Differences in plasma ACTH and cortisol between depressed patients and normal controls

An exercise prescription for patients with lung cancer improves the quality of life, depression, and anxiety

Introduction

Lung cancer has the highest rates of morbidity and mortality among all cancers. Patients with lung cancer inevitably confront psychosocial discomforts and progressively experience depression and anxiety that potentially impact the clinical outcomes [e.g., quality of life (QoL)]. These mental disorders in patients with lung cancer may effectively be alleviated with prescribed Chinese traditional mind-body exercises. This study aimed to determine the effect of the exercise prescription containing Chinese traditional mind-body exercise on QoL, depression, and anxiety in patients with lung cancer.

Methods

In this study, 52 patients with non-small cell lung cancer (NSCLC) recruited from the China-Japan Friendship Hospital were divided into two groups, namely, the experimental group (N = 26) and the control group (N = 26). The experimental group was treated with an 8-week exercise prescription containing aerobic and resistance training. The control group received the usual care during the study period. The QoL, depression, and anxiety were separately investigated using EORTC QLQ-C30, EORTC QLQ-LC13, the Self-Rating Depression Scale (SDS), and the Self-Rating Anxiety Scale (SAS) at baseline and post-intervention. The scores of questionnaires were analyzed using the paired sample and independent sample t-tests to explore the intragroup and intergroup differences, respectively.

Results

The EORTC QLQ-C30 scores for physical functioning, role functioning, emotional functioning, and global QoL in the experimental group at post-intervention were significantly higher than those at baseline. The EORTC QLQ-C30 scores for fatigue, pain, dyspnea, and insomnia in the experimental group at post-intervention were significantly lower than those at the baseline. The SDS scores (baseline: 57.74 ± 8.77 vs. post-intervention: 51.42 ± 7.31, p < 0.05) and the SAS scores (baseline: 56.63 ± 9.39 vs. post-intervention: 49.16 ± 7.83, p < 0.05) in the experimental group at post-intervention were significantly lower than those at baseline.

Conclusions

The 8-week exercise prescription containing moderate-intensity Baduanjin (5 days per week) can effectively alleviate QoL, depression, and anxiety in patients with NSCLC. Our exercise prescription is an effective supportive treatment for lung cancer patients with depression and anxiety.

Clinical trial registration

Chinese Clinical Trial Registry (ChiCTR1900025121).

Psychological and endocrine factors and pain after mastectomy

BACKGROUND

This prospective study was designed to examine the associations of demographic, clinical, psychological and neuroendocrine factors with acute and chronic post-operative pain following partial mastectomy.

METHODS

Sixty-four female patients scheduled for partial mastectomy were enrolled. Pre-operative anxiety/depression was assessed, using the Hospital Anxiety and Depression Scale (HADS). Pre-operative 24-h urinary cortisol levels were measured 2 days before surgery. Post-operative pain was examined using a visual analog scale (VAS) for acute pain on 0-2 post-operative day (POD), and a short-form McGill Pain Questionnaire for chronic pain at 6 months after surgery. In the last 29 subjects, post-operative 24-h urinary cortisol levels were also measured on 0 POD and were subjected to correlation analysis.

RESULTS

Multivariate logistic regression analysis revealed that lower pre-operative cortisol secretion and greater pre-operative anxiety were significantly associated with an increased risk of moderate to severe acute post-operative pain [Odds Ratio (95% Confidence Interval); 0.96 (0.92-0.98), and 1.24 (1.04-1.54)], and that patients with greater pre-operative anxiety and moderate to severe acute pain were more likely to develop chronic post-operative pain [OR (95% CI); 1.63 (1.23-2.40), and 5.07 (1.30-24.6)]. Correlational analysis demonstrated that the post-operative cortisol level was inversely correlated with pre-operative anxiety and the intensity of acute post-operative pain (r = -0.40, p < 0.05, and r = -0.50, p < 0.01), but not with the intensity of chronic pain.

CONCLUSIONS

This study confirms that pre-operative anxiety is associated with both acute and chronic post-operative pain after partial mastectomy. It also suggests that lower perioperative cortisol secretion might be associated with greater acute post-operative pain.

SIGNIFICANCE

Although the associations between psychological stress/stress hormone levels and chronic post-operative pain remain to be determined, pre-operative psychological stress and perioperative cortisol levels are correlated with acute post-operative pain.

HPA Axis Interactions with Behavioral Systems

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

Relationship between white matter integrity and serum cortisol levels in drug-naive patients with major depressive disorder: diffusion tensor imaging study using tract-based spatial statistics

BACKGROUND

Higher daytime cortisol levels because of a hyperactive hypothalamic-pituitary-adrenal axis have been reported in patients with major depressive disorder (MDD). The elevated glucocorticoids inhibit the proliferation of the oligodendrocytes that are responsible for myelinating the axons of white matter fibre tracts.

AIMS

To evaluate the relationship between white matter integrity and serum cortisol levels during a first depressive episode in drug-naive patients with MDD (MDD group) using a tract-based spatial statistics (TBSS) method.

METHOD

The MDD group (n = 29) and a healthy control group (n = 47) underwent diffusion tensor imaging (DTI) scans and an analysis was conducted using TBSS. Morning blood samples were obtained from both groups for cortisol measurement.

RESULTS

Compared with the controls, the MDD group had significantly reduced fractional anisotropy values (P<0.05, family-wise error (FWE)-corrected) in the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation. The fractional anisotropy values of the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation had significantly negative correlations with the serum cortisol levels in the MDD group (P<0.05, FWE-corrected).

CONCLUSIONS

Our findings indicate that the elevated cortisol levels in the MDD group may injure the white matter integrity in the frontal-subcortical and frontal-limbic circuits.

Serratia marcescens osteomyelitis in Cushing's disease

We report a case of a 46-year-old man with fever, hypotension and arthralgias of the ankles and knees after brain surgery for a pituitary tumour causing Cushing's disease. Blood and urine cultures isolated Serratia marcescens; antibiotic susceptibility testing showed sensitivity to piperacillin-tazobactan and ciprofloxacin. Articular MRI showed inflammation and necrosis of both knees and ankles, and left hip and right elbow (compatible with osteomyelitis). Culture of an ankle abscess on the ankle joint was positive for Serratia marcescens. Bone scintigraphy confirmed osteomyelitic lesions. Medical treatment included antibiotics and strong opioid therapy for 14 weeks. The patient was discharged clinically improved maintaining ciprofloxacin for 24 additional weeks based on clinical and analytic recovery.

