Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Macrophages produced proinflammatory cytokines and inflammatory responses can cause many symptoms of depression, including direct stimulation of the HPA axis and secretion of cortisol. In depressed patients, hypercortisolism has been well described as one of the major symptoms and also as the cause for hippocampal atrophy and memory impairment. In this paper, the relationships between thymectomy, increased IL-1 levels, and changes in corticosterone and neurotransmitter concentrations in rats are discussed, as well as their implications for memory impairments and depression. In thymectomized rats, deficits in both spatial and fear conditioned memory have been observed. Thymectomy decreases noradrenaline and dopamine levels, and increases serotonergic neurotransmission in limbic areas, without affecting corticosterone concentrations. In a depression model, thymopeptides or IL-2 treatment significantly attenuated changes in behavior, lymphocyte proliferation and neurotransmitters caused by bulbectomy. The reduction of thymic functions may increase IL-1 synthesis. Central IL-1beta administration impairs rat's spatial memory in the Morris water maze and 8 arms radial maze, but enhances conditioned memory in the passive avoidance. These changes can be reversed by either IL-1 receptor antagonist or a glucocorticoid receptor antagonist (RU 486). Furthermore, IL-1-induced changes in some neurotransmitter systems are similar to those observed in thymectomized rats. However, both acute and sub-chronic IL-1 administration increases plasma corticosterone concentrations. Together, these findings suggest that changes in the function of the thymus gland may play an important role in the unbalance between macrophages, cytokines, and lymphocytes, which induces neurotransmitter and neuroendocrine changes, and memory disturbances in depressive illness.
 ...
PMID:The effect of thymectomy and IL-1 on memory: implications for the relationship between immunity and depression. 1240 69

Major depression with melancholia is associated with hypercortisolaemia. Loss of the early-phase of negative feedback - acute suppression of ACTH in response to rising cortisol levels - is the subject of conflicting reports in patients with major depression. Using a within-subjects design, six patients with DSM-IIIR melancholic depression received a 60 min infusion of hydrocortisone at 0900 with measurement of ACTH and cortisol before and after 4 weeks of antidepressant treatment. All patients responded clinically. ACTH responses (early feedback) did not differ between test conditions. Baseline cortisol fell significantly following treatment response. This provides further evidence for the preservation of the acute phase of negative feedback, even in the presence of hypercortisolism. Copyright 2000 John Wiley & Sons, Ltd.
 ...
PMID:Hypothalamic-pituitary-adrenal axis early-feedback responses are preserved in melancholic depression: a study of sertraline treatment. 1240 13

Many patients with major depression show evidence of over-activation of the hypothalamic - pituitary - adrenal axis (HPA), as evidenced by hypercortisolism and adrenal hyperplasia. Such over-activity is associated with increased corticotropin releasing factor (CRF) reactivity in the CSF and blunted release of ACTH in response to CRF infusion. Recent evidence suggests a switch from CRF to AVP regulation of the axis during depression, with depressed patients showing enhanced response to ddAVP infusion. The HPA provides multiple potential sites for antidepressant development. The use of glucocorticoid antagonists, cortisol synthesis inhibitors, CRF and AVP antagonists have been suggested. Copyright 2001 John Wiley & Sons, Ltd.
 ...
PMID:Novel approaches to the treatment of depression by modulating the hypothalamic - pituitary - adrenal axis. 1240 3

Unlike other antidepressants, mirtazapine does not inhibit the reuptake of norepinephrine or serotonin but acts as an antagonist at presynaptic alpha(2)-receptors, at postsynaptic 5-HT2 and 5-HT3 receptors, and at histaminergic H1 receptors. Furthermore, mirtazapine has been shown to acutely inhibit cortisol secretion in healthy subjects. In the present study, the impact of mirtazapine treatment on salivary cortisol secretion was investigated in 12 patients (4 men, 8 women) suffering from major depression according to DSM-IV criteria. Patients were treated with mirtazapine for 3 weeks, receiving 15 mg mirtazapine on day 0, 30 mg on day 1 and 45 mg per day from day 2 up to the end of the study (day 21). Response to mirtazapine treatment was defined by a reduction of at least 50% in the Hamilton Rating Scale for Depression after 3 weeks of therapy. Salivary cortisol concentrations were measured before treatment (day -1), at the beginning of treatment (day 0), after 1 week (day 7) and after 3 weeks (day 21) of treatment with mirtazapine. Saliva samples were collected hourly from 08.00 until 20.00 h. The area under the curve values served as parameter for the salivary cortisol secretion. Following analysis of variance with a repeated measures design, tests with contrasts revealed a significant reduction of cortisol concentrations already after 1 day of mirtazapine treatment that was comparable in responders and nonresponders. In addition to new pharmacological approaches such as CRH1 receptor antagonists, mirtazapine therefore appears to be an effective strategy to decrease hypercortisolism and restore HPA system dysregulation in depression. However, the importance of the acute inhibitory effects of mirtazapine on cortisol secretion for its antidepressant efficacy has to be further clarified.
 ...
PMID:Influence of mirtazapine on salivary cortisol in depressed patients. 1260 43

