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

Endocrine and inflammatory profiles in type 2 diabetic patients with and without major depressive disorder

Background

There is a high prevalence of depression in individuals with type 2 diabetes mellitus. Depressive disorders are associated with increased medical morbidity and mortality in individuals with diabetes. It has been demonstrated that there is a higher prevalence of diabetic complications among individuals with diabetes and depression compared to those without depression. Several biological alterations have been reported in individuals with depressive disorders, particularly abnormal levels of endocrine-inflammatory markers.

This study aims to determine the prevalence of major depressive disorder (MDD) in type 2 diabetes patients, the prevalence of cardiovascular events in individuals with and without MDD and to compare the endocrine-inflammatory profile between groups.

Methods

The study was approved by the “Comité de Etica de Protocolos de Investigación del Departamento de Docencia e Investigación del Hospital Italiano de Buenos Aires” with the number “1262” and included only patients who provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and the Habeas Data law on protection of personal data (Law Nª 25326, Argentina).

Type 2 diabetes patients (n = 61) were included and they were classified as having MDD or not according to DSM-IV. Macrovascular disease was obtained from the medical history. Additionally, the intima-media thickness of the common carotid, carotid bifurcations and internal carotid arteries was measured non-invasively by two-dimensional ultrasound imaging. Fasting glucose, fasting lipid profile, inflammatory (CRP, TNF-α) and endocrine (urine free cortisol and saliva cortisol) markers. Student t tests were used to compare means for normally distributed variables and Mann-Whitney test for variables without normal distribution. Relative frequencies were calculated and a chi-square analysis was conducted. Data were expressed as mean ± standard deviation (SD) or median and interquartile range. Multivariable logistic regression was used to determine the relative odds of clinical cardiovascular disease in individuals with compared to those without depression. Differences were considered significant using a two-sided p < 0.05.

Results

21 patients (34%) had MDD and 40 patients (66%) didn’t have MDD. Diabetic patients with MDD had significantly higher CRP levels (4.1(1.9-7.6) vs 1.5(0.5-4.4) mg/l; p = 0.02) and 24-hour urine free cortisol (71.4 ± 21.3 vs 59.8 ± 29.3 ug/24 h; p = 0.03). The other metabolic and inflammatory parameters were not statistically different between groups. There was a significantly higher prevalence of cardiovascular events in individuals with MDD: 38% for the depressive group vs 15% for non-depressive group, p = 0.04). Patients with MDD had a 3.5-fold greater odd of having cardiovascular disease.

Conclusions

Diabetic patients with depression are more likely to have cardiovascular events, and different factors can determine this high association.

Prevalence of depression in relation to glucose intolerance in urban south Indians--the Chennai Urban Rural Epidemiology Study (CURES-76)

BACKGROUND

This study investigated the association between depression and glucose intolerance in urban residents of southern India.

METHODS

Subjects were recruited from the Chennai Urban Rural Epidemiology Study, carried out on a representative sample of 26,001 subjects recruited from Chennai city in southern India. Subjects with known diabetes were excluded (n = 1,498). Of the remaining 24,503 subjects, fasting capillary blood glucose (FBG) estimation were available for 23,787 subjects (response rate, 97.1%) in whom depression was assessed using a validated instrument, the Patient Health Questionnaire-12. Subjects with FBG values ≥126 mg/dL were termed as subjects with newly diagnosed diabetes (NDD), those with values between 100 and 125 mg/dL as having impaired fasting glucose (IFG), and those with <100 mg/dL as having normal fasting glucose (NFG).

