The dexamethasone suppression test in depression

HPA Axis in the Pathomechanism of Depression and Schizophrenia: New Therapeutic Strategies Based on Its Participation

The hypothalamic-pituitary-adrenal (HPA) axis is involved in the pathophysiology of many neuropsychiatric disorders. Increased HPA axis activity can be observed during chronic stress, which plays a key role in the pathophysiology of depression. Overactivity of the HPA axis occurs in major depressive disorder (MDD), leading to cognitive dysfunction and reduced mood. There is also a correlation between the HPA axis activation and gut microbiota, which has a significant impact on the development of MDD. It is believed that the gut microbiota can influence the HPA axis function through the activity of cytokines, prostaglandins, or bacterial antigens of various microbial species. The activity of the HPA axis in schizophrenia varies and depends mainly on the severity of the disease. This review summarizes the involvement of the HPA axis in the pathogenesis of neuropsychiatric disorders, focusing on major depression and schizophrenia, and highlights a possible correlation between these conditions. Although many effective antidepressants are available, a large proportion of patients do not respond to initial treatment. This review also discusses new therapeutic strategies that affect the HPA axis, such as glucocorticoid receptor (GR) antagonists, vasopressin V1B receptor antagonists and non-psychoactive CB1 receptor agonists in depression and/or schizophrenia.

The Neurocircuitry of Posttraumatic Stress Disorder and Major Depression: Insights Into Overlapping and Distinct Circuit Dysfunction-A Tribute to Ron Duman

The neurocircuitry that contributes to the pathophysiology of posttraumatic stress disorder and major depressive disorder, psychiatric conditions that exhibit a high degree of comorbidity, likely involves both overlapping and unique structural and functional changes within multiple limbic brain regions. In this review, we discuss neurobiological alterations that are associated with posttraumatic stress disorder and major depressive disorder and highlight both similarities and differences that may exist between these disorders to argue for the existence of a shared neurobiology. We highlight the key contributions based on preclinical studies, emerging from the late Professor Ronald Duman's research, that have shaped our understanding of the neurocircuitry that contributes to both the etiopathology and treatment of major depressive disorder and posttraumatic stress disorder.

A Load to Find Clinically Useful Biomarkers for Depression

Depression is heterogeneous and complex disease with diverse symptoms. Its neurobiological underpinning is still not completely understood. For now, there are still no validated, easy obtainable, clinically useful noninvasive biomarker(s) or biomarker panel that will be able to confirm a diagnosis of depression, its subtypes and improve diagnostic procedures. Future multimodal preclinical and clinical research that involves (epi)genetic, molecular, cellular, imaging, and other studies is necessary to advance our understanding of the role of monoamines, GABA, HPA axis, neurotrophins, metabolome, and glycome in the pathogenesis of depression and their potential as diagnostic, prognostic, and treatment response biomarkers. These studies should be focused to include the first-episode depression and antidepressant drug-naïve patients with large sample sizes to reduce variability in different biological and clinical parameters. At present, metabolomics study revealed with high precision that a neurometabolite panel consisting of plasma metabolite biomarkers (GABA, dopamine, tyramine, kynurenine) might represent clinically useful biomarkers of MDD.

The impact of chronic stress on energy metabolism

The brain is exceptionally demanding in terms of energy metabolism. Approximately 20% of the calories consumed are devoted to our cerebral faculties, with the lion's share provided in the form of glucose. The brain's stringent energy dependency requires a high degree of harmonization between the elements responsible for supplying- and metabolizing energetic substrates. However, chronic stress may jeopardize this homeostatic energy balance by disruption of critical metabolic processes. In agreement, stress-related mental disorders have been linked with perturbations in energy metabolism. Prominent stress-induced metabolic alterations include the actions of hormones, glucose uptake and mitochondrial adjustments. Importantly, fundamental stress-responsive metabolic adjustments in humans and animal models bear a striking resemblance. Here, an overview is provided of key findings, demonstrating the pervasive impact of chronic stress on energy metabolism. Furthermore, I argue that medications, aimed primarily at restoring metabolic homeostasis, may constitute a novel approach to treat mental disorders.

