Stress responsive neurohormones in depression and anxiety

Clinical and preclinical studies have gathered substantial evidence that stress response alterations play a major role in the development of major depression, panic disorder and posttraumatic stress disorder. The stress response, the hypothalamic pituitary adrenocortical (HPA) system and its modulation by CRH, corticosteroids and their receptors as well as the role of natriuretic peptides and neuroactive steroids are described. Examplarily, we review the role of the HPA system in major depression, panic disorder and posttraumatic stress disorder as well as its possible relevance for treatment. Impaired glucocorticoid receptor function in major depression is associated with an excessive release of neurohormones, like CRH to which a number of signs and symptoms characteristic of depression can be ascribed. In panic disorder, a role of central CRH in panic attacks has been suggested. Atrial natriuretic peptide (ANP) is causally involved in sodium lactate-induced panic attacks. Furthermore, preclinical and clinical data on its anxiolytic activity suggest that non-peptidergic ANP receptor ligands may be of potential use in the treatment of anxiety disorders. Recent data further suggest a role of 3alpha-reduced neuroactive steroids in major depression, panic attacks and panic disorder. Posttraumatic stress disorder is characterized by a peripheral hyporesponsive HPA-system and elevated CRH concentrations in CSF. This dissociation is probably related to an increased risk for this disorder. Antidepressants are effective both in depression and anxiety disorders and have major effects on the HPA-system, especially on glucocorticoid and mineralocorticoid receptors. Normalization of HPA-system abnormalities is a strong predictor of the clinical course, at least in major depression and panic disorder. CRH-R1 or glucorticoid receptor antagonists and ANP receptor agonists are currently being studied and may provide future treatment options more closely related to the pathophysiology of the disorders.     

GABA(A) receptor-modulating neuroactive steroid composition in patients with panic disorder before and during paroxetine treatment.

OBJECTIVE: Previous studies have shown that neuroactive steroids modulate anxiety and stress reactivity. However, no data on the possible role of these gamma-aminobutyric acid(A) (GABA(A)) receptor-modulating neuroactive steroids in patients with anxiety disorders are available. METHOD: The concentrations of 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP), 3alpha,5beta-THP, 3beta,5alpha-THP, and their precursors were studied in the plasma of 10 patients with panic disorder and 10 matched healthy comparison subjects. In addition, the effects of paroxetine treatment on neuroactive steroid concentrations were studied in the panic disorder patients over a 24-week period. RESULTS: Unexpectedly, patients with panic disorder had significantly greater concentrations of the positive allosteric modulators 3alpha,5alpha-THP and 3alpha,5beta-THP and significantly lower concentrations of 3beta,5alpha-THP (a functional antagonist for GABA(A) agonistic steroids), which might result in greater GABA(A) receptor-mediated neuronal activity. Paroxetine treatment did not affect neuroactive steroid concentrations, which were highly stable over 24 weeks. CONCLUSIONS: Differences in neuroactive steroid composition in patients with panic disorder were the opposite of those seen in patients with major depression and may reflect counterregulative mechanisms against the occurrence of spontaneous panic attacks.     

Susceptibility to stress in transgenic mice overexpressing TrkC, a model of panic disorder

Stressful life events increase the susceptibility for subsequent onset of psychiatric disorders in humans. Previous research has implicated neurotrophins in the onset of some stress-related diseases, such as major depression disorder, post-traumatic stress disorder or panic disorder. We have tested the hypothesis that the neurotrophin-3 (NT-3)/TrkC system is a genetic interface mediating the deleterious effects of stress on the initiation of panic disorder and other pathologies. To this aim, we have analyzed the functionality of HPA axis and the behavioral consequences of different types of stressful conditions in a mouse model of panic disorder, which overexpresses TrkC, the high affinity-receptor for NT-3 (TgNTRK3). Our results reveal that TgNTRK3 mice exhibit an altered circadian corticosterone rhythm that is reversed by clonidine treatment, but normal expression of genes involved in the control of the hypothalamus-pituitary-adrenal (HPA) axis (CRH, GR) and normal corticosterone response to acute and chronic stressors. In contrast, they exhibit an altered pattern of activation of stress-related brain areas and showed enhanced anxiety-related behavior and more passive strategies than wild types under some chronic stress conditions. We conclude that TgNTRK3 mice present differences in their response to stress characterized by subtle changes in the HPA axis, marked changes in acute stress-induced brain activation and altered coping strategies, suggesting a key role of TrkC receptor in the stress neural circuitry and in the behavioral consequences of chronic stress.     

