Cortisol, 11-deoxycortisol, and ACTH concentrations after dexamethasone in depressed patients and healthy volunteers

The adrenal steroid profile in adolescent depression: a valuable bio-readout?

There is preliminary evidence that adrenal steroids other than cortisol may be valuable biomarkers for major depressive disorder (MDD). So far, studies have been conducted in adults only, and conclusions are limited, mainly due to small sample sizes. Therefore, the present study assessed whether adrenal steroids serve as biomarkers for adolescent MDD. In 261 depressed adolescents (170 females) treated at a single psychiatric hospital, serum adrenal steroids (progesterone, 17-hydroxyprogesterone, 21-deoxycortisol, 11-deoxycortisol, cortisol, cortisone, deoxycorticosterone, corticosterone) were determined by liquid chromatography-tandem mass spectrometry. Findings were compared to that of an age- and sex-matched reference cohort (N = 255) by nonparametric analysis of variance. Nonparametric receiver operating characteristics (ROC) analyses were conducted to evaluate the diagnostic performance of single steroids and steroid ratios to classify depression status. Sensitivity analyses considered important confounders of adrenal functioning, and ROC results were verified by cross-validation. Compared to the reference cohort, levels of deoxycorticosterone and 21-deoxycortisol were decreased (P < 0.001). All other glucocorticoid- and mineralocorticoid-related steroids were increased (P < 0.001). The corticosterone to deoxycorticosterone ratio evidenced excellent classification characteristics, especially in females (AUC: 0.957; sensitivity: 0.902; specificity: 0.891). The adrenal steroid metabolome qualifies as a bio-readout reflecting adolescent MDD by a distinct steroid pattern that indicates dysfunction of the hypothalamus-pituitary-adrenal axis. Moreover, the corticosterone to deoxycorticosterone ratio may prospectively qualify to contribute to precision medicine in psychiatry by identifying those patients who might benefit from antiglucocorticoid treatment or those at risk for recurrence when adrenal dysfunction has not resolved.

Altered glucocorticoid metabolism in girls with central obesity

BACKGROUND

Dysregulation of glucocorticoid metabolism is known to be a causative factor of obesity. However, only a few studies have evaluated the enzymatic activities involved in glucocorticoid metabolism in the pediatric population.

OBJECTIVE

To examine whether circulating glucocorticoid metabolites and their ratios reflecting the activities of metabolic enzyme are associated with obesity and body composition in girls.

METHODS

A total of 227 girls aged 7-13 years (131 control, 45 overweight, 51 obese) were enrolled in this study. Serum concentrations of glucocorticoids (11-deoxycortisol, cortisol, tetrahydrocortisol [THF], allo-THF, allo-dihydrocortisol [allo-DHF], and cortisone) were evaluated by gas chromatography-mass spectrometry. Enzyme activities corresponding to the ratios of cortisol and cortisone to their respective precursors and metabolites were also assessed.

RESULTS

Serum levels of allo-THF were significantly higher in obese girls compared with those in overweight and control girls (P = 0.018); however, concentrations of other cortisol metabolites were not significantly different between the groups studied. According to the severity of obesity, increasing trends in the metabolic ratios reflecting the activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) [(cortisol + allo-DHF + allo-THF + THF)/cortisone], relative 5α/5β-reductase [allo-THF/THF] activity, and 3α-HSD [allo-THF/allo-DHF] activity, were noted (P-for-trend <0.05). Body fat percentage and waist-to-height ratio positively correlated with the activities of 11β-HSD1 and 3α-HSD (P < 0.05). Following covariate control, girls with central obesity demonstrated significantly higher metabolic ratios reflecting 11β-HSD1, relative 5α/5β-reductase, and 3α-HSD activities (P < 0.05).

CONCLUSIONS

We found an altered glucocorticoid metabolism suggesting increased production of cortisol by 11β-HSD1 and increased metabolic clearance of cortisol catalyzed by 3α-HSD in girls with central obesity.

Chronic psychosocial stress affects corticotropin-releasing factor in the paraventricular nucleus and central extended amygdala as well as urocortin 1 in the non-preganglionic Edinger-Westphal nucleus of the tree shrew

Stressful stimuli evoke neuronal and neuroendocrine responses helping an organism to adapt to changed environmental conditions. Chronic stressors may induce maladaptive responses leading to psychiatric diseases, such as anxiety and major depression. A suitable animal model to unravel mechanisms involved in the control of adaptation to chronic stress is the psychological subordination stress in the male tree shrew. Subordinate male tree shrews exhibit chronic hypothalamo-pituitary-adrenal (HPA) activation as reflected in continuously elevated cortisol secretion, and structural changes in the hippocampal formation. Corticotropin-releasing factor (CRF) is the major peptide released upon activation of the HPA axis in response to stress. Recent evidence suggests that besides CRF, urocortin 1 (Ucn1) also plays a role in stress adaptation. We have tested the significance of CRF and Ucn1 in adaptation to chronic psychosocial stress in male tree shrews exposed for 35 days to daily psychosocial conflict, by performing semi-quantitative immunocytochemistry for CRF in the parvocellular hypothalamic paraventricular nucleus (pPVN), extended amygdala, viz. central extended amygdala (CeA) and dorsolateral nucleus of the bed nucleus of the stria terminalis (BNSTdl) as well as that for Ucn1 in the non-preganglionic Edinger-Westphal nucleus (npEW). Compared to unstressed animals, psychosocial stress resulted in an immediate and sustained activation of the HPA axis and sympathetic tone as well as reduced testosterone concentration and decreased body and testis weights vs. non-stressed tree shrews. In the pPVN, the number of CRF-immunoreactive neurons and the specific signal density of CRF-immunoreactive fiber terminals in the CeA were strongly reduced (-300 and -40%, respectively; P<0.05), whereas no significant difference in CRF fiber density was found in BNSTdl. The npEW revealed 4 times less Ucn1-immunoreactive neurons (P<0.05). These clear effects on both Ucn1- and CRF-neuropeptide contents may reflect a crucial mechanism enabling the animal to adapt successfully to the stressors, and point to the significance of the pPVN, CeA and npEW in stress-induced brain diseases.

