Psychoneuroendocrinology of depression. Hypothalamic-pituitary-adrenal axis

Cerebrospinal fluid corticotropin-releasing factor (CRF) and vasopressin concentrations predict pituitary response in the CRF stimulation test: a multiple regression analysis

There is considerable evidence that stress-related psychiatric disorders, including depression and post-traumatic stress disorder (PTSD), are associated with hypersecretion of corticotropin-releasing factor (CRF) within the central nervous system (CNS). One line of evidence that is consistent with central CRF hypersecretion in these disorders is the blunted adrenocorticotropin hormone (ACTH) response to intravenous CRF administration, likely a consequence, at least in part, of downregulation of anterior pituitary CRF receptors. The present study tests the hypothesis that elevated cerebrospinal fluid (CSF) concentrations of CRF and a secondary ACTH secretagogue, arginine vasopressin (AVP), are associated with diminished adenohypophyseal responses in a standard CRF stimulation test. CSF concentrations of CRF and AVP, and plasma ACTH responses to the administration of 1 microg/kg ovine CRF (oCRF) were measured in healthy adult women with and without current major depression and/or a history of significant childhood abuse. The primary outcome measure was ACTH area under the curve (AUC) in the CRF stimulation test. Multiple linear regression was performed to identify the impact of CSF CRF and AVP concentrations upon the pituitary response to CRF stimulation. The regression model explained 56.5% of the variation in the ACTH response to CRF stimulation. The relationship of CSF concentrations of CRF to ACTH responses to CRF were best described by a third-order function that was inversely correlated over most of the range of studied values. The association of ACTH response with CSF concentration of AVP and the dose of oCRF followed second-order kinetics. These findings support the hypothesis that central CRF hypersecretion is associated with a blunted ACTH response to exogenously administered CRF, explaining almost 60% of the variation in the ACTH response to CRF.

5-HT1A receptor knockout mouse as a genetic model of anxiety

Low levels of the serotonin(1A) (5-HT(1A)) receptor have been repeatedly found in mood and anxiety disorders. Stress often exacerbates psychiatric disease and can also reduce 5-HT(1A) receptor levels. When receptor deficiency was produced in mice by genetic knockout, an anxiety-like phenotype was observed. Anxiety in mice is defined as a high level of avoidance of novel and unfamiliar environment and increased fear reaction. Other aspects of anxiety such as autonomic activation, increased stress responsiveness, and neuroendocrine abnormalities have also been described in receptor knockout mice. These data indicate that 5-HT(1A) receptor knockout mice represent a genetic animal model of anxiety with both construct and face validities. Although the core phenotype of anxiety can be reproduced in knockout mice in various inbred and outbred backgrounds, abnormalities in 5-HT dynamics and resistance to the anxiolitic drug diazepam have been seen in one but not on other genetic backgrounds. This indicates that while the development of anxiety is an invariable consequence of receptor deficit, other features induced by receptor loss are strongly modulated by other gene(s). Strain-dependent variability within the core phenotype does not diminish the value of 5-HT(1A) receptor knockout mice as a model of anxiety. Indeed, it is consistent with the manifestation of anxiety in genetically heterogeneous human population.

Neuroendocrine pharmacology of stress

Exposure to hostile conditions initiates responses organized to enhance the probability of survival. These coordinated responses, known as stress responses, are composed of alterations in behavior, autonomic function and the secretion of multiple hormones. The activation of the renin-angiotensin system and the hypothalamic-pituitary-adrenocortical axis plays a pivotal role in the stress response. Neuroendocrine components activated by stressors include the increased secretion of epinephrine and norepinephrine from the sympathetic nervous system and adrenal medulla, the release of corticotropin-releasing factor (CRF) and vasopressin from parvicellular neurons into the portal circulation, and seconds later, the secretion of pituitary adrenocorticotropin (ACTH), leading to secretion of glucocorticoids by the adrenal gland. Corticotropin-releasing factor coordinates the endocrine, autonomic, behavioral and immune responses to stress and also acts as a neurotransmitter or neuromodulator in the amygdala, dorsal raphe nucleus, hippocampus and locus coeruleus, to integrate brain multi-system responses to stress. This review discussed the role of classical mediators of the stress response, such as corticotropin-releasing factor, vasopressin, serotonin (5-hydroxytryptamine or 5-HT) and catecholamines. Also discussed are the roles of other neuropeptides/neuromodulators involved in the stress response that have previously received little attention, such as substance P, vasoactive intestinal polypeptide, neuropeptide Y and cholecystokinin. Anxiolytic drugs of the benzodiazepine class and other drugs that affect catecholamine, GABA(A), histamine and serotonin receptors have been used to attenuate the neuroendocrine response to stressors. The neuroendocrine information for these drugs is still incomplete; however, they are a new class of potential antidepressant and anxiolytic drugs that offer new therapeutic approaches to treating anxiety disorders. The studies described in this review suggest that multiple brain mechanisms are responsible for the regulation of each hormone and that not all hormones are regulated by the same neural circuits. In particular, the renin-angiotensin system seems to be regulated by different brain mechanisms than the hypothalamic-pituitary-adrenal system. This could be an important survival mechanism to ensure that dysfunction of one neurotransmitter system will not endanger the appropriate secretion of hormones during exposure to adverse conditions. The measurement of several hormones to examine the mechanisms underlying the stress response and the effects of drugs and lesions on these responses can provide insight into the nature and location of brain circuits and neurotransmitter receptors involved in anxiety and stress.

Altered rapid eye movement sleep timing in serotonin transporter knockout mice

The monoamine neurotransmitter serotonin has long been implicated in development and maintenance of sleep patterns, yet the role of the serotonin transporter (SERT) in these processes has not been evaluated in detail. We report that genetically engineered SERT knockout mice exhibit more REM sleep (REMS) than wild type littermates (11 vs 7% of recording time under baseline conditions) and display more frequent REMS bouts that last longer. This phenotype resembles the previously reported long-term effect of repeated treatment with SERT inhibitor compounds rather than the acute REMS suppressing effect of treatment with such compounds, and is thus likely to reflect neuroadaptations to the absence of SERT, rather than an acute effect of its absence in the adult. While electroencephalographic (EEG) spectra did not differ between SERT knockout and wild type mice during non-REM sleep (NREMS) or REMS, the dynamics of the EEG during the transition from NREMS to REMS differed between the genotypes. The surge in EEG power in both the 6-9 Hz and 10-16 Hz ranges that occurs just prior to the onset of REMS (pre-REMS power surge) is of greater magnitude in SERT knockout mice than in wild type littermate controls. This observation contrasts with the reduced magnitude pre-REMS power surge observed in rats subjected to REMS deprivation relative to yoked controls. These results indicate that the pre-REMS power surge is influenced by REMS history and by monoaminergic transmission. Genetic differences in serotonin systems and developmental exposure to SERT blockers are likely to exert effects on REMS.

Treating children and adolescents with selective serotonin reuptake inhibitors: how long is appropriate?

