Lower serum zinc in major depression in relation to changes in serum acute phase proteins

Time course of zinc deprivation-induced alterations of mice behavior in the forced swim test

BACKGROUND

Zinc is an important trace element essential for numerous bodily functions. It is believed that a deficiency of zinc can lead to various conditions, including depression, on which this study is focused. It is still not known if hypozincemia leads to the development of depression or whether zinc deficiency is a result of depression. It is hypothesized that zinc may be a therapeutic agent or supplement that would help to reverse the symptoms of this disease.

METHODS

In the present study, the behavior of mice was assessed 2, 4, and 10 weeks following administration of a zinc deficient diet. To evaluate animal activity we used the forced swim test (FST).

RESULTS

After 2-week zinc deprivation we demonstrated a significant reduction in the immobility time. However, after 4 and 10 weeks of zinc deprivation the mice exhibited an increased immobility time. There were no changes in locomotor activity at each time period. After 2-, 4- and 10-week zinc deprivation and the subsequent FST, serum zinc concentration was decreased and determined to be 59, 61 and 20%, respectively, compared with appropriate controls. The serum corticosterone concentration in mice after 2-, 4- and 10-week zinc deprivation and subjected to the FST was also assessed, whereby the differences between the control and experimental animals were demonstrated (increased by: 11, 97 and 225%, respectively).

CONCLUSIONS

The obtained results indicate that zinc deprivation induced "pro-depressive" behavior (after the initial period of "antidepressive" behavior). This pro-depressive behavior correlates with enhanced serum corticosterone concentration.

Nutrient intakes and the common mental disorders in women

BACKGROUND

There is an increasing recognition of the role of nutrition in depression and anxiety. Magnesium, folate and zinc have all been implicated in depressive illness, however there are few data on these nutrients in anxiety disorders and the data from population-studies are limited.

AIMS

In a large, randomly-selected, population-based sample of women, this study aimed to examine the relationship between the dietary intakes of these three micronutrients and clinically determined depressive and anxiety disorders and symptoms.

METHODS

Nutrient intakes were determined using a validated food frequency questionnaire. The General Health Questionnaire-12 measured psychological symptoms, and a clinical interview (Structured Clinical Interview for DSM-IV-TR, non-patient edition) assessed current depressive and anxiety disorders.

RESULTS

After adjustments for energy intake, each standard deviation increase in the intake of zinc, magnesium and folate was associated with reduced odds ratio (OR) for major depression/dysthymia (zinc: OR=0.52, 95% confidence interval (CI) 0.31 to 0.88; magnesium: OR=0.60, 95% CI 0.37 to 0.96; folate: OR=0.66, 95% CI 0.45 to 0.97). There was also an inverse association between the intake of magnesium and zinc and GHQ-12 scores (zinc: zβ=-0.16, 95% CI -0.29 to -0.04; magnesium: -0.14, 95% CI -0.26 to -0.03). These relationships were not confounded by age, socioeconomic status, education or other health behaviours. There was no relationship observed between any nutrient and anxiety disorders.

CONCLUSION

These results demonstrate an association between the dietary intakes of magnesium, folate and zinc and depressive illnesses, although reverse causality and/or confounding cannot be ruled out as explanations.

The role of the GPR39 receptor in zinc deficient-animal model of depression

During the last decade it has been shown that zinc may activate neural transmissions via the GPR39 Zn(2+)-sensing receptor, which can be involved in the regulation of neuronal plasticity. According to the neurotrophic hypothesis of depression, decreased brain derived neurotrophic factor (BDNF) levels in depressed patients play a key role in the pathogenesis of this disorder. BDNF, similarly as zinc, is known to be involved in the process of neuron survival and the regulation of neuronal plasticity. The aim of the present study was to determine whether the administration of a 6-week diet deficient in zinc would cause depressive-like behaviour and if such behavioural alterations would correlate with changes in the expression of the BDNF protein and GPR39 receptor. In the first part of the present study the animal behaviour after a 6-week zinc-deficient diet, in the forced swim test (FST) was investigated. In the second part expression of the GPR39 and BDNF protein level in the frontal cortex was measured using the Western Blot method. Administration of a zinc-deficient diet for 6 weeks increased immobility time in the FST by 24%, so exerted depression-like behaviour. A biochemical study showed a significant reduction in GPR39 (by 53%) and BDNF (by 49%) protein expression in the frontal cortex in mice receiving the zinc deficient diet for 6 weeks. Our study provides evidence that the GPR39 Zn(2+)-sensing receptor may be responsible for lowering the BDNF protein level and in consequence may be involved in the pathogenesis of depression.

