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

Neurobiological Underpinnings of Hyperarousal in Depression: A Comprehensive Review

Patients with major depressive disorder (MDD) exhibit an abnormal physiological arousal pattern known as hyperarousal, which may contribute to their depressive symptoms. However, the neurobiological mechanisms linking this abnormal arousal to depressive symptoms are not yet fully understood. In this review, we summarize the physiological and neural features of arousal, and review the literature indicating abnormal arousal in depressed patients. Evidence suggests that a hyperarousal state in depression is characterized by abnormalities in sleep behavior, physiological (e.g., heart rate, skin conductance, pupil diameter) and electroencephalography (EEG) features, and altered activity in subcortical (e.g., hypothalamus and locus coeruleus) and cortical regions. While recent studies highlight the importance of subcortical-cortical interactions in arousal, few have explored the relationship between subcortical-cortical interactions and hyperarousal in depressed patients. This gap limits our understanding of the neural mechanism through which hyperarousal affects depressive symptoms, which involves various cognitive processes and the cerebral cortex. Based on the current literature, we propose that the hyperconnectivity in the thalamocortical circuit may contribute to both the hyperarousal pattern and depressive symptoms. Future research should investigate the relationship between thalamocortical connections and abnormal arousal in depression, and explore its implications for non-invasive treatments for depression.

In major depression, increased kappa and mu opioid receptor levels are associated with immune activation

OBJECTIVE

This study was carried out to delineate differences between major depressive disorder (MDD) and healthy controls in dynorphin and kappa opioid receptor (KOR) levels in association with changes in the β-endorphin - mu opioid receptor (MOR) and immune-inflammatory system.

METHODS

The present study examines dynorphin, KOR, β-endorphin, MOR, interleukin (IL)-6 and IL-10 in 60 drug-free male participants with MDD and 30 age-matched healthy males.

RESULTS

Serum dynorphin, KOR, β-endorphin and MOR are significantly higher in MDD as compared to controls. The increases in the dynorphin/KOR system and β-endorphin/MOR system are significantly intercorrelated and are both strongly associated with increased IL-6 and IL-10 levels. Dynorphin, β-endorphin, KOR and both cytokines showed a good diagnostic performance for MDD versus controls with a bootstrapped (n = 2000) area under the receiver operating curve of 0.972. The dynorphin/KOR system is significantly decreased in depression with comorbid nicotine dependence.

CONCLUSION

Our findings suggest that, in MDD, immune activation is associated with a simultaneous activation of dynorphin/KOR and β-endorphin/MOR signaling and that these opioid systems may participate in the pathophysiology of depression by (a) exerting immune-regulatory activities attenuating the primary immune response and (b) modulating reward responses and mood as well as emotional and behavioural responses to stress.

CRF test in melancholic depressive patients with partial versus complete relapses: a 2-year follow-up study

BACKGROUND

Patients with depressive disorders present abnormalities in the hypothalamic pituitary adrenal (HPA) axis. The effects of a partial relapse with regard to HPA axis has not been studied so far.

AIM

To assess whether patients with partial relapse have a different neuroendocrine profile compared with those with complete relapse and with those without relapse over a 2-year follow-up.

METHODS

The adrenocorticotropin hormone (ACTH) and cortisol responses to corticotrophin releasing factor (CRF) stimulation was assessed in 62 outpatients diagnosed with unipolar depressive disorder with melancholic features according to DSM-IV. Twenty-three healthy controls were included in the study for comparison. Monthly follow-up visits were performed over a 2-year period after remission; partial and complete relapses were established using the Hamilton Depression Rating Scale (HDRS) and according to Frank's criteria. Fifty-four patients completed the study. A comparative statistical analysis was performed.

RESULTS

Stratifying the net area under cortisol curve (NAUCC) (µg/ml/min) at three levels-< 150, 150-350 and ≤ 350-significant differences appear between the three depressive groups of patients (non-relapsers, partial relapsers and complete relapsers). Particularly, there are more patients with a NAUCC ≤ 350 who show partial or complete relapses than patients with a NAUCC ≤ 350 who do not relapse (P ≤ 0.05).

CONCLUSIONS

Our results show an increasingly altered HPA axis in those depressive patients with complete or partial relapses compared with those who did not relapse or with healthy controls, but there are not differences in HPA axis between partial and complete relapsers.