This article addresses a key question on the use of selective serotonin reuptake inhibitors (SSRIs) among children and adolescents. As briefly reviewed, recent randomized controlled trials have established the safety and efficacy of SSRIs in the acute treatment of major depression and anxiety disorders among children and adolescents. Major questions emerge in light of these data concerning the potential risks and benefits of long-term SSRI use among children and adolescents who receive significant short-term benefits from SSRI treatment. The current review summarizes research on longitudinal outcomes, neuroscience, and psychopharmacology to formulate a set of preliminary recommendations on long-term SSRI use. A review of data in these areas supports three conclusions. First, for children who achieve marked reduction in anxiety or depressive symptoms on an SSRI, clinicians should consider recommending a medication-free trial. Second, when indicated, this medication-free trial should coincide with the first low-stress period occurring after 1 year of continual SSRI treatment. Third, SSRI treatment should be reinitiated in children who exhibit signs of relapse during this medication-free trial.

Self-reported depressive symptoms and stress levels in healthy young men: associations with the cortisol response to awakening

OBJECTIVE

There is evidence that clinical depression and negative mood are associated with elevated basal cortisol levels. Recently, measuring the cortisol response during the first hour in the morning with strict reference to the time of awakening was established as a reliable marker of individual adrenocortical activity. In studies using this marker, a relationship with self-reported stress levels and psychosomatic symptoms has been found. The goal of the present study was to investigate the association of self-reported depressive symptomatology with early morning free cortisol levels and their relationship to measures of stress.

METHODS

We assessed the severity of depressive symptoms using the Hamilton Depression Inventory and chronic and acute stress perception in 40 healthy young men. Once a week, for 4 consecutive weeks, subjects provided saliva samples collected at 0, 30, and 60 minutes after awakening.

RESULTS

Higher levels of depressive symptomatology were associated with a greater cortisol response after awakening. This association seemed to be stronger when only subjects in the nonclinical range of depression were included. Furthermore, cortisol levels and depressive symptomatology were significantly positively correlated with measures of chronic and acute stress perception.

CONCLUSIONS

The present study extends earlier findings of hypothalamus-pituitary-adrenal axis hyperactivity in clinical depression to healthy young men with mild levels of depressive symptomatology. Measuring the cortisol response to awakening is proposed as an economical alternative to traditional approaches for determining basal hypothalamus-pituitary-adrenal axis activity. Associations between depressive symptomatology and chronic stress, as well as implications for future studies, are discussed.

Experience effects on brain development: possible contributions to psychopathology

Researchers and clinicians are increasingly recognizing that psychological and psychiatric disorders are often developmentally progressive, and that diagnosis often represents a point along that progression that is defined largely by our abilities to detect symptoms. As a result, strategies that guide our searches for the root causes and etiologies of these disorders are beginning to change. This review describes interactions between genetics and experience that influence the development of psychopathologies. Following a discussion of normal brain development that highlights how specific cellular processes may be targeted by genetic or environmental factors, we focus on four disorders whose origins range from genetic (fragile X syndrome) to environmental (fetal alcohol syndrome) or a mixture of both factors (depression and schizophrenia). C.H. Waddington's canalization model (slightly modified) is used as a tool to conceptualize the interactive influences of genetics and experience in the development of these psychopathologies. Although this model was originally proposed to describe the 'canalizing' role of genetics in promoting normative development, it serves here to help visualize, for example, the effects of adverse (stressful) experience in the kindling model of depression, and the multiple etiologies that may underlie the development of schizophrenia. Waddington's model is also useful in understanding the canalizing influence of experience-based therapeutic approaches, which also likely bring about 'organic' changes in the brain. Finally, in light of increased evidence for the role of experience in the development and treatment of psychopathologies, we suggest that future strategies for identifying the underlying causes of these disorders be based less on the mechanisms of action of effective pharmacological treatments, and more on increased knowledge of the brain's cellular mechanisms of plastic change.

Early life environment: does it have implications for predisposition to disease?

Early life environmental factors have been associated with altered predisposition to a variety of pathologies. A considerable literature examines pre- and postnatal factors associated with increased risk of cardiovascular, metabolic (i.e. insulin resistance, hyperlipidemia) and psychiatric disease, and the importance of hormonal programming. The brain is exquisitely sensitive to environmental inputs during development and the stress responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis has been shown to be both up- and down-regulated by early life exposure to limited nutrition, stress, altered maternal behaviors, synthetic steroids and inflammation. It has been suggested that peri-natal programming of HPA axis regulation might therefore contribute to metabolic and psychiatric disease etiology. In addition, glucocorticoids play modulatory roles regulating many aspects of immune function, notably controlling both acute and chronic inflammatory responses. Neuroendocrine-immune communication is bidirectional, and therefore it is expected that environmental factors altering HPA regulation have implications for stress effects on immune function and predisposition to inflammation. The impact of pre- and postnatal factors altering immune function, stress responsivity and predisposition to inflammatory disease are reviewed. It is also examined whether the early 'immune environment' might similarly influence predisposition to disease and alter neuroendocrine function. Evidence indicating a role for early life inflammation and infection as an important factor programming the neuroendocrine-immune axis and altering predisposition to disease is considered.

Mood stabilizer psychopharmacology

Mood stabilizers represent a class of drugs that are efficacious in the treatment of bipolar disorder. The most established medications in this class are lithium, valproic acid, and carbamazepine. In addition to their therapeutic effects for treatment of acute manic episodes, these medications often are useful as prophylaxis against future episodes and as adjunctive antidepressant medications. While important extracellular effects have not been excluded, most available evidence suggests that the therapeutically relevant targets of this class of medications are in the interior of cells. Herein we give a prospective of a rapidly evolving field, discussing common effects of mood stabilizers as well as effects that are unique to individual medications. Mood stabilizers have been shown to modulate the activity of enzymes, ion channels, arachidonic acid turnover, G protein coupled receptors and intracellular pathways involved in synaptic plasticity and neuroprotection. Understanding the therapeutic targets of mood stabilizers will undoubtedly lead to a better understanding of the pathophysiology of bipolar disorder and to the development of improved therapeutics for the treatment of this disease. Furthermore, the involvement of mood stabilizers in pathways operative in neuroprotection suggests that they may have utility in the treatment of classical neurodegenerative disorders.

Pharmacy-based care for perimenopausal and postmenopausal women

Perimenopause and menopause represent a major physiologic and, often, psychosocial transition in the lives of women. During this time, women often experience disturbing new symptoms and develop an increased awareness of their risks for major chronic illnesses. Women in this stage of life are often highly motivated to improve their health and can benefit greatly from pharmacy-based preventive health care services. Although perimenopausal and menopausal women represent an important target market, some pharmacists may wish to offer more focused services within the broader arena of women's health. For example, a number of community pharmacies have developed niche services for these patients, such as osteoporosis screening, (46) breast cancer risk assessment, (50) or bioidentical HRT consulting and compounding. (59) Other pharmacy care services that may be targeted to women in midlife include smoking cessation, weight management, and dietary supplement consulting. Based on the experiences of the Mar-Main Pharmacy staff, a practical approach is to implement new services gradually, while focusing on providing high-quality, individualized service to a small number of patients. Using this strategy, Mar-Main Pharmacy has experienced tremendous growth in its bioidentical HRT services. This increase in demand for pharmacy services has arisen from word-of-mouth referrals from patients and physicians rather than formal marketing. Perimenopausal and menopausal women represent a growing and increasingly knowledgeable group of patients. Many of these women are seeking care that is individualized, responsive to their health beliefs, and designed to help them maintain a high quality of life. Providing pharmacy-based consulting services for these patients can be extremely rewarding, both professionally and personally.