Inflammatory biomarkers predict depressive, but not anxiety symptoms during aging: the prospective Sydney Memory and Aging Study

This study addresses the paucity of research on the prospective relationship between a range of inflammatory markers and symptoms of depression and anxiety during aging. In the Sydney Memory and Aging Study, the relationships between remitted depression, current and first onset of symptoms of depression or anxiety (Geriatric Depression Scale and Goldberg Anxiety Scale (GDS, GAS), and markers of systemic inflammation (C-reactive protein (CRP), interleukins-1β, -6, -8, -10, -12, plasminogen activator inhibitor-1 (PAI-1), serum amyloid A, tumor necrosis factor-α, and vascular adhesion molecule-1) were investigated. The sample consists of N=1037 non-demented community-dwelling elderly participants aged 70-90 years assessed at baseline and after 2-years. All analyses were adjusted for gender, age, years of education, total number of medical disorders diagnosed by a doctor, cardiovascular disorders, endocrine disorders, smoking, body mass index, currently using anti-depressants, NSAIDS or statins and diabetes mellitus. The results show a significant linear relationship between increasing levels of IL-6 and depressive symptoms at baseline only, whereas IL-8 was associated with depressed symptoms at baseline and at 2 years follow-up. In addition, IL-8 was associated with first onset of mild to moderate depressive symptoms over 2 years. Logistic regression analyses showed that PAI-1 (OR=1.37, 95% CI=1.10-1.71, p=0.005) was associated with remitted depression. Results for anxiety symptoms were negative. The findings are suggestive of IL-6 and IL-8 being associated with current symptoms and IL-8 being associated with first onset of depressive symptoms, whereas PAI-1 could be regarded as a marker of remitted depression.

Targeting IL-1 in depression

INTRODUCTION

Depression is associated with inflammation, Th1 and Th17 responses, oxidative and nitrosative stress (O&NS), autoimmune responses against neoantigenic determinants, and neuroprogression (i.e., neurodegeneration, impaired plasticity and reduced neurogenesis). These pathways involve increased monocytic activation and interleukin-1 (IL-1) levels.

AREAS COVERED

This review will highlight the putative role of IL-1 in depression and the potential use of IL-1 signaling blockade as a treatment of depression. Electronic databases, i.e., Scopus, PUBMED and Google Scholar were employed using keywords: depression, depressive-like, interleukin-1, and interleukin-1 receptor antagonist (IL-1RA).

EXPERT OPINION

Ample studies show that depression is accompanied by increased levels of IL-1 and IL-1RA, which attenuates the pro-inflammatory activities of IL-1. In some, but not all studies, antidepressant treatment decreased IL-1β levels. In translational models, IL-1β administration elicits depressive-like behaviors, neuroinflammation and neuroprogression, whereas treatment with IL-1RA yields antidepressant-like effects and attenuates neuroprogression. Anakinra, an IL-1RA, targets not only IL-1 signaling, but also Th1, Th17, O&NS and neuroprogressive pathways and therefore may be advanced to clinical Phase-II trials in depression due to medical conditions associated with an elevated IL-1/IL-1RA ratio.

Mechanistic explanations how cell-mediated immune activation, inflammation and oxidative and nitrosative stress pathways and their sequels and concomitants play a role in the pathophysiology of unipolar depression