The role of neuroendocrine pathways in prognosis after stroke

A number of neuroendocrine changes have been described after stroke, which may serve adaptive or deleterious functions. The neuroendocrine changes include activation of the hypothalamo-pituitary-adrenal axis, sympathetic nervous system and alterations of several hormonal levels. Alterations of the HPA axis, increased catecholamines, natriuretic peptides and, decreased melatonin and IGF-1 levels are associated with poor post-stroke outcome, although there is no definitive proof of causality. Therefore, it remains to be established whether alteration of neuroendocrine responses could be used as a potential therapeutic target to improve stroke outcome. This article gives an overview of the major neuroendocrine pathways altered by stroke and highlights their potential for clinical use and further neurotherapeutic development by summarizing the evidence for their association with stroke outcome including functional outcome, post-stroke infection, delirium, depression and stroke-related myocardial injury.

The role of mineralocorticoid receptor function in treatment-resistant depression

BACKGROUND

Treatment-resistant depression patients show both reduced glucocorticoid receptor function and a hyperactive hypothalamic-pituitary-adrenal axis. However, few studies have examined the role of the mineralocorticoid receptor. This study aimed to evaluate the functional activity of the mineralocorticoid receptor system in regulating the hypothalamic-pituitary-adrenal axis in well-defined treatment-resistant depression patients.

MATERIAL AND METHOD

We recruited 24 subjects divided into: (a) treatment-resistant depression; (b) healthy controls. We evaluated: (a) the effect of combined glucocorticoid receptor/mineralocorticoid receptor stimulation with prednisolone; (b) the effect of prednisolone with the mineralocorticoid receptor antagonist spironolactone; and (c) the effect of spironolactone alone. The response of the hypothalamic-pituitary-adrenal axis was measured using salivary cortisol and plasma levels of drugs were also measured.

RESULTS

Treatment-resistant depression patients had higher cortisol compared with controls after all challenges. In controls, spironolactone increased cortisol compared to placebo. The co-administration of spironolactone with prednisolone in controls decreases the suppressive effects of prednisolone. In contrast, in treatment-resistant depression, spironolactone did not increase cortisol compared to placebo and spironolactone with prednisolone had no effect on the suppressive effects of prednisolone. Patients with treatment-resistant depression had a reduction in the conversation of spironolactone to the active metabolite canrenone.

CONCLUSION

Our data confirmed that treatment-resistant depression is associated with hypercortisolism and these patients no longer show an hypothalamic-pituitary-adrenal response to the administration of a mineralocorticoid receptor antagonist, suggesting that there is a mineralocorticoid receptor malfunctioning, such as a down regulation, however, pharmacokinetics and pharmacodynamics in these subjects could also have had an effect on the lack of mineralocorticoid receptor response.

Age-dependent and gender-dependent regulation of hypothalamic-adrenocorticotropic-adrenal axis

Tightly regulated output of glucocorticoids is critical to maintaining immune competence, the structure of neurons, muscle, and bone, blood pressure, glucose homeostasis, work capacity, and vitality in the human and experimental animal. Age, sex steroids, gender, stress, body composition, and disease govern glucocorticoid availability through incompletely understood mechanisms. According to an ensemble concept of neuroendocrine regulation, successful stress adaptations require repeated incremental signaling adjustments among hypothalamic corticotropin-releasing hormone and arginine vasopressin, pituitary adrenocorticotropic hormone, and adrenal corticosteroids. Signals are transduced via (positive) feedforward and (negative) feedback effects. Age and gonadal steroids strongly modulate stress-adaptive glucocorticoid secretion by such interlinked pathways.

In search of HPA axis dysregulation in child and adolescent depression

Dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis in adults with major depressive disorder is among the most consistent and robust biological findings in psychiatry. Given the importance of the adolescent transition to the development and recurrence of depressive phenomena over the lifespan, it is important to have an integrative perspective on research investigating the various components of HPA axis functioning among depressed young people. The present narrative review synthesizes evidence from the following five categories of studies conducted with children and adolescents: (1) those examining the HPA system’s response to the dexamethasone suppression test (DST); (2) those assessing basal HPA axis functioning; (3) those administering corticotropin-releasing hormone (CRH) challenge; (4) those incorporating psychological probes of the HPA axis; and (5) those examining HPA axis functioning in children of depressed mothers. Evidence is generally consistent with models of developmental psychopathology that hypothesize that atypical HPA axis functioning precedes the emergence of clinical levels of depression and that the HPA axis becomes increasingly dysregulated from child to adult manifestations of depression. Multidisciplinary approaches and longitudinal research designs that extend across development are needed to more clearly and usefully elucidate the role of the HPA axis in depression.

Type 7 adenylyl cyclase-mediated hypothalamic-pituitary-adrenal axis responsiveness: influence of ethanol and sex

Although ethanol has been considered to be an anxiolytic agent, consumption of ethanol has also been shown to increase plasma adrenocorticotropin and glucocorticoids. The corticotrophin-releasing factor (CRF) receptor 1alpha (CRF-R1) is a G protein-coupled receptor that activates adenylyl cyclase (AC), leading to adrenocorticotropin (and subsequently glucocorticoid) release into the circulation. There are nine members of the membrane-bound AC family, and the type 7 AC (AC7) is most sensitive to ethanol, which enhances the responsiveness of AC7 to G protein-coupled receptor activation. We determined the time course of ethanol's effect on plasma adrenocorticotropin and corticosterone levels in male and female AC7 transgenic (Adcy7(huTG)) mice (in which AC7 is overexpressed in neural tissue) and AC7 heterozygous knockdown [Adcy7(+/-)] mice (in which AC7 is underexpressed in neural tissue), and their respective littermate controls [wild type (WT)]. CRF-R1 mRNA and mRNA and protein for different forms of ACs were measured by using gene expression arrays, quantitative reverse transcription-polymerase chain reaction, and immunoblotting in pituitaries of all animals. Our results demonstrated increased levels of AC7 in pituitary of Adcy7(huTG) mice and decreased levels in pituitary of Adcy7(+/-) mice compared with WT animals. Male and female Adcy7(huTG) mice displayed higher plasma adrenocorticotropin and corticosterone levels than WT and/or Adcy7(+/-) mice after ethanol injection. Female mice displayed higher adrenocorticotropin and corticosterone levels after ethanol injection than males, regardless of genotype. The data provide evidence for an integral role of AC7 in the increase of plasma adrenocorticotropin and corticosterone levels during alcohol intoxication.