RESULTS

The overall prevalence of depression was 14.3% (3391 of 23,787 subjects), and an increasing prevalence of depression was seen with increasing grades of glucose intolerance: NFG (13.1%), IFG (15.7%), and NDD (19.7%) (trend χ(2) = 57.1, P < 0.001). The prevalence of depression was higher in females at all grades of glucose intolerance. Risk for depression was higher among NDD subjects compared to NFG subjects (odds ratio = 1.12, 95% confidence interval 1.03-1.22, P = 0.01) and IFG subjects (odds ratio 1.21, 95% confidence interval 1.02-1.44, P = 0.03) and also for IFG compared to NFG subjects (odds ratio = 1.12, 95% confidence interval 1.02-1.21, P = 0.01) after adjusting for age, gender, body mass index, hypertension, and socioeconomic status.

CONCLUSION

The prevalence of depression increases with increasing grades of glucose intolerance and is highest among those with diabetes.

Chronic diseases and risk for depression in old age: a meta-analysis of published literature

OBJECTIVE

We assessed the relationship between chronic diseases and risk for depression in old age.

METHOD

MEDLINE, EMBASE, The Cochrane Library database were used to identify potential studies. All of the clinical studies that obtained data on the association between chronic diseases and risk of depression among individuals aged 55 years or older were identified and included in this review. The studies were classified into cross-sectional and longitudinal subsets. The quantitative meta-analysis of cross-sectional studies and that of longitudinal studies were preformed, respectively. For prevalence and incidence rates of depression, odds risk (OR) and relative risk (RR) were calculated, respectively.

RESULTS

Since all but one study found in the search was for individuals 60 years of age or over, we assessed and report on results for this larger group only. 24 cross-sectional and 7 prospective longitudinal studies were included in this review. The quantitative meta-analysis showed that, among chronic diseases, stroke, loss of hearing, loss of vision, cardiac disease or chronic lung disease had both a significant OR and RR for increased depression in old age; arthritis, hypertension or diabetes had a significant OR but an un-significant RR for increased depression in old age; and gastrointestinal disease had neither a significant OR nor a significant RR for increased depression in old age.

CONCLUSIONS

We concluded here that in old age, the associations of depression with some chronic diseases were definite; among these chronic diseases, stroke, loss of hearing, loss of vision, cardiac disease and chronic lung disease were risk factors for increased depression, but it should be further investigated whether arthritis, hypertension and diabetes were risk factors for increased depression or not.

Affective Disorders, Bone Metabolism, and Osteoporosis

The nature of the relationship between affective disorders, bone mineral density (BMD), and bone metabolism is unresolved, although there is growing evidence that many medications used to treat affective disorders are associated with low BMD or alterations in neuroendocrine systems that influence bone turnover. The objective of this review is to describe the current evidence regarding the association of unipolar and bipolar depression with BMD and indicators of bone metabolism, and to explore potential mediating and confounding influences of those relationships. The majority of studies of unipolar depression and BMD indicate that depressive symptoms are associated with low BMD. In contrast, evidence regarding the relationship between bipolar depression and BMD is inconsistent. There is limited but suggestive evidence to support an association between affective disorders and some markers of bone turnover. Many medications used to treat affective disorders have effects on physiologic systems that influence bone metabolism, and these conditions are also associated with a range of health behaviors that can influence osteoporosis risk. Future research should focus on disentangling the pathways linking psychotropic medications and their clinical indications with BMD and fracture risk.

Examining a bidirectional association between depressive symptoms and diabetes

CONTEXT

Depressive symptoms are associated with development of type 2 diabetes, but it is unclear whether type 2 diabetes is a risk factor for elevated depressive symptoms.

OBJECTIVE

To examine the bidirectional association between depressive symptoms and type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

Multi-Ethnic Study of Atherosclerosis, a longitudinal, ethnically diverse cohort study of US men and women aged 45 to 84 years enrolled in 2000-2002 and followed up until 2004-2005.