This paper reviews that cell-mediated-immune (CMI) activation and inflammation contribute to depressive symptoms, including anhedonia; anxiety-like behaviors; fatigue and somatic symptoms, e.g. illness behavior or malaise; and mild cognitive impairment (MCI). These effects are in part mediated by increased levels of pro-inflammatory cytokines (PICs), e.g. interleukin-1 (IL-1), IL-6 and tumor necrosis factor (TNF)α, and Th-1-derived cytokines, such as IL-2 and interferon (IFN)γ. Moreover, new pathways, i.e. concomitants and sequels of CMI activation and inflammation, were detected in depression: (1) Induction of indoleamine 2,3-dioxygenase (IDO) by IFNγ and some PICs is associated with depleted plasma tryptophan, which may interfere with brain 5-HT synthesis, and increased production of anxiogenic and depressogenic tryptophan catabolites. (2) Increased bacterial translocation may cause depression-like behaviors by activating the cytokine network, oxidative and nitrosative stress (O&NS) pathways and IDO. (3) Induction of O&NS causes damage to membrane ω3 PUFAs, functional proteins, DNA and mitochondria, and autoimmune responses directed against intracellular molecules that may cause dysfunctions in intracellular signaling. (4) Decreased levels of ω3 PUFAs and antioxidants, such as coenzyme Q10, glutathione peroxidase or zinc, are associated with an increased inflammatory potential; more oxidative damage; the onset of specific symptoms; and changes in the expression or functions of brain 5-HT and N-methyl-d-aspartate receptors. (5) All abovementioned factors cause neuroprogression, that is a combination of neurodegeneration, neuronal apoptosis, and lowered neurogenesis and neuroplasticity. It is concluded that depression may be the consequence of a complex interplay between CMI activation and inflammation and their sequels/concomitants which all together cause neuroprogression that further shapes the depression phenotype. Future research should employ high throughput technologies to collect genetic and gene expression and protein data from patients with depression and analyze these data by means of systems biology methods to define the dynamic interactions between the different cell signaling networks and O&NS pathways that cause depression.

Significance of serum glucocorticoid and chelatable zinc in depression and cognition in zinc deficiency

Dietary zinc deficiency elicits neuropsychological symptoms and cognitive dysfunction. To pursue the mechanisms of these symptoms, in the present study, the relationship among serum glucocorticoid, chelatable zinc in the synaptic cleft and brain function based on behavior was examined in young rats fed a zinc-deficient diet for 4 weeks. Serum glucocorticoid level was significantly increased in zinc-deficient rats. However, the induction of in vivo dentate gyrus LTP and object recognition memory were not affected in zinc-deficient rats. Chelatable zinc levels were decreased in the stratum lucidum of the hippocampal CA3, but not in the molecular layer of the dentate gyrus. It is reported that dentate gyrus LTP and object recognition memory are affected in clioquinol (30mg/kg)-administered rats, in which chelatable zinc is significantly decreased in the molecular layer of the dentate gyrus. Thus, the significant decrease in chelatable zinc in the molecular layer of the dentate gyrus may be required for object recognition memory deficit in zinc deficiency. On the other hand, the time of grooming in the open-field test was decreased in zinc-deficient rats. Immobility time in the forced swim test was increased in zinc-deficient rats, but not in clioquinol-administered rats, in which chelatable zinc was more markedly decreased than in zinc-deficient rats, suggesting that the lack of chelatable zinc does not increase depression-like behavior. These results suggest that the chronic increase in serum glucocorticoid level is involved in the increase in depression-like behavior rather than the decrease in chelatable zinc after 4-week zinc deficiency.

Zinc signaling through glucocorticoid and glutamate signaling in stressful circumstances

Humans and animals are constantly exposed to environmental stress. The hypothalamic-pituitary-adrenal (HPA) axis responds to stress, followed by glucocorticoid secretion from the adrenal glands. This response serves to maintain homeostasis in the living body through energy mobilization or to restore it. The brain is an important target for glucocorticoids. The hippocampus participates in the regulation of the HPA axis. Stress activates glutamatergic neurons in the hippocampus, and serious stress induces dyshomeostasis of extracellular glutamate. This dyshomeostasis, which is potentiated by glucocorticoids, modifies cognitive and emotional behavior. On the other hand, zinc is necessary for glucocorticoid signaling and is released from glutamatergic (zincergic) neurons to modulate synaptic glutamate signaling. Stress also induces dyshomeostasis of extracellular zinc, which may be linked to dyshomeostasis of extracellular glutamate. Thus, glucocorticoid signaling might also contribute to dyshomeostasis of extracellular zinc. It is likely that zinc signaling participates in cognitive and emotional behavior through glucocorticoid and glutamate signaling under stressful circumstances. This Mini-Review analyzes the relationship among signals of glucocorticoid, glutamate, and zinc under stressful circumstances to elucidate the significance of the zinc signaling in response to stress.

