol and ACTH response (peak level and area under the curve (AUC)) to DEX/CRH were in turn significantly negatively correlated with CSF CRH concentration.

CONCLUSION

Childhood trauma in adults with personality disorder is associated with blunted cortisol and ACTH secretion following DEX/CRH challenge. These effects are independent of depression or posttraumatic stress disorder. Previous work would suggest that blunted pituitary-adrenal response is related to elevated central CRH drive. Corroborating this, CSF CRH levels were significantly and negatively correlated with peak level and AUC of both cortisol and ACTH.

Stress and the HPA axis: role of glucocorticoids in alcohol dependence

Stress has long been suggested to be an important correlate of uncontrolled drinking and relapse. An important hormonal response system to stress-the hypothalamic-pituitary-adrenal (HPA) axis-may be involved in this process, particularly stress hormones known as glucocorticoids and primarily cortisol. The actions of this hormone system normally are tightly regulated to ensure that the body can respond quickly to stressful events and return to a normal state just as rapidly. The main determinants of HPA axis activity are genetic background, early-life environment, and current life stress. Alterations in HPA axis regulation are associated with problematic alcohol use and dependence; however, the nature of this dysregulation appears to vary with respect to stage of alcohol dependence. Much of this research has focused specifically on the role of cortisol in the risk for, development of, and relapse to chronic alcohol use. These studies found that cortisol can interact with the brain's reward system, which may contribute to alcohol's reinforcing effects. Cortisol also can influence a person's cognitive processes, promoting habit-based learning, which may contribute to habit formation and risk of relapse. Finally, cortisol levels during abstinence may be useful clinical indicators of relapse vulnerability in alcohol-dependent people.

Effects of chronic social defeat on behavioral and neural correlates of sociality: Vasopressin, oxytocin and the vasopressinergic V1b receptor

Chronic social stress in rodents produces behavioral and neuroendocrine patterns analogous to symptoms associated with psychopathologies in humans. Chronic social defeat in mice has been used to study the genetic and epigenetic precursors of stress-related social disorders. The neuropeptides arginine vasopressin (AVP) and oxytocin (OT) are released in central targets to modulate anti- and pro-social behaviors, respectively. AVP binds to V1a and V1b receptors (V1bRs) in discrete brain regions related to anxiety, depression and affiliative behaviors. Recent evidence suggests that V1bRs are involved in stress and anxiety and may be an attractive target for the treatment of associated disorders. In the present series of experiments, we aimed to evaluate the effects of chronic social defeat stress on: 1) anxiety-related behaviors in a social investigation paradigm and their potential modulation by an acute dose of SSR149415, a V1bR antagonist; 2) AVP and Fos protein levels in the paraventricular nucleus of the hypothalamus (PVN) and; 3) AVP- and OT-receptor (OTR) mRNA levels in brain regions associated with sociality. When compared to undefeated animals, socially defeated mice exhibited an anxiogenic behavioral profile towards a novel male conspecific, with SSR149415 partly attenuating these effects. Histochemistry using immunofluorescence showed defeat produced significant elevations of Fos and double labeling of AVP and Fos proteins in the paraventricular nucleus of the hypothalamus (PVN). SSR149415 attenuated the effects of defeat on Fos and AVP/Fos double labeling, consistent with an anxiolytic effect. Defeated mice showed elevated levels of OTR mRNA levels in the lateral septum (LS) in addition to increased V1bR and OTR mRNA in the medial amygdala (MeA). We suggest the involvement of V1bRs and OTRs in a circuit involving the PVN, MeA and LS in the effects of defeat on sociality. SSR149415 attenuated anxiogenesis in the social investigation model and both Fos and AVP/Fos labeling, suggesting V1bRs are an attractive target for the treatment of anxiety in general and disorders of sociality in particular.

Temperament and character in psychotic depression compared with other subcategories of depression and normal controls

Background. Support has been found for high harm avoidance as general vulnerability trait for depression and decreased self-directedness (SD) as central state-related personality change. Additional personality characteristics could be present in psychotic depression (PD). Increased noradrenergic activation in PD predicts the involvement of reward dependence (RD). Methods. The data during the acute episode and after full remission from the same subjects, that we used before, were reanalyzed. The dependence of the 7 dimensions of the Temperament and Character Inventory version 9 on PD, three other subcategories of depression, and a group of normal controls was tested by MANCOVA. Results. Low RD at both time points, and low Cooperativeness during the acute episode, were found as additional characteristics of PD. Conclusion. The combination of two premorbid temperaments, high HA and low RD, and the development of a state-related reduction of two character functions, SD and CO, may be the precondition for the development of combined depressive and psychotic psychopathology.