Hormonal responses to the 5-HT1A agonist buspirone in remitted endogenous depressive patients after long-term imipramine treatment

INTRODUCTION

The serotonin-1A (5-HT1A) receptor subtypes are considered as targets of a variety of antidepressant drugs. Previous studies have suggested different adaptive changes in pre- and post-synaptic 5-HT receptors in the brain after treatment with non-selective tricyclic antidepressants (TCA) and selective 5-HT re-uptake inhibitors (SSRIs). The present study aimed to investigate the adaptive effect of the TCA imipramine on the post-synaptic 5-HT1A receptor function in the hypothalamus.

METHODS

A longitudinal design was used in 14 patients with major depressive disorder (DSM-IV) with endogenous features (Newcastle Scale) in order to assess the functional status of post-synaptic 5-HT1A receptors before and after successful antidepressant treatment with imipramine. The effect of the 5-HT1A receptor agonist, buspirone, on ACTH, cortisol, and prolactine (PRL) plasma levels was used to assess the functional status of hypothalamic 5-HT1A receptors. A group of 15 concurrent normal subjects were used as control.

RESULTS

Endogenous depressed patients in remission and currently receiving treatment with imipramine (mean length of treatment 145 days, SD=27) presented significantly lower buspirone responses to ACTH and cortisol than in the pre-treatment condition (Deltamax p< or =.05; AUC p<.001) and to ACTH in comparison with healthy controls (Deltamax p<.01; AUC p<.05). No significant differences were found between the post-treatment and pre-treatment PRL responses, or between patients in both conditions and controls; nevertheless, the PRL response in patients in remission and receiving treatment almost reached the values seen in controls.

CONCLUSIONS

This study extends previous findings from our group using the SSRI citalopram as an antidepressant. Imipramine and citalopram induce similar changes in the endocrine response to buspirone in depressed patients. As the direction of change in ACTH-cortisol and PRL responses after treatment is the opposite, we cannot substantiate increases or decreases in the sensitivity of post-synaptic 5-HT1A receptors in the hypothalamus by long-term imipramine treatment and/or resolution of illness. Therefore, the hormonal changes may result from different or multiples unknown mechanisms.

Prediction of relapse in melancholic depressive patients in a 2-year follow-up study with corticotropin releasing factor test

PURPOSE

To study the power of CRF stimulation test to predict relapse in a sample of melancholic depressive patients in depressed phase, followed-up over a two-year period from the moment they achieved complete remission of depressive symptoms.

METHODS

Fifty-one outpatients diagnosed with unipolar depressive disorder with melancholic features according to DSM-IV were assessed with the CRF test. The Structured Clinical Interview for DSM-IV (SCID-IV) was used for diagnosis. Monthly follow-up visits were held over a two-year period after remission; relapse was established using HDRS according to Frank's criteria [Frank E, Prien RF, Jarret RB, Keller MB, Kupfer DJ, Lavori PW, et al. Conceptualization and rationale for consensus definitions of terms in major depressive disorder: remission, recovery, relapse, and recurrence. Arch Gen Psychiatry 1991;48:851-5]. Forty-three patients completed the study. Non-controlled antidepressant treatment protocols were used. Predictive statistical analysis was performed through logistic regression.

FINDINGS

The final predictive model included three variables: net area under cortisol curve (NAUCC), previous suicide attempt, and stress during follow-up. Sensitivity was of 89%, and specificity was of 92%. NAUCC has shown a predictive power of 80%, with an optimal cut-off point of 251.24 microg/ml/min.

CONCLUSIONS

Cortisol is the hormone of the HPA axis which shows the highest power to predict relapse. NAUCC is the most relevant variable. The complete predictive model is a complex combination of biological, clinical and psychoenvironmental variables (NAUCC, previous suicide attempts, and stress during follow-up). Further studies with better control of the psychoenvironmental variables are required to obtain more precise neuroendocrine findings.

Corticotropin-releasing factor test in melancholic patients in depressed state versus recovery: a comparative study

PURPOSE

Basal adrenocorticotropin hormone (ACTH) and cortisol levels and their response to corticotropin-releasing factor (CRF) test were studied in melancholic depressive patients in depressed state and recovery, and compared with healthy controls.

METHODS

Fifty-four outpatients diagnosed with unipolar depressive disorder with melancholic features according to DSM-IV and 23 healthy controls were included in the study. The Structured Clinical Interview for DSM-IV (SCID-IV) was used for diagnosis. Twenty-nine patients were in recovery, while 25 were in depressed state at the moment of the administration of the CRF test.

