Stress, depression and the activation of the immune system

Psychostimulant withdrawal as an inducing condition in animal models of depression

A large body of evidence indicates that the withdrawal from high doses of psychostimulant drugs in humans induces a transient syndrome, with symptoms that appear isomorphic to those of major depressive disorder. Pharmacological treatment strategies for psychostimulant withdrawal in humans have focused mainly on compounds with antidepressant properties. Animal models of psychostimulant withdrawal have been shown to demonstrate a wide range of deficits, including changes in homeostatic, affective and cognitive behaviors, as well as numerous physiological changes. Many of these behavioral and physiological sequelae parallel specific symptoms of major depressive disorder, and have been reversed by treatment with antidepressant drugs. These combined findings provide strong support for the use of psychostimulant withdrawal as an inducing condition in animal models of depression. In the current review we propound that the psychostimulant withdrawal model displays high levels of predictive and construct validity. Recent progress and limitations in the development of this model, as well as future directions for research, are evaluated and discussed.

Preoperative somatic symptoms are associated with disease progression in patients with bladder carcinoma after cystectomy

BACKGROUND

A link between patient psychologic factors and bladder carcinoma outcome has not been demonstrated. The purpose of the current study was to assess the association of psychologic factors measured preoperatively with bladder carcinoma progression after cystectomy.

METHODS

The Brief Symptom Inventory (BSI)-18 was administered prospectively to 65 patients with clinically localized bladder carcinoma before surgery. The BSI-18 measures distress in three specific domains-depression, anxiety, and somatization (i.e., distress due to somatic symptoms)-as well as general distress. Preoperative BSI-18 scores, tumor pathologic stage, and certain clinical variables were compared with disease status. Disease progression was defined as the development of either local disease recurrence or distant metastasis. Univariate and multivariate Cox proportional hazards models were constructed for statistical analysis.

RESULTS

Of the 65 patients, 49 (79.4%) had no evidence of disease, 4 (6.2%) had local disease recurrence, and 12 (18.5%) had metastatic disease at last follow-up. The mean follow-up time was 1.3 years and did not differ significantly between survival outcomes (P = 0.577). Both tumor pathologic stage and preoperative somatic distress scores were associated with time to disease progression by univariate analysis (P = 0.038 and P = 0.055, respectively). After adjusting for tumor pathologic stage, a somatic distress score of > or = 2.00 was a significant predictor of disease progression (P = 0.044, hazard ratio = 3.31, 95% confidence interval = 1.03-10.60). Patient age, gender, reconstruction type, and BSI-18 scores for depression, anxiety, and general distress were not significantly associated with disease outcome.

CONCLUSIONS

The authors found no correlation between psychologic symptoms measured preoperatively (i.e., depression, anxiety, and general distress) and bladder carcinoma progression. However, they reported an association between somatic symptoms and cancer outcome. If confirmed by other studies, these results may have important implications for the diagnosis, staging, and potential treatment of patients with bladder carcinoma.

Psychosocial working conditions and the risk of esophageal and gastric cardia cancers

BACKGROUND

For reasons yet unknown, the incidence of esophageal and gastric cardia adenocarcinoma is increasing rapidly and moderately, respectively. These tumors occur predominantly among males. We hypothesized that stressful psychosocial working conditions might be involved in the etiology of these cancers.

OBJECTIVE

To study if job strain, work pace satisfaction and coping are linked to the risk of esophageal or cardia cancers.

METHODS

A nationwide Swedish population-based case-control study including 189 and 262 esophageal and cardia adenocarcinoma cases, respectively, 167 esophageal squamous-cell carcinoma cases, and 820 controls. All study subjects were interviewed. The relative risk was estimated using odds ratios, with 95% confidence intervals, adjusted for potential confounders.

RESULTS

We found no statistically significant associations between two different measures of job strain and the three cancer types, except between one job strain measure and risk of cardia adenocarcinoma (OR: 2.2; 95% CI: 1.0-4.8). There was a moderately strong association between having a covert coping style, compared to an overt, and risk of both esophageal (OR: 1.8; 95% CI: 1.2-2.8) and cardia adenocarcinoma (OR: 1.5; 95% CI: 1.0-2.3). Among subjects reporting low work pace satisfaction we found an almost 4-fold increased risk of esophageal squamous-cell carcinoma (OR: 3.8; 95% CI: 1.3-11.0), and a nearly 3-fold increased risk of esophageal adenocarcinoma (OR: 2.8; 95% CI: 1.1-7.0).

CONCLUSIONS

Work-related stress does not seem to be of importance in the etiology of adenocarcinoma of the esophagus or the gastric cardia. However, the interaction of a stressful work environment and the individual's responses to it may be associated with a moderately increased risk of these cancer types.

Physiological and psychological effects of exercise interventions in HIV disease

The use of both aerobic and resistance exercise has been shown to improve physiologic parameters such as strength, endurance, time to fatigue, and body composition in the HIV-infected population. Exercise has also been used successfully to treat psychologic conditions such as depression and anxiety that are common in HIV-infected individuals. However, the effects of exercise on immune function in these individuals are uncertain because of conflicting results found among studies. Additionally, many ventures into this area have been attempted with poor research design, resulting in inconclusive evidence or poor generalizability. The focus of this paper is to review the research that has been performed using exercise as an intervention for HIV-infected persons and to determine what needs to be done next to further our understanding of how the HIV-infected body and mind respond to exercise training.