Posttranslational modulation of glucocorticoid feedback inhibition at the pituitary level

Diagnostic tests of hypothalamic-pituitary-adrenocortical function in psychiatric illness largely report the interaction of hypothalamic secretagogues with glucocorticoids at the pituitary level. This study investigated whether the efficiency of glucocorticoid inhibition is subject to modulation by intracellular processes that enhance cAMP accumulation and/or facilitate membrane depolarization. The secretion of ACTH induced by corticotropin-releasing factor (CRF; 0.1 nM) in primary cultures of rat anterior pituitary cells was markedly inhibited upon a 2-h exposure to 100 nM corticosterone. Arginine vasopressin (2 nM) enhanced the cAMP as well as the ACTH responses to CRF and reduced the efficiency of glucocorticoid inhibition of ACTH release. The action of arginine vasopressin was mimicked by rolipram, an inhibitor of cyclic nucleotide phosphodiesterase type 4. Application of the broad specificity K(+) channel blockers clofilium and astemizole produced minor or no significant enhancement of CRF-induced ACTH release, respectively, but opposed the inhibitory effect of corticosterone. Specific blockers of HERG, KCNQ, and Isk channels had no effect on ACTH release under any condition examined. In summary, these data reveal multiple sites of posttranslational modulation of adrenal corticosteroid action at the level of the pituitary gland, which appear important for the outcome of diagnostic tests of hypothalamic-pituitary- adrenocortical function.

Modulation of cellular expression of glucocorticoid receptor and glucocorticoid response element-DNA binding in rat brain during alcohol drinking and withdrawal

To define the molecular mechanisms of abnormal hypothalamic pituitary adrenal (HPA) axis during ethanol dependence, we investigated the effect of chronic ethanol treatment (15 days) and its withdrawal (24 h) on the expression of glucocorticoid receptors (GRs) and glucocorticoid response element (GRE)-DNA binding in the rat brain. The effects of chronic mianserin [serotonin (5-HT)(2A/2C) antagonist] treatment on these parameters in various brain structures of control diet-fed and ethanol-fed rats were also investigated. It was found that ethanol treatment and withdrawal significantly decreased the GR protein levels in cortical (cingulate gyrus, frontal, parietal, and piriform cortex) and amygdaloid (central, medial, and basolateral) structures and paraventricular nucleus (PVN) of hypothalamus of rats. It was also observed that ethanol treatment produced significant reductions in GR protein levels in various hippocampal structures (CA1, CA2, CA3, and dentate gyrus), but these changes were normalized during ethanol withdrawal. Ethanol treatment also significantly decreased GRE-DNA binding in rat cortex and hippocampus, which remained decreased in the cortex but reverted to normal in hippocampus during ethanol withdrawal. Chronic mianserin (alone) treatment had no effect on cortical GRE-DNA binding and GR protein levels in cortical, amygdaloid, or PVN structures but significantly decreased the GR protein expression in various hippocampal structures and GRE-DNA binding in whole hippocampus. However, when administered concurrently with ethanol treatment, mianserin significantly antagonized the reductions in cortical GRE-DNA binding and in GR protein expression in cortical, PVN, and central, but not medial and basolateral, amygdaloid structures during ethanol withdrawal. On the other hand, mianserin treatment along with ethanol administration significantly decreased the hippocampal GRE-DNA binding and GR protein expression in various hippocampal structures during ethanol withdrawal. Furthermore, ethanol treatment and its withdrawal or mianserin treatment had no effect on the neuron-specific nuclear protein levels in the various brain structures. Taken together, these results indicate that interaction of 5-HT(2A/2C) receptors with GRs in cortical, central amygdaloid, and PVN structures may play a role in neural mechanisms of alcohol dependence. It is possible that decreased GR expression in PVN may be responsible for the abnormal HPA axis during ethanol exposure and withdrawal.

Self-esteem, cortisol reactivity, and depressed mood mediated by perceptions of control

This study investigated cortisol reactivity (CR) as a moderator and perceptions of control as a mediator between low self-esteem (SE) and depressed mood. Fifty-four participants completed SE and mood inventories before an uncontrollable laboratory stressor. Salivary cortisol was determined before and after the stressor. Analyses indicated significance for SE (beta=-0.30), CR (beta=-0.92) and their interaction (beta=-0.90) in predicting depressed mood (P=0.03 for all). Low SE and decreased CR predicted the highest levels of depressed mood. The interaction indicated that depressed mood was predicted by increases in cortisol in individuals with higher SE, but by decreases in cortisol in individuals with lower SE. These relationships were statistically explained by low perceptions of control at baseline. Findings support biopsychological explanations for depression, with SE, CR, and uncontrollability as putative markers of depressed mood that may be even more pronounced in depressive disorders.

Early physical and sexual abuse associated with an adverse course of bipolar illness

BACKGROUND

There is growing awareness of the association between physical and sexual abuse and subsequent development of psychopathology, but little is known, however, about their relationship to the longitudinal course of bipolar disorder.

METHODS

We evaluated 631 outpatients with bipolar I or II disorder for general demographics, a history of physical or sexual abuse as a child or adolescent, course of illness variables, and prior suicide attempts, as well as SCID-derived Axis I and patient endorsed Axis II comorbidity.

RESULTS

Those who endorsed a history of child or adolescent physical or sexual abuse, compared with those who did not, had a history of an earlier onset of bipolar illness, an increased number of Axis I, II, and III comorbid disorders, including drug and alcohol abuse, faster cycling frequencies, a higher rate of suicide attempts, and more psychosocial stressors occurring before the first and most recent affective episode. The retrospectively reported associations of early abuse with a more severe course of illness were validated prospectively.

CONCLUSIONS

Greater appreciation of the association of early traumatic experiences and an adverse course of bipolar illness should lead to preventive and early intervention approaches that may lessen the associated risk of a poor outcome.

Decreased corticotropin-releasing factor receptor expression and adrenocorticotropic hormone responsiveness in anterior pituitary cells of Wistar-Kyoto rats

The Wistar-Kyoto (WKY) rat shows signs of persistent activation of the hypothalamic-pituitary-adrenal axis, but the cause and site of this activation is not yet known. Chronically activated corticotrophs generally show blunted adrenocorticotropic hormone (ACTH) response to corticotropin releasing factor (CRF); therefore, the anterior pituitary responsiveness to ACTH secretagogues, CRF and vasopressin, was compared in male WKY and Wistar rats. Anterior pituitary CRF binding and CRF receptor mRNA expression was significantly decreased in WKY rats. ACTH response to CRF or vasopressin was markedly impaired, and vasopressin failed to potentiate the CRF-stimulated ACTH release in cultured WKY anterior pituitary cells. In contrast, CRF and vasopressin alone and in combination stimulated large, concentration-dependent increases in ACTH release in Wistar anterior pituitary cells. By contrast to the decreased ACTH secretory responses, steady-state anterior pituitary pro-opiomelanocortin mRNA levels were approximately 12-fold greater in WKY rats compared to Wistar rats, and they further increased in response to CRF stimulation. These findings suggest that, although the WKY rat corticotroph is under a chronic state of activation or disinhibition, the in vitro secretory responses to classic ACTH secretagogues are impaired.