FINDINGS

No differences were found between the recovered and depressed groups with respect to CRF test. Lower ACTH and higher cortisol levels with significant differences were shown in the neuroendocrine variables at 15, 30, and 60 min, and in peak response and increase, in the ACTH and cortisol response curves to CRF challenge between the groups of melancholic patients, both recovered and depressed, compared with the healthy control subjects. Moreover, recovered and depressed melancholic patients had a higher whole cortisol area under the curve with significant differences than the healthy control subjects.

CONCLUSIONS

The crossover clinical status at the moment of the CRF test doesn't differentiate changes in the HPA axis in melancholic patients, while we did find significant differences in the group of healthy controls in comparison with the groups of melancholic patients both in depressive state and recovery. This supports the hypothesis that hypothalamic pituitary adrenal (HPA) axis shows alterations that remain in depressive patients even after recovery.

Increased 24-hour urinary cortisol excretion in patients with post-traumatic stress disorder and patients with major depression, but not in patients with fibromyalgia

There is now firm evidence that major depression is accompanied by increased baseline activity of the hypothalamic-pituitary-adrenal (HPA) axis, as assessed by means of 24-h urinary cortisol (UC) excretion. Recently, there were some reports that fibromyalgia and post-traumatic stress disorder (PTSD), two disorders which show a significant amplitude of depressive symptoms, are associated with changes in the baseline activity of the HPA axis, such as low 24-h UC excretion. The aim of the present study was to examine 24-h UC excretion in fibromyalgia and PTSD patients compared to normal controls and patients with major depression. In the three patient groups, severity of depressive symptoms was measured by means of the Hamilton Depression Rating Scale (HDRS) score. Severity of fibromyalgia was measured using a dolorimetrically obtained myalgic score, and severity of PTSD was assessed by means of factor analytical scores computed on the items of the Composite International Diagnostic Interview (CIDI), PTSD Module. Patients with PTSD and major depression had significantly higher 24-h UC excretion than normal controls and fibromyalgia patients. At a threshold value of > or = 240 micrograms/24 h, 80% of PTSD patients and 80% of depressed patients had increased 24 h UC excretion with a specificity of 100%. There were no significant differences in 24-h UC excretion either between fibromyalgia patients and normal controls, or between patients with major depression and PTSD patients. In the three patient groups, no significant correlations were found between 24-h UC excretion and the HDRS score. In fibromyalgia, no significant correlations were found between 24-h UC excretion and the myalgic score. In PTSD, no significant correlations were found between 24-h UC excretion and severity of either depression-avoidance or anxiety-arousal symptoms. In conclusion, this study found increased 24-h UC excretion in patients with PTSD comparable to that in patients with major depression, whereas in fibromyalgia no significant changes in 24-h UC were found.

Lower serum transcortin (CBG) in major depressed females: relationships with baseline and postdexamethasone cortisol values

This study has been carried out to examine (i) transcortin or corticosteroid binding globulin (CBG), the major glucocorticoid transport protein, in major depressed versus minor depressed and normal subjects; and (ii) the relationships between CBG and basal and postdexamethasone cortisol or adrenocorticotropic hormone (ACTH) values. Serum CBG was significantly lower in major depressed than in minor depressed subjects and normal controls. The significant decrease in serum CBG was observed in major depressed women but not in major depressed men. In depressed subjects, there was a significant and negative relationship between serum CBG and severity of illness. There were significant positive relationships between serum CBG and basal 8:00 a.m. plasma cortisol in normal volunteers (r = 0.87, P < 10(-4)) and depressed subjects (r = 0.40, P = 0.0002). There was no significant relationship between serum CBG and 24-h urinary cortisol. In depressed patients, there was a positive relationship between serum CBG and postdexamethasone cortisol (r = 0.31, P = 0.003). It is concluded that, in depression, serum CBG levels should be taken into consideration for the interpretation of baseline and postdexamethasone plasma total cortisol levels.

