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.     

Plasma cortisol, prolactin, growth hormone, and immunoreactive beta-endorphin response to fenfluramine challenge in depressed patients

The effect of a single dose (60 mg p.o.) of the serotonin agonistic agent fenfluramine (FNF) on plasma cortisol, prolactin (PRL), growth hormone (GH), and immunoreactive beta-endorphin (ir-beta-EP) levels was assessed in eight major depressed patients and eight controls. The hormones were monitored at basal level (0') and hourly during 5 h following FNF administration. The pharmacological challenge caused an elevation of 80% in PRL secretion in the healthy controls and only 42% in the depressed patients. However, the actual prolactin response (delta max) failed to discriminate depressed patients from controls. A blunted response followed by a decrease (33%) in serum cortisol levels was observed in depressed patients 5 h after drug administration while an increase of 94% was obtained in controls after 3 h. FNF provocation did not affect GH and ir-beta-EP plasma levels. The blunted cortisol responsiveness to FNF administration in depressed patients may reflect functional hypoactivity of central serotonergic system at least during the acute phase of major depression. It is not clear why the cortisol hyporesponsivity in depressed patients is not accompanied by a similar reduced PRL response to FNF challenge.     

Behavioral, neuroendocrine, and biochemical effects of 5-hydroxytryptophan administration in panic disorder

L-5-Hydroxytryptophan (5HTP) was administered to 20 patients suffering from panic disorder and to 20 healthy controls. Subjects received 60 mg 5HTP in 300 ml saline solution. Before, during, and up to 2 hours after 5HTP administration, symptoms of anxiety and depression were assessed. In addition, plasma 5HTP, 3-methoxy-4-hydroxyethylglycol (MHPG), cortisol, beta-endorphin, and melatonin levels were measured at several time points, and the kinetics of 5-hydroxytryptamine (5HT) in blood platelets were measured. During and after the infusion of 5HTP, none of the patients showed an increase in anxiety or depressive symptoms, despite the presence of severe side effects. Some patients even experienced the 5HTP infusion as a relief. In contrast to the patients, nine control subjects reported depressed mood, although no increases in anxiety were noted. In both patients and controls, the 5HTP infusion led to substantial increases in plasma cortisol and beta-endorphin levels, while the plasma MHPG level was unchanged. Plasma melatonin increased significantly after 5HTP administration, suggesting that increasing 5HT availability in man might affect melatonin synthesis. The results of this study are at odds with the hypothesis that there is a supersensitivity of 5HT2 receptors in panic disorder.     

Plasma levels of beta-endorphin, cortisol, prolactin and growth hormone in depressed patients

Basal serum cortisol, growth hormone, prolactin and immunoreactive (IR) plasma beta-endorphin levels were measured in 31 depressed patients (14 endogenous, 17 nonendogenous) undergoing the dexamethasone suppression test. The endogenously depressed patients had significantly higher (22.55 +/- 1.34 micrograms/dl) predexamethasone cortisol levels than the nonendogenous patients (16.34 +/- 1.93 micrograms/dl). The mean serum prolactin and growth hormone values of these two groups were not significantly different, while plasma IR-beta-endorphin levels of the endogenous group (40.11 +/- 3.57 pg/ml) were significantly lower than those of the nonendogenous group (120.33 +/- 27.98 pg/ml). Neither group showed a significant correlation between plasma IR-beta-endorphin and serum cortisol values. These results indicate that measurement of predexamethasone serum cortisol values and plasma IR-beta-endorphin could be valuable laboratory tests in the diagnosis of depression.     

Plasma cortisol and beta-endorphin immunoreactivity in nonmajor and major depression

Plasma cortisol levels of 28 hospitalized patients meeting Research Diagnostic Criteria for major or nonmajor (minor or intermittent) depression were significantly higher than those of eight normal subjects. In contrast, plasma beta-endorphin immunoreactivity was significantly lower in patients with nonmajor depression than in those with major depression or in normal subjects. A low ratio of plasma beta-endorphin to cortisol immunoreactivity was found to characterize patients in both groups. Through the use of only this ratio, a post-hoc analysis identified 25 depressed patients and seven controls. These findings have implications for psychiatric diagnosis and the involvement of the endogenous opioid system in the pathogenesis of depression.     