Neurohormonal and inflammatory hyper-responsiveness to acute mental stress in depression

Depression is associated with dysregulated hypothalamic-pituitary-adrenal (HPA) axis function, overactivity of the sympathoadrenal system, and increased levels of inflammation markers. It is not known whether these biological processes are disproportionately elevated in response to acute negative emotional arousal by mental stress (MS). The present study investigates responses of neurohormones and inflammatory markers to MS in 14 clinically depressed (age: 42+/-10 years; 50% female) and 14 non-depressed control (age: 39+/-6 years; 50% female) participants. Heightened acute MS reactivity was documented in depressed participants (adrenocorticotropic hormone, rho=0.001; norepinephrine, rho=0.042; epinephrine, rho=0.039), and a delayed increase in cortisol was observed (rho=0.002). Inflammation markers increased more strongly in depressed versus non-depressed participants (IL-6, rho=0.027; tumor necrosis factor-alpha, rho=0.050; and recovery C-reactive protein, rho=0.003). It is concluded that depressed individuals display hyper-reactivity of neuroimmunological markers in response to acute negative emotions. This hyper-reactivity may serve a pathologic role in the elevated morbidity and mortality risk associated with depression.

[Pseudo-Cushing states]

Pseudo-Cushing syndromes are a heterogeneous group of disorders, including alcoholism, anorexia nervosa, visceral obesity, and depression, which share many of the clinical and biochemical features of Cushing's syndrome. The mechanisms responsible for the genesis of pseudo-Cushing's syndrome are poorly understood. It has been suggested that hypercortisolism of pseudo-Cushing syndrome may be the result of increased hypothalamic corticotrophin-releasing hormone (CRH) secretion in the context of a hypothalamic-pituitary-adrenal axis that is otherwise normally constituted. The substantial overlap in clinical and biochemical features among several patients with Cushing syndrome and those with pseudo-Cushing syndromes can make the differential diagnosis difficult. Distinguishing between pseudo-Cushing's syndrome and true Cushing's syndrome is critical for preventing the unnecessary and potentially harmful treatment of such patients. This brief review summarizes the main pathophysiological events of pseudo-Cushing syndromes and provides a useful strategy for differential diagnosis.

Corticosterone as a marker of susceptibility to oxidative/nitrosative cerebral damage after stress exposure in rats

There are important individual differences in susceptibility to stress-induced diseases, most of them associated to the hypothalamic-pituitary and sympatho-medullo-adrenal axis functioning. Characterization of individual differences in animals may help to find the origin of this susceptibility. In order to study differences in oxidative and neuroinflammatory consequences in brain after stress exposure, we used an adult, male, outbred (Wistar:Hannover) population of 60 rats. Animals were subjected to 6h of immobilisation stress. Basal (1 week before stress) and post-stress (immediately after stress) plasma corticosterone (CC) was measured for each animal from the tail vein (basal: 239.74+/-19.44 ng/ml at 1500 h). Group H was assigned to animals with 33% higher levels of CC (>279.53 ng/ml) and group L to animals with 33% lower levels of CC (<199.09 ng/ml). After stress, animals with higher plasma CC levels in basal conditions showed higher adrenal response (higher post-stress CC levels) than rats with lower levels of basal CC. Furthermore, rats from H group are more vulnerable to accumulation of oxidative/nitrosative mediators in brain (higher calcium-independent nitric oxide activity and higher lipid peroxidation, by malondialdehyde determination, MDA) and also to the accumulation of proinflammatory mediators (higher PGE(2) levels) whereas showing less antiinflammatory protection (less 15-deoxy-PGJ(2) levels). Statistical analysis, by using ROC curves revealed cut-off values of basal plasma CC predicting animals with higher post-stress MDA and PGE(2) and lower PGJ(2) levels in brain. These data indicate that plasma basal levels of CC are an easily detectable and reproducible parameter for predicting the response of the individuals after an acute stress, providing further support for studies on individual differences.

Effect of coping on endocrinoimmune functions in different stress situations

The objective of this study was to examine the effects of coping strategies on the endocrine and immune functions in different stress situations. Thirty-eight medical students were enrolled in this study. Cell-mediated immune function was measured using the lymphocyte proliferative response to phytohemagglutinin (PHA) and interleukin-2 (IL-2) production during the nonexamination period and during the preexamination period. Endocrine functions were assessed by measuring the plasma levels of norepinephrine, adrenocorticotropic hormone (ACTH) and cortisol. The Global Assessment of Recent Stress (GARS) scale, the Stress Response Inventory, the anxiety, depression, and somatization subscales of the Symptom Checklist-90-revised, the Way of Coping-revised, the Toronto Alexithymia Scale and the Anger Expression Scale were used as psychometric measures. The subjects with higher levels of total GARS scores showed significantly higher IL-2 production during the nonexam period than those with lower levels of total GARS scores. During the same period, IL-2 production in the less positive reappraisal group was significantly higher than in the more positive reappraisal group. Lymphocyte proliferation in the group seeking less social support was also significantly higher than in the group seeking more social support. However, no significant association was found between the coping strategies and each of the hormone levels. These results suggest that positive reappraisal and seeking social support can be associated with the alteration of immune function during a chronic stress period. In particular, positive reappraisal is likely to reverse the stress-induced immune responses. This study did not find that neuroendocrine function such as the sympathetic-adrenal medullary axis or the hypothalamic-pituitary-adrenal axis is playing a mediating role in the relationship between coping and immunity.

Neuroendocrine (HPA axis) and clinical correlates during fluvoxamine and amitriptyline treatment

The effect of amitriptyline on hypothalamic-pituitary-adrenocortical (HPA) axis activity was compared with that of fluvoxamine in 38 patients suffering from DMS-IV major depressive disorder. Basal plasma adrenocorticotropic hormone and cortisol levels were determined in the so-called "observation window" of an hour (08:00-09:00 h), and cortisol levels were determined again at 20:00 h. Clinical and biochemical assessments were performed before therapy (T0), at day 14 (T14), and at day 42 (T42) of the course of antidepressant treatment. At T0, neuroendocrine parameters did not differ in patients from those in controls, except for the ratio between cortisol levels at 20:00 h and the mean level of the "window" (ratio F20/F8), which was significantly higher, suggesting a dysregulation of the circadian pattern of cortisol. Although a decrease in the ratio F20/F8 was already apparent at T14 of both treatments, the repeated measures analysis of variance failed to demonstrate a significant variation with time (T0, T14, and T42) and with treatment (amitriptyline and fluvoxamine) for any hormonal measure. At T42, both treated groups showed a similar level of clinical improvement. Our results did not demonstrate any effect of antidepressant therapy on the cortisol circadian rhythm abnormality.

