Altered plasma dexamethasone and cortisol suppressibility in patients with panic disorders

Some abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis in patients with panic disorders were recently reported. The possibility that the disposition of dexamethasone, which has been reported to influence the Dexamethasone Suppression Test (DST), might be altered in this subgroup of patients has not, as yet, been reported. We report that 4:00 PM dexamethasone plasma concentrations following a 1-mg oral DST were significantly (p less than 0.01) lower in 23 patients with panic disorders (0.49 +/- 0.44 ng/ml) compared to 52 normal control subjects (1.09 +/- 0.64 ng/ml). This is in addition to the significantly higher (p less than 0.05) 4:00 PM postdexamethasone cortisol values per nanogram per milliliter of dexamethasone in the panic disorder patients compared to normal controls (17.7 +/- 29.6 versus 5.0 +/- 11.2 micrograms/dl). The mean percent suppression of cortisol from baseline in panic disorder was normal despite one-half the dexamethasone concentrations in these subjects. The cortisol suppression versus dexamethasone concentration curve was also shifted lower (greater fraction of cortisol suppression) and to the left (toward lower dexamethasone concentrations). These results further suggest that the HPA system is indeed altered in panic disorders, but in a manner that is not readily apparent from the DST alone.     

Plasma dexamethasone levels in children given the dexamethasone suppression test

To determine whether children who demonstrate dexamethasone suppression test (DST) nonsuppression have lower plasma dexamethasone levels than DST suppressors, we administered the DST to 73 patients ranging in age from 5-14 years. Plasma dexamethasone levels and postdexamethasone cortisol levels were measured at 4:00 PM on day 2. We found: (1) DST nonsuppressors had significantly lower plasma dexamethasone levels (p less than 0.03) than suppressors; similar trends were observed when the population was divided into depressed and nondepressed patients; (2) mg/m2 dose of dexamethasone was directly correlated with plasma dexamethasone (p less than 0.003) and inversely correlated with postdexamethasone plasma cortisol levels (p less than 0.04); and (3) a statistically significant inverse correlation between plasma dexamethasone levels and postdexamethasone cortisol levels (p less than 0.04). Our findings show that plasma dexamethasone levels are important in evaluating DST results in psychiatrically disturbed children and suggest that dexamethasone dosage for use in the DST in children might be better calculated in terms of body surface area.     

Neuroendocrine evidence of deranged noradrenergic activity in chronic migraine

Migraine is a psychobiological disorder in which a recurrent failure of opioid and adrenergic systems might occur, as plasma and CSF studies suggest. In order to elucidate the relationship between noradrenergic and opioidergic functions, the plasma beta-endorphin (beta-EP) response to clonidine and the cortisol response to dexamethasone were evaluated together in 25 patients suffering from migraine without aura, and with chronic tension headache (MTH). Baseline beta-EP plasma levels and beta-EP response to clonidine were significantly lower in MTH subjects than in controls, suggesting a postsynaptic hypothalamo-pituitary impairment. Forty-four percent of the MTH subjects showed either a lack of suppression of plasma cortisol following dexamethasone administration, or basal cortisol concentrations higher than controls and suppressors, suggesting a disinhibition of the hypothalamopituitary-adrenal (HPA) axis. An inverse correlation was found between pain severity and beta-EP secretion induced by clonidine (delta max), and no relationship was found between beta-EP and mood. These data suggest a failure of central noradrenergic activity, or perhaps an impaired secretion of beta-EP not related to HPA axis hyperactivity or to affective state.     

Effects of parental PTSD on the cortisol response to dexamethasone administration in their adult offspring

OBJECTIVE: The authors used a low-dose dexamethasone suppression test to examine the effect of a PTSD risk factor, parental PTSD, on cortisol negative feedback inhibition in adult offspring of Holocaust survivors with PTSD (N=13) versus without PTSD (N=12) as well as a comparison group of offspring whose parents had no Holocaust exposure (N=16). METHOD: Blood samples were obtained at 8:00 a.m. for the determination of baseline cortisol. Participants ingested 0.5 mg of dexamethasone at 11:00 p.m., and blood samples were obtained again at 8:00 a.m. the following day. RESULTS: Enhanced cortisol suppression in response to dexamethasone was associated primarily with parental PTSD status, with minimal contribution of subjects' own trauma-related symptoms. CONCLUSIONS: Enhanced cortisol negative feedback inhibition may be associated with PTSD because it is related to the PTSD risk factor of parental PTSD.     