Zinc supplementation provides behavioral resiliency in a rat model of traumatic brain injury

Depression, anxiety, and impairments in learning and memory are all associated with traumatic brain injury (TBI). Because of the strong link between zinc deficiency, depression, and anxiety, in both humans and rodent models, we hypothesized that dietary zinc supplementation prior to injury could provide behavioral resiliency to lessen the severity of these outcomes after TBI. Rats were fed a marginal zinc deficient (5 ppm), zinc adequate (30 ppm), or zinc supplemented (180 ppm) diet for 4 weeks followed by a moderately-severe TBI using the well-established model of controlled cortical impact (CCI). Following CCI, rats displayed depression-like behaviors as measured by the 2-bottle saccharin preference test for anhedonia. Injury also resulted in evidence of stress and impairments in Morris water maze (MWM) performance compared to sham-injured controls. While moderate zinc deficiency did not worsen outcomes following TBI, rats that were fed the zinc supplemented diet for 4 weeks showed significantly attenuated increases in adrenal weight (p<0.05) as well as reduced depression-like behaviors (p<0.001). Supplementation prior to injury improved resilience such that there was not only significant improvements in cognitive behavior compared to injured rats fed an adequate diet (p<0.01), there were no significant differences between supplemented and sham-operated rats in MWM performance at any point in the 10-day trial. These data suggest a role for supplemental zinc in preventing cognitive and behavioral deficits associated with TBI.

Depression, cytokines and experimental pain: evidence for sex-related association patterns

BACKGROUND

There is robust evidence that altered neural-immune interactions including increased levels of proinflammatory cytokines are involved in both the pathogenesis of depression and altered pain processing. Proinflammatory cytokines induce sickness behavior, a constellation of symptoms that bears a strong similarity to those of depression. A feature of sickness behavior is enhanced pain sensitivity and it has been suggested that proinflammatory cytokines interact with pain processing directly and via several neurobiological pathways. Previous research indicates that depression and pain are closely related. We investigated the association between proinflammatory cytokines and experimental pain in major depression.

METHODS

Psychopathological variables, pressure pain thresholds (PPT) and concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured in 37 outpatients with major depression and 48 healthy controls.

RESULTS

Compared with controls, depressed patients exhibited significantly higher levels of TNF-α and significantly decreased PPT indicating enhanced pain sensitivity. The group differences were robust when adjusting for sex and body mass index, although sex was significantly related to PPT. No group difference was observed in IL-6. PPT correlated significantly with TNF-α in women but not in men.

LIMITATIONS

Because of the cross-sectional design, causality of the relation between TNF-α and pain cannot be determined. Results should be considered preliminary given the small sample size.

CONCLUSION

The present findings suggest that increased pain sensitivity in depression may be linked to increased TNF-α concentration. The absence of this association in men is discussed in terms of pain-related psychobiological sex differences.

The role of zinc in neurodegenerative inflammatory pathways in depression

According to new hypothesis, depression is characterized by decreased neurogenesis and enhanced neurodegeneration which, in part, may be caused by inflammatory processes. There is much evidence indicating that depression, age-related changes often associated with impaired brain function and cognitive performances or neurodegenerative processes could be related to dysfunctions affecting the zinc ion availability. Clinical studies revealed that depression is accompanied by serum hypozincemia, which can be normalized by successful antidepressant treatment. In patients with major depression, a low zinc serum level was correlated with an increase in the activation of markers of the immune system, suggesting that this effect may result in part from a depression-related alteration in the immune-inflammatory system. Moreover, a preliminary clinical study demonstrated the benefit of zinc supplementation in antidepressant therapy in both treatment non-resistant and resistant patients. In the preclinical study, the antidepressant activity of zinc was observed in the majority of rodent tests and models of depression and revealed a causative role for zinc deficiency in the induction of depressive-like symptoms, the reduction of neurogenesis and neuronal survival or impaired learning and memory ability. This paper provides an overview of the clinical and experimental evidence that implicates the role of zinc in the pathophysiology and therapy of depression within the context of the inflammatory and neurodegenerative hypothesis of this disease.

Decreased zinc and increased copper in individuals with anxiety

Aim:

To assess plasma zinc and copper levels in individuals with anxiety and to test the hypothesis that there is a relationship between copper and zinc concentration and improved symptoms.

Subjects and methods:

Serum from 38 individuals with anxiety and 16 neurotypical age, gender and size similar controls were tested for plasma zinc and copper concentration using inductively-coupled plasma-mass spectrometry. Zinc and copper levels, pre and post therapy, were compared and assessed for perceived anxiety symptoms.