MAIN OUTCOME MEASURES

Elevated depressive symptoms defined by Center for Epidemiologic Studies Depression Scale (CES-D) score of 16 or higher, use of antidepressant medications, or both. The CES-D score was also modeled continuously. Participants were categorized as normal fasting glucose (< 100 mg/dL), impaired fasting glucose (100-125 mg/dL), or type 2 diabetes (> or = 126 mg/dL or receiving treatment). Analysis 1 included 5201 participants without type 2 diabetes at baseline and estimated the relative hazard of incident type 2 diabetes over 3.2 years for those with and without depressive symptoms. Analysis 2 included 4847 participants without depressive symptoms at baseline and calculated the relative odds of developing depressive symptoms over 3.1 years for those with and without type 2 diabetes.

RESULTS

In analysis 1, the incidence rate of type 2 diabetes was 22.0 and 16.6 per 1000 person-years for those with and without elevated depressive symptoms, respectively. The risk of incident type 2 diabetes was 1.10 times higher for each 5-unit increment in CES-D score (95% confidence interval [CI], 1.02-1.19) after adjustment for demographic factors and body mass index. This association persisted following adjustment for metabolic, inflammatory, socioeconomic, or lifestyle factors, although it was no longer statistically significant following adjustment for the latter (relative hazard, 1.08; 95% CI, 0.99-1.19). In analysis 2, the incidence rates of elevated depressive symptoms per 1000-person years were 36.8 for participants with normal fasting glucose; 27.9 for impaired fasting glucose; 31.2 for untreated type 2 diabetes, and 61.9 for treated type 2 diabetes. Compared with normal fasting glucose, the demographic-adjusted odds ratios of developing elevated depressive symptoms were 0.79 (95% CI, 0.63-0.99) for impaired fasting glucose, 0.75 (95% CI, 0.44-1.27) for untreated type 2 diabetes, and 1.54 (95% CI, 1.13-2.09) for treated type 2 diabetes. None of these associations with incident depressive symptoms were materially altered with adjustment for body mass index, socioeconomic and lifestyle factors, and comorbidities. Findings in both analyses were comparable across ethnic groups.

CONCLUSIONS

A modest association of baseline depressive symptoms with incident type 2 diabetes existed that was partially explained by lifestyle factors. Impaired fasting glucose and untreated type 2 diabetes were inversely associated with incident depressive symptoms, whereas treated type 2 diabetes showed a positive association with depressive symptoms. These associations were not substantively affected by adjustment for potential confounding or mediating factors.

Depression and osteoporosis: epidemiology and potential mediating pathways

INTRODUCTION

There have been numerous studies examining the association between depression and bone mineral density (BMD), but the underlying nature of this relationship remains unclear. Independent of this association, there is a growing body of evidence that depression impacts the risk for fracture in older adults. This article reviews the current epidemiological evidence regarding comorbidity of depression, low bone mineral density, and fracture.

METHODS

A review of the literature on depression, depressive symptoms, low BMD, osteoporosis, and fracture using electronic databases.

RESULTS

We reviewed 20 studies of the association between depression and BMD and five reports of the relationship between depression and fractures. Potential mediating mechanisms (both physiological and behavioral) are discussed, as well as potential confounding influences (e.g., medication use).

CONCLUSIONS

Most studies support the finding that depression is associated with increased risk for both low BMD and fractures, but variation in study design, sample composition, and exposure measurement make comparisons across studies difficult. Researchers should be aware of potential confounders, such as medication use, that may influence results. Future research should focus on identifying mediating pathways and targets for intervention in the relationships between depression, low BMD, and fracture.

Depression and type 2 diabetes mellitus: the multiethnic study of atherosclerosis

OBJECTIVE

To assess the cross-sectional association between depression and glucose tolerance status.

METHODS

We conducted a study of 6754 White, Black, Hispanic, and Chinese men and women aged 45 to 84 years in the Multiethnic Study of Atherosclerosis (MESA). Depression was defined as Center for Epidemiologic Studies Depression scale score of > or =16 and/or antidepressant use. Glucose tolerance status was defined as normal, impaired fasting glucose (IFG) or Type 2 diabetes mellitus (untreated and treated).