Psychosocial stress attenuates general sound processing and duration change detection

An EEG-compatible adaptation of the Trier Social Stress Test was developed to induce psychosocial stress in healthy subjects while investigating their auditory processing of unattended sounds and salivary levels of the stress hormone cortisol. The mismatch negativity (MMN) and N1/P2 were assessed using a multifeature paradigm, while subjects were attending to visual tasks with high or low attentional workload. Only the responses to duration change were affected by the stress manipulation. Cortisol levels during stress were inversely related to the MMN amplitudes of duration deviants. During anticipatory stress, responses to the standard tones (general sound processing) increased, but their amplitude was not correlated with cortisol levels. We found that psychosocial stressor anticipation attenuates both general and deviance-specific sound processing, suggesting that cortisol interferes with cortical memory-trace formation.

Social stress in tree shrews as an animal model of depression: an example of a behavioral model of a CNS disorder

Animal models are invaluable in preclinical research on human psychopathology. Valid animal models to study the pathophysiology of depression and specific biological and behavioral responses to antidepressant drug treatments are of prime interest. In order to improve our knowledge of the causal mechanisms of stress-related disorders such as depression, we need animal models that mirror the situation seen in patients. One promising model is the chronic psychosocial stress paradigm in male tree shrews. Coexistence of two males in visual and olfactory contact leads to a stable dominant/subordinate relationship, with the subordinates showing obvious changes in behavioral, neuroendocrine, and central nervous activity that are similar to the signs and symptoms observed during episodes of depression in patients. To discover whether this model, besides its "face validity" for depression, also has "predictive validity," we treated subordinate animals with the tricyclic antidepressant clomipramine and found a time-dependent recovery of both endocrine function and normal behavior. In contrast, the anxiolytic diazepam was ineffective. Chronic psychosocial stress in male tree shrews significantly decreased hippocampal volume and the proliferation rate of the granule precursor cells in the dentate gyrus. These stress-induced changes can be prevented by treating the animals with clomipramine, tianeptine, or the selective neurokinin receptor antagonist L-760,735. In addition to its apparent face and predictive validity, the tree shrew model also has a "molecular validity" due to the degradation routes of psychotropic compounds and gene sequences of receptors are very similar to those in humans. Although further research is required to validate this model fully, it provides an adequate and interesting non-rodent experimental paradigm for preclinical research on depression.

Prenatal stress in rats predicts immobility behavior in the forced swim test

Prenatally-stressed (PS) rats are characterized by a general impairment of the hypothalamo-pituitary-adrenal (HPA) axis and sleep disturbances indicating that this model has face validity with some clinical features observed in a subpopulation of depressed patients. The prolonged corticosterone secretion shown by PS rats in response to stress was positively correlated with an increased immobility behavior in the forced swim test. To investigate the predictive validity of this model, a separate group of animals was chronically treated with the antidepressant tianeptine (10 mg/kg i.p. for 21 days). Such chronic treatment reduced in PS rats immobility time in the forced swim test. These findings suggest that the PS rat is an interesting animal model for the evaluation of antidepressant treatment.

Social stress in tree shrews: effects on physiology, brain function, and behavior of subordinate individuals

Social stress is known to be involved in the etiology of central nervous disorders such as depression. In recent years, animal models have been developed that use chronic stress to induce neuroendocrine and central nervous changes that might be similar to those occurring in the course of the development of depressive disorders. The present review gives a summary of observations made in the tree shrew chronic social stress model. During periods of daily social stress, male tree shrews develop symptoms that are known from many depressed patients such as persistent hyperactivities of both the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system, disturbances in sleeping patterns, and reduced motor activity. Moreover, various physiological parameters indicate an acceleration of the over all metabolic rate in socially stressed tree shrews. Some of these parameters can be renormalized by antidepressants thus supporting the view of the tree shrew social stress paradigm as model for major depression. In the brains of socially stressed animals, monoamine receptors show dynamic changes that reflect adaptation to the persistent monoaminergic hyperactivity during periods of chronic stress. In addition to the changes in neurotransmitter systems, there are structural changes in neurons, e.g., retraction of the dendrites of hippocampal pyramidal neurons. Together, these processes are suggested as a cause of behavioral alterations that can be counteracted by antidepressants in this naturalistic social stress model.

Chronic psychosocial stress and antidepressant treatment in tree shrews: time-dependent behavioral and endocrine effects

Social defeat has been shown to cause a number of behavioral, physiological, and central nervous changes in male tree shrews. The present study was designed to assess: (i) a potential time lag in the occurrence of behavioral alterations (locomotor activity, self-grooming, marking behavior, food and water intake, and avoidance behavior) after stress and long-term antidepressant treatment; and (ii) to investigate potential interactions between behavioral and endocrine variables (urinary cortisol and norepinephrine). Male tree shrews were submitted to chronic psychosocial stress for 39 days. In this paradigm, the stress-induced behavioral and endocrine alterations in subordinate animals are based exclusively on the central nervous interpretation of the continuous visual presence of the dominant conspecific. During the last 29 days of stress exposure, the tricyclic antidepressant clomipramine was administered daily to the subordinate animals (50 mg/kg, p.o). Results from this group were compared with three other experimental groups: one group was just stressed, one group received only clomipramine, and one group only vehicle. To determine the time-dependent effects of psychosocial stress and clomipramine treatment, behavior was recorded immediately after and 9 h after daily social encounters. Depending on the observation time, significant differences between the effects of psychosocial stress and antidepressant treatment were found. Generally, the effect of stress on behavioral parameters tended to be less distinct immediately after the social encounter compared to the later observation time. Furthermore the drug had a time-dependent restorative influence on marking and grooming behavior, locomotor activity, avoidance behavior, as well as on urinary cortisol, and norepinephrine excretion. Correlation analysis revealed significant interdependencies between locomotor activity, marking behavior, and avoidance behavior on 1 day with cortisol and norepinephrine quantified in the morning urine of the following day. These findings indicate that experimental manipulations, stress, and psychotropic drug application have a time lag on bio-behavioral parameters which should be considered when studying animal behavior in response to stressors and/or to drug treatment.

