Hypercortisolemia decreases dexamethasone half-life in rabbit

The pharmacokinetics of dexamethasone have been found to be related to endogenous hypothalamic-pituitary-adrenal (HPA) axis activity. Lower plasma dexamethasone levels in psychiatric patients (especially depressed) who are dexamethasone suppression test (DST) nonsuppressors have previously been reported. Since DST nonsuppression is one measure of HPA axis hyperactivity and is usually associated with relatively increased plasma cortisol levels and lower post dose plasma dexamethasone levels, we hypothesized that hypercortisolemia can induce a more rapid disappearance of dexamethasone from plasma. We therefore studied the kinetics of dexamethasone in rabbits before and after a period of sustained hypercortisolemia produced by administration of IM hydrocortisone acetate, a slowly absorbed salt of cortisol. Mean dexamethasone half-life decreased significantly from baseline of 1.92 h on day zero in seven rabbits to 1.17 h on experimental day 17 of induced hypercortisolemia (P<0.001), while there was no significant change in saline treated controls (n=3). Dexamethasone half-life had returned to the baseline levels when retested 88 days later on experimental day 105. The results indicate that pronounced hypercortisolemia decreases dexamethasone half-life in rabbits, and support the concept that increased circulating cortisol levels induce hepatic enzymes that metabolize dexamethasone. Thus, the lower postdexamethasone plasma dexamethasone levels and decreased dexamethasone half-life in DST nonsuppressors may in part reflect the effect of prior or coincident hypercortisolemia.     

In search of the HPA axis activity in unipolar depression patients with childhood trauma: Combined cortisol awakening response and dexamethasone suppression test

The aim of the present study was to examine the impact of childhood trauma on HPA axis activity both in depression patients and healthy controls in order to determine the role of HPA axis abnormalities in depression and to find the differences in HPA axis functioning that may lead certain individuals more susceptible to the depressogenic effects of childhood trauma. Eighty subjects aged 18–45 years were recruited into four study groups (n = 18, depression patients with childhood trauma exposures, CTE/MDD; n = 17, depression patients without childhood adversity, non-CTE/MDD; n = 23, healthy persons with childhood trauma, CTE/non-MDD; and n = 22, healthy persons without childhood adversity, non-CTE/non-MDD). Each participant collected salivary samples in the morning at four time points: immediately upon awakening, 30, 45, and 60 min after awakening for the assessment of CAR and underwent a 1 mg-dexamethasone suppression test (DST). Regardless of depression, subjects with CTE exhibited an enhanced CAR and the CAR areas under the curve to ground (AUCg) were associated with their childhood trauma questionnaire (CTQ) physical neglect scores and CTQ total scores. In addition, the CTE/MDD group also showed a highest post-DST cortisol concentration and a decreased glucocorticoid feedback inhibition among four groups of subjects. The present findings suggested that childhood trauma was associated with hyperactivity of HPA axis as measured with CAR, potentially reflecting the vulnerability for developing depression after early life stress exposures. Moreover, dysfunction of the GR-mediated negative feedback control might contribute to the development of depression after CTE.     

HPA axis hyperactivity as suicide predictor in elderly mood disorder inpatients

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis function is associated with suicidal behaviour and age-associated alterations in HPA axis functioning may render elderly individuals more susceptible to HPA dysregulation related to mood disorders. Research on HPA axis function in suicide prediction in elderly mood disorder patients is sparse. The study sample consisted of 99 depressed elderly inpatients 65 years of age or older admitted to the department of Psychiatry at the Karolinska University Hospital between 1980 and 2000. The hypothesis was that elderly mood disorder inpatients who fail to suppress cortisol in the dexamethasone suppression test (DST) are at higher risk of suicide. The DST non-suppression distinguished between suicides and survivors in elderly depressed inpatients and the suicide attempt at the index episode was a strong predictor for suicide. Additionally, the DST non-suppression showed higher specificity and predictive value in the suicide attempter group. Due to age-associated alterations in HPA axis functioning, the optimal cut-off for DST non-suppression in suicide prediction may be higher in elderly mood disorder inpatients. These data demonstrate the importance of attempted suicide and DST non-suppression as predictors of suicide risk in late-life depression and suggest the use for neuroendocrine testing of HPA axis functioning as a complementary tool in suicide prevention.     