Corticotropin-releasing hormone challenge in prepubertal major depression

This study investigates cortisol and ACTH (corticotropin) responses to an infusion of human CRH (corticotropin-releasing hormone) in prepubertal children with major depressive disorder (MDD). Following a period of 24 hours of adaptation to the laboratory environment with an intravenous catheter in place, 34 children with MDD and 22 healthy controls received 1 microgram/kg of human CRH at 5:00 PM. Blood samples for cortisol and ACTH were measured at baseline and post-CRH. Overall, there were no significant differences between the MDD and the normal controls in baseline or post CRH stimulation values of either cortisol or ACTH. Melancholic (n = 4) patients had significantly higher baseline cortisol levels than nonmelancholic (n = 24) patients. Compared with the outpatients and the nonmelancholics, the inpatients (n = 10) and the melancholics showed significantly lower total ACTH secretion (effect size: 0.9 and 1.4, respectively) after CRH infusion. These results are consistent with a broad literature suggesting that the HPA axis abnormalities occur less frequently in early-onset depression than reported in adult studies. The pattern of results in the subgroups of inpatients and in melancholic children, however, raise questions about possible continuities with adult studies.

Enhanced adrenal sensitivity to adrenocorticotrophic hormone (ACTH) is evidence of HPA axis hyperactivity in Alzheimer's disease

Adrenal sensitivity was assessed in 16 non-depressed patients with NINCDS/ADRDA Alzheimer's disease (AD) and 18 control subjects by measuring cortisol response to low dose (0.05 microgram/kg i.v.) exogenous adrenocorticotrophic hormone (ACTH). Controlling for sex and medication, both peak cortisol level (peak-baseline) and area under cortisol response curve (AUC above baseline) were significantly greater in AD subjects. This shows that HPA axis hyperactivity, as demonstrated by enhanced adrenal sensitivity to ACTH, occurs in AD. Similar findings have been reported to occur in depression. Among AD subjects, AUC cortisol response correlated with current age (r = 0.70, P = 0.001) and age at onset of dementia (r = 0.73, P = 0.001) and an inverse correlation was seen between cortisol AUC and cognitive test (CAMCOG) score (r = -0.51, P = 0.044). Our findings suggest that HPA axis hyperactivity in AD is associated with advancing age and cognitive dysfunction. Such changes may be cause, or consequence, of neuronal loss.

An augmented escape of androstenedione from suppression by dexamethasone in melancholia: relationships to intact ACTH and cortisol nonsuppression

To further examine the association between basal and postdexamethasone (DST) pituitary and adrenal activity in depression, the authors measured intact adrenocorticotropic hormone (ACTH), androstenedione and cortisol, both in baseline and post-DST conditions, in 63 depressed subjects (14 minor, 33 simple major and 16 melancholic subjects). It was found that post-DST androstenedione, cortisol and ACTH values were significantly higher in melancholic than in minor depressed subjects. There were highly significant correlations between plasma androstenedione and ACTH both in baseline and post-DST conditions. The significant intercategory differences in post-DST androstenedione were determined by differences in post-DST ACTH. Basal and post-DST androstenedione values were significantly higher in men than in women and both values were significantly and negatively related to age. There were highly significant, positive relationships between cortisol and ACTH and between cortisol and androstenedione both in baseline and post-DST conditions. The results corroborate our hypotheses that, in depression, pituitary (ACTH) and adrenal (cortisol and androstenedione) hormonal secretion are tightly coupled in post-DST conditions and that the augmented escape of ACTH-target hormones in melancholia is, in part, related to that of pituitary ACTH.

Adrenocorticotropic hormone, beta-endorphin and cortisol responses to oCRH in unipolar depressed patients pretreated with dexamethasone

1. Corticotropin-releasing hormone (ovine CRH, 100 micrograms intravenous bolus) was given to 63 unipolar depressed inpatients following the 1 mg overnight dexamethasone suppression test (DST). The depressed patients included 18 minor, 24 simple major and 21 melancholic subtypes. 2. Baseline or postdexamethasone plasma levels of intact adrenocorticotropic hormone (ACTH), beta-endorphin/beta-lipotropin (beta END/beta LPH), cortisol, and dexamethasone were measured, as well as the post DST+CRH hormone responses. 3. CRH administration 9.5 hr after dexamethasone resulted in a significant enhancement of ACTH, beta END/beta LPH and cortisol secretion. The post DST+CRH ACTH and beta END/beta LPH- but not cortisol-values exceeded their baseline hormone levels. The post DST+CRH ACTH--but not beta END/beta LPH or cortisol-levels were significantly higher in major depressives compared to minor depressives. The post DST+CRH ACTH and beta END/beta LPH--but not cortisol-levels were significantly higher in DST nonsuppressors than suppressors. The post DST+CRH ACTH levels were significantly and positively related to severity of illness. 4. The results provide evidence that the pathophysiology underlying the abnormal DST+CRH and DST tests in melancholia is localized at the pituitary level and may consist of a CRH-driven breakthrough of corticotropic cell secretion synergized by central and peripheral agents, in conjunction with a decrease in glucocorticoid feedback suppressibility.