beta-Endorphin/beta-lipotropin immunoreactivity in endogenous depression. Effect of dexamethasone

This study addresses the question of whether pituitary peptides (ie, beta-endorphin) show regulatory disruption in endogenous depression and, if so, does it co-occur in the same subjects who show cortisol dysregulation. Endogenously depressed patients and psychiatric controls from three centers were evaluated, when not taking medications, and studied for plasma cortisol and beta-endorphin levels. Plasma samples were taken at four time points over one hour, on the basal day, and 16 hours after 1 mg of dexamethasone. From 33% to 69% of the endogenous patients were abnormal in their postdexamethasone cortisol levels, and from 50% to 69% were abnormal on postdexamethasone beta-endorphin values (vs 0% and 8%, respectively, for controls). When endogenous subjects were evaluated for abnormality on both cortisol and beta-endorphin, after dexamethasone, it was found that the two measures of hypothalamic-pituitary-adrenal dysfunction did not necessarily co-vary. In fact when having either abnormal beta-endorphin or cortisol levels (or both) was used as a biological marker a larger number of the endogenous patients were detected than with either measure alone. Our conclusions are as follows: Plasma beta-endorphin shows a circadian rhythm similar to that seen with corticotropin (ACTH) and is suppressable by dexamethasone. In many endogenous patients plasma beta-endorphin levels escape from dexamethasone suppression. Many of these subjects are not cortisol escapers. When abnormality of either the beta-endorphin or cortisol is considered it is clear that both levels of the hypothalamic-pituitary-adrenal axis can be dysregulated in endogenous depression.     

Corticotropin, cortisol and beta-endorphin responses to the human corticotropin-releasing hormone during melancholia and after unilateral electroconvulsive therapy

Previous research in neuroendocrinology has evidenced that hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) depends on hypersecretion of corticotropin-releasing hormone (CRH). The aim of this study was to investigate the activity of HPA before and after recovery in depressed patients treated with electroconvulsive therapy (ECT). An h-CRH-stimulation test was performed on 2 occasions with examination of the HPA axis before ECT treatment during episodes of major depressive disorders with melancholia, and during the recovery phase after treatment. The results showed that patients during depression had significantly higher plasma levels of cortisol at 15 and 30 min after h-CRH-administration than after recovery. Depressed patients had significantly higher plasma levels of beta-endorphin 30 min after h-CRH-stimulation. The results are in agreement with previous studies, which have shown hypercortisolemia during depression. A possible hypersecretion of CRH may explain the effect on cortisol and beta-endorphin. No significant differences were found between cumulative responses of corticotropin, cortisol and beta-endorphin, calculated as the areas under the concentration curves.     

Cortisol, ACTH, and beta-endorphin after dexamethasone administration in Parkinson's dementia

The dexamethasone suppression test (DST) has been suggested as an effective tool for differentiating between depression and dementia. After administering 1 mg dexamethasone, we measured cortisol, ACTH, and beta-endorphin levels in 32 nondepressed patients with idiopathic Parkinson's disease (PD) (14 also with dementia) and 20 healthy, age-matched controls. Four of the 20 controls, 9 of the 18 with PD alone, and 8 of the 14 with PD and dementia were dexamethasone nonsuppressors (cortisol value greater than or equal to 5 micrograms/100 ml). PD patients without dementia (nonsuppressors) showed higher basal plasma values of cortisol (22.06 +/- 5.30 micrograms/100 ml) compared with the suppressors (13.38 +/- 3.30 micrograms/100 ml). Plasma ACTH and beta-endorphin responded in a coupled way to dexamethasone challenge. Higher basal levels of both peptides were found among PD patients (demented and nondemented), nonresponders to DST. Thus, the DST does not appear to be effective in differentiating between depression and dementia in PD. In addition, PD nonsuppressors showed higher basal values of plasma ACTH, beta-endorphin, and cortisol (similar to patients with major depression). This suggests that although the depression is clinically undetectable, both disorders may share some pathophysiological features at the hypothalamic hypophyseal adrenal level.     

Imipramine and desipramine in plasma and spinal fluid: relationship to clinical response and serotonin metabolism.

