Dexamethasone suppression test and urinary MHPG X SO4 determination in depressive disorders

Epistatic interaction between CRHR1 and AVPR1b variants as a predictor of major depressive disorder

OBJECTIVE

Genes involved in the regulation of the hypothalamus-pituitary-adrenal axis are responsible for altered susceptibility to mood disorders. The aim of this study was to analyze the possible association of CRHR1 and AVPR1b gene variants with bipolar disorder and major depressive disorder (MDD).

METHODS

In the study, we included 486 patients with bipolar disorder and 215 patients with MDD. Consensus diagnosis was made according to Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria, using the Structured Clinical Interview for DSM Disorders. The control group consisted of 712 healthy participants. Genotyping of CRHR1 and AVPR1b polymorphisms was performed using TaqMan single nucleotide polymorphism genotyping assays. Linkage disequilibrium analysis was carried out on Haploview. Gene-gene interactions were analyzed using the multifactor dimensionality reduction method.

RESULTS

By single marker analysis we have found an association of rs28536160 of AVPR1b and rs4076452 and rs16940655 of CRHR1 with mood disorders (P=0.036, 0.0013, and 0.003, respectively). We observed strong linkage disequilibrium between seven CRHR1 polymorphisms grouped in two haplotype blocks; however, none of them showed an association with MDD or bipolar disorder. Similarly, no association was found for three of four strongly linked AVPR1b polymorphisms. Gene-gene interaction analysis revealed a significant epistatic interaction between AVPR1b and CRHR1 genes in susceptibility to MDD (P=0.017).

CONCLUSION

Polymorphisms of CRHR1 and AVPR1b may modify susceptibility to mood disorders.

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.

Antiglucocoticoid treatments for depression

OBJECTIVE

To selectively review the literature germane to antiglucocoticoid treatments for depression.

METHOD

Selective review of the relevant literature.

RESULTS

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has been well-described in both bipolar and unipolar depression. Hypercortisolaemia, possibly secondary to breakdown in glucocorticoid-receptor-mediated negative feedback mechanisms within the HPA axis, may be central to the pathogenesis of both depressive symptoms and the neurocognitive deficits which characterize these disorders. Strategies to counteract the effects of elevated cortisol, which may potentially restore HPA axis integrity, have been the focus of recent research.

CONCLUSIONS

Both preclinical and clinical studies report encouraging results which suggest that lowering circulating cortisol levels or blocking the effects of elevated cortisol with antagonists, which may up-regulate glucocorticoid receptors, has therapeutic benefits in terms of improvements in depressive symptoms and some domains of neurocognitive function.

Hypothalamic-pituitary-adrenal axis and bipolar disorder

There is robust evidence demonstrating abnormalities of the HPA axis in bipolar disorder. Hypercortisolism may be central to the pathogenesis of depressive symptoms and cognitive deficits, which may in turn result from neurocytotoxic effects of raised cortisol levels. Manic episodes may be preceded by increased ACTH and cortisol levels, leading to cognitive problems and functional impairments. Identification and effective treatment of mood and cognitive symptoms of mood disorders are clinical goals, but currently available treatments may fall short of this ideal. Manipulation of the HPA axis has been shown to have therapeutic effects in preclinical and clinical studies, and recent data suggest that direct antagonism of GRs maybe a future therapeutic strategy in the treatment of mood disorders.

Cortisol in mood disorders

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has been well-described in mood disorders. Hypercortisolaemia, which has been attributed to a breakdown in glucocorticoid-receptor-mediated negative feedback mechanisms within the HPA axis, may be central to the pathogenesis of both the depressive symptoms and the cognitive deficits, which characterise severe mood disorders. Strategies to normalise glucocorticoid receptor (GR) function, and thus restore HPA functional integrity, have been the focus of recent research. Preliminary preclinical and clinical studies report encouraging results which suggest that lowering circulating cortisol levels, by up-regulating GRs, may have therapeutic efficacy in terms of improvements in depressive symptoms and cognitive functioning.