Management of anxiety in late life

Epidemiologic data are used as a framework to discuss the pharmacologic and cognitive-behavioral management of anxiety disorders in late life. Generalized anxiety disorder (GAD) and phobias account for most cases of anxiety in late life. The high level of comorbidity between GAD and major depression, and the observation that the anxiety usually arises secondarily to the depression, suggests that antidepressant medication should be the primary pharmacologic treatment for many older people with GAD. Most individuals with late-onset agoraphobia do not have a history of panic attacks and the illness often starts after a traumatic event. Exposure therapy is the treatment of choice for agoraphobia without panic. It is uncommon for obsessive-compulsive disorder (OCD) and panic disorder to start for the first time in old age, but these disorders can persist from younger years into late life. Case reports and uncontrolled case series suggest that elderly people with OCD or panic disorder can benefit from pharmacologic and cognitive-behavioral treatments that are known to be effective in younger patients. However, it is not known whether the rate of response among elderly patients is adversely affected by the chronicity of these disorders. The prevalence and incidence of post-traumatic stress disorder in late life are not known. Uncontrolled data support the use of selective serotonin reuptake inhibitors in war veterans with chronic symptoms of post-traumatic stress disorder; other treatments for this condition await evaluation in the elderly.     

Endocrine and cardiovascular responses to corticotropin-releasing hormone in patients with posttraumatic stress disorder: a role for atrial natriuretic peptide?

Hypothalamic-pituitary-adrenocortical (HPA) axis data, such as low plasma cortisol concentrations in spite of increased corticotropin-releasing hormone (CRH) levels in patients with posttraumatic stress disorder (PTSD), are difficult to interpret. Atrial natriuretic peptide (ANP) may be an explanatory link in the neuroendocrine pathophysiology of the disorder, since it is a neuromodulator with antianxiety effects that inhibits HPA activity at multiple levels. Seventeen patients with chronic PTSD and 17 healthy control subjects were given 100 microg of human CRH at 3 p.m. ANP, adrenocorticotropic hormone (ACTH), and cortisol levels in plasma as well as blood pressure and heart rate were measured during basal conditions and after CRH stimulation. Basal ANP levels were significantly lower in PTSD patients in comparison with normal controls, but the response to CRH was undistinguishable. In contrast to our expectation, no significant differences in basal or CRH-stimulated ACTH or cortisol parameters could be observed. Systolic and diastolic blood pressures at baseline and after CRH were significantly elevated in PTSD patients. All group differences remained significant after controlling for basal blood pressure and/or body mass index. Our data do not support a role of ANP in abnormal HPA axis regulation in PTSD. However, the persistently low ANP plasma levels in PTSD patients despite elevated blood pressure may serve to facilitate anxiety behavior and have adverse long-term cardiovascular consequences. Further studies to assess ANP secretion in PTSD patients and to clarify its pathophysiological impact are needed.     

Effects of genetically altered brain glucocorticoid receptor action on behavior and adrenal axis regulation in mice

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with vulnerability to a number of psychiatric diseases including major depression, bipolar disorder, anxiety disorders, and schizophrenia. The HPA axis is activated in response to stress and in a characteristic circadian rhythm, resulting in the release of glucocorticoid hormones from the adrenal cortex. These hormones act on peripheral target tissues to restore homeostasis to the organism and engage glucocorticoid receptors (GR) in the CNS to control the intensity and duration of the stress response. Alterations in this glucocorticoid sensing system may underlie the HPA axis changes associated with psychiatric disorders. Recently, a number of lines of mice with genetically altered GR signaling in the CNS have been generated to address this hypothesis. Here, we summarize findings from new genetic models that indicate a critical role for GR signaling in the CNS in normal regulation of the HPA axis and behavioral/emotional stability.     

The rationale for corticotropin-releasing hormone receptor (CRH-R) antagonists to treat depression and anxiety.