Psychoimmunoendocrine aspects of panic disorder.

Immunological, neuroendocrine and psychological parameters were examined in 14 psychophysically healthy subjects and in 17 panic disorder patients before and after a 30-day course of alprazolam therapy. T lymphocyte proliferation in response to the mitogen phytohemagglutinin, lymphocyte beta-endorphin (beta-EP) concentrations, plasma ACTH, cortisol and beta-EP levels were examined in basal conditions and after corticotropin-releasing hormone (CRH) stimulation. Cortisol inhibition by dexamethasone (DST) and basal growth hormone (GH) and prolactin levels were also examined. Depression, state or trait anxiety, anticipatory anxiety, agoraphobia, simple and social phobias, severity and frequency of panic attacks were monitored by rating scales. The immune study did not reveal any significant difference between patients and controls, or any effect of alprazolam therapy. The hormonal data for the two groups were similar, except for higher than normal basal ACTH and GH plasma levels, lower than normal ratios between the ACTH and cortisol responses to CRH, and blunted DST in some patients. All the impairments improved after alprazolam therapy, in parallel with decreases in anxiety and in severity and frequency of panic attacks.     

焦虑症的生化病理机制探讨

目的：从神经递质与神经内分泌角度探讨焦虑症的生化病理机制。方法：采用高效液相色谱法及放射免疫测定法，分别测定25例焦虑症患者和28例正常对照者血小板5—羟色胺(5—HT)含量及血浆催乳素(PRL)含量、地塞米松抑制实验(DST)皮质醇含量。结果：广泛性焦虑(GAD)组血小板5—HT水平高于正常对照组，惊恐障碍(PD)组与正常对照组无显著差异；GAD组与对照组血浆PRL均极显著低于PD组；GAD组与PD组血浆基础皮质醇含量均显著高于正常对照组，两组DST阳性率均为20％，正常对照组为14．3％，3组阳性率无显著性差异；汉密尔顿焦虑量表(HAMA)评分与血浆皮质醇浓度呈显著正相关。结论：焦虑症患者存在神经递质和神经内分泌功能的紊乱，但不同亚型间可能存在不同的病理机制，皮质醇浓度可能是焦虑水平的标志因子。     

Cortisol and Alzheimer's disease, I: Basal studies

Patients with Alzheimer's disease and nondemented elderly control subjects participated in studies of cortisol secretion during sleep and at 9:00 a.m. and were given dexamethasone suppression tests (DSTs) and lumbar punctures. Nocturnal and 9:00 a.m. cortisol concentrations were significantly higher in the demented patients. CSF MHPG negatively correlated with mean nocturnal cortisol. The most severely demented patients had the highest 9:00 a.m. and mean nocturnal cortisol concentrations. DST results did not distinguish samples with substantially different nocturnal cortisol concentrations. These results suggest that measurements of basal plasma cortisol concentrations and dexamethasone suppression provide different information but support the notion of somewhat higher than normal cortisol concentrations in Alzheimer's disease patients.     