Effects of antidepressant treatment on corticotropin-induced cortisol responses in patients with melancholic depression

To date, there appears to be no consensus of opinion as to whether the adrenal glands are hyperresponsive during depression and, if so, whether this a state-dependent phenomenon. We aimed to determine the effects of antidepressant treatment on ACTH-induced cortisol responses in patients with melancholic depression. Seven female patients with DSM-III-R major depressive disorder, non-psychotic, melancholic subtype, were evaluated using the following rating scales: the Hamilton Depression Rating Scale, the Montgomery-Asberg Depression Rating Scale and the Newcastle Endogenicity Scale. All subjects were then given an intravenous bolus dose (250 micrograms) of tetracosactrin, a potent stimulus of adrenocortical hormone secretion. Plasma levels of cortisol were measured at times 0, + 30, + 60, + 90, + 120 and + 180 min. Patients were then randomised to receive either 50 mg of sertraline or 20 mg of paroxetine (both of which are selective serotonin re-uptake inhibitors) and were re-tested while medication-free. Treatment resulted in a significant decrease in delta (the difference between the baseline values and the maximum increase post-ACTH administration) cortisol values of 1633.3 +/- 378.5 nmol/l vs. 595.1 +/- 207.7 nmol/l. Successful pharmacological treatment of major depressive disorder appears to be associated with a reduction in ACTH-induced cortisol release in drug-free patients.

Hypothalamic-pituitary-adrenal axis function, psychopathological traits, and natural killer (NK) cell activity in anorexia nervosa

To evaluate the role of Hypothalamic-Pituitary-Adrenal (HPA) hormones and psychoneuroendocrine modulation on NK cell activity in Anorexia Nervosa (AN) we studied in 24 patients and 20 sex- and age-matched healthy controls, the spontaneous NK activity of peripheral blood mononuclear (PBM) cells and the susceptibility in vitro to cortisol or immune interferon or interleukin-2. NK cytotoxicity of PBM cells was measured in a direct non-radiometric 4h cytolytic assay using K562 cells as targets. HPA axis function was evaluated by IV ovine Corticotropin Releasing Hormone (o-CRH) administration. We did not find clear-cut abnormalities of NK cytotoxicities either in basal conditions or after exposure to challengers. The extent of cortisol-dependent inhibition was comparable in patients and controls. Significant inverse and direct correlations were found respectively between the spontaneous NK cell activity and baseline serum cortisol at 0800 h (r = -0.5; p < .02), and between IL-2 dependent boosting of NK cell cytotoxicity and ACTH, beta-endorphin or cortisol responses after o-CRH, expressed as areas under the curve (AUC) (r = 0.46, p < .05; r = 0.46, p < .05; and r = -0.48, p < .05, respectively). Correlations observed with AUC ratios yielded more significant results (r = 0.62; p < .01 and r = 0.51; p < .05 respectively). These data suggest a role for Proopiomelanocortin (POMC) derived peptides in the regulation of NK cell activity in AN, and multifaceted relationships between this particular immune function, on the one hand, and certain patterns of HPA axis function on the other.

Psychosocial stress in tree shrews: clomipramine counteracts behavioral and endocrine changes

Male tree shrews (Tupaia belangeri) provide an animal model to study the neurobehavioral consequences of chronic psychosocial stress. When living in visual and olfactory contact with a male conspecific by which it has been defeated, the subordinante tree shrew shows dramatic behavioral, physiological, and neuroendocrine changes. Because the over all pattern of these changes resemble a depression-like symptomatology, we investigated to what extent the behavioral and endocrine changes in subordinate animals can be reversed by treatment with the tricyclic antidepressant clomipramine. In the present study, animals were subjected to a 10-day period of psychosocial conflict to elicit stress-induced behavioral and endocrine alterations before the onset of drug treatment, and psychosocial stress continued throughout the treatment period of 30 days. Clomipramine was administered orally once daily at a dose of 50 mg/kg. The drug had a time-dependent restorative influence on marking and grooming behavior, locomotor activity, risk assessment, as well as on urinary cortisol and norepinephrine excretion. It, thus, appears that the clomipramine treatment counteracts the behavioral and endocrine effects of chronic psychosocial stress in tree shrews, and the time course of recovery corresponds closely to that observed when treating depressed patients in the clinic.

Evidence against changes in corticotroph CRF receptors in depressed patients

Previous studies by a number have investigators have documented a decreased adrenocortotropic hormone (ACTH) and beta-lipotropin/beta-endorphin (beta-End) response to ovine corticotropin-releasing factor (oCRF) in depressed patients. Since depressed patients demonstrate higher plasma cortisol concentrations at the time of oCRF challenge, it is difficult to determine if the decreased ACTH response is due to enhanced negative feedback of cortisol on ACTH release or an alteration in CRF receptors in depressed patients. To evaluate the response to oCRF in an "open feedback loop" system, we administered metyrapone 750 mg at 4 PM and 7:30 PM, followed by administration of oCRF 0.3 microgram/kg at 8 PM in 10 normal controls and 10 depressed patients. Administration of metyrapone at this time in the circadian rhythm clamped plasma cortisol concentrations to less than 2 micrograms/dl but did not result in rebound ACTH or beta-End secretion in control subjects. In control subjects, metyrapone administration produced a 85% blockade of the cortisol response as well as a 3-fold greater beta-End response compared to administration of the same dose of oCRF without metyrapone. The 10 depressed patients and their matched controls demonstrated identical beta-End responses (integrated response for controls = 291 +/- 61, for patients = 352 +/- 86) and cortisol responses (integrated response for controls = 187 +/- 38, for patients = 206 +/- 52) to oCRF following metyrapone pretreatment. These data confirm that corticotroph CRF receptors are normal in depressed patients, and that cortisol feedback plays an essential role in the abnormal ACTH and beta-End response to oCRF in depressed patients.