In a double-blind study of depressed patients treated with imipramine hydrochloride, levels of imipramine and desipramine were measured in plasma and in CSF. Levels of both drugs in CSF were approximately 10% of plasma levels, but the levels in the two body fluids were highly correlated. The levels of both drugs were approximately equal in plasma, but desipramine predominated in CSF (imipramine/desipramine ratio of 0.8). The imipramine-induced alteration in CSF levels of the serotonin metabolite (5-hydroxy-indoleacetic acid [5HIAA]) correlated with imipramine levels but not with desipramine. For the group of patients showing a clear antidepressant response, the mean drug levels were nearly double those of the nonresponder group, a difference that did not quite reach statistical significance in this relatively small sample. The desipramine levels showed no responder-nonresponder difference, while the ratio of imipramine/desipramine was significantly higher among the responders. On the average this particular patient group had relatively low pretreatment levels of 5HIAA in CSF, an observation that may partially account for the relatively low overall response rate to imipramine.     

Plasma corticotropin-releasing factor in depressed patients before and after the dexamethasone suppression test.

BACKGROUND: Plasma cortisol, beta-endorphin, corticotropin, corticotropin-releasing factor, and salivary cortisol concentrations, resting and after ingestion of 1 mg of dexamethasone, were investigated in depressed patients and controls. METHODS: Fourteen outpatients from the psychiatric department diagnosed with depressive disorder (ICD-10 Classification) participated in the study. The comparison group consisted of 12 healthy volunteers from the hospital staff. All hormones were measured using direct iodine-125 radioimmunoassay, except corticotropin-releasing factor, which included a sample preextraction and concentration step. RESULTS: The basal plasma cortisol and corticotropin-releasing factor levels in depressive disorder were significantly higher than in the healthy group. After dexamethasone administration, corticotropin-releasing factor plasma values decreased significantly in the depressed group, but showed no significant changes in the controls. In depressive disorder baseline values correlated significantly for salivary cortisol and plasma cortisol, salivary cortisol and plasma corticotropin-releasing factor and plasma corticotropin and beta-endorphin. Similar correlations were found in the healthy subjects, except for salivary cortisol and plasma corticotropin-releasing factor. CONCLUSIONS: These findings indicate that the increased corticotropin-releasing factor plasma concentrations demonstrated in depressive disorder reflect the hypothalamic corticotropin-releasing factor hypersecretion evidenced in this illness. Therefore, measurements of plasma corticotropin-releasing factor levels can be considered a reliable tool for investigating the role of this peptide in the pathophysiology of depression.     

Concentration of 5-hydroxyindoleacetic acid, homovanillic acid, and tryptophan in the cerebrospinal fluid of depressed patients before and after ECT.

Cerebrospinal fluid (CSF) levels of 5-hydroxyindoleacetic acid (5HIAA), tryptophan (TRYP), and homovanillic acid (HVA), were determined prior to electroconvulsive therapy (ECT) and after an average course of 6.7 ECT in six endogenous depressed patients. Depression rating scale (DRS) scores were also obtained by a "blind" research psychiatrist before and after ECT at the time of each lumbar puncture. ECT markedly reduced DRS scores but did not significantly alter CSF levels of 5HIAA, TRYP, or HVA. We found no correlation between ECT-induced DRS score reductions and changes in any of the CSF constituents studied, or between the absolute DRS score and the corresponding CSF concentration of any of the compounds. These data are consistent with those previously reported for ECT and do not suggest that ECT alters cerebral amine metabolism in depressed patients. Neither do they provide any evidence for direct amine mediation of the depression-relieving effects of ECT in man, nor for any relation between severity of depressive illness and CSF concentrations of 5HIAA, TRYP, or HVA.     