Decreased plasma prolactin release in euthymic lithium-treated women with bipolar disorder

In order to evaluate the effect of treatment with citalopram (CIT) and lithium (Li) on hormone levels in women with bipolar disorder, morning plasma prolactin (PRL) and cortisol (CORT) were measured in 14 nonmedicated depressed patients, 13 depressed patients responding to CIT treatment, 17 euthymic patients on long-term Li treatment, and 11 healthy controls. Plasma PRL values in the Li group were significantly lower than those of the three other groups, suggesting a net inhibitory impact of augmentative effects of Li on dopaminergic activity and serotonergic neurotransmission in the central nervous system. Plasma CORT values in nonmedicated depressed patients were significantly higher than those of healthy controls, indicating hyperactivity of the hypothalamic-pituitary-adrenal system in depression, which appears to be a state-dependent phenomenon, and is normalized upon successful treatment with Li and CIT.

Neuroendocrine aspects of hypercortisolism in major depression

A consistent finding in biological psychiatry is that hypothalamic-pituitary-adrenal (HPA) axis physiology is altered in humans with major depression. These findings include hypersecretion of cortisol at baseline and on the dexamethasone suppression test. In this review, we present a process-oriented model for HPA axis regulation in major depression. Specifically, we suggest that acute depressions are characterized by hypersecretion of hypothalamic corticotropin-releasing factor, pituitary adrenocorticotropic hormone (ACTH), and adrenal cortisol. In chronic depressions, however, enhanced adrenal responsiveness to ACTH and glucocorticoid negative feedback work in complementary fashion so that cortisol levels remain elevated while ACTH levels are reduced. In considering the evidence for hypercortisolism in humans, studies of nonhuman primates are presented and their utility and limitations as comparative models of human depression are discussed.

Circadian variation in Cushing's disease and pseudo-Cushing states by analysis of F and ACTH pulsatility

Distinguishing pituitary-dependent Cushing's disease from pseudo-Cushing's states can present a diagnostic challenge. Although many studies potentially discriminate between the 2, only the dexamethasone-suppressed corticotropin-releasing hormone (CRF) stimulation test at 15 minutes is 100% sensitive or specific. We measured baseline profiles of F and ACTH in 31 Cushing's disease patients, 11 with pseudo-Cushing's and 17 controls. Venous blood was collected at 30 minute intervals for 24-h. Subjects also had CRF stimulation tests and 2.0 mg/day dexamethasone suppression tests. F and ACTH profiles were analyzed for circadian rhythmicity, variability, and pulsatility. Relative circadian amplitude was decreased in Cushing's disease compared to both pseudo-Cushing's and normal states. Relative pulse amplitude was reduced in Cushing's disease. Because of this dampening of circadian and pulsatile variations, the overall variability of F and ACTH levels around their mean levels as quantified by the intra-series coefficient of variation (CV), was also decreased in Cushing's disease compared to pseudo-Cushing's and normal states. A F 24-h CV<40% was able to distinguish Cushing's disease from pseudo-Cushing's with 100% sensitivity (95% confidence interval (CI), 88-100%) and specificity (CI, 71-100%). An ACTH CV<40% had 97% sensitivity (CI, 83-100%) and 100% specificity (CI, 71-100%). An overnight 8-h F CV <40% also distinguished Cushing's disease from pseudo-Cushing's with 100% sensitivity (CI, 88-100%) and specificity (CI, 71-100%). These data show that a simple index of total temporal variability (the intra-series CV) derived from the analysis of basal F profiles, provides a useful method to distinguish Cushing's disease from pseudo-Cushing's. A F or ACTH CV <40% discriminates Cushing's disease from pseudo-Cushing's and reflects reduced circadian and pulsatile variations.

HPA axis dysregulation in mice overexpressing corticotropin releasing hormone

BACKGROUND

Hypersecretion of corticotropin-releasing hormone (CRH) in the brain has been implicated in stress-related human pathologies. We developed a transgenic mouse line overexpressing CRH (CRH-OE) exclusively in neural tissues to assess the effect of long-term CRH overproduction on regulation of the hypothalamic-pituitary-adrenal (HPA) axis.

METHODS

Male transgenic CRH-OE(2122) mice on a C57BL/6J background were used. Littermate wildtype mice served as control animals. Basal plasma corticotropin and corticosterone concentrations were measured, and adrenal gland weight was determined. A dexamethasone suppression test measured the effects of long-term CRH hypersecretion on negative feedback control. Additionally, we measured plasma corticosterone concentrations in reaction to stress.

RESULTS

CRH-OE(2122) mice showed elevated basal plasma corticosterone concentrations, hypertrophy of the adrenal gland, and dexamethasone nonsuppression. Basal plasma ACTH concentrations of wildtype and CRH-OE(2122) mice did not differ significantly. In reaction to stress, CRH-OE(2122) mice showed a normal corticosterone response.

CONCLUSIONS

The HPA axis abnormalities observed in CRH-OE(2122) mice suggest that long-term hypersecretion of CRH in the brain can be a main cause of HPA axis dysregulation. The alterations in HPA axis regulation are reminiscent of changes reported in major depressive disorder. As such, these CRH -OE(2122) mice may model the neuroendocrine changes observed in major depressive disorder.

Cushing’s disease and melancholia

Striking similarities exist in the endocrinology of Cushing's disease and melancholic depression.Laboratory abnormalities, which have been found in both, include raised urinary,plasma and salivary cortisol, non-suppression of cortisol in the dexamethasone suppression test and adrenocorticotrophin (ACTH) hypersecretion. The hypercortisolism can be so severe in melancholic depression that it is difficult to distinguish from Cushing's disease and has been described as a "pseudo-Cushing's" state. Cerebrospinal fluid corticotrophin-releasing hormone (CRH) levels have been found to be lower in patients with Cushing's disease than in depressed subjects. Dynamic endocrine tests may help to distinguish between the two disorders.An exaggerated response to synacthen has been found in both but a reduced ACTH response to CRH occurs in depression, unlike those with Cushing's disease who show ACTH hyper-responsiveness. Other tests, which may help to distinguish between the two disorders,include the dexamethasone-CRH test, the naloxone test, the insulin-induced hypoglycemia test and the desmopressin stimulation test. Similarities in psychiatric symptoms have been recognised for many years. More recently, the physical complications of melancholic depression have been noted. These include osteoporosis, an increased risk of death from cardiovascular disease, hypertension, a redistribution of fat to intra abdominal sites and insulin resistance. Cushing's disease shares these physical complications and we propose that the common underlying factor is excessive plasma glucocorticoids. The increasing recognition of the physical complications and the increased morbidity and mortality in those who suffer from depression underscores the necessity for early detection and treatment of this illness and screening for undetected physical complications.