RESULTS

In the minimally adjusted model, although depression was not associated with a greater odds of IFG (odds ratio (OR) = 1.01; 95% confidence interval (CI): 0.87-1.18) or untreated diabetes (OR = 1.03; 95% CI: 0.74-1.45), it was associated with a greater odds of treated diabetes (OR = 1.57; 95% CI: 1.27-1.96). This persisted following adjustment for body mass index (OR = 1.52; 95% CI: 1.22-1.90), metabolic (OR = 1.54; 95% CI: 1.23-1.93), and inflammatory (OR=1.53; 95% CI: 1.21-1.92) factors, daily caloric intake and smoking (OR = 1.48; 95% CI: 1.16-1.88), and socioeconomic markers (OR = 1.47; 95% CI: 1.17-1.85). Among individuals with treated diabetes, median depression scores were higher in those with microalbuminuria compared with those without microalbuminuria (median = 7; interquartile range: 3-13 versus median = 6; interquartile range: 2-11; p = .046). Depression scores were not associated with homeostatic model assessment of insulin resistance among individuals without diabetes.

CONCLUSIONS

In MESA, depression was significantly associated with treated diabetes. Further studies are needed to determine the temporality of this association.

Depression in diabetic patients: the relationship between mood and glycemic control

PROBLEM

Evidence from prospective and cross-sectional studies demonstrates that the presence of diabetes doubles the risk of comorbid depression. This commonly overlooked comorbidity affects more than one quarter of the diabetic population, making its recognition and treatment in diabetic patients clinically relevant.

METHODS

PubMed, PsycINFO, and MEDLINE databases were searched (search words: diabetes, depression, metabolic control, hyperglycemia, hypoglycemia) for articles that evaluated outcomes, relationships, and/or management of comorbid depression and diabetes published between 1980 and 2002. This review represents a synthesis of the findings including treatment recommendations.

RESULTS

Concurrent depression is associated with a decrease in metabolic control, poor adherence to medication and diet regimens, a reduction in quality of life, and an increase in health care expenditures. In turn, poor metabolic control may exacerbate depression and diminish response to antidepressant regimens. Psychotherapy and pharmacotherapy are effective in the presence of diabetes; both cognitive behavior therapy and selective serotonin reuptake inhibitors are weight neutral and have been associated with glycemic improvement in some studies.

CONCLUSION

Depression is common in both type 1 and type 2 diabetes and has significant effects on the course and outcome of this medical illness. Conventional antidepressant management strategies are effective and the regimen should be tailored to the individual patient. Enhanced efforts toward good glycemic control may also contribute to improvements in mood and perceptions of well-being.

Depressive symptoms and the risk of type 2 diabetes: the Atherosclerosis Risk in Communities study

OBJECTIVE

The goal of this study was to determine whether depressive symptoms predict type 2 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed data on depressive symptoms (including recent fatigue, sleep disturbance, feelings of hopelessness, loss of libido, and increased irritability) in a longitudinal, biracial cohort study of 11,615 initially nondiabetic adults aged 48-67 years, who were subsequently followed for 6 years for the development of type 2 diabetes.

RESULTS

At baseline, depressive symptoms were positively associated with BMI, fasting insulin, systolic blood pressure, caloric intake, physical inactivity, and current smoking (all P < 0.05). In prospective analyses, after adjusting for age, race, sex, and education, individuals in the highest quartile of depressive symptoms had a 63% increased risk of developing diabetes compared with those in the lowest quartile (relative hazard [RH] 1.63, 95% CI 1.31-2.02). This relation persisted after adjustment for stress-associated lifestyle factors (smoking, physical activity, caloric intake, and adiposity) (1.28, 1.02-1.60) and metabolic covariates (fasting insulin and glucose, lipids, blood pressure, and adiposity) (1.38, 1.10-1.73).

CONCLUSIONS

In this cohort, depressive symptoms predicted incident type 2 diabetes. This relation is only partially explained by demographic, metabolic, and lifestyle factors. Possible neuroendocrine mediators of the stress-obesity-diabetes relationship require further evaluation in prospective cohort studies that use an established tool to assess depression and incorporate neurohormonal measurements.