Prefrontal cortical regulation of hypothalamic-pituitary-adrenal function in the rat and implications for psychopathology: side matters

In recent years, dysfunction of hypothalamic-pituitary-adrenal (HPA) axis function has been implicated in a wide variety of psychiatric conditions. The importance of this system in responding to and coping with stress is well documented, and the integrity of such systems is of obvious significance to good mental health. The prefrontal cortex (PFC) is also heavily implicated in numerous psychopathological conditions. There is thus a growing interest in the potential role the PFC might play in regulating HPA function, and whether abnormalities of these systems are linked. The present paper reviews a number of recent animal studies which have attempted to elucidate the role of the PFC in regulation of HPA axis function, and how these systems may interact. It is concluded that the PFC is involved both in activating HPA responses to stress and in the negative feedback regulation of this system. Cerebral laterality is an important feature of this regulation, with the right PFC being most directly linked to stress-regulatory systems. On this basis, a number of parallels are drawn to the human literature, where asymmetrical disturbances in PFC activity may help explain associated patterns of HPA dysfunction.

Chronic pain, chronic stress and depression: coincidence or consequence?

Chronic pain and depressive illness are debilitating disease states that are variably resistant to currently available therapeutic agents. Animal models of chronic pain are associated with activation of the hypothalamo-pituitary-adrenal (HPA) axis, upon which chronic pain acts as an inescapable stressor. Inescapable stress is also associated with 'depressive-like' symptoms in experimental animals. Based on reports of the comorbidity between chronic pain and depressive illness in human patients, it is possible that these disease states are linked, via chronic stress-induced HPA dysfunction. Here, we discuss the possible involvement of the HPA axis in the aetiology of both chronic pain and clinical depression, and suggest a strategy for the development of novel pharmacotherapies.

Hypothalamic involvement in chronic migraine

OBJECTIVES

Chronic migraine (CM), previously called transformed migraine, is a frequent headache disorder that affects 2%-3% of the general population. Analgesic overuse, insomnia, depression, and anxiety are disorders that are often comorbid with CM. Hypothalamic dysfunction has been implicated in its pathogenesis, but it has never been studied in patients with CM. The aim was to analyze hypothalamic involvement in CM by measurement of melatonin, prolactin, growth hormone, and cortisol nocturnal secretion.

METHODS

A total of 338 blood samples (13/patient) from 17 patients with CM and nine age and sex matched healthy volunteers were taken. Melatonin, prolactin, growth hormone, and cortisol concentrations were determined every hour for 12 hours. The presence of comorbid disorders was also evaluated.

RESULTS

An abnormal pattern of hypothalamic hormonal secretion was found in CM. This included: (1) a decreased nocturnal prolactin peak, (2) increased cortisol concentrations, (3) a delayed nocturnal melatonin peak in patients with CM, and (4) lower melatonin concentrations in patients with CM with insomnia. Growth hormone secretion did not differ from controls.

CONCLUSION

These results support hypothalamic involvement in CM, shown by a chronobiologic dysregulation, and a possible hyperdopaminergic state in patients with CM. Insomnia might be an important variable in the study findings.

Endocrine levels at the start of treatment are associated with subsequent psychological adjustment in cancer patients with metastatic disease

OBJECTIVE

This study examined the association between hormonal profiles at the start of cancer treatment and subsequent psychological symptomatology.

METHODS

Twenty-seven patients with metastatic renal cell carcinoma and 18 patients with metastatic melanoma completed three assessments during the course of treatment: at the start of treatment (baseline), at the end of treatment (3 weeks after baseline), and at a follow-up appointment 1 month later. Cortisol, norepinephrine, and epinephrine levels were measured at baseline using 15-hour urine samples. At each assessment, patients completed the Impact of Event Scale (IES) and the Brief Symptom Inventory (BSI).

RESULTS

Patients reported moderate levels of distress throughout treatment as measured by the IES and BSI. Norepinephrine levels at the start of treatment were positively associated with IES total scores at the end of treatment and at follow-up, and cortisol levels were positively associated with IES total scores at follow-up after adjusting for baseline IES and overall distress scores. Norepinephrine levels were also positively associated with depression scores at follow-up, and cortisol levels were positively associated with depression scores at the end of treatment and at follow-up after adjusting for baseline depression and overall distress scores.

CONCLUSIONS

Hormonal profiles at the start of cancer treatment are associated with subsequent psychological adjustment.

The impact of repetitive transcranial magnetic stimulation on pituitary hormone levels and cortisol in healthy subjects

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a new therapeutic tool in the treatment of affective disorders but only few studies on its safety exist. We aimed to determine the impact of rTMS on (neuro)endocrinological serum levels by a placebo-controlled cross-over study.

METHODS

23 healthy subjects were stimulated by rTMS in a typical paradigm used in the treatment of depression (coil placed over left dorsolateral prefrontal cortex, 10 and 20 Hz stimulation). Placebo, infrathreshold, and suprathreshold stimulation were applied in random order. The serum levels of cortisol, prolactin, FSH, and TSH were measured before and after stimulation.

RESULTS

After infrathreshold stimulation, cortisol and TSH serum levels decreased mildly but significantly. All other stimulations had no significant impact on hormone levels. In female, but not in male, subjects placebo stimulation yielded a significant increase of prolactin.

CONCLUSIONS

rTMS as applied for the treatment of depression leads to only very mild and safe changes of hormones. These changes, in particular the decrease of cortisol levels, might explain in part the efficacy of rTMS.

Possible role of cortisol and dehydroepiandrosterone in human development and psychopathology

BACKGROUND

The characteristics of adrenal hormone secretion change markedly during infancy. Disturbances in basal levels may precipitate psychological dysfunction and are associated with psychopathology in young people.

AIMS

To relate three aspects of behavioural endocrinology: developmental changes in cortisol and dehydroepiandrosterone (DHEA), the role of these hormones in the psychopathology of young people, and the action of these steroids in the brain.

METHOD

A selective review from the human developmental, psychiatric and neurosciences literature.

RESULTS

There are developmentally mediated changes in brain sensitivity following excess exposure to cortisol. This may result in impairments of mental and behavioural function. DHEA and gonadal steroids may modulate the actions of cortisol.

CONCLUSIONS

Steroid hormones contribute to shaping behavioural function during early development and act as risk factors for psychopathology.

Role of serotonergic and noradrenergic systems in the pathophysiology of depression and anxiety disorders

There is abundant evidence for abnormalities of the norepinephrine (NE) and serotonin (5HT) neurotransmitter systems in depression and anxiety disorders. The majority of evidence supports underactivation of serotonergic function and complex dysregulation of noradrenergic function, most consistent with overactivation of this system. Treatment for these disorders requires perturbation of these systems. Reproducible increases in serotonergic function and decreases in noradrenergic function accompany treatment with antidepressants, and these alterations may be necessary for antidepressant efficacy. Dysregulation of these systems clearly mediates many symptoms of depression and anxiety. The underlying causes of these disorders, however, are less likely to be found within the NE and 5HT systems, per se. Rather their dysfunction is likely due to their role in modulating, and being modulated by, other neurobiologic systems that together mediate the symptoms of affective illness. Clarification of noradrenergic and serotonergic modulation of various brain regions may yield a greater understanding of specific symptomatology, as well as the underlying circuitry involved in euthymic and abnormal mood and anxiety states. Disrupted cortical regulation may mediate impaired concentration and memory, together with uncontrollable worry. Hypothalamic abnormalities likely contribute to altered appetite, libido, and autonomic symptoms. Thalamic and brainstem dysregulation contributes to altered sleep and arousal states. Finally, abnormal modulation of cortical-hippocampal-amygdala pathways may contribute to chronically hypersensitive stress and fear responses, possibly mediating features of anxiety, anhedonia, aggression, and affective dyscontrol. The continued appreciation of the neural circuitry mediating affective states and their modulation by neurotransmitter systems should further the understanding of the pathophysiology of affective and anxiety disorders.