Neuropsychiatric toxicity of antiviral treatment in chronic hepatitis C

Dose-dependent, reversible neuropsychiatric toxicity is reported in up to 30-40% of chronic hepatitis C patients treated with 6-12 months of interferon-alpha or interferon-alpha plus ribavirin combination therapy. Although risk factors remain poorly defined, neuropsychiatric side effects may be severe and dose-limiting in as many as 10-20% of treated patients. Diagnosis relies upon the detection of clinically apparent neuropsychiatric symptoms and the emerging use of self-administered mood inventories and questionnaires. The current stepwise approach to management includes evaluation and treatment of systemic side effects, early use of adjuvant medications, and interferon-alpha and ribavirin dose reduction or cessation with psychiatric referral in selected cases. Although the cellular basis of the neuropsychiatric toxicity of interferon-alpha remains unknown, several hypothesis involving changes in central adrenergic, seratonergic, opioid and neuroendocrine pathways have been proposed. Recognition and management of the neuropsychiatric side effects of antiviral therapy will be of growing clinical importance as additional patients with chronic hepatitis C are treated and longer durations of therapy are utilized.

Obesity and cortisol

Cortisol in obesity is a much-studied problem. Previous information indicates that cortisol secretion is elevated but that circulatory concentrations are normal or low, suggesting that peripheral disappearance rate is elevated. These studies have usually not taken into account the difference between central and peripheral types of obesity. Recent studies using saliva cortisol have indicated that the problem is complex with both high and low secretion of cortisol, perhaps depending on the status of the function of the hypothalamic-pituitary-adrenal gland axis. A significant background factor seems to be environmental stress. The results also suggest that the pattern of cortisol secretion may be important. Other neuroendocrine pathways are also involved, including the central sympathetic nervous system, the gonadal and growth hormone axes, and the leptin system. In concert, these abnormalities seem to be responsible for the abnormal metabolism often seen in central obesity. Several associated polymorphisms of candidate genes may provide a genetic background. Cortisol conversion to inactive metabolites may be a factor increasing central signals to secretion and may add to the increased secretion of cortisol induced by centrally acting factors. Perinatal factors have been found to be involved in the pathogenesis of obesity and its complications. The mechanism involved is not known, but available information suggests that programming of the hypothalamic-pituitary-adrenal axis may be responsible.

An investigation of serotonergic involvement in the regulation of ACTH and corticosterone in the olfactory bulbectomized rat

The bilateral olfactory bulbectomy resulted in significantly higher plasma concentration of corticosterone, but not of ACTH in basal conditions and much higher plasma ACTH and corticosterone concentrations after 15 min of immobilization stress than were observed in sham-operated animals. Daily treatment with fluoxetine-a specific serotonin reuptake inhibitor-(15 mg/kg/day) had no effect on basal ACTH and corticosterone concentrations in OB rats. Fluoxetine treatment caused lower levels of ACTH, but not of corticosterone secretion, in response to immobilization stress. Bulbectomy significantly reducing 5-HT concentration in the amygdala. Stress increased serotonergic activity in the hypothalamus but not in the amygdala of OB rats. Chronic fluoxetine treatment of both unstressed and stressed OB rats resulted in a lower turnover rate in the two structures. Our results suggest that the hypercorticosteronemia observed after bulbectomy in unstressed OB rats is independent of the serotonergic system in both hypothalamus and amygdala. In contrast, they also demonstrate hypothalamic 5-HT changes in the HPA hyperactivity of OB rats in response to stress. Chronic fluoxetine treatment may normalize pituitary ACTH secretion in response to stress, possibly desensitization of the 5-HT receptors in the hypothalamus due to 5-HT being move available at the synapses.

Effects of bilateral olfactory bulbectomy on circadian rhythms of ACTH, corticosterone, motor activity and body temperature in male rats

Bilateral olfactory bulbectomy (BOX) has major biochemical and behavioral effects, and is one of the most widely investigated of animal models of depression. We studied the consequences of BOX in male rats, on the organization of endogenous circadian rhythms for ACTH, corticosterone (Cort), motor activity (MA) and body temperature (BT). Mean levels were increased for Cort and MA, whereas no significant changes were observed for ACTH and BT. Significantly higher plasma Cort morning values were evidenced in BOX than sham-operated animals. In addition, compared with the single prominent power spectrum for the 24 hours period of control rats, the BOX animals displayed substantially lower 24 hours spectral power for the MA and BT circadian rhythms. These alterations suggest that olfactory bulbectomy, by disruption of the afferences and efferences, induced drastic changes in the function of the endogenous clock or of its regulating systems. From this point of view, bulbectomized rats may therefore be a valuable model to studying the etiology of psychiatric disorders with rhythm disturbance.

No early effects of electroconvulsive therapy on tryptophan metabolism and disposition in endogenous depression

The possibility that a single electroconvulsive therapy (ECT) could increase tryptophan (Trp) availability to the brain for 5-hydroxytryptamine (5-HT, serotonin) synthesis was examined in 10 depressed patients before and during the 1st hour following an ECT and in 4 control (minor ear, nose, and throat surgical) subjects receiving similar premedication. Trp availability to the brain, expressed as the serum Trp: competing amino acid ratio, and related aspects of Trp disposition were not significantly altered by ECT any differently than from preoperative stress and premedication. We suggest that Trp availability to the brain and, hence, cerebral 5-HT synthesis are not altered in depressed patients early after a single ECT.