Differential expression of pentraxin 3 in fibroblasts from patients with major depression

In this study, differential display technology was used to compare gene expression in cultured fibroblasts from patients with major depression, melancholic subtype vs nonmelancholic depressives and normal volunteer controls. Genes differentially expressed in depressives and normals included an overexpressed 269 bp sequence tag showing approximately 95% identity with the Homo sapiens long pentraxin 3 (PTX3) gene sequence in the 3' noncoding region. The 269 bp complimentary DNA probe hybridized with the 1.9 kb PTX3 mRNA. The densitometric analysis of slot blots showed that the mean steady-state mRNA level of PTX3 was 3.5-fold higher in the melancholic group as compared to that in normal controls and in nonmelancholic depressives (n=8, all groups). Incubation experiments were then conducted: confluent fibroblasts from melancholics and normal volunteers were incubated with isoproterenol 1 microM, dexamethasone (DEX) 500 nM, and interleukin 1beta (IL-1beta) 50 ng/ml, for 0, 0.5, 1, 4, and 24 h. mRNA was isolated and quantitated using Northern blot analysis. Isoproterenol produced no significant change in PTX3 expression; DEX produced a significant increase at 4 and 24 h; IL-1beta induced an increase in both the groups that peaked at 4 h, declining to near basal levels at 24 h. There were no differences between melancholics or controls in mean change or maximum response with either DEX or IL-1beta. The results are consistent with the reported effects of IL-1beta on PTX3 expression in mouse brain. The results are of potential importance because PTX3 is a member of the long pentraxin subfamily of acute-phase proteins, which is inducible by IL-1beta, and may play roles in neuroimmunity and neuroprotection.

Cancer-related fatigue: evolving concepts in evaluation and treatment

BACKGROUND

Although fatigue is one of the most common complaints of patients with cancer, it went unrecognized or overlooked for many years, until clinicians achieved better control over the more acute symptoms of nausea, emesis, and pain. A number of treatment-related and disease-related factors may contribute to the development of fatigue, but its physiologic basis remains poorly understood, and many proposed interventions have not been studied systematically. The lack of a standard of care for the assessment or treatment of fatigue in patients with cancer has limited research in this field. A critical appraisal of these issues is presented in this review.

METHODS

The published literature was reviewed for definition, prevalence, causes, and means of managing cancer-related fatigue (CRF).

RESULTS

Fatigue was reportedly present at the time of diagnosis in approximately 50-75% of cancer patients. The prevalence of CRF increased to 80-96% in patients undergoing chemotherapy and to 60-93% in patients receiving radiotherapy. Two tested interventions that showed consistent effects to alleviate CRF were treatment of cancer-related anemia with erythropoietin agents (recombinant human erythropoietin and darbepotin alpha) and aerobic exercise.

CONCLUSIONS

Several lines of research are needed to bridge the specific gaps in the current knowledge of CRF. These involve the pathophysiology of the symptom, the validation of diagnostic criteria, and specific therapeutic interventions. Current practice guidelines are based on a combination of research and expert clinical judgment and should be used to guide care with the expectation that they will evolve to incorporate the results of studies currently underway.

Hypothalamo-pituitary-adrenal function in patients with depressive disorders is correlated with baseline cytokine levels, but not with cytokine responses to hydrocortisone

Dysfunction of the hyopthalamo-pituitary adrenal (HPA) system is frequently found in major depression. In addition, signs of non-specific inflammatory system activation have been reported. However, very little is known about interactions between the HPA and immune systems in depressive patients. To assess HPA system function, we performed a combined dexamethasone suppression and corticotropin-releasing hormone stimulation (DEX/CRH) test in 14 depressive patients. Moreover, baseline nocturnal plasma levels of the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha were measured. In addition, the system was challenged with an intraveneous pulsatile injection of hydrocortisone (1 mg/kg body weight in total) and again cytokine levels were measured across one night. Baseline TNF-alpha levels were negatively correlated with the amount of ACTH released upon CRH stimulation during the DEX/CRH test. Acute hydrocortisone administration suppressed TNF-alpha and IL-6 levels independently of baseline HPA system activity. We conclude that chronic HPA system overactivity in depressed patients might compromise the production of inflammatory cytokines under baseline conditions. However, the responsivity of the cytokine production to acutely administered glucocorticoids does not seem to correlate with the state of the HPA system.

Effects of dexamethasone on cytokine plasma levels and white blood cell counts in depressed patients

In major depression, alterations of some aspects of the host defense system and the hypothalamo-pituitary-adrenal (HPA) system have been reported. Both systems are closely related, but their interaction in major depression has not yet been explored. Moreover, little is known about the effects of glucocorticoids on the circulating amounts of cytokines in humans in the absence of immunological challenges. Therefore, we investigated the effects of dexamethasone (DEX) in 17 depressed patients who underwent a combined DEX-suppression and corticotropine-releasing-hormone (CRH)-stimulation test on white blood cell counts, and on the plasma levels of granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-alpha, and soluble TNF-receptors (sTNF-R) p55 and p75. DEX induced an increase in granulocyte counts, which was positively correlated with increases in the circulating amounts of G-CSF and paralleled by decreased lymphocyte and monocyte counts. Moreover, DEX reduced the plasma levels of IL-6, TNF-alpha and sTNF-R p75. The levels of sTNF-R p55 and IL-10 were not affected. DEX-induced changes in immunological parameters did not differ between patients who had different amounts of HPA-system alteration, and were neither related to the severity of depressive symptomatology or to other clinical features. We conclude that a single oral dose of DEX, even in the absence of infection and inflammation, affects the circulating amounts of cytokines and soluble cytokine receptors, further supporting the pivotal role of these immune-mediators in glucocorticoid-induced immunomodulation. Neuroendocrinological alterations associated with major depression seem to be independent from these processes.