Elevated 3,4-dihydroxyphenylethyleneglycol (DHPG) excretion in dexamethasone resistant depressed patients

1. Urinary and plasma DHPG and MHPG were estimated in patients with MADD and showing DST non-suppression as compared to those with normal suppression.

2. Day and night 12h urine collections and morning plasma samples were analyzed by GC-MS for total MHPG and DHPG and free MHPG levels.

3. Urinary DHPG excretion was significantly elevated in DST non-suppressors compared to suppressors, but no differences were found in urinary MHPG or plasma glycol levels.

4. Elevated DHPG excretion in DST non-suppressors suggests that increased peripheral sympathetic NE activity occurs in association with dexamethasone resistance in MADD.     

Vasopressin-neurophysin and DST in major depression: relationship with suicidal behavior

The purpose of the present study was to assess if AVP-neurophysin is associated with hypercortisolemia and suicidal behaviour in depressed patients. The study included 28 patients subgrouped into suicide attempters (n=13) and nonattempters (n=15). We assessed basal AVP-neurophysins concentrations and post-dexamethasone (DST) cortisol levels. Concentrations of AVP-neurophysins did not differ between DST suppressors and nonsuppressors: 0.29+/-0.13 ng/ml vs 0.36+/-0.21 ng/ml, (F=1.1, df=1, 27, p=0.30). Suicide attempters did not differ from nonattempters for AVP-neurophysins levels. Our results fail to support a role of AVP in the early cortisol escape.     

Dexamethasone suppresion test (DST) and plasma dexamethasone levels in depressed patients

The dexamethasone suppression test (DST) was evaluated in newly hospitalized patients with a DSM-III diagnosis of major depression. Patients with other psychiatric disorders and a normal control group were also studied. Plasma dexamethasone levels were obtained in all patients, and the relationship between plasma cortisol and plasma dexamethasone was examined. Rates of non-suppression in patients with major depression (39%) were not significantly different from those in patients with minor depression (25%), mania (38%), or other psychiatric illnesses (17%). The ranges of dexamethasone levels at 8 a.m. and 4 p.m. were similar between patient groups and controls. However, there was a significant difference in dexamethasone levels between suppressors and nonsuppressors, irrespective of diagnosis, which could not be explained by differences in weight or plasma dexamethasone half-life. Inappropriately high dexamethasone levels were found in some patients with a 1 mg test, a problem that critically affects the sensitivity of the test procedure.     

Clinical burnout is not reflected in the cortisol awakening response, the day-curve or the response to a low-dose dexamethasone suppression test

Burnout is presumed to be the result of chronic stress, and chronic stress is known to affect the HPA-axis. To date, studies on HPA-axis functioning in burnout have showed inconsistent results. In the present study, a large sample (n=74) of clinically diagnosed burnout individuals, mostly on sick-leave, were included and compared with 35 healthy controls. Salivary cortisol was sampled on 2 days to determine the cortisol awakening response (CAR) and the day-curve. In addition, the dexamethasone suppression test (DST) was applied to assess the feedback efficacy of the HPA-axis. There were no differences observed in the CAR, day-curve or CAR after DST in the burnout group as compared to a healthy control group. Burnout shows overlap in symptoms with chronic fatigue syndrome (CFS) and depression. Therefore, differential changes in HPA-axis functioning that resemble the hypo-functioning of the HPA-axis in CFS, or rather the hyper-functioning of the HPA-axis in depression, might have obscured the findings. However, no effect of fatigue or depressive mood on HPA-axis functioning was found in the burnout group. We concluded that HPA-axis functioning in clinically diagnosed burnout participants as tested in the present study, seems to be normal.     

Comparison of the cortisol suppression index and the DST within major depressive disorder

The authors compared the Cortisol Suppression Index (CSI) and raw postdexamethasone cortisol values for their usefulness in detecting endogeneity and severity in major depressive disorder (MDD). The 8 AM postdexamethasone cortisol provided the best correlation with both endogeneity and severity. The CSI does not appear to be a satisfactory alternative to the current DST for this purpose.     