Depressive symptoms and risk of type 2 diabetes in women

OBJECTIVE

To explore the relationship between depressive symptoms and incidence of type 2 diabetes in women.

RESEARCH DESIGN AND METHODS

We conducted an analysis of 72,178 female nurses aged 45-72 years who did not have diagnosed diabetes and who answered the Medical Outcomes Study 36-Item Short-Form Health Status Survey (SF-36) at baseline in 1992. We calculated relative risks (RR) of type 2 diabetes for women with presence of depressive symptoms (i.e., Five-Item Mental Health Index [MHI-5] score >52).

RESULTS

During 4 years of follow-up (282,317 person-years), 973 incident cases of type 2 diabetes were documented. Age-adjusted RR of developing type 2 diabetes for women with presence of depressive symptoms was 1.55 (95% CI 1.27-1.90). Additional adjustment for BMI resulted in a RR of developing type 2 diabetes of 1.36 (1.11-1.67). The multivariate RR of developing type 2 diabetes was 1.22 (1.00-1.50). After excluding women diagnosed with diabetes between 1992 and 1994, 472 incident cases of type 2 diabetes were documented for the follow-up period from 1994 to 1996 (148,889 person-years). The multivariate RR of developing type 2 diabetes for women with depressive symptoms was 1.29 (0.96-1.72).

CONCLUSIONS

Our data suggest that depressive symptoms are associated with a modest increase in the risk of type 2 diabetes.

Depressive symptoms and the risk of type 2 diabetes mellitus in a US sample

OBJECTIVE

There is some evidence to suggest that individuals with depression are at an almost twofold increased risk of developing type 2 diabetes mellitus, but results are far from conclusive. Therefore, to determine if depressive symptoms increased the risk of type 2 diabetes, we conducted longitudinal analyses using data from the NHANES I Epidemiologic Follow-up Survey (NHEFS).

RESEARCH DESIGN AND METHODS

Participants included individuals who were white or African-American, did not report previous diagnosis of diabetes, and who completed the Centers for Epidemiologic Studies Depression (CES-D) questionnaire in the 1982-1984 study (n = 8870). Participants were followed up for incident-diagnosed diabetes through 1992 (mean follow-up 9.0 years).

RESULTS

There were 1444 (15.9%) participants with high depressive symptoms in the 1982-1984 study (CES-D score > or = 16). During follow-up, there were 465 incident cases of diabetes. Incidence of diabetes was 6.9/1000 person years among those with high depressive symptoms, 6.0/1000 person years among those with moderate symptoms, and 5.0/1000 person years among those with no symptoms. After adjusting for age, sex, and race, the relative hazard (RH) of diabetes among those with high depressive symptoms was 1.27 (95% CI: 0.93 to 1.73) compared to those without symptoms. Further adjustment for education and known diabetes risk factors (body mass index and physical activity) further attenuated the relationship (RH 1.11, 95% CI: 0.79 to 1.56).

CONCLUSIONS

There was no increased incidence of diabetes for those with high or moderate depressive symptoms compared to those with no depressive symptoms. These results do not support the etiologic relationship of depression predisposing individuals to diabetes.

The effects of reboxetine, a noradrenaline reuptake inhibitor, on the plasma noradrenaline response to a cold pressor test in healthy volunteers

Previous studies have shown peripheral abnormalities in noradrenergic activity in depressed melancholic patients. These abnormalities have a relationship with short-term and long-term outcome. Little is known about the effects of antidepressant treatment on these peripheral measures such as plasma noradrenaline (NA) and the plasma NA response to a laboratory stressor, the cold pressor test (CPT). The present study examines the effects of the antidepressant reboxetine, a noradrenaline reuptake inhibitor, on baseline plasma NA and the plasma NA response to a CPT, in nine healthy volunteers compared to placebo. A double-blind crossover design was used, with each agent given for 4 weeks with a 4-week washout period. There was no effect of reboxetine on baseline plasma NA. The plasma NA response to reboxetine, with a CPT, was blunted 3 days after commencing treatment. Reboxetine alters the plasma NA response to a CPT independent of baseline plasma NA.