Circadian temperature and cortisol rhythms during a constant routine are phase-delayed in hypersomnic winter depression

Circadian temperature, cortisol, and thyroid-stimulating hormone (TSH) rhythms during a constant routine were assessed in 6 female controls and 6 female patients with hypersomnic winter depression (seasonal affective disorder, SAD) before and after morning bright light treatment. After sleep was standardized for 6 days, the subjects were sleep-deprived and at bed rest for 27 hours while rectal temperature, cortisol, and TSH levels were assessed. The minimum of the fitted rectal temperature rhythm was phase-delayed in the SAD group compared to the controls 5:42 AM vs. 3:16 AM (p < .005); with bright light treatment, the minimum advanced from 5:42 AM to 3:36 AM (p = .06). The minimum of the cortisol rhythm was phase-delayed in the SAD group compared to the control group, 12:11 AM vs. 10:03 PM (P < .05); with bright light treatment, the minimum advanced from 12:11 AM to 10:38 PM (P = .06) [corrected]. The acrophase of the TSH rhythm was not significantly phase-delayed in SAD subjects compared to control, though the trend appeared to be toward a phase-delay (p = .07). After bright light therapy, the TSH acrophase was not significantly different in the SAD subjects; the trend was a phase-advance (p = .09). Overall, the data suggest that circadian rhythms are phase-delayed relative to sleep in SAD patients and that morning bright light phase-advances those rhythms.

Psychobiological consequences of social relationships

Social separations can induce long-lasting increases in cortisol, whereas companionship can result in social buffering. Preliminary evidence from studies of squirrel monkeys suggests that social separation-induced hypersecretion of cortisol is initially driven by hypersecretion of ACTH. From 1-21 days postseparation, however, cortisol remains elevated above pre-separation controls, while ACTH levels are consistently reduced. Hypercortisolism is maintained despite reductions in ACTH, because adrenal responsiveness to ACTH is enhanced. Low circulating ACTH, in turn, is maintained by robust feedback mechanisms that apparently inhibit biosynthesis or release of pituitary ACTH. These findings are consistent with neuroendocrine interactions known or hypothesized to occur during major depressive disorders in humans and raise unique possibilities for comparative research in human and nonhuman primates.

Circadian immune measures in healthy volunteers: relationship to hypothalamic-pituitary-adrenal axis hormones and sympathetic neurotransmitters

OBJECTIVE

The purpose of this study is to examine the circadian pattern of specific immunologic measures and to compare observed circadian rhythms of these measures with the well-established circadian rhythms of hypothalamic-pituitary-adrenal axis hormones and sympathetic neurotransmitters.

METHODS

Blood samples were collected every 2 hours for a total of 24 hours from nine healthy volunteers. The blood samples were assayed for hormones and immune measures, including adrenocorticotropic hormone (ACTH), cortisol, norepinephrine, and epinephrine. The immune measures included percentage and absolute number of neutrophils, lymphocytes, the lymphocyte subsets CD3+ (T cells), CD4+ (T helper/inducer), CD8+ (T suppressor/cytotoxic), CD56+ (natural killer [NK] cells) and NK cell activity (NKCA).

RESULTS

The following immune measures exhibited a significant circadian rhythm: the percentages of neutrophils, CD4+ cells, and CD56+ cells; the absolute numbers of total lymphocytes, CD3+ cells, CD4+ cells, and CD8+ cells; and NKCA. Cross-correlations between the circadian rhythms of selected hormones and immune measures indicated a strong inverse association between the circadian rhythms of cortisol and the different T cell subsets on the one hand, and a strong direct association between the rhythms of cortisol and the percentage of CD56+ and NKCA on the other. Cross-correlations involving the circadian rhythms of norepinephrine and the same immune measures were in general much weaker and statistically nonsignificant.

CONCLUSION

In healthy individuals, both enumerative and functional immune measures exhibit circadian rhythms that seem to be associated most closely with the circadian rhythm of cortisol.

The relationship between longitudinal clinical course and sleep and cortisol changes in adolescent depression

This study examined the relationship between longitudinal clinical course and sleep and cortisol findings in adolescent unipolar major depressive disorder (MDD). Subjects were 28 adolescents (15.4 +/- 1.3 years) systematically diagnosed with unipolar MDD and 35 group-matched normal controls who participated in EEG sleep and neuroendocrine studies. Follow-up clinical assessments were conducted 7.0 +/- 0.5 years later in 94% of the original cohort. Although initial group comparisons failed to show significant differences in biologic measures, analyses incorporating clinical follow-up reveal that changes in sleep and cortisol measures are associated with differential longitudinal course. Normal controls who would develop depression after the biologic studies had shown significantly higher density of rapid eye movements (REM) and a trend for reduced REM latency compared to controls with no psychiatric disorder at follow-up. Depressed subjects with a recurrent unipolar course showed a trend towards elevated plasma cortisol near sleep onset compared to MDD subjects with no further episodes during the follow-up interval.

Circadian profiles of cortisol, prolactin, and thyrotropin in seasonal affective disorder

To determine whether circadian profiles of various plasma hormones are abnormal in patients with winter seasonal affective disorder (SAD), we obtained 24-hour profiles of plasma cortisol, prolactin, and thyrotropin in subsets of a sample of 22 depressed patients with SAD on and off light therapy and in subsets of a sample of 24 normal controls. Cortisol levels did not differ between patients and controls, and levels in patients were not affected by light therapy. Prolactin levels were lower in patients than in controls throughout the day (p < 0.03) but were unaffected by light therapy. Independent of patient vs. control status, prolactin levels were higher in women than in men throughout the day (p < 0.003). Thyrotropin levels were no different in patients and controls, but levels in patients were lower following light therapy (p < 0.05).

Depressive symptoms in the elderly: association with total white blood cell count

1. The white blood cell (WBC) count in those with high depressive symptoms and non-depressed participants in the Established Populations for Epidemiologic Studies of the Elderly (EPESE) were compared. 2. Of 3769 participants 10.8% had high depressive symptoms as assessed by the Centers for Epidemiologic Studies Depression (CES-D) Scale. The mean white blood cell count was higher in the high depressive symptoms group compared to the non-depressed group (6.8 +/- 0.12 x 10(9) WBC/1 and 6.5 +/- 0.03 x 10(9) WBC/1, respectively, p < 0.01). 3. Because older adults frequently have disabling chronic conditions which could both influence their leukocyte count and cause depressive symptoms, models were developed which controlled for the potential confounding. Even after adjusting for potential confounders, high depressive symptoms were still associated with higher white blood cell counts.