Results:

In this preliminary study, individuals with anxiety had significantly higher plasma levels of Cu (P = 0.0348), Cu/Zn (P = 0.0493) and lower Zn (P = 0.0294) compared to controls. Zn levels normalized (increased to the normal range) and Cu/Zn significantly decreased after zinc therapy (P = 0.0004, P = 0.0033, respectively), but Cu did not significantly decrease (0.3577). These same patients improved significantly with respect to perceived overall symptoms after zinc and anti-oxidant therapy (P = 0.013).

Discussion:

These results suggest an association between Zn plasma levels and individuals with anxiety, demonstrate that zinc therapy is effective in increasing zinc plasma levels, and show that zinc supplementation may play a role in improved symptoms.

Zinc for attention-deficit/hyperactivity disorder: placebo-controlled double-blind pilot trial alone and combined with amphetamine

OBJECTIVE

To explore effects of zinc supplementation in American children with attention-deficit/hyperactivity disorder (ADHD). Mideastern trials reported significant benefit from 13-40 mg elemental zinc as the sulfate.

METHOD

We randomly assigned 52 children aged 6-14 with DSM-IV ADHD to zinc supplementation (15 mg every morning [qAM] or two times per day [b.i.d.] as glycinate, n = 28) or matched placebo (n = 24) for 13 weeks: 8 weeks monotherapy and then 5 weeks with added d-amphetamine (AMPH). AMPH dose was weight-standardized for 2 weeks and then clinically optimized by week 13. Zinc glycinate was chosen as having less gastrointestinal discomfort than sulfate. Hypotheses were that zinc would improve inattention more than placebo by effect size of d > 0.25 at 8 weeks; zinc+AMPH would improve ADHD symptoms more than placebo+AMPH by d > 0.25, and optimal dose of AMPH with zinc would be 20% lower than with placebo. An interim analysis requested by the National Institute of Mental Health resulted in an increased dosage, so that 20 received 15 mg/day qAM and 8 received 30 mg/day (15 mg b.i.d.)

RESULTS

Only the third hypothesis was upheld: Optimal mg/kg AMPH dose with b.i.d. zinc was 37% lower than with placebo. Other clinical outcomes were equivocal, sometimes favoring zinc, sometimes placebo, but objective neuropsychological measures mostly favored b.i.d. zinc (d = 0.36-0.7). Safety tests and adverse events were not different between groups. Copper and iron blood indices were not impaired by 8 weeks of 30 mg/day zinc.

CONCLUSION

Doses up to 30 mg/day of zinc were safe for at least 8 weeks, but clinical effect was equivocal except for 37% reduction in amphetamine optimal dose with 30 mg/day zinc (not with 15 mg). Possible reasons for difference from mideastern reports include endemic diets, population genetics, relative rate of zinc deficiency, difference in background nutrition, insufficient dosage or absorption, or wrong anion (sulfate may be necessary for reported benefit). Dose may be especially important: All visually impressive advantages over placebo appeared only with 15 mg b.i.d. rather than once a day. Future research should use larger doses than 15 mg/day, provide a basic recommended daily allowance/intake multivitamin/mineral supplement for all to standardize background nutrition, select participants for low zinc, and consider the issue of anion interaction.

Supplemented zinc does not alter mood in healthy older European adults – a randomised placebo-controlled trial: the Zenith study

Objective

Older people are vulnerable to zinc deficiency, which may impact upon their mood. This randomised, placebo-controlled, double-blind intervention study aimed to investigate the effect of oral zinc gluconate supplementation (15 mg/d; 30 mg/d; and placebo) on subjective mood (affect) in older Europeans.

Subjects

Healthy volunteers (n 387) aged 55–87 years were recruited.

Setting

Volunteers in Rome (Italy; n 108) and Grenoble (France; n 91) were aged 70–87 years and those in Coleraine (Northern Ireland; n 93) and Clermont-Ferrand (France; n 95) were aged 55–70 years.

Design

Mood was measured using the Positive and Negative Affect Scale on four occasions per day over 4 d at baseline, 3 and 6 months post-intervention.

Results

Mixed ANOVA indicated that neither positive nor negative affect altered in response to zinc (15 mg/d or 30 mg/d) compared to placebo in either the 55–70 years or the ≥70 years age group.

Conclusions

These results suggest that zinc does not benefit mood in healthy older people.