Neuroendocrine and psychological variables relating to post-operative psychosis after open-heart surgery

Post-operative psychosis is a frequent complication after open-heart surgery. To investigate relationships between psychopathological outcome and endocrine and psychological variables, serum levels of cortisol, beta-endorphin, norepinephrine, TSH, and cholesterol were measured in 23 male patients undergoing aortic valve replacement from the day before operation (OP) until the seventh day after OP. State and trait anxiety, stress appraisal and the use of coping styles also were assessed. After OP, eight patients suffered from post-OP psychosis and nine from minor psychopathological symptoms. Post-OP psychopathology was significantly correlated with pre-OP psychopathological score as well as with state anxiety, pre- and post-OP stress, and the use of a self-controlling coping style. Serum cortisol, beta-endorphin, norepinephrine, and TSH levels were markedly elevated after OP. Cholesterol levels showed a decline. With regard to endocrine variables, the eight psychotic patients did not differ from 15 non-psychotic subjects, but a subgroup of three major depressed patients had distinctly elevated levels of cortisol and norepinephrine. For all 23 patients, pre-OP cholesterol correlated with pre-OP psychopathology and post-OP depression. Furthermore, post-OP depression was significantly correlated with both post-OP cortisol and norepinephrine. These results indicate the stressful nature of the OP and suggest a multifactorial association of endocrine and psychological variables with psychiatric complications after open-heart surgery.     

5-Hydroxytryptophan-induced cortisol response and CSF 5-HIAA in depressed patients

To determine if the enhanced cortisol response to oral administration of the serotonin (5-HT) precursor 5-hydroxytryptophan (5-HTP) that has been reported in unmedicated depressed and manic patients might be related to brain monoaminergic metabolism, the authors assessed correlations between 5-HTP-induced cortisol response and CSF in nine depressed patients. They found a significant negative correlation with CSF levels of 5-hydroxyindoleacetic acid, a 5-HT metabolite, but not with CSF levels of other monoamine metabolites. This finding is consistent with the hypothesis that low presynaptic brain serotonergic activity may be related to enhanced cortisol response to 5-HTP in depressed patients.     

Measurement of 5–Hydroxyindole Compounds During L-5–HTP Treatment in Depressed Patients

L-5–hydroxytryptophan (L-5–HTP), an immediate serotonin precursor, was given to the hospitalized depressed patients in an open clinical trial of the Phase 2 study for an-tidepressive effects of the agent. A relatively small dose, 150 mg orally for seven days, was employed, and seven of 14 patients responded to the treatment with mild or moderate amelioration of their depressive symptoms. Urinary excretion levels and plasma concentrations of three 5–hydroxyindole compounds, 5–HTP, 5–HT and 5–HIAA, were measured during the drug treatment. Approximately 70% of the orally administered dose of L-5–HTP was recovered from the urine of depressed patients. Major part of urinary indoleamine metabolites was free and conjugate 5–HIAA. Excretion levels of these compounds in urine were not consistently altered in the depressed patients as compared to those in normal subjects. Clinical response to L-5–HTP treatment appeared to have some correlation with the biochemical measures in the depressed patients, that is, non-responders exhibited significantly lower excretion levels of 5–HT and 5–HIAA in urine, and lower plasma levels of 5–HT than responders. Administered L-5–HTP may not be fully utilized in the depressed patients who did not react to the agent.     

Relationship between urinary free cortisol and CSF opioid binding activity in depressed patients and normal volunteers

We investigated the relationship between hypothalamic-pituitary-adrenal (HPA) activity, as measured by 24-hour mean urinary free cortisol (MUFC), and cerebrospinal fluid (CSF) opioid activity in patients with major affective disorder and normal volunteers. Among depressed patients, but not normal volunteers, mean 24-hour urinary cortisol values were significantly correlated with CSF opioid activity measured by radioreceptor assay, but were not significantly correlated with beta-endorphin immunoreactivity measured by radioimmunoassay. MUFC, as expected, was significantly higher in depressed patients than in normal volunteers. Mean values of CSF opioid activity and beta-endorphin immunoreactivity did not differ significantly in the two groups. The positive opioid-MUFC correlation found in the depressed group appeared to depend on patients who were cortisol hypersecretors. These data, using relatively crude measures of cortisol and opioid activity, are suggestive of a relationship between these two systems, particularly under "activated" conditions such as those observed in depression.     

Endocrine and amine responses to D,L-fenfluramine in normal subjects.