Clinical association to FKBP5 rs1360780 in patients with depression

The FKBP5 protein is of importance for the function of the glucocorticoid receptor. The purpose of the present study was to examine the possible association between the different genotypes of rs1360780 in the FKBP5 gene, and clinical symptoms in patients with unipolar depression. Seven hundred eighteen patients and 673 controls from the Danish Psychiatric Biobank were participated. No association was found between any genotype and diagnosis of unipolar depression. It was found that the group of depressed patients with the CC genotype showed significantly earlier start of treatment with medicine, had a significantly greater tendency to be treated with electroconvulsive therapy and showed a significantly higher frequency of family history of depression compared with the combined group of patients with the CT and TT genotypes. The only informations about controls were their sex and that they were recruited from the blood bank. The clinical data were not complete for all patients.

Cortisol and Major Depressive Disorder-Translating Findings From Humans to Animal Models and Back

Major depressive disorder (MDD) is a global problem for which current pharmacotherapies are not completely effective. Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has long been associated with MDD; however, the value of assessing cortisol as a biological benchmark of the pathophysiology or treatment of MDD is still debated. In this review, we critically evaluate the relationship between HPA axis dysfunction and cortisol level in relation to MDD subtype, stress, gender and treatment regime, as well as in rodent models. We find that an elevated cortisol response to stress is associated with acute and severe, but not mild or atypical, forms of MDD. Furthermore, the increased incidence of MDD in females is associated with greater cortisol response variability rather than higher baseline levels of cortisol. Despite almost all current MDD treatments influencing cortisol levels, we could find no convincing relationship between cortisol level and therapeutic response in either a clinical or preclinical setting. Thus, we argue that the absolute level of cortisol is unreliable for predicting the efficacy of antidepressant treatment. We propose that future preclinical models should reliably produce exaggerated HPA axis responses to acute or chronic stress a priori, which may, or may not, alter baseline cortisol levels, while also modelling the core symptoms of MDD that can be targeted for reversal. Combining genetic and environmental risk factors in such a model, together with the interrogation of the resultant molecular, cellular, and behavioral changes, promises a new mechanistic understanding of MDD and focused therapeutic strategies.

A randomised controlled study of risperidone and olanzapine for schizophrenic patients with neuroleptic-induced acute dystonia or parkinsonism

The objective of this study was to compare the effects of risperidone and olanzapine in schizophrenic patients with intolerant extrapyramidal side effects (EPS) on first generation antipsychotics. We conducted an 8-week, rater-blinded, flexible dose study. Seventy patients with schizophrenia, who met the DSM-IV research criteria of having neuroleptic-induced acute dystonia or parkinsonism, were randomly assigned to risperidone or olanzapine group. The primary outcome was a comparison of the incidence of concomitant anticholinergic drugs usage between the groups to manage their acute dystonia and parkinsonism. The average doses of risperidone and olanzapine from baseline to study end point were 1.8-3.5 mg/day and 7.7-11.7 mg/day, respectively. There were no significant differences in demographic data, severity of EPS or psychotic symptoms between the groups at baseline assessment. Patients taking risperidone had significantly higher incidence of using anticholinergic drugs to manage acute dystonia or parkinsonism overall during the study (OR = 5.17, 95%CI = 1.49-17.88, P = 0.013). There was no significant between-group difference in the changing of rating scales of EPS and psychotic symptoms. The results of our study favour olanzapine as a better choice in schizophrenic patients with intolerant EPS. Double-blinded, fixed dose and different ethnical study for EPS-intolerant schizophrenic patients is needed to confirm the results of our study.

A systematic review of hypothalamic-pituitary-adrenal axis function in schizophrenia: implications for mortality

There is convincing evidence that environmental stress plays a significant role in modifying both mental and physical health. The biological mechanisms linking stress to ill health are not fully understood, but significant evidence points to a central role of the stress axes; the hypothalamic- pituitary-adrenal (HPA) axis and the sympathetic nervous system. Together these two systems link the brain and the body and are crucial in maintaining homeostasis as well as improving an organism's survival chances in the face of environmental challenge. There is evidence of altered HPA axis function in people with a range of mental disorders, and this may in part explain the poor physical health of people with psychotic, mood and anxiety disorders. This paper systematically reviews HPA axis function in people with schizophrenia and relates this to the pattern of physical health seen in this disease. In summary, the evidence suggests people with schizophrenia can experience both hyper- and hypo-function of the HPA axis. It is likely that this contributes to the pattern of poor physical health and premature mortality suffered by people with schizophrenia, in particular the high rates of cardiovascular and metabolic disturbance.