Neuroendocrine studies strongly suggest that dysregulation of the hypothalamic pituitary-adrenocortical (HPA) system plays a causal role in the development and course of depression. Whereas the initial mechanism resulting in HPA hyperdrive remains to be elucidated, evidence has emerged that corticosteroid receptor function is impaired in many patients with depression and in many healthy individuals at increased genetic risk for an depressive disorder. Assuming such impaired receptor function, then central secretion of CRH would be enhanced in many brain areas, which would account for a variety of depressive symptoms. As shown in rats and also in transgenic mice with impaired glucocorticoid receptor function, antidepressants enhance the signaling through corticosteroid receptors. This mechanism of action can be amplified through blocking central mechanisms that drive the HPA system. Animal experiments using antisense oligodeoxynucleotides directed against the mRNA of both CRH receptor subtypes identified the CRH1 receptor as the mediator of the anxiogenic effects of CRH. Studies in mouse mutants in which this receptor subtype had been deleted extended these findings as the animals were less anxious than wild-type mice when experimentally stressed. Thus, patients with clinical conditions that are causally related to HPA hyperactivity may profit from treatment with a CRH1 receptor antagonist.     

Anxiety Disorder-Specific Predictors of Treatment Outcome in the Coordinated Anxiety Learning and Management (CALM) Trial

Identifying baseline characteristics associated with treatment outcome in generalized anxiety disorder, panic disorder, social anxiety disorder (SAD) or post-traumatic stress disorder. We performed two secondary analyses of the Coordinated Anxiety Learning and Management trial. Baseline characteristics and their interactions with treatment assignment were analyzed via stepwise logistic regression models and receiver-operating criterion analyses by disorder predicting remission and response for each disorder. Predictors for poor outcome across diagnoses were comorbid depression and low socioeconomic status. Good outcome was associated with positive treatment expectancy and high self-efficacy expectancy. SAD had the lowest rate of remission and response compared to the other anxiety disorders, and differed in respect to its predictors of treatment outcome. Perceived social support predicted treatment outcome in SAD. The special role of SAD among the other anxiety disorders requires further study both because of its worse prognosis and its more specific treatment needs.     

Extended-release formulation of venlafaxine in the treatment of post-traumatic stress disorder

There is abundant evidence for abnormalities of both norepinephrine and serotonin neurotransmitter systems in post-traumatic stress disorder (PTSD). Venlafaxine extended-release formulation (venlafaxine XR) is a serotonin and norepinephrine re-uptake inhibitor with antidepressant and anxiolytic properties relevant to the pathophysiology of PTSD. Venlafaxine XR is currently approved for the treatment of panic disorder, generalized anxiety disorder and social anxiety disorder, as well as major depression in adults, based on a number of randomized, double blind, placebo-controlled clinical trials. Limited data also demonstrate that venlafaxine XR maintains a therapeutic response for more than 6 months in these anxiety disorders. Venlafaxine XR has demonstrated short- and long-term efficacy for the treatment of PTSD in two recent randomized, double-blind, placebo-controlled clinical trials, although it has not been extensively studied for PTSD, compared with other anxiety disorders. This review focuses on the potential role of venlafaxine XR in the treatment of PTSD, based on currently available evidence.     

Pharmacogenomics and therapeutic prospects in dementia

OBJECTIVE: To describe the prevalence and correlates of post-traumatic stress disorder (PTSD), depressive and anxiety disorders, or any other mental disorder among adult victims treated in a hospital at different points in time after the 11 March 2004 terrorist attacks in Madrid. DESIGN, SETTING, AND PARTICIPANTS: A random sample of 56 individuals injured in the attacks was interviewed in person at one, six, and twelve months after the attacks. MAIN OUTCOME MEASURES: Current DSM-IV mental disorders: depressive disorders and anxiety disorders (PTSD, generalised anxiety, agoraphobia, social phobia, and panic disorder) were assessed with the Spanish version of the MINI (Mini International Neuropsychiatric Interview), a structured, lay-administered psychiatric interview. RESULTS: PTSD was the most prevalent psychiatric disorder (35.7% at month 1, 34.1% at month 6, and 28.6% at month 12), followed by major depression (28.6%, 22.7%, and 28.6%, respectively). Others relevant conditions were suicide risk, generalised anxiety disorder (GAD), agoraphobia, and panic disorder. No significant differences in the prevalence of the disorders were found between the different assessment times. Patients with a psychiatric history prior to 11 March had a higher prevalence of PTSD, major depression, GAD, and panic disorder at month 1. Females had higher prevalence of PTSD, agoraphobia, and panic disorder at month 1. The only predictive factor for PTSD at month 12 was PTSD at month 6 (OR = 14.007). The only predictive factor for major depression at month 12 was major depression at month 6 (OR = 15.847). CONCLUSION: The prevalence of PTSD and major depression was high and remained stable between month 1, month 6, and month 12. The only predictive factor for PTSD at month 12 was PTSD at month 6.     