Plasma dexamethasone concentrations and the dexamethasone suppression test

Altered bioavailability or altered pharmacokinetics of dexamethasone (dex) may contribute to a positive Dexamethasone Suppression Test (DST) in psychiatric patients. We measured plasma dex and plasma cortisol concentrations in 32 patients with primary major depressive disorder (MDD), 14 patients with other psychiatric disorders, and 16 normal controls. Cortisol was measured by the competitive protein binding (CPB) assay and dex by RIA (IgG Corp.). Additionally, cortisol was measured by a fluorescent polarization immunoassay (FPIA) available on the Abbott TDx analyzer in an attempt to validate this method for use in the DST. The agreement between FPIA and CPB cortisol results was excellent. Depressed nonsuppressors, by definition, had significantly higher mean plasma cortisol concentrations than depressed suppressors, psychiatric controls, and normal volunteers at 8:00 AM, 3:00 PM, and 10:00 PM postdex. When DST nonsuppressors and suppressors were compared regardless of diagnostic group, plasma dex concentrations were significantly lower (p less than 0.01) in the DST nonsuppressors. There was a significant negative correlation between plasma cortisol levels and plasma dex levels across all subjects at 8:00 AM (r = -0.365, n = 44, p less than 0.05). When the subjects were sorted by diagnostic category, there was a strong, but not statistically significant, trend toward lower plasma dex concentrations in the melancholic nonsuppressors versus the melancholic suppressors and between the psychiatric control non-suppressors and the corresponding suppressor group. These relationships disappeared when we restricted our analyses to an empirically derived middle range of plasma dex concentrations within which the DST results were considered to be valid. We conclude that bioavailability or pharmacokinetics of dex may significantly contribute to DST results. Further investigation is needed to determine whether or not the quantification of dex and its metabolites and their determination at which specific timepoints during the DST will enhance the predictive or interpretive value of the DST in psychiatric patients.     

Lack of effects of hospitalization and oral contraceptives on DST results in control subjects

The effect of oral contraceptive use and hospitalization stress on the results of the dexamethasone suppression test (DST) were assessed. This test, in which 1 mg dexamethasone is given at 11:00 p.m., and blood cortisol is analyzed the following day, is used as an indicator or major or endogenous depression, as opposed to situational depression, but specificity of the test remains in dispute. The test subjects were 15 normal volunteers, mostly staff, and 27 surgical patients, who were planning orthopedic surgery the following day. Of the 20 women, 7 took oral contraceptives, (Sequilar, Microgynon 50, Trigynon, Microgynon 30 and Diane). Cortisol was radioimmunoassayed at 4:00 p.m. in volunteers and at 8:00, 4:00 and 11:00 p.m. in hospital patients. Only 1 subject had a positive test (non-suppressor), a non oral contraceptive user, with a cut-off point of 50 mcg/L. The hospital patients' cortisol levels were slightly higher (n.s.). Pill users' cortisol levels were unchanged.     

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.     

A combined dexamethasone/corticotropin-releasing hormone test in patients with chronic PTSD--first preliminary results

BACKGROUND: Reports about alterations of hypothalamic-pituitary-adrenocortical (HPA) function in patients with chronic posttraumatic stress disorder (PTSD) are inconsistent and controversial. More refined laboratory tests and subgrouping of PTSD patients might help to decrease variance of findings. METHODS: 14 subjects with chronic PTSD and 14 healthy controls were examined between 13:00 and 17:00 using a modified combined dexamethasone/CRH test (0.5 mg dexamethasone at 23:00, 100 microg CRH at 15:00). Plasma adenocorticotropic hormone (ACTH), cortisol and blood pressure were measured every 15 min from 14:45 until 17:00. RESULTS: No significant differences between patients and controls were found in the analyses of ACTH and cortisol levels, but a significantly elevated systolic and diastolic blood pressure in PTSD. Severity of depressive symptoms had no influence. However, explorative analyses showed that patients with a history of childhood traumatization had significantly higher post-dexamethasone-ACTH levels and a significantly lower diastolic blood pressure in comparison to patients without early trauma. CONCLUSIONS: In this first pilot study in a typical clinical sample of patients with chronic PTSD we found effects of severe adverse events in childhood on HPA axis regulation. Maybe, childhood traumatization could influence HPA axis findings in PTSD. Further research is needed, especially dose-response studies with different doses of dexamethasone in dexamethasone/CRH tests in PTSD.     

Clonidine stimulation in anorexia nervosa: growth hormone, cortisol, and beta-endorphin responses

Clinical and biochemical findings link anorexia nervosa (AN) and primary effective disorders (PAD). Clonidine, an alpha 2-adrenoceptor agonist, has been shown to blunt growth hormone (GH) response and greatly lower plasma cortisol in PAD patients. We examined the GH, cortisol, and beta-endorphin (beta-EP) responses to an acute clonidine challenge (150 micrograms i.v. as a bolus) before and after 30 days of treatment with desmethylimipramine in 14 women with AN. Both before and after treatment, the AN patients showed normal plasma GH and cortisol responses, but an increased plasma beta-EP response. The increased beta-EP response in AN was independent of weight and depressive symptomatology. Our data indicate that alpha 2-adrenoceptors involved in the control of GH and adrenocorticotropic hormone are not altered in AN. The increased beta-EP response may indicate elevated opioid activity in the hypothalamo-pituitary system of AN patients.     