To investigate indirectly the central neurotransmitter mechanisms of D,L-fenfluramine-induced hormone release, prolactin, adrenocorticotropic hormone, cortisol, growth hormone, 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5HIAA) responses to D,L-fenfluramine (60 mg, oral) were examined in a single-blind, placebo-controlled trial in 14 normal subjects. As compared with placebo, D,L-fenfluramine significantly increased both prolactin and cortisol. There was a significant correlation between the cortisol and prolactin responses. HVA levels were also significantly increased, but there were no changes in MHPG or 5HIAA. The elevation in HVA significantly correlated with increases in both prolactin and cortisol. These findings are consistent with recent animal studies suggesting that D,L-fenfluramine-induced prolactin and cortisol release may be mediated, at least in part, by catecholaminergic systems.     

Platelet serotonin and plasma prolactin and cortisol in healthy, depressed and schizophrenic women

Serotonin (5-hydroxytryptamine, 5-HT) is involved in the regulation of hypothalamic-pituitary-adrenal axis (HPA) activity and prolactin (PRL) secretion. The present study examined the relationship between platelet 5-HT and plasma cortisol and PRL concentrations in 20 schizophrenic, 25 depressed, and 25 healthy women. At the time of blood sampling, the schizophrenic and depressed patients had been drug-free for at least 7 days. Platelet 5-HT, plasma cortisol and PRL concentrations were determined by spectrofluorimetric, radioimmunoassay and immunoradiometric methods, respectively. Platelet 5-HT concentration was significantly higher in schizophrenic patients than in depressed patients or in healthy controls, while it was significantly lower in depressed patients than in healthy controls or in schizophrenic patients. Plasma cortisol levels were significantly increased both in schizophrenic and in depressed patients compared with values in healthy controls. Values of plasma PRL were similar across groups. A significant correlation was found between platelet 5-HT and plasma cortisol, and platelet 5-HT and plasma PRL concentrations in healthy controls, but not in schizophrenic or depressed patients. There was no significant relationship between plasma PRL and cortisol levels in any of the groups. Our data, although obtained on peripheral biochemical markers, indicate that depression and schizophrenia are characterized by disturbed 5-HT transmission and dysregulated HPA axis activity.     

Platelet MAO activity and monoamine metabolites in cerebrospinal fluid in depressed and suicidal patients and in healthy controls

Platelet monoamine oxidase (MAO) activity and cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacetic acid (5HIAA), homovanillic acid (HVA), and 4-hydroxy-3-methoxyphenylglycol (HMPG) were simultaneously measured in 20 currently depressed patients, 11 recovered depressed patients, 15 nondepressed suicide attempters, and 42 healthy control subjects. Both 5HIAA and HVA were positively and significantly correlated to platelet MAO activity in the healthy subjects, but not in any of the patient groups. Suicide attempters had significantly lower CSF 5HIAA than nonsuicidal patients.     

Release of vasopressin, cortisol and beta-endorphin in tetraplegic subjects in response to head-up tilt

Plasma levels of beta-endorphin, vasopressin and cortisol during head-up tilt were measured in tetraplegic patients and in normal healthy subjects. In tetraplegic patients rapid tilt from the horizontal to 30 degrees or 60 degrees head-up induced orthostatic hypotension and increased plasma levels of cortisol, beta-endorphin and vasopressin. In control subjects head-up tilt failed to alter plasma levels of these hormones. These data show that the head-up position in tetraplegics causes various endocrine reactions.     

Plasma levels of homovanillic acid, 5-hydroxyindoleacetic acid and cortisol, and serotonin turnover in depressed patients

Plasma levels of ACTH, cortisol and monoamines were examined in 23 depressed patients and 31 healthy subjects. Patients showed increased plasma cortisol levels, but not plasma adrenocorticotropic hormone (ACTH) levels. The plasma levels of a dopamine metabolite, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), were significantly decreased in the patients. In contrast, the plasma levels of a serotonin (5-HT) metabolite, hydroxyindoleacetic acid (5-HIAA), and 5-HT turnover (5-HIAA/5-HT) were increased in the depressed patients. Therefore, plasma levels of HVA and 5-HIAA are proven to be dissociable. Furthermore, plasma levels of 5-HIAA and L-DOPA have positive relationships with severity of depression. On the basis of this and the previous studies, we speculate that an increase in the plasma 5-HIAA levels might be a compensatory mechanism for stress, whereas 5-HT turnover might reflect depressive state. Taken together, plasma levels of HVA and 5-HIAA, and 5-HT turnover (5-HIAA/5-HT) could be good markers for evaluating depression.