Glucocorticoid inhibition in the treatment of depression: can we think outside the endocrine hypothalamus?

Background: Major depressive disorder affects a substantial percentage of the U.S. population, and can be highly debilitating. Selective serotonin reuptake inhibitors are commonly prescribed to treat depression, but may not be as effective for more severe or persistent depression. Methods: The authors review data concerning the effects of corticosteroid synthesis inhibitors (CSIs) in the management of depressive disorders, present a hypothesis as to their possible mechanisms of action based on recent data suggesting synergistic effects of glucocorticoids on extrahypothalamic corticotropin‐releasing hormone (CRH), and consider alternative hypotheses. Published reports evaluating the efficacy of CSIs in treating depression are reviewed and presented in light of recent findings regarding actions of glucocorticoids on the central CRH system. Results: Results from open label and double‐blind studies by several groups have indicated that CSIs may be efficacious or of adjunctive value in some patients with depression, including those refractory to other agents; however, there is a need for more controlled studies. Several lines of data suggest that the mechanism of action of these agents may not be solely a function of inhibition of adrenal cortisol production. Conclusions: The authors propose that CSIs may be efficacious in part by reducing glucocorticoid enhancement of CRH action in neurons of the central nucleus of the amygdala and other structures outside the endocrine hypothalamus. Possible effects of systemically administered CSIs on glucocorticoid receptor regulation, neuroactive steroids, and classical monoamine systems are also discussed. We conclude that available clinical data suggest a potential role for CSIs in the management of depressive disorders, especially major depression with psychotic features. Depression and Anxiety, 2009. © 2009 Wiley‐Liss, Inc.     

Psychopathological sequelae of the 11 March terrorist attacks in Madrid

Objective To describe the prevalence and correlates of post-traumatic stress disorder (PTSD), depressive and anxiety disorders, or any other mental disorder among adult victims treated in a hospital at different points in time after the 11 March 2004 terrorist attacks in Madrid. Design, Setting, and Participants A random sample of 56 individuals injured in the attacks was interviewed in person at one, six, and twelve months after the attacks. Main Outcome Measures Current DSM-IV mental disorders: depressive disorders and anxiety disorders (PTSD, generalised anxiety, agoraphobia, social phobia, and panic disorder) were assessed with the Spanish version of the MINI (Mini International Neuropsychiatric Interview), a structured, lay-administered psychiatric interview. Results PTSD was the most prevalent psychiatric disorder (35.7% at month 1, 34.1% at month 6, and 28.6% at month 12), followed by major depression (28.6%, 22.7%, and 28.6%, respectively). Others relevant conditions were suicide risk, generalised anxiety disorder (GAD), agoraphobia, and panic disorder. No significant differences in the prevalence of the disorders were found between the different assessment times. Patients with a psychiatric history prior to 11 March had a higher prevalence of PTSD, major depression, GAD, and panic disorder at month 1. Females had higher prevalence of PTSD, agoraphobia, and panic disorder at month 1. The only predictive factor for PTSD at month 12 was PTSD at month 6 (OR = 14.007). The only predictive factor for major depression at month 12 was major depression at month 6 (OR = 15.847). Conclusion The prevalence of PTSD and major depression was high and remained stable between month 1, month 6, and month 12. The only predictive factor for PTSD at month 12 was PTSD at month 6.     