Immunoglobulin production in vitro in major depression: a pilot study on the modulating action of endogenous cortisol

To investigate the possible differential sensitivity of hydrocortisone (HCO) on immunoglobulin (Ig) production in depression in relation to endogenous cortisol levels, blood was obtained at 8 AM and 4 PM from 10 inpatients with major depression according to DSM-III-R criteria and 10 age- and sex-matched healthy subjects. Peripheral blood lymphocytes were cultured in the presence of graded concentrations (10(-9)-10(-5) M) of HCO to study the effect on immunoglobulin (IgG and IgM) synthesis. In addition, peripheral blood lymphocytes were cultured in the presence of pokeweed mitogen (PWM) to study any additional effect of graded concentrations of HCO (10(-9)-10(-5) M) on IgG and IgM synthesis. Mean plasma cortisol levels at both time points were higher in patients compared to controls. HCO--preferentially at concentrations of 10(-8)-10(-6) molar--stimulated IgG and IgM production in controls, except for IgM production in the 8 AM samples, when the cells were cultured in the absence of PWM. Under these culture conditions, HCO stimulated IgG but not IgM synthesis in depressed patients. PWM-driven IgG and IgM synthesis in controls was stimulated by HCO in both the 8 AM and the 4 PM samples. In patients PWM driven IgG synthesis was stimulated by HCO in the 8 AM but not in the 4 PM samples. PWM-stimulated IgM synthesis was not augmented by HCO in depressed patients. We conclude that a differential sensitivity to the effects of HCO exists in in vitro IgG and IgM synthesis between depressed patients and controls. Furthermore, we suggest that immunocompetent cells of depressed patients possess corticosteroid-resistant properties.

Relationship between erythrocyte magnesium, plasma electrolytes and cortisol, and intensity of symptoms in major depressed patients

53 male and female drug-free major depressed patients were separated into three groups according to the severity of the depression. In the entire regrouped population, plasma and erythrocyte magnesium (Mg) were shown to increase as compared with 48 healthy controls, confirming our previous studies. The middle and highly depressed patients had higher erythrocyte and also plasma Mg levels than either lowly depressed patients or controls. Only, a few differences were noticed in plasma sodium, potassium and calcium (Ca) in the three groups of patients, except for ultrafiltrable plasma Ca, measured for the first time in affective disorders. Thus, erythrocyte and also plasma Mg are shown to be associated with the intensity of the depression. As blood hypomagnaesemia is often related to hyperexcitability, further investigations are actually in process to shown whether hypermagnesaemia might be, in contrast, associated with psychomotor retardation as observed in many depressed patients.

Cushing's syndrome

Cushing's syndrome is usually caused by the secretion of corticotropin or cortisol by a pituitary or adrenal tumor, respectively, or by ectopic secretion of corticotropin. It is possible to determine the specific abnormality in most patients, but it can sometimes be difficult to decide whether the patient has hypercortisolism and whether it is primary or due to major depressive disorder or to the stress of other diseases. Determining the cause of the hypercortisolism involves performing multiple tests in a logical sequence; the results should all be consistent with the same diagnosis. Treatment should aim to cure the hypercortisolism and to eliminate any tumor that threatens the patient's health, while minimizing the chance of an endocrine deficiency or long-term dependence on medications.

The potential role of excessive cortisol induced by HPA hyperfunction in the pathogenesis of depression

Prolonged hypothalamic-pituitary-adrenocortical (HPA) axis overactivity occurs at all levels of this axis during stress in normals and some depressed patients. This can induce enlargement of the pituitary and adrenals. Various reports showed that cortisol can affect mood and behavior, and disrupt memory and recall. The integrity of the hippocampus is essential for memory function and, via the high density of its cortisol receptors, cortisol induced inhibitory feedback to the HPA axis. Animal data suggest that over time aging and stress can permanently downregulate hippocampal cell receptors, produce chronic hippocampal inflammation (astroglial), and kill cells. Cushing's syndrome patients (high cortisol) show diminished hippocampal size and verbal recall inversely related to cortisol levels. All the above is consistent with the 'cascade hypothesis' of cortisol induced hippocampal damage with resultant diminished inhibition to HPA hyperactivity in a circular manner. High cortisol is associated with altered neurotransmitter function, e.g., diminished brain serotonin synthesis, low CSF 5HIAA, and increased noradrenergic activity.

Do cortisol and thyroxin correlate with nervousness and depression among male army veterans?

Elevated cortisol is recognized as a transient response to stress, and is also found among patients with major depressive disorder. Abnormally high levels of thyroxin are associated with nervousness and irritability, while very low levels are associated with lethargy. Therefore it is reasonable to ask if variations in cortisol and thyroxin within a normal population are associated with differences in anxiety and depression. These expectations were tested in a large sample of male army veterans. Nervousness is significantly associated with both thyroxin and cortisol, although several other symptoms of anxiety or depression are not.

Involvement of corticosteroids in the processing of stressful life-events. A possible implication for the development of depression

In a sub-population of endogenously depressed patients, disturbances of the hypothalamic-pituitary-adrenal axis can be observed. Increased cortisol and CRH levels combined with normal ACTH concentrations have often been reported. Corticosteroids appear to play a role in the mood changes, in depressed subjects. However, their mechanism of action is unknown. In animal experiments, the involvement of corticosteroids in stressor-induced learning was investigated. Three paradigms were used. In the Porsolt swimtest an animal had to learn to adapt to an inescapable situation. In the lithium chloride conditioned taste aversion an animal learned to avoid sugar water. In the amphetamine sensitization a second injection of amphetamine caused a potentiated response, because of conditioning. All three conditions appeared to be stressful because they induced a corticosterone release. When adrenalectomized (ADX) mice were compared to control animals it appeared that, in all three paradigms, their memory function was disturbed. The data indicated that this was a specific glucocorticoid-mediated effect since corticosterone and dexamethasone injections were able to reverse the ADX-induced deficit. The ADX-induced disturbances were only observable at moderate stress levels. More severe stressors (lower water temperature in the Porsolt swimtest, higher lithium chloride and amphetamine doses) also made ADX mice remember their previous experiences. The results suggest that corticosteroids are involved in the consolidation of stressful events and the corresponding coping responses. They play, however, only a role in the case of moderate stressors. In ADX animals no stressor-induced corticosterone increase can occur and therefore these animals only remember severe stressors. In a depressed patient basal steroid levels are increased and consequently very mild stressors, which induce only a small extra steroid release, will be remembered. The remembering of all these negative experiences might be of importance for the development and maintenance of the depression.