Multiple HPA profiles in endogenous depression: effect of age and sex on cortisol and beta-endorphin

We have previously shown that a number of depressed patients demonstrated a failure to suppress corticotrophic secretion, as measured by beta-Endorphin/beta-Lipotropin (beta-End/beta-LPH levels), following dexamethasone challenge. The current study is an extension and replication of these findings, as well as an analysis of some of the biological variables which may contribute to the variance in beta-End/beta-LPH nonsuppression. We continue to observe a high rate of beta-End/beta-LPH nonsuppression in depressed patients following dexamethasone; this escape at the pituitary level is even observed in a number of patients who demonstrate normal cortisol suppression. Advancing age, particularly in women, led to higher baseline cortisol, lower baseline beta-End/beta-LPH, and a greater likelihood of being a nonsuppressor on one or both measures.

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.

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.

Adrenocorticotropin hormone, beta-endorphin and cortisol responses to oCRF in melancholic patients

Several authors have reported attenuated adrenocorticotropin hormone (ACTH) responses to corticotropin releasing factor (CRF) administration in melancholic patients as compared with healthy controls. In order to explore the integrity of the hypothalamic-pituitary-adrenal (HPA)-axis in melancholics, we examined the following parameters in 98 subjects: the ACTH; beta-endorphin; and cortisol responses to ovine CRF (oCRF) (100 micrograms/i.v.); and the postdexamethasone cortisol values. We found significant lower CRF-induced ACTH responses in melancholic patients as opposed to healthy controls and minor depressives, while major depressives occupied an intermediate position. The psychopathological correlates of the blunted CRF-induced ACTH responses were feelings of worthlessness, self-reproach, or excessive guilt. The CRF-stimulated beta-endorphin and cortisol response did not differ between the study samples. Higher baseline plasma cortisol was associated with attenuated CRF-induced ACTH responses, but these effects were not pertinent to melancholia. There were no relationships between the disordered oCRF test results, and postdexamethasone cortisol values, age, body size, sex and severity of illness. The diagnostic power of the oCRF and the dexamethasone suppression test for melancholia is enhanced when both test results are combined.

Decreased serum dipeptidyl peptidase IV activity in major depression

It has been recently shown that severe depression is characterized by immune dysfunctions such as blunted mitogen-induced blast transformation, which is linked to interleukin-2 (IL-2) mechanisms, and to autoimmune responses. In order to explore one of the putative pathophysiological mechanisms underlying both factors, we have measured the predexamethasone and postdexamethasone serum dipeptidyl-peptidase IV (DPP IV) activity in depressed inpatients and normal controls. This enzyme is an important mediator of IL-2-related blast proliferation, and it may play a role in autoimmunity. We found significantly lower DPP IV levels in major depressives as compared with healthy controls, and melancholics exhibited significantly lower enzyme activity than minor depressives. There was a significant negative correlation between serum DPP IV activity and the severity of illness. However, we were unable to detect any significant relationships between DPP IV on the one hand, and mitogen-induced blast transformation, soluble IL-2 receptor accumulation in PHA culture supernatant, total number of leukocytes and lymphocytes, T lymphocytes, CD4+ and CD25+ cells, on the other. Men exhibited significantly higher serum DPP IV levels than women.

Abnormal pituitary function during melancholia: reduced alpha-melanocyte-stimulating hormone secretion and increased intact ACTH non-suppression

In order to investigate pituitary alpha-melanocyte-stimulating hormone (alpha-MSH), intact (1-39 structure) adrenocorticotropic hormone (ACTH), and adrenal cortisol secretion, we measured 8 a.m. plasma levels of those hormones before and after administration of 1 mg dexamethasone in 39 depressed inpatients and 10 healthy controls. We found a significantly lower baseline alpha-MSH secretion in melancholic patients as opposed to healthy controls. There were no significant relations between alpha-MSH secretion on the one hand and ACTH or cortisol secretion on the other. Dexamethasone did not affect the 8 a.m. alpha-MSH circulating levels. The post-dexamethasone intact ACTH and cortisol values were significantly higher in melancholics as compared with healthy, minor and simple major depressed subjects. ACTH non-suppression was defined as post-dexamethasone intact ACTH greater than or equal to 12 pg/ml. ACTH non-suppression was found to be more sensitive (70%) and specific (100%) for melancholia than cortisol non-suppression. By means of pathway analysis we have established that cortisol non-suppression during a severe depression is completely determined by an augmented ACTH escape from suppression by dexamethasone. It is concluded that the assay of post-dexamethasone intact ACTH could, in the future, replace post-dexamethasone cortisol determination.

Steroids and depression

Patients with endogenous depression (major affective disorder) frequently have high cortisol levels, but the diurnal rhythm is usually maintained and they do not develop the physical signs of Cushing's syndrome. On the other hand, depression is a frequent feature of Cushing's syndrome regardless of etiology, and it is often relieved when the cortisol levels are reduced, by whatever means. The mechanisms of the hypercortisolemia and resistance to dexamethasone suppression commonly found in endogenous depression are poorly understood; contrary to expectations, ACTH levels are not clearly elevated. There is a striking difference in the psychiatric features seen in endogenous hypercorticism compared to those seen after exogenous administration of glucocorticoids or ACTH. This suggests that either there are other stimulating or modifying factors besides ACTH or that the steroids stimulated by ACTH or other peptides differ from those in control subjects, i.e. there may be an alteration in the metabolism of steroids in depression. Little is known about the metabolic changes or the many steroids besides glucocorticoids produced by the hyperactive steroid-producing tissue. Preliminary studies suggest that major depression may be improved by steroid suppression. It is hypothesized that steroids themselves may be important in causing and perpetuating depression.