A consistent finding in biological psychiatry is that hypothalamic-pituitary-adrenal (HPA) axis physiology is altered in humans with major depression. These findings include hypersecretion of cortisol at baseline and on the dexamethasone suppression test. In this review, we present a process-oriented model for HPA axis regulation in major depression. Specifically, we suggest that acute depressions are characterized by hypersecretion of hypothalamic corticotropin-releasing factor, pituitary adrenocorticotropic hormone (ACTH), and adrenal cortisol. In chronic depressions, however, enhanced adrenal responsiveness to ACTH and glucocorticoid negative feedback work in complementary fashion so that cortisol levels remain elevated while ACTH levels are reduced. In considering the evidence for hypercortisolism in humans, studies of nonhuman primates are presented and their utility and limitations as comparative models of human depression are discussed.
 ...
PMID:Neuroendocrine aspects of hypercortisolism in major depression. 1261 35

Stress activates the central and peripheral components of the stress system, i.e., the hypothalamic-pituitary-adrenal (HPA) axis and the arousal/sympathetic system. The principal effectors of the stress system are corticotropin-releasing hormone (CRH), arginine vasopressin, the proopiomelanocortin-derived peptides alpha-melanocyte-stimulating hormone and beta-endorphin, the glucocorticoids, and the catecholamines norepinephrine and epinephrine. Appropriate responsiveness of the stress system to stressors is a crucial prerequisite for a sense of well-being, adequate performance of tasks and positive social interactions. By contrast, inappropriate responsiveness of the stress system may impair growth and development, and may account for a number of endocrine, metabolic, autoimmune and psychiatric disorders. The development and severity of these conditions primarily depend on the genetic vulnerability of the individual, the exposure to adverse environmental factors and the timing of the stressful event(s), given that prenatal life, infancy, childhood and adolescence are critical periods characterized by increased vulnerability to stressors. The developing brain undergoes rapid growth and is characterized by high turnover of neuronal connections during the prenatal and early postnatal life. These processes and, hence, brain plasticity, slow down during childhood and puberty, and plateau in young adulthood. Hormonal actions in early life, and to a much lesser extent later, can be organizational, i.e., can have effects that last for long periods of time, often for the entire life of the individual. Hormones of the stress system and sex steroids have such effects, which influence the behavior and certain physiologic functions of individuals for life. Exposure of the developing brain to severe and/or prolonged stress may result in hyperactivity/hyperreactivity of the stress system, with resultant amygdala hyperfunction (fear reaction), decreased activity of the hippocampus (defective glucocorticoid-negative feedback, cognition), and the mesocorticolimbic dopaminergic system (dysthymia, novelty-seeking, addictive behaviors), hyperactivation of the HPA axis (hypercortisolism), suppression of reproductive, growth, thyroid and immune functions, and changes in pain perception. These changes may be accompanied by abnormal childhood, adolescent and adult behaviors, including excessive fear ('inhibited child syndrome') and addictive behaviors, dysthymia and/or depression, and gradual development of components of the metabolic syndrome X, including visceral obesity and essential hypertension. Prenatal stress exerted during the period of sexual differentiation may be accompanied by impairment of this process with behavioral and/or somatic sequelae. The vulnerability of individuals to develop varying degrees and/or components of the above life-long syndrome is defined by as yet unidentified genetic factors, which account for up to 60% of the variance. CRH has marked kindling and glucocorticoids have strong consolidating properties, hence both of these hormones are crucial in development and can alone produce the above syndrome. CRH and glucocorticoids may act in synergy, as in acoustic startle, while glucocorticoids may suppress or stimulate CRH, as in the hypothalamus and amygdala, respectively. A CRH type 1 receptor antagonist, antalarmin, inhibits both the development and expression of conditioned fear in rats, and has anxiolytic properties in monkeys. Profound stressors, such as those from sexual abuse, may elicit the syndrome in older children, adolescents and adults. Most frequently, chronic dysthymia and/or depression may develop in association with gastrointestinal complaints and/or the premenstrual tension syndrome. A lesser proportion of individuals may develop the classic posttraumatic stress disorder, which is characterized by hypocortisolism and intrusive and avoidance symptoms; in younger individuals it may present as dissociative personality disorder.
 ...
PMID:Pediatric stress: hormonal mediators and human development. 1264 70