Hypothalamic-pituitary-adrenal axis dysregulation among diabetic outpatients

We compared insulin-requiring diabetic outpatients (n = 49) with normal controls (n = 42) for indices of hypothalamic-pituitary-adrenal (HPA) axis activity. Diabetic patients showed significantly elevated 9 a.m. plasma levels of cortisol as well as significantly elevated plasma levels of cortisol and adrenocorticotropic hormone (ACTH) at both 4 p.m. before and 4 p.m. after dexamethasone. Also, there was a significant correlation between postdexamethasone plasma levels of ACTH and duration of diabetes. These results suggest that HPA-axis dysregulation is found among diabetic outpatients. The possible psychiatric implications are discussed.     

CSF corticotropin-releasing hormone in depressed patients and normal control subjects

The authors studied CSF corticotropin-releasing hormone (CRH) and plasma cortisol in 22 depressed patients and 18 normal control subjects. CRH levels were similar in the two groups. Depressed patients who were nonsuppressors on the dexamethasone suppression test had significantly higher levels of CRH than suppressors did. The depressed patients' CRH levels were significantly correlated with 4:00 p.m. postdexamethasone plasma cortisol levels. While the inclusion of a depressed patient with an outlier CRH value resulted in the loss of statistical significance for both of these findings, the authors suggest that these results support the hypothesis that hypercortisolism in depressed patients in part reflects a defect at or above the hypothalamus, resulting in hypersecretion of CRH.     

The dexamethasone suppression test: importance of dexamethasone concentrations

Plasma dexamethasone concentrations and cortisol response to dexamethasone were measured in 29 normal healthy volunteers, 23 depressed patients, and 10 patients with anorexia nervosa at 4:00 PM postdexamethasone. In each of the 3 groups, nonsuppressors had lower dexamethasone concentrations than suppressors. Of the subjects with plasma dexamethasone at or below 0.7 ng/ml, a significantly higher proportion (48%) were nonsuppressors compared to the proportion above 0.7 ng/ml (14%), all of whom were patients. Plasma dexamethasone concentrations in a subgroup of depressed nonsuppressors were high (mean 1.35 ng/ml), whereas the remainder were low (0.42 ng/ml) and were similar to the normal nonsuppressors (0.35 ng/ml), suggesting different mechanisms for nonsuppression in the subgroups. Plasma dexamethasone concentrations were similar in nonendogenous and endogenous depressives, in men and women, and in medicated and drug-free patients. None of the variables of age, weight, history of weight loss, Hamilton depression rating score, predexamethasone cortisol, or postdexamethasone cortisol were significantly correlated with plasma dexamethasone, except for body weight and a history of weight loss in the depressed group only. Mean plasma dexamethasone concentrations increased significantly from week 1 to week 2 in 7 depressed patients, whereas plasma cortisol decreased; however, the relationship between dexamethasone and cortisol varied considerably for individual patients.     

Depression, natural killer cell activity, and cortisol secretion

Natural killer (NK) cell activity was evaluated in 34 ambulatory patients with Major Depressive Disorder (MDD) and 21 healthy controls. No mean differences between the groups were found. However, female depressives (n = 19) exhibited higher NK activity than female controls (n = 14). The relationship between cortisol secretion and NK activity was examined using an integrated cortisol value derived from multiple blood samples taken between 1:00 and 4:00 PM. This comprehensive assessment of cortisol secretion circumvents spurious "single stick" cortisol values and provides a more accurate determination of hypercortisolemia than the dexamethasone suppression test. NK activity in depressives with cortisol hypersecretion (greater than 11 micrograms/dl) (n = 7) was no different than NK activity in depressives and controls with normal cortisol secretion. Furthermore, there was no correlation between cortisol secretion and NK activity in any of the groups. These results indicate that decreased NK activity is not a consistent finding in MDD and cannot be predicted by the presence of hypercortisolemia in these patients.     