A further exploration of the relationships between immune parameters and the HPA-axis activity in depressed patients

In order to investigate the relationship between the immune apparatus and the hypothalamic-pituitary-adrenal (HPA)-axis activity in depressed patients, we measured in vitro lymphocyte responses to the mitogens Phytohaemagglutinin (PHA), Pokeweed (PWM) and Concanavalin A (Con A) and 8 a.m. baseline cortisol values in plasma, free cortisol excretion in 24 h urine (UFC), basal and post-dexamethasone beta-endorphin values. Major depressed patients with melancholia/psychotic features exhibited a significantly lower mitogen-induced blast transformation as compared to minor and simple major depressed patients. The lymphocyte responses to the three mitogens were significantly inversely related to baseline cortisol values and postdexamethasone beta-endorphin values. The proliferative capacity of lymphocytes to stimulation with PHA and PWM was significantly and positively related to UFC excretion. Up to 45% of the variance in the immune-responses to the mitogens was explained by the baseline cortisol, post-dexamethasone beta-endorphin and UFC values.

Postdexamethason intact and multisequentia ACTH in melancholia

The dexamethasone suppression test has been carried out in 111 depressed inpatients. Fasting, 8 a.m. plasma levels of Cortisol and adrenocorticotropic hormone (ACTH) were determined before and after administration of 1 mg dexamethasone. In 64 subjects multisequential (1-17,1-24,1-39) ACTH, and in 47 subjects intact (1-39) ACTH has been determined. Patients with melancholia exhibited significantly higher postdexamethasone Cortisol and intact ACTH values as compared with minor and simple major depressives. Severity of illness was significantly and positively related to postdexamethasone intact ACTH - but not to multisequential ACTH. Cortisol nonsuppressors showed higher postdexamethasone (only intact) ACTH values than Cortisol suppressors. Both postdexamethasone ACTH values were significantly and positively related with the postdexamethasone Cortisol values. We have established that Cortisol nonsuppression during melancholia is determined by an augmented escape of ACTH from suppression by dexamethasone. Intact ACTH showed the most significant clinical relevance for depression and Cortisol nonsuppression. In the clinical practice we advize the use of postdexamethasone intact ACTH in stead of plasma Cortisol or multisequential ACTH.

Plasma cortisol and 11-deoxycortisol activity in depressed patients and normal volunteers

Plasma cortisol and 11-deoxycortisol were measured in 30 depressed patients and 110 normal volunteers before and after a 1.0 mg dexamethasone suppression test (DST). Post-dexamethasone plasma cortisol, 11-deoxycortisol and the cortisol/11-deoxycortisol ratio were significantly higher in the depressives compared to the controls, even when age and sex were taken into account. Pre-dexamethasone plasma cortisol, post-dexamethasone cortisol, 11-deoxycortisol and their ratio were significantly higher in the cortisol nonsuppressors than in the suppressors. The measurement of post-dexamethasone 11-deoxycortisol and the ratio did not differentiate between endogenous and reactive depression. Using the normative data, we explored several methods for determining a criterion value to define abnormal post-dexamethasone plasma 11-deoxycortisol and the cortisol/11-deoxycortisol ratio in depressed patients. All showed poor sensitivity and a low positive predictive value for depression. The measurement of 11-deoxycortisol thus does not enhance the clinical utility of the DST.

A revised interpretation of postdexamethasone ACTH and cortisol findings in unipolar depressed females

Baseline 8 a.m. adrenocorticotropic hormone (ACTH) and cortisol levels and the postdexamethasone ACTH/cortisol values at 8 a.m. and 4 p.m. were determined in 86 depressed females diagnosed using DSM-III criteria. Postdexamethasone ACTH and cortisol values were significantly correlated with their baseline levels. We have shown that regression analysis should be used to assess dexamethasone-induced changes as the residual ACTH and cortisol responses, with the relative effects of the baseline data on the hormone responses being partialed out. The residual ACTH and cortisol values were significantly increased in the most severely depressed females as compared to minor depressives. The residual ACTH responses were markedly correlated with the residual cortisol responses. Cortisol nonsuppression during a depressive episode appeared to be determined by an augmented ACTH escape from dexamethasone suppression. The residual ACTH and cortisol responses could prove to be the most sensitive reflection of the disorder in the negative feedback by dexamethasone on the pituitary. In clinical practice, the ratio ln (postdexamethasone ACTH): ln (basal ACTH) can be used, since this ratio is linearly correlated with the residual ACTH responses.

Prediction of the DST results in depressives by means of urinary-free cortisol excretion, dexamethasone levels, and age

This study investigates the relationships between cortisol escape from suppression by dexamethasone during a depressive episode, and the baseline activity of the hypothalamic-pituitary-adrenal (HPA) axis, circulating dexamethasone levels, and age. To this end, we measured urinary-free cortisol (UFC) excretion in 24-hr urine samples and the 8 AM cortisol and dexamethasone levels after administration of 1 mg dexamethasone in 50 depressive patients. We found that up to 54% of the variance in the postdexamethasone cortisol values could be explained by the multiple regression on UFC, age, and dexamethasone levels. By utilizing these three parameters, the dexamethasone suppression test (DST) nonsuppressor/suppressor state was correctly identified in 92% of the subjects. It was shown that an important part of the variance in postdexamethasone cortisol is actually background variance, irrelevant to depression and produced by the cumulative effects of the three aforementioned parameters. Only a small part (less than 20%) of the variance in postdexamethasone cortisol is determined by the actual depressive state. It was concluded that (1) baseline hypersecretion of cortisol, (2) decrements in the bioavailability of the test substance, (3) increasing age, and (4) the depressive state per se--all of which are cumulative--contribute independently to cortisol escape from suppression by 1 mg dexamethasone.