Discrimination between patients with melancholic depression and healthy controls: comparison between 24-h cortisol profiles, the DST and the Dex/CRH test

Diurnal (24-h) cortisol profiles were compared to DST and Dex/CRH test outcomes with regard to their discriminative power in depressive disorder. With regard to several statistical measures (effect sizes, area under the curve) we found 24-h cortisol profiles to better discriminate between healthy controls and inpatients with the melancholic subtype of depression compared to the DST and Dex/CRH test. In search of a shortened time interval we found the 2-h time window 1000-1200 h of the cortisol profile to be the one with the highest sensitivity (83.3%) and specificity (87.9%). The specificity of the DST was 93.3% and somewhat higher than that of the cortisol profiles and the Dex/CRH test (87.9% and 78.8.%, respectively). However, the sensitivity of the DST was very low (30.8%), in fact similar to that of the Dex/CRH test (30.8%), but much lower than that of the 1000-1200 h interval (83.3%). The assessment of cortisol in plasma is an easy to perform, cost-saving method for the evaluation of the HPA system activity, which may have a series of clinical and scientific implications for the depressive disorder.     

Enhanced cortisol suppression in response to dexamethasone administration in traumatized veterans with and without posttraumatic stress disorder

BACKGROUND: While enhanced cortisol suppression in response to dexamethasone is one of the most consistent biological findings in posttraumatic stress disorder (PTSD), the relative contribution of trauma exposure to this finding remains unclear. METHODS: Assessment of diurnal salivary cortisol levels and 1600 h salivary cortisol before and after oral administration of 0.5mg dexamethasone in veterans with PTSD, veterans without PTSD (trauma controls) and healthy controls. Assessment of 1600 h plasma cortisol, ACTH and corticotrophin binding globulin (CBG) in response to dexamethasone in PTSD patients and trauma controls. RESULTS: Both PTSD patients and trauma controls demonstrated significantly more salivary cortisol suppression compared to healthy controls. Salivary cortisol, plasma cortisol and ACTH suppression as well as CBG levels did not differ between PTSD patients and trauma controls. PTSD patients showed a reduced awakening cortisol response (ACR) compared to healthy controls that correlated significantly with PTSD symptoms. No significant differences were observed in ACR between PTSD patients and trauma controls. CONCLUSIONS: These data suggest that enhanced cortisol suppression to dexamethasone is related to trauma exposure and not specifically to PTSD. The correlation between the ACR and PTSD severity suggests that a flattened ACR may be a result of clinical symptoms.     

Diagnostic heterogeneity and the DST in consecutive psychiatric admissions

There is uncertainty about the clinical usefulness of the dexamethasone suppression test (DST). It is also unclear whether there are advantages to a 1-mg or 2-mg DST. Eighty-three consecutive psychiatric inpatients were randomly given a 1-mg or 2-mg DST within the first week of admission. Sensitivity, specificity, and diagnostic confidence are reported for this group, and also in combination with those for 119 semi-consecutive psychiatric admissions. Although rates of nonsuppression were consistently higher in patients with affective disorders than in patients with other diagnoses, the diagnostic confidence of the DST for major depression in a diverse and unselected patient population was not greater than the prevalence of the disorder. The DST does not appear to be useful for clinical diagnostic decision-making. Nonetheless, the DST may still be an important biological marker in neuroendocrine psychiatric research.     

The effect of weight loss and inappropriate plasma dexamethasone levels on the DST

Recent studies from different research groups have raised fundamental questions about the postulated specificity of the dexamethasone suppression test (DST) for endogenous depression. Findings in 116 psychiatric inpatients and 24 semi-starved healthy volunteers underline the importance of weight loss as a factor affecting DST results. A study of 160 DSTs in 93 psychiatric inpatients further revealed a significant negative correlation of plasma cortisol and plasma dexamethasone levels 10 hours after oral administration of 1 mg of dexamethasone. These results suggest a decisive effect of the pharmacokinetics of dexamethasone, at least on the 1-mg DST.     

Salivary cortisol in women with and without perimenstrual mood changes

An increase in the activity of the hypothalamic–pituitary–adrenal axis (HPA axis) is frequently associated with major depression. During the premenstrual phase of their reproductive cycle some women experience depressive mood changes that are proposed to be of similar intensity to that experienced during periods of major depression. This study examined the secretion of cortisol, the end-product in the HPA axis, at different stages of the menstrual cycle in women with and without premenstrual depression. Women who experienced only mild physical and emotional changes in the premenstrual phase of their cycle had a significantly higher cortisol secretion on a premenstrual day (measured hourly) compared to a postmenstrual day. Those who were significantly more depressed premenstrually showed the opposite pattern of cortisol secretion with significantly lower levels on the premenstrual day compared with the postmenstrual day. Across the menstrual cycle, women who were significantly more depressed premenstrually also had lower evening cortisol levels in their premenstrual phase. The results of this study indicate that, unlike major depression where the underlying neurological changes are manifest as overactivity of the HPA axis, premenstrual depressive changes are associated with reduced HPA axis activity. Premenstrual depression may, therefore, be similar neurologically to seasonal affective disorder, which is associated with underactivity of the HPA axis.     