Antidepressants differentially influence the transcriptional activity of the glucocorticoid receptor in vitro

Functional normalization of the hypothalamic-pituitary-adrenal axis in depressive patients by successful treatment with antidepressants is associated with increased efficiency of corticosteroid signal transduction. Accordingly, some antidepressants have been shown to influence the activity of the glucocorticoid receptor (GR) in cultured cells. It is not clear, however, whether this is a common principle for all antidepressants throughout all classes. Therefore, we screened a range of 18 antidepressants of different classes for their effect on GR signaling in a reporter gene assay using the mouse hippocampal cell line HT22. We evaluated GR-mediated gene transcription after short-time incubation (24 h) with different concentrations of each antidepressant (1 or 10 microM) in the presence or absence of the synthetic steroid dexamethasone (0.01 or 1 microM). The majority of antidepressants had a tendency to enhance steroid-induced GR-mediated gene transcription at high concentrations of antidepressant and low concentrations of steroid. Some antidepressants reduced the steroid-independent background activity of GR. This reduction was not due to unspecific inhibition of GR by oxidative stress, since no induction of intracellular peroxides was detectable in the concentration range of antidepressants used in our study. Furthermore, no significant change in GR activity was observed by concomitant treatment of HT22 cells with the antioxidant alpha-tocopherol (vitamin E). In conclusion, we report that many antidepressants enhance GR signaling in an in vitro neuronal system at clinically relevant concentrations. Those not showing an effect in vitro apparently use different mechanisms to influence GR activity that require an in vivo setting.

Emerging targets for the treatment of depressive disorder

New agents offering novel mechanisms of action are required in the treatment of depressive disorder. Established agents targeting monoamine systems are unsatisfactory because of full and partial treatment resistance, delay in the onset of their effect and the occurrence of side effects. The monoamine hypothesis of depression is now recognised to provide an incomplete explanation of the pathophysiology of depression. New theories have recently developed and new targets for treatment have emerged. We briefly review some important candidate systems and therapeutic targets in depression: the hypothalamic-pituitary-adrenal axis (HPA) and the glucocorticoid and corticotrophin-releasing factor receptors, synaptic plasticity and neurotrophins and the N-methyl-D-aspartate (NMDA) receptor. The putative role of the neuropeptides substance P and neuropeptide Y, the nicotinic system and the potential therapeutic benefits of cannabinoids are also reviewed. Vagal nerve stimulation (VNS) and transcranial magnetic stimulation, serendipitous advances in treatment, are discussed briefly.

Future therapeutic targets in mood disorders: the glucocorticoid receptor

BACKGROUND

The hypercortisolaemia and dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis associated with mood disorders have been attributed to a breakdown in the glucocorticoid-receptor-mediated negative feedback mechanism regulating HPA activity. Reinstating normal feedback may be therapeutic in mood disorders.

AIMS

To review the evidence for the involvement of the glucocorticoid receptor in the pathogenesis and treatment of mood disorders.

METHOD

Medline and hand searches were carried out, selecting literature relevant to psychiatrists and psychopharmacologists.

RESULTS

A dysfunction in glucocorticoid receptors is integral to the HPA abnormalities of mood disorders. Antidepressant and mood-stabilising drugs can up-regulate glucocorticoid receptors, restoring glucocorticoid function. Preliminary clinical studies targeting the glucocorticoid receptor are encouraging.

CONCLUSIONS

Drugs designed specifically to up-regulate glucocorticoid receptors may be integral to future strategies in treating mood disorders.