Chronic psychosocial stress differentially affects apoptosis in hippocampal subregions and cortex of the adult tree shrew

We studied the effect of chronic psychosocial stress on cell death and volume changes in the tree shrew hippocampus. In situ end labelling (ISEL) identified low frequent but convincing apoptosis in many hippocampal subregions. Also in entorhinal cortex, apoptosis was found, generally at higher frequencies. After 28 days of chronic stress, apoptosis was significantly reduced in the CA1 stratum radiatum, whereas an increase was observed in the hilus (P < 0.04). With all subregions taken together, the hippocampus showed a decrease, whereas in the cortex, an increase in apoptosis was found after stress (P < 0.04). In a parallel and similar chronic stress study, post mortem morphometry of the same brain regions was performed, revealing mild decreases (7.6%) in entire hippocampal volume. We conclude that (i) low frequent apoptosis occurs throughout the adult tree shrew brain, and (ii) 28 days of chronic stress differentially affects its occurrence in distinct hippocampal subregions and entorhinal cortex. As previous stereological investigations failed to detect any loss in the principal neuronal layers, psychosocial stress, therefore, must affect other (structural) parameters like dendritic tree, interneurons, neurogenesis, or glia.

Are child-, adolescent-, and adult-onset depression one and the same disorder?

This paper reviews prior research studies examining neurobiological correlates and treatment response of depression in children, adolescents, and adults. Although there are some similarities in research findings observed across the life cycle, both children and adolescents have been found to differ from depressed adults on measures of basal cortisol secretion, corticotropin stimulation post-corticotropin releasing hormone (CRH) infusion, response to several serotonergic probes, immunity indices, and efficacy of tricyclic medications. These differences are proposed to be due to 1) developmental factors, 2) stage of illness factors (e.g., number of episodes, total duration of illness), or 3) heterogeneity in clinical outcome (e.g., recurrent unipolar course vs. new-onset bipolar disorder). Relevant clinical and preclinical studies that provide support for these alternate explanations of the discrepant findings are reviewed, and directions for future research are discussed. To determine whether child-, adolescent-, and adult-onset depression represent the same condition, it is recommended that researchers 1) use the same neuroimaging paradigms in child, adolescent, and adult depressed cohorts; 2) carefully characterize subjects' stage of illness; and 3) conduct longitudinal clinical and repeat neurobiological assessments of patients of different ages at various stages of illness. In addition, careful attention to familial subtypes (e.g., depressive spectrum disorders vs. familial pure depressive disorders) and environmental factors (e.g., trauma history) are suggested for future investigations.

Current perspectives on the pathophysiology of schizophrenia, depression, and anxiety disorders

This article reviews the rapidly changing concepts related to the pathophysiology of major psychiatric disorders. The current era is an exciting one for psychiatric research and the rapidity with which advances are being made is a source of hope to patients with these disorders and for society.

Expanding the horizons of depression: beyond the monoamine hypothesis

The monoamine hypothesis has dominated our understanding of depression and of pharmacological approaches to its management and it has produced several generations of antidepressant agents, ranging from the monoamine oxidase inhibitors (MAOIs), through tricyclics (TCAs) and selective serotonin reuptake inhibitors (SSRIs), to the recently introduced selective noradrenaline reuptake inhibitor (NARI), reboxetine. Greater receptor selectivity has improved tolerability, but not efficacy, when newer compounds are compared with the original tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors. Essentially, the newer antidepressants have the same distinguishing feature as older ones, i.e. acute enhancement of monoaminergic neurotransmission. The monoamine hypothesis cannot conclusively link the acute biochemical action of antidepressants on monoamine levels with their delayed clinical effect of 10-14 days, nor can it explain the mode of action of antidepressants that are effective despite being very weak inhibitors of monoaminergic transmission (e.g. iprindole) or, incongruously, enhancing monoamine uptake (e.g. tianeptine). Compared with other fields of medicine, there has been a lack of progress in understanding the pathophysiology of depression and producing truly novel antidepressant agents. Other biological approaches to depression, such as overactivity of the hypothalamic-pituitary-adrenal axis, hippocampal neural plasticity in response to stress, and the link between the inflammatory response and depression, offer new approaches to finding pharmacological agents, aided by improved techniques for visualising the human brain, better animal models, and increased knowledge of human markers of depression. Copyright 2001 John Wiley & Sons, Ltd.

Cushing's syndrome

During the past 30 years, there have been advances in understanding of the pathogenesis of Cushing's syndrome and in differential diagnosis of its various forms. Improved diagnostic tests and procedures have increased the ability to recognise even mild hypercortisolism and have provided the means to obtain an accurate diagnosis. Despite these advances, the occurrence of unusual clinical presentations and laboratory shortcomings may produce diagnostic problems and challenge clinical intuition. This article reviews recent pathogenic views, new tests, and new diagnostic problems in the evaluation of Cushing's syndrome. Atypical clinical presentations of hypercortisolism and some laboratory shortcomings that may confuse the diagnosis of Cushing's syndrome are also reported.

High and low neuroticism predict different cortisol responses to the combined dexamethasone--CRH test

BACKGROUND

Depression and posttraumatic stress disorder are both associated with altered function of the hypothalamic--pituitary--adrenal axis. Neuroticism is a strong predisposing factor for depression and probably also a risk factor for posttraumatic stress disorder. This study investigated whether young adults with high and low neuroticism scores show differences in hypothalamic-pituitary-adrenal axis regulation that might relate to their differential vulnerability to psychopathology.

METHODS

Neuroticism was measured with the Eysenck Personality Questionnaire in 258 students aged 18--25. Fourteen scoring in each of the upper and lower quartiles of the neuroticism distribution according to gender participated in a combined dexamethasone-corticotropin-releasing hormone test.

RESULTS

Low-neuroticism individuals showed a significantly greater cortisol response than high-neuroticism individuals.

CONCLUSIONS

The mechanism of this effect remains to be elucidated. High-neuroticism subjects may have a downregulated hypothalamic--pituitary--adrenal axis to prevent harmful overactivation. This is the first demonstration of a difference in hypothalamic--pituitary--adrenal axis regulation associated with neuroticism.

Effects of estrogen on congnition mood, and degenerative brain diseases

OBJECTIVE

To review research findings on the effects of estrogen on cognition, mood, memory, and degenerative brain disease in women.

DATA SOURCES

English-language journal articles published primarily since 1995, retrieved from a MEDLINE search and from bibliographies of selected reviews.

STUDY SELECTION

Investigational studies, clinical trials, and review articles examining the effects of estrogen on the central nervous system.