The function of the hypothalamic-pituitary-adrenal axis in Alzheimer's disease. Response to insulin hypoglycaemia

BACKGROUND

To investigate an association between HPA axis dysfunction, depression and cognitive impairment, we assessed subjects with mild Alzheimer's disease (AD).

METHOD

Sixteen non-depressed subjects with AD according to NINCDS/ADRDA criteria and 18 normal controls underwent the insulin hypoglycaemia (IH) test and the dexamethasone suppression test (DST).

RESULTS

The AD subjects showed a blunted response of adrenocorticotrophic hormone (ACTH) to IH compared with controls (P = 0.019). ACTH response (area under curve) correlated with a score for cognitive ability (CAMCOG) (r = 0.64, P < 0.01). AD subjects had a shorter time to peak cortisol level than controls (P = 0.004), although total cortisol response was normal.

CONCLUSIONS

The AD subjects show evidence of adrenal hyper-responsiveness and normal immediate (rate-sensitive) glucocorticoid feedback. An association between HPA axis dysfunction and organic brain pathology in AD subjects may be mediated by cell loss in the hippocampus.

The elevation of plasma beta-endorphin levels in major depression

Day-time plasma beta-endorphin/beta-lipotrophic hormone (beta-ENDO/beta-LPH), ACTH and cortisol have been determined in 26 patients with major depression and 25 controls. beta-ENDO/beta-LPH and cortisol were significantly elevated in patients, while ACTH was not. Cortisol levels were significantly negatively correlated with age in controls as were beta-ENDO/beta-LPH and ACTH. In patients, by contrast, cortisol levels were positively, albeit not significantly, related to age. Peptide levels were not related to age in the patient group. Instead, beta-ENDO/beta-LPH was negatively correlated with clinical ratings of symptom severity in patients and positively associated with an acute psychosocial precipitant. The findings cast further light on beta-ENDO/beta-LPH as a measure of hypothalamic-pituitary over activity in depressive illness. A negative association with symptom severity suggests that beta-ENDO/beta-LPH responses are, like those of ACTH, down-regulated in the course of depressive illness.

Endogenous opiates: 1992

This paper is the fifteenth installment of our annual review of research concerning the opiate system. It includes papers published during 1992 involving the behavioral, non-analgesic, effects of the endogenous opiate peptides. The specific topics this year include stress; tolerance and dependence; eating; drinking; gastrointestinal and renal function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunological responses; and other behaviors.

Pituitary and adrenal hormone responsiveness to Synacthen in melancholic subjects versus subjects with minor depression

Increased adrenal cortex responsiveness to adrenocorticotropic hormone (ACTH) has been suggested to contribute to increased cortisol secretion in dexamethasone nonsuppression and melancholia. To further examine this hypothesis, the following variables were examined in 68 patients with unipolar depression (minor, n = 24; simple major, n = 25; melancholic, n = 19): basal or post-Synacthen [ACTH(1-24), 250 micrograms IV] intact ACTH(1-39), beta-endorphin/beta-lipotropin, cortisol, and androstenedione concentrations, as well as the postdexamethasone (DST) plasma ACTH(1-39) and cortisol values. Melancholic subjects showed significantly higher baseline ACTH(1-39), beta-endorphin/beta-lipotropin, and androstenedione values compared with subjects with minor depression. No significant differences in post-Synacthen cortisol or androstenedione secretion between any of the groups or between [ACTH(1-39) or cortisol] DST nonsuppressors and suppressors were found. No significant relationships between DST and ACTH test results were observed. Abnormally increased post-DST cortisol values in melancholic subjects were highly predicted (> 68% of the variance) by post-DST intact ACTH levels. ACTH(1-39) values were significantly lower after Synacthen administration in melancholic subjects than in subjects with minor depression. These results are not consistent with the hypothesis that melancholia is characterized by an increased adrenocortical responsivity to exogenous ACTH compared with minor depression or that DST nonsuppression is due to adrenal hyperresponsiveness.