Dexamethasone suppression test

A connection between a high level of plasma cortisol and psychopathology has long been observed. In depressive patients increased plasma cortisol and non-suppression to the dexamethasone suppression test (DST) has often been described. In this study it was found that endogenously depressed patients more often than non-endogenously depressed patients showed abnormal results to the DST. No difference was found in delta MAX TSH between suppressors and non-suppressors to the DST.

Neuroendocrine and sleep variables in major depressed inpatients: role of severity

To evaluate the reliability of the endogenous concept of depressive illness according to the Newcastle Endogenous Depression Diagnostic Index (NEDDI), 155 major depressive inpatients with NEDDI scores > or = 6 (endogenous) were matched for gender and age (+/- 5 years) to 155 major depressive inpatients with NEDDI scores < 6 (nonendogenous). When sleep polygraphic variables, neuroendocrine parameters (dexamethasone suppression and thyrotropin-releasing hormone tests), and various clinical variables (unipolar/bipolar status, psychotic/nonpsychotic subtype, and severity of the depressive episode) were examined, statistically significant differences between endogenous and nonendogenous patients emerged for three variables: the thyroid-stimulating hormone response to the thyrotropin-releasing hormone test, the dexamethasone suppression test response at 16:00 h, and the percentage of time awake during the night. However, when the effects of age and severity of depression were controlled, those differences disappeared.

Neuroendocrine tests in depressive stroke patients

1. In the present study 63 stroke patients and 23 control patients participated. The presence and degree of depression was defined by the Hamilton Rating Scale for Depression and the Research Diagnostic Criteria. 2. The TRH stimulation test was performed in all the patients. 3. No difference in Delta Max TSH was found between stroke patients and control patients. 4. No difference in Delta Max TSH was found between patients with the lesion in the right or left hemisphere. 5. No correlation was found between the frequency of blunted response to the TRH stimulation test and the presence of depression. 6. No difference in Delta Max TSH was found between suppressors and non-suppressors to the DST.

Biological correlates of the Newcastle Scale in depressive illness: a multivariate approach

Rapid eye movement latency (RL), delta max thyroid-stimulating hormone (dmTSH) and 1600 (DST16) and 2300 (DST23) post-dexamethasone cortisol values were determined in a group of 93 depressed patients who were assessed with the Newcastle Endogenous Depression Diagnostic Index (NEDDI). After the effects of age, gender and severity of illness were controlled for, stepwise multiple regression showed that depressive psychomotor activity and weight loss were the 2 NEDDI items most contributing to explain DST23 variance, as was depressive psychomotor activity for dmTSH variance. When the depressive sample was dichotomized according to the presence of these 2 items, the 2 groups had significantly different DST16, DST23, dmTSH and RL values. This suggests that weight loss, agitation and retardation could represent a core feature of a biologically mediated depressive subtype.

Dexamethasone suppression test in depressive stroke patients

Depressive psychiatric patients often shown non-suppression to the dexamethasone suppression test (DST). Stroke patients shows a high frequency of depression. In the present study the DST was studied in 76 stroke patients and 26 controls. No difference was found in frequency of non-suppression to the DST between depressive and non-depressive stroke patients. It was found that postdexamethasone plasma cortisol level at 08 a.m. was significantly higher in patient with the lesion in the right hemisphere compared to patients with the lesion in the left hemisphere.