Psychoneuroendocrine research in depression. I. Hormone levels of different neuroendocrine axes and the dexamethasone suppression test

Psychoneuroendocrinology is of major importance in the biological research of depression. Most studies have focussed on the regulation of the hypothalamic-pituitary-adrenal (HPA) axis but other endocrine systems such as the hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-somatotropic (HPS), and the hypothalamic-pituitary-gonadal (HPG) axis have also been shown to be involved in the psychobiology of depression. There are close interrelations between various endocrine axes which possibly are affected during depressive illness. A variety of neuroendocrine abnormalities has been detected in depressive disorder but the pathophysiology of these derangements remains still unclear. Although the currently used neuroendocrine tests are not of diagnostic validity they may help to clarify the pathophysiological significance of the complex regulatory mechanisms of different neuroendocrine axes in affective disorders. Neuroendocrine regulation is determined both by peripheral and central mechanisms which both have to be adequately considered as well as potent interactions between various endocrine systems in further neuroendocrine depression research.

The influences of dexamethasone levels on the predictive value of the DST for unipolar major depression and the relationships between post-dexamethasone cortisol and ACTH levels

To investigate the relationships between dexamethasone (DEX) and post-DEX cortisol and adrenocorticotropic hormone (ACTH) levels, the authors measured DEX at 8.00 a.m. and post-DEX cortisol and ACTH levels at 8.00 a.m. and 4.00 p.m. in 72 depressed patients categorized according to DSM-III. Cortisol non-suppressors exhibited significantly (P = 0.0006) decreased levels of DEX compared to suppressors. DEX levels at 8.00 a.m. explained 21.1% of the variance in the post-DEX cortisol values at 8.00 a.m. and 34.5% of those at 4.00 p.m. DEX levels were not significantly different among minor depressives (300.40, 309.00), major depressives without melancholia (296.X2) or with melancholia and/or psychotic features (296.X3, 296.X4). In the latter the post-DEX cortisol was significantly increased compared to all other depressives and these differences remained significant even after adjusting for the variations in DEX (by means of regression analysis). Also the diagnostic performance of the post-DEX cortisol values for major depression with associated features versus minor depression was not substantially affected when the DEX levels were accounted for. ACTH levels after DEX were shown to correlate significantly (P less than 0.05) and negatively with DEX. Although post-DEX ACTH levels did not differ among the DSM-III diagnostic categories, cortisol non-suppressors averaged significantly (P = 0.0004) higher ACTH levels than suppressors.

The assessment of abnormalities in hormonal responsiveness at multiple levels of the hypothalamic-pituitary-adrenocortical axis in depressive illness

A substantial body of data suggests that excessive cortisol secretion in depression may result from dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. The alterations in regulatory mechanisms are thought to result from a limbic system-hypothalamic "overdrive" of corticotropin-releasing hormone (CRH). We also have demonstrated that excessive secretion of cortisol may result from an abnormal adrenocortical responsiveness to adrenocorticotropic hormone (ACTH), and we have postulated that corticotropic cells within the pituitary mediate between excessive secretion of CRH from the hypothalamus and hypercortisolemia secondary to adrenocortical hyperplasia and enhanced sensitivity to ACTH at the adrenal cortex. The present report describes a series of clinical experiments utilizing several neuroendocrine probes, as well as computer-assisted tomography, to examine the complexities of the HPA axis dysregulation in depression. These studies support the hypothesis that a limbic system-hypothalamic disturbance results in excessive CRH secretion as well as enhanced adrenocortical activity, and that these factors contribute to excessive cortisol secretion in patients with depression. These data further support the hypothesis that endogenous affective disorders are best characterized in the framework of a generalized biological disturbance of HPA axis function which involves both central and peripheral endocrine sites.

Comparison of in vivo and in vitro glucocorticoid sensitivity in depression: relationship to the dexamethasone suppression test

The effect of in vivo (1 mg) and in vitro (10(-7)-10(-10) M) dexamethasone administration on mitogen-induced lymphocyte proliferation was examined in drug-free depressed patients, nondepressed psychiatric patients, as well as normal controls, and was related to the results of a standard overnight Dexamethasone Suppression Test (DST). The effect of oral dexamethasone administration was also examined for its effect on lymphocyte cytosolic glucocorticoid receptor content. Oral dexamethasone administration significantly decreased both phytohemagglutinin (PHA) and concanavalin A (Con-A) induced lymphocyte proliferation, as well as glucocorticoid receptor number in suppressors, whereas dexamethasone failed to decrease these responses in nonsuppressors. Nonsuppressors had significantly lower serum dexamethasone levels compared to suppressors at both 8:00 AM and 4:00 PM. However, when differences in serum dexamethasone levels were covaried out, there were still significant differences between suppressors and nonsuppressors on the dexamethasone-induced mitogen changes, but the changes in glucocorticoid receptor content were no longer significant. In vitro incubation of lymphocytes with dexamethasone produced a dose-related decrease in mitogenesis, which was not different between the depressed and nondepressed groups. However, at physiologically relevant concentrations of dexamethasone (10(-9)-10(-10) M), nonsuppressors as compared to suppressors were more resistant to the immunosuppressive effects of in vitro dexamethasone on the Con-A response. The inhibitory effect of in vitro dexamethasone on Con-A-stimulated lymphocytes was positively correlated with basal 4:00 PM cortisol values. In conclusion, in vitro techniques are useful probes to assess glucocorticoid sensitivity in depression. The present results also further support the hypothesis that glucocorticoid insensitivity is associated with DST nonsuppression.

The oCRH stimulation test before and after clinical recovery from depression

A substantial body of data suggests that excessive cortisol secretion in depression may result from a dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. These alterations in regulatory mechanisms are thought to be the result of a hypothalamic 'overdrive' of corticotropin-releasing hormone (CRH). Previous studies have demonstrated a diminished adrenocorticotropin (ACTH) secretory response, as well as a heightened adrenocortical responsiveness after ovine-CRH administration in depressed patients. In the present investigation, we examined pituitary and adrenocortical responsiveness after an ovine-CRH stimulation test before and during clinical recovery in seven depressed patients. Cumulative ACTH responses increased significantly during clinical recovery (P = 0.014). Paradoxically, maximum and peak cortisol responses increased after recovery, suggesting that heightened adrenocortical responsiveness to ACTH during depression may take longer to 'normalize' than abnormal pituitary responsiveness to ovine-CRH stimulation.