Association of plasma free-3-methoxy-4-hydroxyphenyl (ethylene)glycol, natural killer cell activity and delirium in postoperative patients

We measured and compared levels of plasma free 3-methoxy-4-hydroxyphenyl (ethylene)glycol (pMHPG), a major metabolite of noradrenaline, and natural killer (NK) cell activity in 26 patients prior to their undergoing an operation for cardiovascular diseases; 11 of whom expressed delirium and 15 who did not. In conclusion, we found that pMHPG levels before an operation were higher in patients with postoperative delirium than in the patients without, while NK cell activity showed no difference between the two groups. It is possible that hyperactivity of noradrenargic neurons is connected with the development of postoperative delirium. Furthermore, we considered that measurement of pMHPG level before operation might be a useful tool to predict the occurrence of postoperative delirium.

Plasma noradrenaline response to a cognitive stressor in subtypes of depressive illness

Noradrenergic function has been shown to be disrupted in depressive illness. The plasma noradrenaline response to a cognitive stressor (the Stroop test) was used to investigate noradenergic activity in subtypes of depressive illness. A Stroop test was carried out, under standardised conditions, on patients with melancholic or psychotic depression, non-melancholic depression, general anxiety disorder and normal controls. Blood samples were taken during testing for measurement of plasma noradrenaline. Although there was a trend for the plasma noradrenergic response to be reduced in the melancholic/psychotic depressed patients compared to all other groups, this did not reach statistical significance. No other inter-group comparisons were statistically significant. The plasma noradrenaline response to a cognitive stressor does not discriminate subtypes of depressive illness from normal controls. Copyright 2000 John Wiley & Sons, Ltd.

Decreased platelet alpha-2 adrenoceptor density in major depression: effects of tricyclic antidepressants and fluoxetine

BACKGROUND

It has been suggested that major depression is accompanied by a subsensitivity of central alpha 2-adrenoceptors (alpha 2-ARs) and, consequently, by an impaired negative feedback on the presynaptic catecholaminergic neuron, which, in turn, may induce a disinhibition of noradrenergic output and norepinephrine release in response to any activation.

METHODS

The maximum number of platelet binding sites (Bmax) and their affinity for [3H]-rauwolscine, a selective alpha 2-AR antagonist, were measured in unmedicated and medicated major depressed patients and in normal volunteers. Specific binding was defined as that inhibited by idazoxan, another alpha 2-AR antagonist.

RESULTS

Unmedicated major depressed patients had significantly decreased platelet [3H]-rauwolscine binding Bmax values compared to normal volunteers. [3H]-rauwolscine binding Kd values did not differ significantly between unmedicated major depressed patients and normal controls. [3H]-rauwolscine binding Kd values were significantly higher in depressed patients treated with tricyclic antidepressants than in unmedicated patients. Subchronic treatment with fluoxetine did not significantly alter either [3H]-rauwolscine binding Bmax or Kd values. [3H]-rauwolscine binding Bmax values were significantly greater in men than in women.

CONCLUSIONS

The results suggest that i) major depression is accompanied by decreased platelet alpha 2-AR density; and that ii) subchronic treatment with tricyclic antidepressants, but not fluoxetine, results in a decreased affinity of rauwolscine for platelet alpha 2-ARs.

Plasma norepinephrine response to a cold pressor test in subtypes of depressive illness

Noradrenergic systems have been shown to be disordered in depressive illness. The plasma norepinephrine response to a cold pressor test was used to investigate norepinephrine activity in subtypes of depressive illness. Patients with melancholic or psychotic depression, non-melancholic depression, general anxiety disorder and normal control subjects had a cold pressor test carried out under standard conditions. Blood samples were taken to measure plasma norepinephrine during the test. The plasma norepinephrine response to a cold pressor test was reduced in the melancholic/psychotic depressed patients compared to control subjects. No other intergroup comparisons were statistically significant. These results suggest noradrenergic systems are disturbed and subresponsive to stress in melancholic/psychotic depressed patients. This does not appear related to other clinical or biochemical factors.