Dexamethasone suppression test in schizophrenia: relationship to symptomatology, ventricular enlargement, and outcome

To relieve confusion about the clinical correlates and prognostic implications of the dexamethasone suppression test (DST) in schizophrenia, we conducted a DST in 44 schizophrenic inpatients at drug-free baseline and approximately 4 weeks after neuroleptic treatment. Patients were rated on positive, negative, and depressive symptoms at both times. A head computed tomography (CT) scan was performed and measures of ventricle-brain ratio (VBR) obtained. Clinical improvement was monitored at four weeks, and longer-term outcome assessed at 1 year. Seventeen of the 44 patients were DST nonsuppressors at baseline, and five of these remained nonsuppressors at 4 weeks posttreatment. Postdexamethasone plasma cortisol levels were correlated with negative symptoms at baseline (r = 0.45; p less than 0.01), but not after 4 weeks of neuroleptic treatment. Postdexamethasone plasma cortisols were not related to global severity, positive, or depressive symptoms at either timepoint or to VBR. Persistent nonsuppression was associated with poor outcome, but baseline postdexamethasone cortisol levels were unrelated to outcome at 4 weeks and 1 year. The literature on DST in schizophrenia is reviewed and attempts are made to reconcile discrepant findings and to discuss pathophysiological implications.

The incidence of abnormal dexamethasone suppression in schizophrenia: a review and a meta-analytic comparison with the incidence in normal controls

Studies on dexamethasone suppression test (DST) and schizophrenia are reviewed and the incidence of nonsuppression in the group of studies on schizophrenic patients is compared to that in the group of studies on normal controls from a previous review article. The incidence of nonsuppression in schizophrenic patients (26.4%) is significantly higher than that in normal controls (5.0%). There may be a subgroup of schizophrenic patients with an increase in cholinergic functioning. The variance of the nonsuppression rates of DST were also significantly higher in patients with schizophrenia compared to normal controls. This may be due to a heterogeneity of mechanisms that is responsible for the DST non-suppression due to the heterogeneous nature of the diagnosis of schizophrenia. The possible mechanisms of abnormal and varied DST results in schizophrenia are discussed.

Depression among patients with stroke

Ninety-two stroke patients and 30 control patients participated in this study. Stroke patients showed a higher frequency of depression than controls. Stroke patients with the lesion in the right hemisphere were more depressed than patients with the lesion in the left hemisphere. No correlation was found between the degree of depression and the degree of impaired physical function, degree of aphasia or volume of lesion.

Results of dexamethasone suppression test in early Alzheimer dementia

The frequency of an abnormal response to the Dexamethasone Suppression Test (DST) was examined in 24 non-depressed patients in the early stages of Alzheimer dementia. Results were compared with those obtained in 51 geriatric medical inpatients: 15 with major depression, 18 with dysthymic disorder and 18 normal controls. As an abnormal lack of suppression was found in 9 demented patients, in 9 with major depression, 1 with dysthymic disorder and in 2 the normal controls, it appears that DST alone is not useful in distinguishing dementia, even in its early stages, from major depression. In our experience abnormal DST results in demented patients were unrelated to mood.

Judgement of the hypothalamic-pituitary-adrenocortical function in psychiatric patients by betamethasone-induced cortisol suppressibility

Betamethasone induced cortisol suppressibility was examined in 62 drug free consecutively admitted psychiatric inpatients. Betamethasone was choosen instead of the commonly used dexamethasone, because its double half-life compared to dexamethasone and its higher tissue availability. After a base-line evaluation with blood samples drawn at 8 a.m., 4 p.m., and 11 p.m., 0.5 mg or 1.0 mg betamethasone was given orally at 11 p.m. Postbetamethasone cortisol as well as betamethasone blood levels were then measured at the same time points as on the baseline day. In the groups receiving 1.0 mg betamethasone non-depressed patients had significantly (p less than 0.05) lower postbetamethasone cortisol levels than depressed patients for each time point measured whereas 0.5 mg betamethasone did not differentiate depressed from non-depressed patients. Patients with other depressions like schizoaffective psychosis-depressive subtype- or organic brain syndrome with depressive symptomatology demonstrated similar postbetamethasone cortisol profiles as the group of patients with major depression. Betamethasone plasma concentrations differed significantly (p less than 0.001) with respect to the oral dosage with higher values for the 1.0 mg betamethasone groups.

The dexamethasone suppression test in depression. A World Health Organization Collaborative Study

The response to the dexamethasone suppression test (DST) was examined in 543 patients suffering from major depressive illness and 246 healthy controls, from 13 research centres, representing 12 different countries, in a World Health Organization Collaborative Study. In almost all the centres, the post-dexamethasone plasma cortisol concentration was significantly higher in the patients than in the controls. Although there is variation between centres, this abnormal response to the DST was shown to be frequent in patients from widely different geographical areas.