Sex,stress and steroids

The hypothalamo–pituitary–adrenal (HPA) axis plays a key role in the neuroendocrine response to stress and in maintaining physiological homoeostasis. However, stress that is chronic in nature can lead to HPA axis dysfunction and increase the risk for developing affective disorders, particularly if the stress is experienced during vulnerable periods in life. Sex differences in how the HPA axis responds to stress are well established, with females typically displaying heightened responses. The underlying cause of these sex differences is important to understand, as many neuropsychiatric disorders disproportionately affect females. Much research has provided evidence for gonadal sex steroids in underpinning sex differences in HPA axis responsivity; however, we suggest that neuroactive metabolites of these steroids also play a key role in the brain in mediating sex differences in HPA axis responses to stress. The relationship between neuroactive steroids and stress is complex. Acute stress rapidly increases neuroactive steroid production, which can in turn modulate activity of the HPA axis. However, under chronic stress conditions, stress can impact the brain's capacity to generate steroids, and this in turn has corollary effects on HPA axis function that may increase the propensity for psychopathology, given both HPA axis dysfunction and deficits in neuroactive steroids are implicated in affective disorders. Hence, here we review the evidence from animal and human studies for sex differences in the interactions between neuroactive steroids and the stress axis at various stages of life, under physiological and pathophysiological stress conditions and consider the implications for health and disease.     

When not enough is too much: the role of insufficient glucocorticoid signaling in the pathophysiology of stress-related disorders

OBJECTIVE: Previous theories have emphasized the role of excessive glucocorticoid activity in the pathology of chronic stress. Nevertheless, insufficient glucocorticoid signaling (resulting from decreased hormone bioavailability or reduced hormone sensitivity) may have equally devastating effects on bodily function. Such effects may be related in part to the role of glucocorticoids in restraining activation of the immune system and other components of the stress response, including the sympathetic nervous system (SNS) and corticotropin-releasing hormone (CRH). METHOD: The literature on neuroendocrine function and glucocorticoid-relevant pathologies in stress-related neuropsychiatric disorders, including posttraumatic stress disorder and major depression, was reviewed. RESULTS: Although not occurring together, both hypocortisolism and reduced responsiveness to glucocorticoids (as determined by dexamethasone challenge tests) were reliably found. Stress-related neuropsychiatric disorders were also associated with immune system activation/inflammation, high SNS tone, and CRH hypersecretion, which are all consistent with insufficient glucocorticoid-mediated regulation of stress hyperresponsiveness. Finally, antidepressants, a mainstay in the treatment of stress-related disorders, were regularly associated with evidence of enhanced glucocorticoid signaling. CONCLUSIONS: Neuroendocrine data provide evidence of insufficient glucocorticoid signaling in stress-related neuropsychiatric disorders. Impaired feedback regulation of relevant stress responses, especially immune activation/inflammation, may, in turn, contribute to stress-related pathology, including alterations in behavior, insulin sensitivity, bone metabolism, and acquired immune responses. From an evolutionary perspective, reduced glucocorticoid signaling, whether achieved at the level of the hormone or its receptor, may foster immune readiness and increase arousal. Emphasis on insufficient glucocorticoid signaling in stress-related pathology encourages development of therapeutic strategies to enhance glucocorticoid signaling pathways.     

Selective GABAergic treatment for panic? Investigations in experimental panic induction and panic disorder

gamma-Aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the central nervous system (CNS). It exerts its rapid inhibitory action mostly through GABA(A) receptors, which are targets for benzodiazepines, barbiturates, neuroactive steroids and distinct anticonvulsive agents. There is considerable evidence that dysfunction of GABA(A) receptors or dysregulation of GABA concentrations in the CNS (or both) plays an important role in the pathophysiology of panic disorder. Currently, benzodiazepines are the only drugs directly targeting the GABA(A) receptors that are approved for the treatment of anxiety disorders. Because of their well-known anxiolytic effects, they are widely used in this setting, but side effects limit their use in long-term treatment. The question of whether drugs that selectively increase GABA concentrations in the CNS could improve symptoms of anxiety has been discussed. Recent investigations by our group have demonstrated that enhancement of endogenous GABA (through blockade of GABA transaminase by vigabatrin or through inhibition of GABA transporters by tiagabine) exerts anxiolytic effects on experimentally induced panic. Our studies in healthy volunteers have shown that both compounds lead to a significant reduction in panic symptoms elicited by cholecystokinin-tetrapeptide. Moreover, benzodiazepine-like effects on the activity of the hypothalamic-pituitary-adrenal axis have been observed in association with vigabatrin treatment. Small open studies in patients with panic disorder also showed an improvement in panic and anxiety with both compounds. This review summarizes our recent research on the effects of selective GABAergic treatment in experimentally induced panic and outlines the possible role of compounds targeting the GABA binding site of the GABA(A)-benzodiazepine receptor for the treatment of panic and anxiety.     