Chronic treatment with zinc and antidepressants induces enhancement of presynaptic/extracellular zinc concentration in the rat prefrontal cortex

Zinc exhibits antidepressant-like activity in preclinical tests/models. Moreover, zinc homeostasis is implicated in the pathophysiology of affective disorders. The aim of the present study was to examine the effect of chronic zinc, citalopram and imipramine intraperitoneal administration on the presynaptic and extracellular zinc concentration in the rat prefrontal cortex and hippocampus. We used two methods: zinc-selenium histochemistry (which images the pool of presynaptic-vesicle zinc) and anodic stripping voltammetry (ASV) for zinc determination in microdialysate (which assays the extracellular zinc concentration). We report that chronic (14 ×) zinc (hydroaspartate, 10 and 65 mg/kg) and citalopram (20 mg/kg) administration increased the pool of presynaptic zinc (by 34, 50 and 37%, respectively) in the rat prefrontal cortex. The 21% increase induced by imipramine (20 mg/kg) was marginally significant. Likewise, zinc (hydroaspartate, 65 mg/kg), citalopram and imipramine increased the extracellular zinc (although with a different pattern: time point, area under the curve and/or basal level) in this brain region. Furthermore, zinc induced an increase in presynaptic (by 65%) and extracellular zinc (by 90%) in the hippocampus, while both citalopram and imipramine did not. These results indicate that all of the treatments increase presynaptic/extracellular zinc concentrations in the rat prefrontal cortex, which may then contribute to their antidepressant mechanisms. Alterations induced by zinc (but not antidepressants) administration in the hippocampus may be related to specific zinc mechanisms. All the data (previous and present) on the effect of antidepressant treatments on the presynaptic/extracellular zinc concentrations suggest the involvement of this biometal presynaptic/synaptic homeostasis in the antidepressant mechanism(s).

Serum zinc level in depressed patients during zinc supplementation of imipramine treatment

BACKGROUND

Recurrent major depression is associated with decreased blood zinc concentrations that may be increased by effective antidepressant therapy. Some clinical investigations point to alterations of the zinc level in blood as a potential marker of depression.

METHODS

A placebo-controlled, double blind study of zinc supplementation to imipramine therapy was conducted on sixty patients fulfilling the DSM-IV criteria for major depression (18-55 years old, 40 females, 20 males). Moreover, a group of 25 healthy volunteers was recruited (16 females, 9 males). Blood samples were drawn for the assay of serum zinc once from the control subjects and four times (before, and then 2, 6 and 12 weeks after the beginning of treatment) from the depressed subjects.

RESULTS

We report that: 1) the serum zinc level was significantly lower (by 22%) in depressed patients than in healthy volunteers, 2) all groups demonstrated a gradual increase in zinc concentrations over the period of imipramine treatment with or without zinc supplementation, 3) treatment-resistant patients demonstrated lower concentrations of zinc (by 14%) than treatment-non-resistant patients, 4) zinc concentrations were higher in zinc-supplemented patients than in placebo-supplemented patients, 5) zinc supplementation increased zinc concentrations over the period of treatment, and 6) at a 12-week imipramine treatment, a significant negative correlation was demonstrated between the Montgomery-Asberg Depression Rating Scale and the serum zinc level together with a concomitant increase in serum zinc in patients in remission.

CONCLUSIONS

Serum zinc is a state marker of depression.

Randomized trial of the effect of zinc supplementation on the mental health of school-age children in Guatemala

BACKGROUND

Rates of mental illness in children are increasing throughout the world. Observational studies of depression, anxiety, and attention-deficit hyperactivity disorder suggest that zinc is an alternative treatment.

OBJECTIVE

We examined the effect of zinc supplementation on the mental health of school-age children in Guatemala.

DESIGN

From January to October 2006, we conducted a 6-mo randomized, double-blind, controlled trial comparing zinc supplementation (10 mg ZnO/d for 5 d/wk) with a placebo (10 mg glucose) in 674 Guatemalan children in grades 1-4. Outcome measures included internalizing (ie, depression and anxiety) and externalizing (ie, hyperactivity and conduct disorder) problem behaviors, positive behaviors (ie, socialization and leadership), and serum zinc concentrations.