Clinical research on the therapeutic effect of the electro-acupuncture treatment in patients with depression

Electroacupuncture (EA) stimulation has been found to influence the brain (norepinephrine metabolism in experimental animals). Preliminary clinical research has shown that EA treatment is as effective as amitriptyline for patients with depression. In this study, two consecutive clinical studies on the treatment of depression with EA are conducted. The first study was double blind placebo controlled, in which 29 depressed inpatients were recruited. Patients were randomly divided into three groups: EA + placebo; amitriptyline; and EA + amitriptyline. They received EA and/or amitriptyline treatment for 6 weeks. The Hamilton Rating Scale for Depression, Clinical Global Impression and ASBERG scales for the side effect of antidepressants were used to evaluate the therapeutic efficacy and side effects. Based on the results and research protocol of the first study, a multi-centered collaborative study was conducted, in which 241 inpatients with depression were recruited. Patients were randomly divided into two treatment groups: the EA + placebo and the amitriptyline groups. The results from both studies showed that the therapeutic efficacy of EA was equal to that of amitriptyline for depressive disorders (P > 0.05). Electro-acupuncture had a better therapeutic effect for anxiety somatization and cognitive process disturbance of depressed patients than amitriptyline (P < 0.05). Moreover, the side effects of EA were much less than that of amitriptyline (P < 0.001). The article suggested that EA treatment was an effective therapeutic method for depressive disorders. Particularly, it was a treatment of choice for depressed patients who were unable to comply with the classic tricyclic antidepressants because of their anticholinergic side effects. The possible mechanism of EA treatment is discussed.

Coexisting dysregulations of both the sympathoadrenal system and hypothalamic-pituitary-adrenal-axis in melancholia

In order to delineate putatively coexisting dysregulations between sympathoadrenal system and hypothalamic-pituitary-adrenal (HPA)-axis during depression, the authors measured the following: the pre and postdexamethasone (1 mg) 24 hr urine excretion of noradrenaline, dopamine, adrenaline, 3-methoxy-4-hydroxyphenylglycol (MHPG), free cortisol (UFC), and plasma cortisol. Melancholic patients were characterized by a significantly higher excretion of noradrenaline, dopamine and adrenaline, combined with significantly increased UFC, postdexamethasone plasma cortisol, and UFC values. We found significant and positive correlations between UFC on the one hand, and the 24hr urine excretion of noradrenaline, dopamine, and adrenaline, on the other. By the same token, we established significant relationships between the 24 hr urine excretion of those catecholamines and the postdexamethasone UFC and plasma cortisol values. Cortisol nonsuppressors exhibited a significantly higher excretion of noradrenaline, dopamine and adrenaline, as compared with cortisol suppressors. Dexamethasone administration did not have a significant effect on the urinary output of noradrenaline, dopamine, adrenaline or MHPG.

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.

Positive relationship between the catecholaminergic turnover and the DST results in depression

In the past some workers have reported positive relationships between indices of noradrenaline activity and measures of hypothalamic-pituitary-adrenal (HPA)-axis function. In order to investigate these relations, the authors measured noradrenaline, adrenaline and vanillylmandelic acid (VMA) in 24 h urine samples of 72 depressed females. Serum adrenocorticotrophic hormone (ACTH) and cortisol concentrations were determined before and after administration of 1 mg of dexamethasone. Cortisol non-suppressors exhibited a significantly higher noradrenaline, adrenaline and VMA excretion as compared to cortisol suppressors. We determined significantly positive correlations between the postdexamethasone cortisol values and the excretion rates of noradrenaline and VMA. These indices of noradrenaline activity correlated neither with the baseline cortisol and ACTH nor with the postdexamethasone ACTH values.

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.