The plasma dexamethasone window: evidence supporting its usefulness to validate dexamethasone suppression test results

Two doses of dexamethasone (DEX) (0.5 and 1.0 mg) were administered in a randomized crossover design to 31 patients with major depression, 9 healthy controls, and 14 nondepressed psychiatric patients. Using this modified Dexamethasone Suppression Test (DST), minimum DEX levels of 6 nmol/liter at 8:00 AM and 2.0 nmol/liter at 4:00 PM were required to achieve reliable suppression of cortisol in healthy controls and nondepressed psychiatric patients. Failure to achieve these minimum plasma DEX levels was associated with similar rates of nonsuppression in both depressed and nondepressed patients, thereby reducing the specificity of the DST. Conversely, high DEX levels greater than 13 nmol/liter at 8:00 AM or 4.0 nmol/liter at 4:00 PM were associated with abnormal "suppressibility" in depressed patients, thereby reducing the sensitivity of the test. Controlling for plasma DEX concentrations by selecting a test result that fell within a plasma DEX window at 8:00 AM and 4:00 PM increased the sensitivity and specificity of the DST. Significant differences in plasma DEX between suppressors and nonsuppressors were no longer evident when comparing patients with adequate DEX levels, thus ensuring that cortisol escape reflected HPA axis changes associated with depression and not peripheral mechanisms responsible for the availability of DEX. These results suggest that the clinical utility of the DST would be significantly enhanced by extending the standard 1.0-mg DST and retesting those patients with levels outside the DEX window with a higher or lower dose. The data also indicate that the measurement of plasma DEX is essential to validly interpret DST status and highlight the need to standardize DEX assays to compare DST results between research centers.     

Results of the 8 a.m. dexamethasone suppression test constitute a suitable tool for confirming the diagnosis of melancholia. A test unaffected by the variations in the bioavailability of dexamethasone

This prospective study was conducted in order (1) to examine which postdexamethasone cortisol value i.e., 8 a.m., 4 p.m. or peak cortisol - is most suitable as a laboratory test to help confirm the diagnosis of melancholia and (2) to investigate the influence of the dexamethasone levels in the results of the dexamethasone suppression test (DST). To this end we administered the DST to 48 controls and 115 depressed inpatients categorized according to DSM-III. The 8 a.m. and 4 p.m. dexamethasone levels were determined in 100 subjects. We found that an 8 a.m. postdexamethasone cortisol value greater than or equal to 3.5 micrograms/dl was of the most significant diagnostic value in order to separate melancholia from normal controls and/or minor depressives. The 8 a.m. and 4 p.m. dexamethasone values did not differ between healthy controls, minor and severely depressed patients. Although cortisol nonsuppressors exhibited significantly lower dexamethasone values, the predictive value of the DST for melancholia was not affected by the large variation in the bioavailability of dexamethasone.     

Dexamethasone suppression in major depression

Overnight 1 mg dexamethasone suppression tests were performed on 37 hospitalized patients with unipolar major depression and 13 psychiatric controls: 62% of the depressives and 38% of controls failed to suppress below 6 micrograms/dl of plasma cortisol at least once on the day after dexamethasone. Specificity for depressive diagnosis was only 62% but rose to 100% when a plasma cortisol value of 10 micrograms/dl was used as the criterion for normal suppression. Depressed patients were significantly more likely to show normal suppression if they were under age 65 (56% vs. 24% in the geriatric sample). Other demographic and clinical variables examined in the depressed sample did not assort by suppressor status.     

Plasma ACTH levels in primary depression: relationship to the 24-hour dexamethasone suppression test

The failure of adequate cortisol suppression after 1 mg dexamethasone in 50% of patients with endogenous depression has been attributed to abnormal hypothalamic-pituitary-adrenal axis regulation, resulting in high levels of adrenocorticotropic hormone (ACTH). Because studies of plasma ACTH have been conflicting, we studied plasma ACTH levels during the 24-hour dexamethasone suppression test in a homogeneous group of 29 hospitalized patients with primary endogenous depression and 19 normal volunteers. No differences were found in ACTH levels among normal volunteers, depressed cortisol suppressors, and depressed cortisol nonsuppressors at either 4 p.m. or 11 p.m.