RESULTS

Zinc and placebo groups did not differ significantly in any behavioral measures at baseline or at follow-up. At baseline, 21.4% of children had serum zinc concentrations <65 μg/dL. At follow-up, both groups improved significantly, and zinc concentrations were higher in the zinc group. Increases in serum zinc concentrations were inversely associated with decreases in depressive symptoms (estimate: -0.01 points per μg Zn/dL; P = 0.01), anxiety (estimate: -0.012 points per μg Zn/dL; P = 0.02), internalizing symptoms (estimate: -0.021 points per μg Zn/dL; P = 0.02), and social skills (estimate: -0.019 points per μg Zn/dL; P = 0.01) in adjusted models that were controlled for child age, sex, socioeconomic status, household, and treatment group.

CONCLUSIONS

Six months of zinc supplementation did not induce differences in mental health outcomes between zinc and placebo groups. However, increases in serum zinc concentrations were associated with decreases in internalizing symptoms (ie, depression and anxiety) in a community-based sample of children at risk of zinc deficiency. This trial was registered at clinicaltrials.gov as NCT00283660.

Early-life stress and antidepressants modulate peripheral biomarkers in a gene-environment rat model of depression

BACKGROUND

Availability of peripheral biomarkers for depression could aid diagnosis and help to predict treatment response. The objective of this work was to analyse the peripheral biomarker response in a gene-environment interaction model of depression. Genetically selected Flinders Sensitive Line (FSL) rats were subjected to maternal separation (MS), since early-life trauma is an important antecedent of depression. An open-ended approach based on a proteomic analysis of serum was combined with the evaluation of depression-associated proteins.

METHODS

Rats experienced MS and chronically received escitalopram (ESC) or nortryptiline (NOR). Serum proteins were compared by two-dimensional gel electrophoresis. Corticosterone, cytokines, BDNF and C-reactive protein (CRP) were measured by immunoassays.

RESULTS

Comparing FSL with the control Flinders Resistant Line (FRL), Apo-AI and Apo-AIV, alpha1-macroglobulin, glutathione peroxidase and complement-C3 were significantly modulated. Significant increases were detected in leptin, interleukin (IL) 1alpha and BDNF. CRP levels were significantly reduced. The impact of early-life stress was assessed by comparing FSL+MS versus FSL. Apo-E, alpha1-macroglobulin, complement-C3, transferrin and hemopexin were significantly modulated. The effect of stress in antidepressant response was then evaluated. In the comparison FSL+ESC+MS versus FSL+ESC, albumin, alpha1-macroglobulin, glutathione peroxidase and complement-C3 were modulated and significant reductions were detected in IL4, IL6, IL10, CRP and BDNF. By comparing FSL+NOR+MS versus FSL+NOR proteins like Apo-AIV, pyruvate dehydrogenase, alpha1-macroglobulin, transferrin and complement-C3 showed different levels.

CONCLUSIONS

Lipid metabolism and immunity proteins were differently expressed in FSL in comparison with FRL. Exposure to MS induced changes in inflammation and transport proteins which became apparent in response to antidepressant treatments. Modulated proteins could suggest biomarker studies in humans.

Lowered omega-3 PUFAs are related to major depression, but not to somatization syndrome

BACKGROUND

Studies indicated a depletion of omega-3 fatty acid levels and an imbalance between omega-3 and omega-6 PUFAs in depressive patients. Depletion of omega-3 PUFAs may be related to the immune and serotonergic pathophysiologies of depression by alterations in membrane fluidity and modulation of membrane receptors, enzyme activities and carriers. Previous studies also found serotonergic and immunological disturbances in subjects with somatoform symptoms. Based on these findings we aimed to investigate PUFA concentrations and its relations to other biological systems in depressed patients and in patients with somatoform symptoms.

METHODS

We examined 150 subjects divided in 4 groups, i.e. somatization syndrome; depression; depression and somatization syndrome; controls. Blood samples were analyzed for fatty acids, markers of the serotonergic system and the immune system.

RESULTS

The study was able to replicate earlier findings in patients with depression (lowered omega-3 PUFAs, increased omega-6/omega-3 ratios in serum cholesteryl esters). The somatization syndrome group showed no abnormalities in the mentioned fatty acid levels. Only depressive patients revealed associations between fatty acids with serotonergic and immunological markers.

LIMITATIONS

We used current state diagnoses, and the consideration of lifetime diagnoses and longitudinal studies could highlight further aspects of the reported results.