The relevance of the in- versus outpatient status for studies on HPA-axis in depression: spontaneous hypercortisolism is a feature of major depressed inpatients and not of major depression per se

Increased spontaneous activity of the hypothalamic-pituitary-adrenal (HPA)-axis is frequently reported in major depressed inpatients. The aim of the present study was to determine whether there are differences in spontaneous HPA-axis activity between major depressed inpatients and outpatients. Toward this end, the authors measured basal 9:00 a.m. plasma cortisol and the integrated assessment of plasma morning cortisol secretion over 2 (AUC 120) hours in 48 major depressed inpatients, 17 major depressed outpatients and 73 normal volunteers. Major depressed inpatients exhibit significantly higher plasma cortisol values than healthy controls and major depressed outpatients. The cortisol data from the latter are not significantly different from these of the healthy controls. The cortisol differences between in and outpatients were still present after considering the influences of age, sex, body mass index, severity or endogeneity of illness, unipolar/bipolar subclassification, or specific symptoms such as suicidal thoughts, insomnia, psychomotor disorders, psychoticism, weight loss or anxiety. The results indicate that hypercortisolism as measured by basal morning plasma levels is not a feature of major depression per se, but rather of an interaction between the illness and hospitalization.

Oral contraceptives and the dexamethasone suppression test

Among other confounding factors, the influence of the intake of estrogen-containing oral contraceptives on the dexamethasone suppression test (DST) results has never been specifically studied. Therefore, we performed 1 mg DSTs in 14 healthy women taking oral contraceptives and 14 age-matched women taking no oral contraceptives. Mean 0800h basal total cortisol was significantly higher among the women taking contraceptives than in the control group, whereas mean free cortisol did not significantly differ. At 1600h following DST, no significant difference existed between the two groups. Two subjects taking contraceptives and one control subject were considered DST nonsuppressors. These results confirm the powerful influence of oral contraceptives on basal total cortisol levels but suggest a lack of significant influence on DST results.

Stimulation of the pituitary-adrenal axis with a low dose [Arg8]-vasopressin in depressed patients and healthy subjects

Graded doses arginine-vasopressin (AVP) were administered to depressed patients and control subjects to compare the sensitivity of the pituitary-adrenal system of these subjects for this compound. The plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and beta-endorphin were measured before and after intravenous AVP injection. The hormonal output was taken as a measure of pituitary-adrenal function. In control subjects 3 doses AVP and placebo were used, whereas in patients two doses AVP, a low and a high dose, and placebo were tested. All tests were carried out in the afternoon when the pituitary-adrenal system is stable and more susceptible for stimulation. Patients were subdivided into dexamethasone suppressors and nonsuppressors based on their DST status before testing to look for differences among these groups. Control subjects showed no response of the hormones to the lowest dose AVP and a moderate response to the higher doses. Interestingly, depressed patients as compared to controls responded more to the lowest dose AVP in particular with respect to ACTH. DST status did not influence the results. These findings suggest an enhanced sensitivity of the pituitary to low doses AVP in depressed patients. Thus, AVP might play a role in HPA dysfunction in depression.

Specific and nonspecific effects of ethanol vapor on plasma corticosterone in mice

The intent of this study was to determine whether chronic ethanol (EtOH) vapor inhalation, with or without adjunct pyrazole (PYR) administration, was stressful in mice, as defined by increases in plasma corticosterone (CORT) concentration. Mice were randomly assigned to groups differentiated both on the basis of EtOH vapor exposure and the presence or absence of PYR administration. Blood samples for blood EtOH concentration (BEC) and plasma CORT concentration were obtained from mice after 72-96 hours of treatment. Mice were sacrificed after 96 hours of treatment and body and adrenal weight determined. BEC was significantly higher in PYR-treated animals and animals treated with the higher EtOH vapor concentration. Plasma CORT was elevated in proportion to BEC; however, other nonspecific stresses, in particular that of PYR administration, also elevated plasma CORT. Nonspecific stresses associated with this protocol may reduce the generality of these observations. Nevertheless, the high correlation between BEC and plasma CORT concentration in the PYR groups indicates that, with suitable control groups, the PYR-EtOH vapor inhalation approach is viable for studies concerned with EtOH effects on hypothalamic-anterior pituitary-adrenocortical function.

Autoradiographic characterization of [3H]imipramine and [3H]citalopram binding in rat and human brain: species differences and relationships to serotonin innervation patterns

The neuroanatomical distribution of binding sites for [3H]imipramine and [3H]citalopram was assessed by in vitro autoradiography in select regions of the rat and human forebrain. To determine involvement of serotonin-containing terminals in the binding of [3H]imipramine and [3H]citalopram, binding of these compounds was measured in rats after destroying serotonin-containing neurons with 5,7-dihydroxytryptamine (5,7-DHT). Treatment with this neurotoxin decreased serotonin content by 90% and reduced [3H]citalopram binding to a similar extent. These results demonstrate that [3H]citalopram binding is a reliable marker for serotonin-containing terminals. Binding of [3H]imipramine was reduced by only 15-35% after 5,7-DHT treatment. These latter results suggest that only a small fraction of [3H]imipramine binding to brain sections is associated with serotonergic terminals under standard conditions used in autoradiographic studies with the ligand. Dose-response effects of fluoxetine and desipramine on displacement of [3H]imipramine binding in forebrain regions indicate that the ligand labels predominantly high capacity, low affinity binding sites. To determine the utility of the rat brain as a model for [3H]imipramine and [3H]citalopram binding in the human brain, binding of the ligands was compared in human and rat hypothalamus, amygdala, and hippocampus. The pharmacological characteristics of [3H]imipramine and [3H]citalopram binding were similar in the rat and human brain. However, substantial species differences were observed in topographic patterns of [3H]imipramine binding within the hippocampus and hypothalamus. The distribution of [3H]citalopram binding sites within the amygdala and hypothalamus were also strikingly different in rats compared to humans. This work provides the first demonstration that marked species differences exist in the topography of serotonergic innervation and in the distribution of [3H]imipramine binding sites within the rat and human brain regions examined.

24-hour cortisol measures in adolescents with major depression: a controlled study

Plasma cortisol levels were determined every 20 min for 24 hr in depressed adolescents (n = 27) meeting research diagnostic criteria (RDC) for major depressive disorder (MDD) and normal controls (n = 32). All subjects were between 12 and 18 years of age, at least Tanner Stage III of sexual development, medically healthy, and medication free at the time of the studies. The results showed that cortisol secretory patterns were very similar between the two groups with the exception that the depressed adolescents showed significantly elevated cortisol levels around sleep onset (a period when cortisol is usually suppressed). Subgroup analyses showed that most of these differences were contributed by the suicidal/inpatient depressed adolescents. The cause of the elevated cortisol during the normally quiescent period warrants further investigation and may be related to other biological disturbances around sleep onset (difficulty initiating sleep, reduced rapid eye movement (REM) latency, and alterations in sleep-stimulated growth hormone secretion).