Partial 11 beta-hydroxylase activity suppression after dexamethasone in patients with major depression

Eleven beta-hydroxylase activity was assessed by measuring the cortisol to 11-deoxycortisol ratio in 20 control subjects, 38 patients with major depression, and five patients with Cushing's disease before and after 1 mg of dexamethasone. The mean levels of 11 beta-hydroxylase activity did not differ among groups before dexamethasone. After dexamethasone patients with Cushing's disease showed a nonsignificant increase in 11 beta-hydroxylase activity while patients with major depression and controls subjects both showed a decrease. Endogenous depressive patients were no more likely to show high 11 beta-hydroxylase activity than neurotic depressive patients; however, depressed patients with cortisol nonsuppression after dexamethasone were. Post-dexamethasone 11 beta-hydroxylase activity is positively correlated with age in both control subjects and patients with depression.

Methodological aspects of hCRF-stimulated ACTH and cortisol secretion in healthy subjects

This study, aimed at clarifying some methodological problems of the hCRF stimulation test, was performed on 12 healthy male volunteers. ACTH and cortisol increases after 30 min and their maximum increase proved to be highly reliable response parameters for the net area under the response curve of both hormones. An influence of baseline hormone values on the maximum response was apparent for cortisol but not for ACTH. Cortisol, but not ACTH, revealed a stable test-retest reliability. There were no correlations between ACTH and cortisol responses to hCRF.

Plasma 11-deoxycortisol and cortisol following dexamethasone in psychiatric patients

As it has been suggested that calculating the ratio of cortisol to its biosynthetic precursor, 11-deoxycortisol, may enhance the sensitivity of the dexamethasone suppression test (DST) for depression, cortisol and 11-deoxycortisol were measured in 90 subjects undergoing this test. Among these subjects, post-dexamethasone cortisol and 11-deoxycortisol levels were significantly correlated (r = 0.65, P less than 0.001) and evaluating the ratio of cortisol to 11-deoxycortisol decreased rather than enhanced sensitivity of the DST.

Stable adrenocorticotropin-stimulated 11-beta-hydroxylase activity but loss of age-related changes in patients with hypercortisolemia

Eleven-beta-hydroxylase activity was measured before and after acute adrenocorticotrophic hormone (ACTH) stimulation in 28 controls, 25 depressed Dexamethasone Suppression Test (DST) suppressors, 13 DST nonsuppressor patients, and 8 patients with Cushing's syndrome to investigate changes in states of cortisol hypersecretion. Eleven-beta-hydroxylase activity was equivalent among groups both before and after stimulation. Such 11-beta-hydroxylase stability, however, resulted in higher cortisol and 11-deoxycortisol poststimulation levels in both depressed DST nonsuppressors and Cushing's patients than in controls. Basal 11-beta-hydroxylase activity is positively correlated and 11-deoxycortisol is negatively correlated with age in controls and DST suppressors, but not in the patients tested with evidence of cortisol hypersecretion. These findings suggest that in vivo basal 11-beta-hydroxylase activity rises gradually with age, but does not rise after acute administration of exogenous ACTH. The age relationship is lost in states of cortisol hypersecretion, but the lack of response to acute exogenous ACTH is not affected.

Diagnostic performance of basal free cortisol/18-hydroxy-11-deoxycorticosterone (18-OH-DOC) ratio in endogenous depression: comparison with the dexamethasone suppression test

We assessed the 8:00 AM ratio of free cortisol/18-hydroxy-11-deoxycorticosterone (18-OH-DOC) in 56 endogenous depressive inpatients and in 22 normal volunteers. A ratio higher than 40 was associated with a diagnostic sensitivity for endogenous depression of 75%, a specificity of 95.5%, and a diagnostic confidence of 97.7%. These diagnostic results were at least equivalent to the Dexamethasone Suppression Test (DST) using a cortisol cut-off limit of 5 micrograms/dl. This may thus represent a simpler procedure than the DST in the diagnostic analysis of endogenous depression.

Plasma endogenous opioids and dexamethasone suppression test in depression

Plasma levels of beta-endorphin plus beta-lipotropin were determined in 35 hospital patients with depression and in 23 controls before and after administration of 1 mg of dexamethasone (dxm). Dxm suppressed opioid secretion in both groups. The opioid levels of the patients were significantly higher than those of the controls both before and after dxm. All the controls were cortisol suppressors. Among the patients the post-dxm opioid levels of cortisol nonsuppressors (n = 14) were higher than those of cortisol suppressors (n = 21). A significant correlation between the opioid and cortisol levels was found in the patients. There was a significant association between the use of neuroleptics and high opioid levels, but the difference between the patients and the controls was not explained by the effect of any single class of drugs. The results support the concept of hypersecretion of corticotropin-releasing factor in depression.

Plasma immunoreactive beta-endorphin in dexamethasone suppressors and non-suppressors of cortisol

Immunoreactive plasma beta-endorphin level was assayed in 33 patients with major affective disorder and in 16 psychiatrically normal controls before and after dexamethasone (1 mg) administration at 23.00 h. There were 18 cortisol suppressors and 15 non-suppressors among the patient group. All controls suppressed cortisol. Plasma beta-endorphin before dexamethasone was significantly different between suppressors, non-suppressors and controls (P less than 0.05, ANOVA). Concentrations of beta-endorphin were 4.7 +/- 0.7, 3.1 +/- 0.3 and 2.8 +/- 0.3 pmol/l for non-suppressors, suppressors and controls respectively. Following dexamethasone, beta-endorphin concentrations were again significantly different between groups (P less than 0.005, ANOVA). Concentrations were 4.6 +/- 0.7, 2.3 +/- 0.2 and 1.6 +/- 0.2 pmol/l for non-suppressors, suppressors and controls respectively. The implications of these findings are discussed.