Dexamethasone bioavailability: implications for DST research

The bioavailability of dexamethasone (DEX) has recently been demonstrated to be a critical factor in determining Dexamethasone Suppression Test (DST) status in psychiatric patients. This brief review focuses on several aspects of DEX bioavailability as they relate to the use of the DST in neuroendocrine research. Several methodologies, including radioimmunoassay, high-performance liquid chromatography, and gas chromatography-mass spectrometry are available for quantification of DEX in biological fluids, although few detailed comparisons between methods have been reported. Surprisingly, little systematic research on the metabolism of DEX has been reported, but it appears that hepatic rather than renal mechanisms are the major source of DEX elimination. The marked variability in serum DEX levels following oral administration in psychiatric patients is also observed in normal controls and patients with Cushing's syndrome. A variety of drugs can modify serum DEX levels and thereby after the effectiveness of DEX in suppressing serum cortisol levels. Simultaneous measurement of serum DEX and cortisol levels appears to be necessary for the appropriate evaluation of DST results. This procedure may help explain many of the inconsistencies in recent DST research.

The dexamethasone suppression test in healthy controls

We have summarized the results of 53 studies which examined the dexamethasone suppression test in normal controls. Only 3.6% of 687 0800 hr postdexamethasone cortisol levels were above 5 micrograms/dl. Corresponding figures for 1600 hr and 2300 hr cortisol levels were 7.4% (85/1144) and 6.3% (28/434), respectively. Neither the type of assay (competitive protein binding or radioimmunoassay) nor mean/median age of the subjects was associated with non-suppression rates.

The dexamethasone suppression test in depressed and non-depressed geriatric medical inpatients

The frequency of an abnormal response to the dexamethasone suppression test (DST) was examined in 38 geriatric patients hospitalized for medical illnesses and affected by depressive disorders diagnosed according to the DSM III, and in 18 medical patients (used as controls) hospitalized in the same ward. Only 11% of the controls and 11% of those affected by dysthymic disorder had an abnormal DST vs 73% of the patients with major depressive disorder (MDD). The sensitivity of the DST for MDD, in this particular setting, was found to be about 73% and the specificity 89%. The importance of this clinical adjunct in diagnosing the severe depressive disorders is discussed.

The TRH stimulation test and the dexamethasone suppression test in depression

The thyrotropin-releasing hormone (TRH) stimulation test and the dexamethasone suppression test (DST) were performed in 40 depressive patients. More endogenously depressed patients than nonendogenously depressed patients showed a blunted response to TRH. No difference was found in delta max thyroid-stimulating hormone (TSH) between patients who responded to dexamethasone administration with a normal suppression of cortisol and those who responded with nonsuppression.

A comparison of DSM-III and ICD-8 diagnoses for major affective disorders and the use of biological markers for depression

The aims of the present study were to investigate the value of adding DSM-III diagnosis and Newcastle Scale Rating to the ICD-8 diagnosis currently used and to investigate the association between Dexamethasone Suppression Test (DST) and the Thyrotropine Releasing Hormone- Thyroid Stimulating Hormone (TRH-TSH) test and the three classification systems for depression. Twenty-six depressed in-patients were included, 17 women and 9 men, with a mean age of 51.5 years. Fourteen patients were psychotic depressed. DST and Newcastle Scale Rating were performed on 18 patients and TRH-TSH test was performed on 16 patients. The addition of DSM-III diagnosis on the 4-digit level did not have any value compared to the ICD-8 diagnosis. However, DSM-III diagnosis on the 5-digit level added important clinical information which corresponded better to Newcastle Scale scores and DST and TRH-TSH test results than ICD-8 diagnosis. The main advantage of the DSM-III classification of depression on the 5-digit level compared to ICD-8 concerns depression on the border between psychosis and neurosis. In clinical practice there is a risk of underestimating the severity of a depression if ICD-8/9 is used as the only criterion for severity. This may have tragic consequences for the patient. This study suggests that rating of the depression on the Newcastle Scale or provision of a DSM-III diagnosis on the 5-digit level are valuable assessment procedures of severity.