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.

Multiple reciprocal relationships between in vivo cellular immunity and hypothalamic-pituitary-adrenal axis in depression

Major depression is reportedly characterized by increased activity of the hypothalamic-pituitary-adrenal (HPA) axis and by in vivo immune activation. The present study was carried out in order to investigate the relationships between HPA-axis activity and in vivo immune function in depression. Towards this end the following parameters were measured: 24 h urinary cortisol (UC) excretion; basal and post-dexamethasone (DST) plasma cortisol, beta-endorphin/beta-lipotropin (beta END/beta LPH) and dexamethasone concentrations; and leucocyte subsets (i.e. lymphocytes, neutrophils, monocytes, CD4+, CD4+CD45RA+, CD4+CD45RO+, CD8+, CD8+CD57+, CD8+CD57-, HLA-DR+, CD25+ T cells, HLA-DR+, CD19+, CD20+, and CD21+ B cells) both pre- and post-DST. Dexamethasone administration (1 mg orally) induced leucocytosis, lymphocytopaenia, monocytopaenia and neutrophilia. HPA-axis non-suppressors exhibited a relative resistance to the enhancing (e.g. neutrophils) or depressant (e.g. lymphocytes, CD4+ T cells) effects of dexamethasone. There were significant correlations between UC excretion and the number of percentage of lymphocytes, monocytes, CD4+CD45RA+ and CD8+CD57- T cells (negatively) and neutrophils (positively). It is concluded that multiple and complex intertwined relationships between HPA-axis hyperactivity and systemic immune stimulation participate in the pathophysiology or pathogenesis of major depression.

Psychomotor retardation, anorexia, weight loss, sleep disturbances, and loss of energy: psychopathological correlates of hyperhaptoglobinemia during major depression

Recently, we have established that major depression is characterized by hyperhaptoglobinemia, which may be regarded as an index of an "acute" phase response in that illness. The present study investigates the psychopathological correlates of increased plasma concentrations of haptoglobin (Hp) in major depression. To this end, the authors studied the Hp levels in relation to depressive items of the Structured Clinical Interview for DSM-III (SCID) and the Hamilton Rating Scale for Depression (HRSD) in 90 depressed subjects. There was a significant positive relationship between the SCID symptoms anorexia/weight loss, sleep, and psychomotor disorders and Hp plasma concentrations. Hp plasma levels were significantly and positively correlated with overall severity of illness (HRSD). The HRSD symptom correlates of higher Hp levels were loss of interest, middle insomnia, and psychomotor retardation. Up to 31.4% of the variance in Hp plasma values could be explained by psychomotor disorders, anorexia, weight loss, middle insomnia, and less diurnal variation of mood. It is suggested that hyperhaptoglobinemia, as an index of an "acute" phase response in major depression, is related to the somatic dimension of depressive illness.

Sleep disorders and anxiety as symptom profiles of sympathoadrenal system hyperactivity in major depression

Recently, it has been reported that major depression is accompanied by an increased sympathoadrenal system (SAS) activity. In order to study the psychopathological correlates of SAS activity in depression, the authors measured the 24 h urinary excretion of catecholamines (CA), i.e., noradrenaline (NE), adrenaline (E), dopamine (DA) and the NE/E metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in 80 unipolar depressed subjects. The excretion of these indices of SAS activity have been studied in relation to the depressive items of the Structured Clinical Interview for DSM-III (SCID) and the Hamilton Depression Rating Scale (HDRS). There were significant positive correlations between the SCID item sleep disorders and the HDRS item middle insomnia, on the one hand, and NE, E and DA excretion, on the other. The MHPG excretion in 24 h urine was significantly and negatively related to somatic anxiety and hypochondriasis. It is suggested that these intertwined relationships between increased CA turnover, sleep discontinuity and anxiety may reflect the occurrence of a hyperarousal state in some major depressives that may be regarded as a coping response to various putative noxious stimuli.