Sertraline in the treatment of anxiety disorders

Sertraline was first developed and approved for the treatment of depression. However, considerable research has been conducted on its use in anxiety disorders. This paper reviews the data emerging from controlled and open trials of the use of sertraline in anxiety disorders. Sertraline has been tested extensively in the treatment of panic and obsessive-compulsive disorders. Less extensive testing has been completed on social phobia and post-traumatic stress disorder. The reviewed studies show that sertraline is an effective and well-tolerated treatment of all of these disorders. A comparison of sertraline with other pharmacotherapeutic options shows it to be at least equivalent to other medications for anxiety disorders.     

Crossroads of corticotropin releasing hormone,corticosteroids and monoamines. About a biological interface between stress and depression

Mental disorders are frequently preceded by stressful events or situations. Depression is a typical case in point. This raises the question, is depression - or possibly better: are certain forms of depression - caused by stress? Can stress be a true pathogenic factor? Phrased differently: can stress destabilize neuronal systems in the central nervous system to such an extent that depressive symptoms are generated? This question is discussed with the corticotrophin releasing hormone (CRH) and MA systems and hypothalamic-pituitary-adrenal (HPA) axis as major foci. The following issues are explored: the effect of antidepressants on corticosteroid receptor gene expression; the behavioral sequellae of CRH administration; CRH disturbances in depression; the impact of early life adversity on the development of the CRH system and on stress reactivity; the interrelationships of stress hormones and monoaminergic (MA ergic) transmission and finally the therapeutic potential of CRH and cortisol antagonists. The available data suggest that CRH overdrive and cortisol overproduction may play a pathogenic role in the occurrence of certain types of depression, directly and/or indirectly, i.e. by induction or exacerbation of disturbances in MA ergic transmission. Stress should, thus, become a major focus of biological depression research.     

The corticotropin-releasing hormone test in patients with posttraumatic stress disorder

To evaluate the hypothalamic-pituitary-adrenal (HPA) axis in patients with posttraumatic stress disorder (PTSD), we measured adrenocorticotropin hormone (ACTH) and cortisol responses following administration of corticotropin-releasing hormone (CRH) in 8 combat veterans with chronic PTSD. The PTSD patients had a significantly lower ACTH response to CRH compared to a control group of normal volunteers. Blunted ACTH responses occurred in patients with PTSD alone, as well as those PTSD patients who also had major depression. The cortisol response, although reduced, was not significantly different from normal. The blunted ACTH response to CRH in PTSD patients is similar to that seen in other psychiatric disorders, such as depression, panic disorder, and anorexia nervosa.     

Patterns of psychopathology and dysfunction in high-risk children of parents with panic disorder and major depression

OBJECTIVE: The purpose of the study was to evaluate 1) whether an underlying familial predisposition is shared by all anxiety disorders or whether specific risks are associated with specific disorders, and 2) whether panic disorder and major depression have a familial link. METHOD: The study compared four groups of children: 1) offspring of parents with panic disorder and comorbid major depression (N=179), 2) offspring of parents with panic disorder without comorbid major depression (N=29), 3) offspring of parents with major depression without comorbid panic disorder (N=59), and 4) offspring of parents with neither panic disorder nor major depression (N=113). RESULTS: Parental panic disorder, regardless of comorbidity with major depression, was associated with an increased risk for panic disorder and agoraphobia in offspring. Parental major depression, regardless of comorbidity with panic disorder, was associated with increased risks for social phobia, major depression, disruptive behavior disorders, and poorer social functioning in offspring. Both parental panic disorder and parental major depression, individually or comorbidly, were associated with increased risk for separation anxiety disorder and multiple (two or more) anxiety disorders in offspring. CONCLUSIONS: These findings confirm and extend previous results documenting significant associations between the presence of panic disorder and major depression in parents and patterns of psychopathology and dysfunction in their offspring.