The clinical correlate of chronic hypercortisolism is Cushing's syndrome (CS). After exclusion of an iatrogenic cause (glucocorticoid administration), two reliable laboratory methods for establishing the diagnosis are (i) measurement of "free" (unmetabolised) cortisol in a 24-hour urine (UFC) sample and (ii) the low-dose (1 or 1.5 mg) dexamethasone (Dex) test. For the latter, Dex is taken orally at midnight, and plasma cortisol is measured at 8 a.m. In normals and in the absence of CS, the morning cortisol (200-650 nmol/L) is suppressed to <80 nmol/L. In endogenous CS of all causes, cortisol suppression by Dex is absent or incomplete. In patients with severe mental depression or stress, suppression may also be incomplete ("false-positives"). However, UFC is normal or only slight increased in the latter group, while it is always markedly increased in clinically apparent CS. In CS, UFC rises proportionally more than plasma cortisol because the cortisol binding plasma protein (transcortin) can bind only about 500 nmol/L cortisol. Protein-bound cortisol is not excreted by the kidney. After establishing the diagnosis CS, the differentiation between its pituitary (ca. 70%), adrenocortical (ca. 20%) or "ectopic" (ACTH production by non-pituitary tumours) (ca. 10%) origin is made by plasma ACTH measurement, a corticotropin releasing hormone injection test (with plasma ACTH/cortisol measurement) and a high-dose Dex (8 mg or more) suppression test. Chronic hypocorticolism can be primary (adrenal disease, Addison's disease) or secondary (pituitary or hypothalamic disorder). UFC measurement is not an established method for confirming hypocortisolism because most analytical methods are too unspecific and insensitive in the subnormal range. Low-normal or subnormal plasma cortisol plus elevated ACTH is the hallmark of Addison's disease. Injection of high doses of ACTH does not lead to a rise in plasma cortisol in these patients. A clearly subnormal cortisol plus low ACTH proves secondary hypocortisolism. Mild forms with low-normal plasma cortisol, however, are more difficult to prove. So-called "dynamic" tests stimulating the whole hypothalamo-pituitary-adrenal axis (insulin hypoglycemia test or metyrapone test) are necessary to confirm the diagnosis. Patients with hypocortisolism, depending on disease severity, must be treated permanently or only in stressful situations with hydrocortisone unless they may die after passing the clinical state of an "adrenal crisis".
 ...
PMID:Clinical diagnosis of hyper- and hypocortisolism. 1268 70

Depression in late life is a recognised public health problem. After establishing socio-demographic and psychological risk factors for depression, epidemiological research has focused on biological factors. This review summarises the evidence on the associations of cerebrovascular pathology, inflammation, and endocrine and nutritional status with depression in the elderly. The most consistent finding in biological psychiatry is the disturbance of the hypothalamic-pituary-adrenal axis in depressed persons. About half of the patients with severe depression have a disturbed glucocorticoid feedback mechanism and many exhibit hypercortisolism. Longitudinal studies show that this endocrine dysfunction increases the risk of relapse. More recently, silent brain infarcts and cerebral white matter lesions on MRI were found to be more frequent in the depressed elderly than in controls. Cerebral small vessel disease has been rediscovered as a potential cause of depression. Furthermore, there is evidence of immune activation in depressed persons. However, it remains unclear as to whether inflammation contributes to the pathological process as longitudinal studies are lacking. Clinical studies have also related many nutrients to psychological symptoms, but the evidence in elderly persons is consistent only for some vitamin deficiencies. In conclusion, despite a substantial body of literature on biological correlates of late life depression, little is known about causal relations. Prospective population-based studies are warranted.
 ...
PMID:Biological risk factors for late life depression. 1297 48

Corticotropin-releasing hormone (CRH), the principal regulator of the hypothalamic-pituitary-adrenal axis, as well as its receptors, have been identified in most female reproductive tissues, including the uterus, placenta, and ovary. Endometrial CRH may participate in decidualization, implantation, and early maternal tolerance; placental CRH may participate in the physiology of pregnancy and the onset of parturition, and ovarian CRH may participate in follicular maturation, ovulation, and luteolysis. The hypercortisolism of the latter half of pregnancy can be explained by increased levels of placental CRH in plasma. This hypercortisolism is followed by a transient suppression of hypothalamic CRH secretion in the postpartum period, which may explain the blues or depression and autoimmune phenomena frequently observed during this period.
 ...
PMID:Roles of reproductive corticotropin-releasing hormone. 1464 19

Daily hassles and/or ongoing stress are associated with increased cortisol secretion in healthy individuals. Hassles are also associated with increased cortisol levels in depressed patients. Considerable evidence suggests that hypercortisolism is involved in the pathogenesis of depressive disorders. Over the past decade, there has been a shift from viewing excessive hypothalamic-pituitary-adrenal (HPA) activity in depression as an epiphenomenon to its having specific effects on symptom formation. The author suggests that increased cortisol secretion caused by daily hassles and/or ongoing stress contributes to the development of depressive disorders. Minor stressful events may lead to depression in vulnerable individuals. Genetic factors interact with environmental factors to influence the vulnerability to stress and mood disorders. The author also proposes that elevated cortisol levels associated with stressful daily events may worsen the condition of depressed patients. The author notes that one of the goals of prevention of stress-related disorders is to help individuals be more competent in managing their behavior and emotions in reaction to negative aspects of their environment, and briefly discusses stress management methods and techniques. The risk of developing depression is determined by a complex interplay between genetic susceptibility, environmental exposures, and aging. These influences also account for long term changes in the regulation of HPA function. Further studies of HPA function may not only advance our understanding of the role of the HPA system in the etiology and pathogenesis of psychiatric disorders, but also be useful in refining conceptions of psychiatric disorders themselves and possible approaches to the treatment of these conditions.
 ...
PMID:Daily hassles, cortisol, and the pathogenesis of depression. 1496 26


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>