DATA SYNTHESIS

Although scientific study of the brain is in its infancy, numerous studies indicate that estrogen is essential to optimal brain function. Estrogen has been shown to increase cerebral blood flow, act as an antiinflammatory agent, enhance activity at neuronal synapses, and exert direct neuroprotective and neurotrophic effects on brain tissue. Through these varied mechanisms, estrogen strongly influences mood and cognition, and the decline of this hormone at menopause can produce significant emotional and cognitive problems in women.

CONCLUSION

Pharmacists can educate women about the various mood and memory changes that can occur during perimenopause and how estrogen replacement therapy may lead to improvements in brain function. The potential use of estrogen replacement therapy to reduce the risk of Alzheimer's disease and ease the symptoms of Parkinson's disease could have a profound effect on women, their families, and society as a whole.

Gender and sexuality in classic congenital adrenal hyperplasia

The current debate about the psychosocial management of intersex patients has significant implications for 46,XX patients with classic congenital adrenal hyperplasia (CAH) in two respects: (1) the question of genital surgery for reasons other than purely medical ones before the patient is old enough to give informed consent, and (2) the question of gender assignment in severely masculinized patients. This article reviews the status of the empirical evidence for the development of gender and sexuality in 46,XX persons with classic CAH and its implications for clinical practice.

Generalized anxiety disorder

The diagnosis of generalized anxiety disorder (GAD) was first introduced in 1980 with the publication of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III) of the American Psychiatric Association. Prior to this, the diagnosis of "anxiety neurosis" was given to patients with symptoms similar to those now incorporated within the GAD category. Originally, GAD was created as a residual category within the anxiety disorders as a rubric for patients with serious anxiety problems but without panic attacks. Panic disorder therefore received far more research attention, and GAD was seen as a diagnosis of exclusion once panic disorder had been ruled out. It is now clear, however, that GAD is a serious psychiatric disorder that is more common than panic disorder and frequently encountered in primary care practice. Indeed, the primary care physician is more likely to see patients with pure GAD than is the psychiatrist. While the treatment of GAD is relatively straightforward, the diagnosis can be difficult. Hence, careful attention to several key symptomatic presentations is important.

Altered fear circuits in 5-HT(1A) receptor KO mice

The study of genetically altered mice has been used successfully to determine the influence of different neurotransmitter receptors on fear and anxiety. Mice with a genetic deletion of the serotonin 1A receptor (5-HT(1A)R knockout [KO]) have been shown to be more fearful in a number of behavioral conflict tests, confirming the important role of this receptor in modulating anxiety. Factor analysis of the behavior of WT and 5-HT(1A)R KO mice in the open field test shows that locomotion and anxiety measures segregate independently, supporting the idea that the anxious behavior of the KO mice is not the result of altered locomotion. KO mice also show increased anxiety in the novelty-suppressed feeding task, which differs from the other conflict tests in the motivational drive of the animals. In response to a discrete aversive stimulus, foot shock, the KO mice show increased freezing and increased tachycardia. However, activation of the hypothalamic-pituitary-adrenal axis in response to stress appears to be slightly blunted in the KO animals. Together, these data support the idea that the 5-HT(1A)R modulates an important fear circuit in the brain. The dual function of the 5-HT(1A)R as both a presynaptic autoreceptor, negatively regulating serotonin activity, and a postsynaptic heteroreceptor, inhibiting the activity of nonserotonergic neurons in forebrain structures, has complicated interpretation of the anxious phenotype of these KO mice. A more complete understanding of the function of the 5-HT(1A)R awaits further study of its role in behaving animals using tissue-specific antagonists and novel transgenic mice with tissue-specific expression of the receptor.

Persistent stress-induced elevations of urinary corticosterone in rats

Exposure of rats to inescapable stressors (IS) results in persistent elevations in plasma corticosterone (CORT), which are selective to the trough of the circadian rhythm. Although affective disorders (depression, anxiety) in humans are also characterized by persistent hypothalamic-pituitary-adrenal axis (HPAA) activation, the predominant measure of HPAA activation in clinical studies is 24-h urinary cortisol. To facilitate interspecies comparisons regarding the persistent effects of stress on HPAA activity, we compared the effects of IS on plasma and urinary CORT in rats. Male Sprague-Dawley rats were exposed to three 2-h sessions of IS (40, 2.0 mA tailshocks) or remained in their home cages. The 24-h urine samples were collected daily from 2 days prior to stress to 5 days after stressor cessation, then weekly for 3 weeks. In addition, plasma samples were obtained at 08:00 (trough) and 20:00 hours (peak) for the first 3 days after stressor cessation and weekly for 3 weeks thereafter. Consistent with our earlier work, plasma CORT elevations were apparent in the trough, but not the peak samples for 3 days after stressor cessation. The 24-h urinary CORT levels were elevated during stressor exposure, and remained elevated for 3 days after stressor cessation. Persistent stress-induced urinary CORT elevations in rats are reminiscent of the clinical HPAA abnormalities described for major depression and affective disorders.

Cellular mechanisms in the vulnerability to depression and response to antidepressants

As a testable heuristic, the concept of stress response and adaptation is highly appealing, and the support for the concept is strong. This explanatory model of depression may account for hitherto apparently discordant facts--contradictory symptoms, antidepressant drugs that act on differing systems, facilitation of antidepressant response by augmentation, and response to psychotherapy and pharmacotherapy. This article has focused narrowly on specific cellular elements of the stress-adaptational mechanisms, including the AC-PKA and PLC-PKC transductional cascades, together with specific response elements, such as the HPA axis, BDNF, and NMDA receptors; however, other important mechanisms, including specific receptor subtypes (e.g., 5-HT1A and NE alpha 2), transmitter systems (e.g., acetylcholine and depamine), and hormones (e.g., thyroid and growth hormones and prolactin), which may be important, have not been discussed. As the complex interactions of these systems gradually yield to investigation, not only will new treatments be developed, but better matching of treatment to patient may become an achievable goal.

Morning cortisol as a risk factor for subsequent major depressive disorder in adult women

BACKGROUND

Whether individual differences in cortisol contribute to subsequent major depressive disorder (MDD) is unknown.

AIMS

To determine whether premorbid levels of salivary cortisol and dehydroepiandrosterone (DHEA) were associated with subsequent MDD and how these related to psychosocial factors known to increase the risk for MDD.

METHOD

Adult women (n=116) were recruited from general practices. None was currently depressed; 83 were 'psychosocially vulnerable' to MDD, 33 were not. Salivary steroids (cortisol and DHEA at 08.00 h and 20.00 h), recent life events, current mood and social support were assessed at entry. Onset of MDD was recorded during 13 months' follow-up.

RESULTS

There were no associations between salivary cortisol or DHEA and recent life events or vulnerability. Twenty-eight onsets of MDD occurred during the follow-up period. This was associated with: severe adverse life events and difficulties during the follow-up period; mean morning cortisol levels at entry; and the presence of any of three vulnerability factors.

CONCLUSIONS

Individual differences in morning salivary cortisol levels may represent an independent risk factor for subsequent MDD. The origin of these differences in cortisol is not yet understood.