Immune disorders in depression: higher T helper/T suppressor-cytotoxic cell ratio

This study investigated the leukocyte T helper and T suppressor-cytotoxic cell (sub)set profile of minor, simple major and melancholic depressives versus normal controls. Using both monoclonal antibody staining and flow cytometry, we determined the absolute numbers and percentages of the following T cell immune subsets: T helper (CD4+), T virgin (CD4+CD45+), T memory (CD4+CD45-), T suppressor/cytotoxic (CD8+), CD8+ T suppressor (CD8+CD57-) and CD8+ T cytotoxic (CD8+CD57+) cells. After computing the CD4+/CD8+ ratio, we detected a significantly increased ratio in depressed patients as compared with healthy controls. Depression per se is characterized by a higher percentage of CD4+ and a lower percentage of CD8+CD57- cells. Melancholic depressed subjects exhibit a significantly increased number of CD4+ and CD4+CD45- cells. The combined use of various percentages of CD4+ and CD8+ (sub)sets yields a high degree of marker positivity for melancholia: through cumulative evaluation of those percentages, the marker positivity increases to 68% (sensitivity) and the specificity is 95%. These results together with our previous reports may refer to a depression-related state of T cell activation.

A study on the blunted natural killer cell activity in severely depressed patients

Recently, some investigators have established a blunted natural killer cell activity (NKCA) in severely depressed patients. In order to replicate these findings NKC cytotoxicity assays--on fresh cell suspensions in human plasma and fetal calf serum--were performed in healthy controls and depressed inpatients. Instead of the commonly used 51Cr-release assay we have used a fluorescent NKC cytotoxicity assay, which allows a greater sensitivity. We observed a significantly blunted NKCA in melancholic patients as compared with healthy controls and minor depressives, whilst simple major depressives exhibited an intermediate position. NKC cytotoxicity assays in fetal calf serum were significantly and negatively correlated with the severity of illness. We were unable to establish any relationship between NKCA and measures of hypothalamic-pituitary-adrenal-axis function, such as baseline, postdexamethasone plasma cortisol and 24 hr urinary cortisol secretion. In addition, we did not find any effects of dexamethasone administration (1 mg orally) on NKCA.

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.

Abnormal pituitary function during melancholia: reduced alpha-melanocyte-stimulating hormone secretion and increased intact ACTH non-suppression

In order to investigate pituitary alpha-melanocyte-stimulating hormone (alpha-MSH), intact (1-39 structure) adrenocorticotropic hormone (ACTH), and adrenal cortisol secretion, we measured 8 a.m. plasma levels of those hormones before and after administration of 1 mg dexamethasone in 39 depressed inpatients and 10 healthy controls. We found a significantly lower baseline alpha-MSH secretion in melancholic patients as opposed to healthy controls. There were no significant relations between alpha-MSH secretion on the one hand and ACTH or cortisol secretion on the other. Dexamethasone did not affect the 8 a.m. alpha-MSH circulating levels. The post-dexamethasone intact ACTH and cortisol values were significantly higher in melancholics as compared with healthy, minor and simple major depressed subjects. ACTH non-suppression was defined as post-dexamethasone intact ACTH greater than or equal to 12 pg/ml. ACTH non-suppression was found to be more sensitive (70%) and specific (100%) for melancholia than cortisol non-suppression. By means of pathway analysis we have established that cortisol non-suppression during a severe depression is completely determined by an augmented ACTH escape from suppression by dexamethasone. It is concluded that the assay of post-dexamethasone intact ACTH could, in the future, replace post-dexamethasone cortisol determination.