Low plasma tryptophan in carcinoid patients is associated with increased urinary cortisol excretion

BACKGROUND: Previously we observed in patients suffering from a metastatic carcinoid tumor that irritability, aggression and lack of impulse control are associated with low levels of plasma tryptophan and presumably with low brain serotonin function. In rats we showed that a diet of low tryptophan resulted in higher stress responses and higher corticosterone production. Here we tested in carcinoid patients whether tryptophan depletion due to tumor 5-HT overproduction is associated with high cortisol production. METHODS: Urinary excretion of cortisol, serotonin, 5-hydroxyindole acetic acid (the main metabolite of serotonin a marker of tumor activity), plasma levels of tryptophan and platelet content of serotonin (index of peripheral serotonin synthesis) were determined in metastatic midgut carcinoid patients. Patients (N=25) were divided into two groups based on their plasma tryptophan levels (/=49mumol/l, n=13). RESULTS: Carcinoid patients with low plasma tryptophan levels had significantly higher urinary excretion of free cortisol (p<0.01), independent of tumor activity. The inter-individual differences in the low tryptophan group, however, were substantial. CONCLUSIONS: In a subgroup of the patients suffering from metastatic carcinoid disease the cerebral access of plasma tryptophan is impaired, thus rendering cerebral serotonin neurotransmission suboptimal and leading to hypercortisolism. The present study provides further support to the idea that low serotonergic function is a risk for developing stress-associated psychopathology.     

Increased diurnal salivary cortisol in women with borderline personality disorder

Borderline personality disorder (BPD) is characterized by a pervasive pattern of instability in affect regulation, impulse control, interpersonal relationships, and self-image. In previous studies, we have used portable mini-computers to assess the severity of recurrent states of aversive emotional distress and dissociation during ambulatory conditions. Here, we used this approach for the assessment of the hypothalamic–pituitary–adrenal (HPA) axis in patients with BPD. We studied 23 unmedicated female patients with BPD and 24 matched healthy controls. Salivary cortisol was collected from all participants during ambulatory conditions in response to reminders provided by portable mini-computers on 3 consecutive days every 2 h for 14 h after awakening. In addition, cortisol in response to awakening was determined in four 15 min intervals on days 1 and 2. After the last collection of cortisol on the second day, 0.5 mg dexamethasone was administered in order to achieve cortisol suppression on day 3 (low-dose dexamethasone suppression test, DST). Patients with BPD displayed significantly higher salivary cortisol levels than healthy controls as demonstrated by higher total cortisol in response to awakening and higher total daily cortisol levels. There were significantly more non-suppressors of cortisol in the low-dose DST in the patient group when compared to the control group. The ambulatory assessment of saliva cortisol is a suitable approach to study basic parameters of the HPA-axis in patients with BPD. Increased adrenal activity and lowered feedback sensitivity of the HPA-axis may characterise BPD. Further studies have to reveal reasons of heightened adrenal activity in these patients.     

Nocturnal melatonin and cortisol secretion in newly admitted psychiatric inpatients

Summary Melatonin secretion has been suggested as a marker of both circadian and noradrenergic dysfunction in affective disorders. Seventy-two newly admitted psychiatric inpatients [49 with major depressive disorder (MDD), 12 with schizophrenia, and 11 with intermittent depressive disorder (IDD)] underwent neuroendocrine screening at 0200, 0800, 1600 and 2300 hours prior to and the day following dexamethasone administration. All groups showed a drop in cortisol following dexamethasone. Dexamethasone nonsuppression was found in 20 of 49 patients with MDD, in none of the schizophrenics and in none of those with intermittent depressive disorder. Mean melatonin levels decreased significantly after the administration of dexamethasone across all four groups. Overall, the schizophrenic group had a significantly greater mean melatonin level than each of other three groups, whereas the three depressive groups did not differ significantly from one another. Only at 2300 hours did both the schizophrenic group and the MDD patients with normal dexamethasone suppression show significantly greater melatonin levels than the MDD patients with dexamethasone nonsuppression or the IDD group. The observed trend for a low circadian melatonin profile in IDD patients with superimposed personality disorders is puzzling.