Effects of early adverse experiences on brain structure and function: clinical implications

Child abuse is associated with markedly elevated rates of major depression and other psychiatric disorders in adulthood. This article reviews preclinical studies examining the effects of early stress, factors that modify the impact of these experiences, and neurobiological changes associated with major depression. Preclinical studies demonstrate that early stress can alter the development of the hypothalamic-pituitary-adrenal axis, hypothalamic and extrahypothalamic corticotropin releasing hormone, monoaminergic, and gamma-aminobutyric acid/benzodiazepine systems. Stress has also been shown to promote structural and functional alterations in brain regions similar to those seen in adults with depression. Emerging data suggest, however, that the long-term effects of early stress can be moderated by genetic factors and the quality of the subsequent caregiving environment. These effects also can be prevented or reversed with various pharmacologic interventions. Preclinical studies of early stress can provide valuable insights in understanding the pathophysiology and treatment of major depression. They also can provide an important tool to use to investigate interactions between genes and environments in determining an individual's sensitivity to stress. More research is needed to understand how inherent factors interact with experiences of abuse and other psychosocial factors to confer vulnerability to develop depression.

Social desirability scores are associated with higher morning cortisol levels in firefighters

OBJECTIVE

To examine the association of social desirability (SD) responding ("defensiveness") and cortisol levels.

METHODS

Marlowe-Crowne SD scores and morning salivary cortisol were measured in firefighters.

RESULTS

SD scores were associated with higher cortisol levels (r=.28) in 60 firefighters under age 45, but not in 25 older firefighters (or the combined sample).

CONCLUSION

The results are consistent not only with SD scores being an indicator of coarctation of experience as a coping mechanism, but also (at least for younger persons) perhaps a risk factor for the psychobiological dysfunctions associated with chronic elevations of cortisol.

Plasma 5alpha-androstane-3alpha,17betadiol, an endogenous steroid that positively modulates GABA(A) receptor function, and anxiety: a study in menopausal women

We tested the hypothesis that changes in endogenous neuroactive steroids acting as positive allosteric modulators of gamma-aminobutyric acid (GABA)(A) receptors may be related to the menopause-associated mood alterations. The study sample consisted of twenty five drug-free menopausal women, 1-3 years since the onset of menopause, homogeneous for age and body mass index (BMI) and without personal history of psychiatric, metabolic or endocrine disorders. Depression and anxiety-related symptoms were assessed with the Zung Self-administered Depression Scale (ZSDS) and the Cornell's Dysthymia Rating Scale (CDRS). The cut-off value predicted by the ZSDS index defined two groups of women (asymptomatic [35.5+/-4.6, n=12] and symptomatic [60.8+/-7.9, n=13]), that were also significantly different according to the CDRS scores (10.6+/-3.4 and 31.5+/-12, respectively, P<0.05). Upon evaluation of the scores relative to the anxiety factor of the CDRS (items 11-15) the symptomatic, but not the asymptomatic, group showed a moderate level of anxiety. The plasma concentrations of several neuroactive steroids were measured, after extraction and HPLC purification, by radioimmunoassay with specific antisera. Only dehydroepiandrosterone and its metabolite 5alpha-androstane-3alpha,17betadiol (3alpha-ADIOL), a positive allosteric modulator of GABA(A) receptors, were significantly (P<0.05 and P<0.005) higher (+110% and +64%, respectively) in the asymptomatic group. A highly significant and negative correlation (r=-0.672, P=0.003) was found between the plasma 3alpha-ADIOL concentrations and the scores of the anxiety factor of the CDRS. These data suggest that endogenous 3alpha-ADIOL modulates the central GABAergic tone and that higher 3alpha-ADIOL concentrations could have a role in preventing the expression of anxiety in the asymptomatic women.

Early environmental regulation of glucocorticoid feedback sensitivity in young adult monkeys

Variations in maternal care induce in neonatal rodents life-long changes in glucocorticoid feedback regulation of the hypothalamic-pituitary-adrenal axis. This aspect of plasticity in neuroendocrine development has not been established in primates. We assessed, in young adult squirrel monkeys, postnatal rearing effects on cortisol-induced suppression of corticotropin-releasing factor (CRF) stimulated secretion of adrenocorticotropic hormone (ACTH). Offspring of randomly bred monkeys were periodically removed from natal groups between 13 and 21 weeks of age. In two other postnatal rearing conditions, systematic differences in maternal availability were produced by manipulating the effort required of lactating mothers to successfully find food. All offspring were subsequently administered, 3-5 years later on two occasions, an intravenous ovine CRF injection preceded 60 min earlier by placebo or cortisol pretreatment. The difference between CRF-stimulated time-integrated secretion of ACTH following placebo vs cortisol pretreatment served as an index of glucocorticoid negative feedback. Difference scores were greatest in monkeys previously separated from natal groups. This finding was not attributable to significant rearing condition differences in plasma cortisol levels achieved following pretreatment with exogenous cortisol, nor plasma ACTH levels produced when the CRF injection was preceded by pretreatment with placebo. The results suggest that postnatal experiences altered glucocorticoid feedback in monkeys at least through early adulthood. This conclusion supports retrospective reports indicating that, for humans with major mood and anxiety disorders, systematic differences in glucocorticoid feedback may reflect neural mechanisms in development linking early life stress with psychopathology in adulthood.

Increased corticotropin-releasing factor concentrations in the bed nucleus of the stria terminalis of anhedonic rats

Chronic mild stress in rats is an antidepressant-responsive model for anhedonic symptoms of major depression. Many patients with depression exhibit alterations in hypothalamic-pituitary-adrenal axis activity, and corticotropin-releasing factor (CRF) neuronal function. This study investigated the potential involvement of CRF and CRF receptors in the development of chronic mild stress-induced anhedonia in rats. Rats were subjected to 19 days of chronic mild stress, during which time anhedonia was periodically assessed by determining the threshold for self-stimulation of the ventral tegmental area. Anhedonic rats exhibited a 50% increase in CRF concentrations in the bed nucleus of the stria terminalis compared to control rats. There were no significant changes in hypothalamic-pituitary-adrenal axis activity, CRF or CRF(1) receptor mRNA expression, or CRF receptor binding in the brain regions analyzed. Though preliminary, these results are consistent with the hypothesis that chronic stress-induced modulation of CRF function in specific brain structures such as the bed nucleus of the stria terminalis may contribute to the pathophysiology of depression.

The relationship between depression and cardiovascular disorders

Expanding scientific evidence supports a long-recognized link between cardiovascular disease and depression. As an independent risk factor, depression increases patient vulnerability to both cardiac events and mortality. Several important pathophysiologic mechanisms have been proposed, including hypothalamic-pituitary axis hyperactivity, autonomic nervous system dysfunction, and increased platelet reactivity, among others. The recently completed Sertraline Antidepressant Heart Attack Randomized Trial (SADHART) inaugurates a series of studies intended to address the impact of antidepressant therapy on cardiovascular risk.

Physiological correlates of childhood abuse: chronic hyperarousal in PTSD, depression, and irritable bowel syndrome

OBJECTIVE

During the past 10 years, researchers have documented how trauma--especially severe trauma--can alter the functioning of the brain. In some cases, these alterations create a state of chronic hyperarousal. The present review serves as an introduction to this research.

FINDINGS

Persons who have experienced traumatic events are often "primed" to over-react to subsequent stressors, making them more vulnerable to these events.