The ACTH stimulation test before and after clinical recovery from depression

Excessive cortisol secretion after cosyntropin (adrenocorticotropic hormone; ACTH) infusion in some depressed patients has suggested the possibility that the adrenal cortex may have heightened responsiveness to ACTH, and that this may contribute, in part, to activation of the hypothalamic-pituitary-adrenocortical axis. We administered an ACTH test and dexamethasone suppression test (DST) to 32 patients before and after treatment. Maximal cortisol response to ACTH demonstrated a significant decrease after treatment in the subgroup of melancholic/DST nonsuppressors (p = 0.04). When the cumulative cortisol response (CCR) to ACTH was examined, the DST nonsuppressors had a greater CCR decrease than suppressors (p = 0.03), and the melancholics a greater decrease than nonmelancholics (p = 0.02). The melancholic/DST nonsuppressor subgroup had the largest CCR decrease after treatment (p = 0.03), and these patients may represent a group of depressives with altered adrenocortical function that tends to "normalize" with clinical recovery.

The HPA axis response to insulin hypoglycemia in depression

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, demonstrated by failure to suppress cortisol secretion after dexamethasone, is found in approximately 50% of patients with major depression (MD). In this study, we examined the response of adrenocorticotrophic hormone (ACTH) and cortisol to insulin-induced hypoglycemia in 20 healthy controls and 18 inpatients with MD [12 dexamethasone suppressors (S) and 5 dexamethasone nonsuppressors (NS)]. After the administration of 0.15 U/kg of regular insulin, both controls and patients with MD showed an increase in plasma ACTH and cortisol levels. Controls had a significantly higher ACTH peak (p less than 0.01) and ACTH increment (p less than 0.01) than MD patients. There were no statistically significant differences between patients who were S and NS. Although baseline plasma cortisol levels were significantly higher in MD patients, there were no significant differences in the peak cortisol or increment in plasma cortisol after hypoglycemia between patients with MD and controls or between patients who were S and those who were NS. These findings suggest that a defect exists in the regulation of the HPA axis at the pituitary level in MD and that this defect is not necessarily reflected in the dexamethasone suppression status of the patient.

The dexamethasone and cortisol suppression test in depression: beta-endorphin as a useful marker

To investigate the mechanism underlying disturbances in hypothalamopituitary-adrenal (HPA) function in depressed patients, the dexamethasone suppression test (DST) was compared with a cortisol suppression test (CST) and placebo treatment in depressed patients and control subjects. Plasma levels of cortisol, ACTH and beta-endorphin were assessed at 3 times during the day after treatment with a single dose of exogenous steroid. Both dexamethasone and cortisol treatment resulted in suppression of cortisol, ACTH and beta-endorphin in control subjects, while neither treatment had any effect on the hormone levels in those depressed patients who showed cortisol nonsuppression after dexamethasone. In the depressed patients who were cortisol suppressors after dexamethasone, cortisol treatment only slightly changed plasma levels of beta-endorphin, although they were suppressed after dexamethasone treatment. In addition, high levels of both cortisol and beta-endorphin were observed after placebo treatment in all depressed patients compared to control subjects, probably due to the absence of the normally occurring decrease of these hormones during the day in these patients. Cortisol treatment, but not dexamethasone treatment, discriminated depressed patients from controls with respect to their beta-endorphin plasma levels. However, it is not yet clear whether these different effects of the two steroids are related to a different mode of action of these steroids in depressed patients. beta-Endorphin seems to be a useful marker in detecting disturbances in HPA function among depressed patients.

Adrenocortical responsiveness to the ACTH stimulation test in depressed patients and healthy volunteers

Adrenocortical activation in depression has been postulated to result from overactivity of limbic system-hypothalamic function. However, some studies suggest the possibility that excessive secretion of cortisol might result, in part, from a heightened adrenocortical responsiveness to ACTH. To further examine this possibility, we utilized both the ACTH stimulation test and the overnight dexamethasone suppression test (DST) in 72 patients with major depression and 37 age- and gender-matched healthy volunteers. The melancholic/DST-nonsuppressor group had larger mean peak cortisol and cumulative cortisol responses (CCR) than any of the other patients groups or healthy controls. However, the differences failed to reach statistical significance as a result of a relatively large cortisol response variability. Nevertheless, the present findings are in general agreement with previous reports suggesting the possibility of an enhanced adrenocortical responsiveness to ACTH.

Pre- and post-dexamethasone plasma ACTH levels in depressed patients and normal controls

Levels of plasma ACTH in relation to dexamethasone administration were evaluated in 16 medication-free patients with a major depressive episode and 39 normal controls. Depressed patients had significantly higher levels of plasma ACTH than controls both at 4:00 p.m. predexamethasone and 4:00 p.m. postdexamethasone. The significance of this finding is discussed.

Cortisol and corticosterone response after syn-corticotropin in relationship to dexamethasone suppressibility of cortisol

The current study was designed to investigate whether glucocorticoid output after syn-ACTH stimulation is different in depression associated with dexamethasone suppression test (DST) nonsuppression from the euthymic state and DST suppression. We gave 28 depressives a DST and an adrenocortical challenge with synthetic ACTH. Fourteen patients were nonsuppressors on the DST. After successful drug treatment, the subjects were reinvestigated by both tests; all DSTs revealed plasma cortisol concentrations below the criterion value of 50 ng/ml. Cortisol and corticosterone responses after syn-ACTH tended to be higher during depression. After clinical remission, higher cortisol and corticosterone responses occurred in those patients who were DST nonsuppressors during depression. This finding suggests that patients who suffer from a depression which is linked to an abnormal pituitary--adrenocortical regulation develop an enhanced sensitivity of the adrenal cortex to ACTH.