Influences on cortisol and noradrenergic turnover of healthy controls and depressed patients during L-tryptophan loading

To investigate the interrelationships between the noradrenergic and serotonergic systems and the hypothalamic-pituitary-adrenal (HPA) axis, we measured the excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) and free cortisol (UFC) in 24-h urine both before and after loading with 2 g L-tryptophan (L-TRP) orally in 24 healthy controls and 33 depressed patients categorized according to DSM-III. Loading with L-TRP reduced MHPG excretion significantly by 56% in major depressives, whereas in healthy controls and in minor depressives no significant effects were observed. Although basal MHPG did not differ among these study groups, loading with L-TRP resulted in MHPG excretion in major depressives being significantly lower than in healthy controls and minor depressives. Loading with L-TRP increased UFC significantly by 49% only in major depressives with associated features. After L-TRP those patients exhibited significantly increased UFC as compared with all other depressives and controls, whereas basal UFC values did not differ among the study groups. In baseline conditions there were no significant correlations between MHPG and UFC excretion.

Biogenic amines and their metabolites in body fluids of normal, psychiatric and neurological subjects

The biogenic monoamines and their metabolites have been isolated, identified and quantified in human body fluids over the past forty years using a wide variety of chromatographic separation and detection techniques. This review summarizes the results of those studies on normal, psychiatric and neurological subjects. Tables of normal values and the methods used to obtain them should prove to be useful as a reference source for benchmark amine and metabolite concentrations and for successful analytical procedures for their chromatographic separation, detection and quantification. Summaries of the often contradictory results of the application of these methods to psychiatric and neurological problems are presented and may assist in the assessment of the validity of the results of experiments in this field. Finally, the individual, environmental and the methodological factors affecting the concentrations of the amines and their metabolites are discussed.

Dexamethasone suppression test, schizophrenia and movement disorder

The dexamethasone suppression test (DST) was administered to 20 patients with schizophrenic illness. Ten of these patients also had tardive dyskinesia (TD). The scores on TD and parkinsonism scales were significantly higher in DST nonsuppressors. There was also a significant positive correlation between the post-dexamethasone cortisol level and the movement disorder scales.

The effect of diagnosis and age on the DST: a metaanalytic approach

The authors present new data on the results of the pretreatment Dexamethasone Suppression Test (DST) in 164 drug-free inpatients, as well as on the effects of age on postdexamethasone cortisol values. Nonsuppression rates were 18% in schizophrenic patients (n = 44), versus 46% in patients with a major depression (n = 56). In addition, a significant correlation was found between age and the 4:00 PM postdexamethasone cortisol value among the depressed patients (r = 0.33). The authors then applied a metaanalysis to summarize 25 other studies that have addressed the schizophrenia/major depression dichotomy as it relates to the DST outcome. Nonsuppression rates were consistently different in schizophrenic patients (19%) when compared to patients with a major depression (51%) or normal controls (7%). These differences were highly significant as measured by the Mantel-Haenszel chi-square statistic. A metaanalysis applied to a series of correlations obtained from 14 other studies reporting an age/postdexamethasone cortisol relationship in affective patients indicated a modest, but significant correlation (r = 0.24) in a total of 1284 patients (p less than 1 x 10(-8)).

Lack of correlation between DST results and urinary MHPG in depressed inpatients

Abnormalities of noradrenaline metabolism and of the activity of hypothalamic-pituitary adrenal axis (HPA) have been reported in depression. To study the possible relationship between these 2 parameters, urinary excretion of 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) and Dexamethasone Suppression Test (DST) were analyzed in 58 depressed patients. A positive correlation was found between the age of depressed patients and 24-h urinary excretion of MHPG. Twenty-two patients (38%) were DST non suppressors. Pre-DST plasma cortisol levels were significantly higher in non suppressors than suppressors. No difference was found however between urinary MHPG levels in suppressors and non suppressors. There was no correlation between pre-DST plasma cortisol and levels of urinary excretion of MHPG. These results do not support the hypothesis of a relationship between these 2 parameters. However, when depressed patients were separated into two groups according to urinary excretion of MHPG ("high MHPG" and "low MHPG"), the "high MHPG" group included significantly more non suppressors then the "low MHPG" one. This result is not sufficient to demonstrate of link between HPA system activity and central noradrenaline metabolism.