CONCLUSION

Chronic hyperarousal underlies three common and often co-occurring sequelae of childhood abuse: post-traumatic stress disorder (PTSD), depression, and irritable bowel syndrome. Knowledge of these physiological correlates can affect treatment decisions as well as our theories about the mechanisms underlying the development of symptoms.

Hypertension incidence is predicted by high levels of hopelessness in Finnish men

Recent studies have reported that hopelessness is an important factor in cardiovascular morbidity and mortality, including ischemic heart disease, acute myocardial infarction, and atherosclerotic progression. This study examined the relationship between hopelessness and incident hypertension in a population-based sample of 616 initially normotensive, middle-aged men from eastern Finland, an area with high rates of cardiovascular disease. Participants completed a medical examination and a series of psychological questionnaires at baseline and at the 4-year follow-up. Hopelessness was measured by 2 items assessing negative expectancy about the future and one's goals. A logistic regression model with adjustments for age, body mass index, baseline resting blood pressure, physical activity, smoking, alcohol consumption, education, parental history of hypertension, and self-reported depressive symptoms revealed that men reporting high levels of hopelessness at baseline were 3 times more likely to become hypertensive (systolic blood pressure > or =165 mm Hg and/or a diastolic blood pressure > or =95 mm Hg or confirmed use of antihypertensive medication) in the intervening 4 years than men who were not hopeless (odds ratio, 3.22; 95% confidence interval, 1. 56, 6.67). Men reporting moderate levels of hopelessness were not at a significantly increased risk of hypertension (odds ratio, 1.27; 95% confidence interval, 0.79, 2.07). This is the first study to identify a significant relationship between hopelessness and incident hypertension. Research is needed to explore the neuroendocrine and central nervous system mechanisms underlying this association.

Corticotropin-releasing factor antagonists in affective disorders

Following a search lasting nearly three decades, corticotropin-releasing factor (CRF), a 41 amino acid-containing peptide, was isolated and characterised in 1981. In the preceding 18 years, a concatenation was developed that appears to show that CRF integrates not only the endocrine, but also the autonomic, immunologic and behavioural responses of mammalian organisms to stress. Direct CNS administration of CRF to laboratory animals produces actions similar to those observed after exposure to stress. Moreover, CNS administration of peptidergic CRF antagonists blocks many of the behavioural responses to stress. Since both early untoward life events as well as recently experienced stress have been implicated in the pathophysiology of affective disorders, and because there is substantial evidence for CRF neuronal hyperactivity in patients with affective disorders, small molecule, lipophilic CRF antagonists have been hypothesised to possess antidepressant and/or anxiolytic activity. Within the last few years, a number of pharmaceutical companies have developed selective, small molecule CRF(1) receptor antagonists. These compounds block the effects of CRF both in vitro and in vivo. There is also evidence that these agents possess anxiolytic and antidepressant activity in animal behavioural models. Compounds that act upon the CRF system have been hypothesised to be of value not only for certain psychiatric disorders, but also in neurodegenerative and inflammatory disorders. Some of these CRF(1) receptor antagonists are currently undergoing clinical trials to determine their efficacy and tolerability in patients with mood and anxiety disorders.

Alpha-1-noradrenergic neurotransmission, corticosterone, and behavioral depression

BACKGROUND

Impaired brain alpha-1 noradrenergic neurotransmission has been implicated in some of the symptoms of depressive illness but has been difficult to investigate experimentally because of the insensitivity of current animal models of depression. The present experiment addressed this problem by examining the effects of pharmacologic blockade and corticosteroid-induced desensitization of alpha-1 receptors on two newer, more sensitive models in mice: the inhibition of nest-leaving and the tail suspension tests (TST).

METHODS

Male mice were administered either prazosin, betaxolol, atipamezole, corticosterone, or repeated restraint stress prior to measurement of either nest-leaving or TST. General behavioral function was assessed in horizontal wire, swim, and latency to escape footshock tests.

RESULTS

Prazosin increased depressive behavior in the nest-leaving and TSTs, whereas corticosterone and restraint stress did so only in the more sensitive nest-leaving test. Betaxolol also reduced nest-leaving, suggestive of an alpha-1 beta-1 receptor synergy. The effects of these agents could not be attributed to hypotension, sedation, or general behavioral impairment.

CONCLUSIONS

The fact that a reduction in alpha-1 noradrenergic neurotransmission increases depressive behavior, coupled with the fact that this change can result from elevated corticosteroid secretion, provides further support for a role of this factor in depressive illness. As not all alpha-1 functions are reduced in depression, it is likely that only a subgroup or specific locality of alpha-1 receptors are affected.

Corticotropin releasing factor receptors and their ligand family

The CRF receptors belong to the VIP/GRF/PTH family of G-protein coupled receptors whose actions are mediated through activation of adenylate cyclase. Two CRF receptors, encoded by distinct genes, CRF-R1 and CRF-R2, and that can exist in two alternatively spliced forms, have been cloned. The type-1 receptor is expressed in many areas of the rodent brain, as well as in the pituitary, gonads, and skin. In the rodent, one splice variant of the type-2 receptor, CRF-R2 alpha, is expressed mainly in the brain, whereas the other variant, CRF-R2 beta, is found not only in the CNS, but also in cardiac and skeletal muscle, epididymis, and the gastrointestinal tract. The poor correlation between the sites of expression of CRF-R2 and CRF, as well as the relatively low affinity of CRF for CRF-R2, suggested the presence of another ligand, whose existence was confirmed in our cloning of urocortin. This CRF-like peptide is found not only in brain, but also in peripheral sites, such as lymphocytes. The broad tissue distribution of CRF receptors and their ligands underscores the important role of this system in maintenance of homeostasis. Functional studies of the two receptor types reveal differences in the specificity for CRF and related ligands. On the basis of its greater affinity for urocortin, in comparison with CRF, as well as its brain distribution, CRF-R2 may be the cognate receptor for urocortin. Mutagenesis studies of CRF receptors directed toward understanding the basis for their specificity, provide insight into the structural determinants for hormone-receptor recognition and signal transduction.

High corticosterone levels in prenatally stressed rats predict persistent paradoxical sleep alterations

Prenatal stress predisposes rats to long-lasting disturbances that persist throughout adulthood (e.g., high anxiety, dysfunction of the hypothalamo-pituitary-adrenal axis, and abnormal circadian timing). These disturbances parallel to a large extent those found in depressed patients, in which hypercortisolemia and sleep alterations may be related to stress-inducing events. We studied sleep-wake parameters in control and prenatally stressed adult rats (3-4 months old) and examined possible relationships with their corticosterone levels (determined at 2 months of age). Under baseline conditions, prenatally stressed rats showed increased amounts of paradoxical sleep, positively correlated to plasma corticosterone levels. Other changes include increased sleep fragmentation, total light slow-wave sleep time, and a slight decrease in the percentage of deep slow-wave sleep relative to total sleep time. During recovery sleep from acute restraint stress, all sleep changes persisted and were correlated with stress-induced corticosterone secretion. High corticosterone levels under baseline conditions as well as an acute stress challenge may thus predict long-term sleep-wake alterations in rats. Taken together with other behavioral and hormonal abnormalities in prenatally stressed animals, the pronounced changes in sleep-wake parameters that are similar to those found in depressed patients suggest that prenatal stress may be a useful animal model of depression.