CONCLUSIONS

The findings are further confirming that the concepts of depression and somatoform disorders should not be merged indiscriminately together, even though they often occur together. We conclude that in depression and somatoform syndrome different biological mechanisms seem to be involved.

Zinc supplementation augments efficacy of imipramine in treatment resistant patients: a double blind, placebo-controlled study

BACKGROUND

One of the main problems in the therapy of depression is the limited efficacy of antidepressants and the limited utility of augmentation strategies. Zinc, a non competitive NMDA receptor antagonist exhibits preclinical antidepressant efficacy. Moreover, a preliminary clinical report suggests augmentation of antidepressant therapy by zinc in depression.

METHODS

A placebo-controlled, double blind study of zinc supplementation in imipramine therapy was conducted in sixty, 18-55-year old, unipolar depressed patients fulfilling the DSM-IV criteria for major depression without psychotic symptoms. After a one week washout period, patients were randomized into two groups treated with imipramine (approximately 140 mg/day) and receiving once daily either placebo (n=30) or zinc supplementation (n=30, 25 mgZn/day) for 12 weeks.

RESULTS

No significant differences in CGI, BDI, HADRS and MADRS scores were demonstrated between zinc-supplemented and placebo-supplemented antidepressant treatment non-resistant patients. However, zinc supplementation significantly reduced depression scores and facilitated the treatment outcome in antidepressant treatment resistant patients.

CONCLUSION

Zinc supplementation augments the efficacy and speed of onset of therapeutic response to imipramine treatment, particularly in patients previously nonresponsive to antidepressant pharmacotherapies. These data suggest the participation of disturbed zinc/glutamatergic transmission in the pathophysiology of drug resistance.

The involvement of serotonergic system in the antidepressant effect of zinc in the forced swim test

Recent preclinical data indicated the antidepressant-like activity of zinc in different tests and models of depression. The present study investigates the involvement of the serotonergic system in zinc activity in the forced swim test (FST) in mice and rats. The combined treatment of sub-effective doses of zinc (hydroaspartate, 2.5 mg Zn/kg) and citalopram (15 mg/kg), fluoxetine (5 mg/kg) but not with reboxetine (2.5 mg/kg) significantly reduces the immobility time in the FST in mice. These treatments had no influence on the spontaneous locomotor activity. Moreover, while the antidepressant-like effect of zinc (5 mg/kg) in the FST was significantly blocked by pretreatment with inhibitor of serotonin synthesis, p-chlorophenylalanine (pCPA, 3x200 mg/kg), 5HT-2(A/C) receptor antagonist, ritanserin (4 mg/kg) or 5HT-1A receptor antagonist, WAY 1006335 (0.1 mg/kg), the zinc-induced reduction in the locomotor activity was not affected by these serotonin modulator agents. These results indicate the specific involvement of the serotonergic system in antidepressant but not the motion behavior of zinc in mice. Also, an increase in the swimming but not climbing parameter of the rat FST observed following zinc administration (2.5 and 5 mg Zn/kg) indicates the serotonin pathway participation. This present data indicates that the antidepressant-like activity of zinc observed in the FST involves interaction with the serotonergic system.

Role of zinc in maternal and child mental health

Mental health problems in women, children, and adolescents are a significant public health issue. Given current barriers to the effective treatment of these problems, researchers are looking to the field of nutrition for potential alternatives to better understand and address mental health issues. The purpose of this article was to review current evidence on the relation between zinc and mental health disorders with a focus on 2 mental health problems that commonly affect women and children: depression and attention-deficit hyperactivity disorder (ADHD). A literature search of the databases Medline and PsychInfo was conducted with the use of key terms. The review included articles from 1975 to May 2008, but focused on articles published in recent years. Relations between zinc concentrations and behavior in animals; the relation between zinc deficiency, depression, and ADHD in patient and community samples; and the potential biological mechanisms for these relations were explored. The data support a relation between low concentrations of zinc and mental health problems, especially in at-risk populations. Evidence for the potential use of zinc in treating mental health problems comes mainly from patient populations and is strongest when zinc is given in combination with pharmacologic treatment. Less conclusive evidence exists for the effectiveness of zinc alone or in general community samples. Recommendations for further research in this area are provided.

Interaction of zinc with antidepressants in the tail suspension test

The antidepressant-like effect of zinc has been shown in several animal models of depression. In this study, zinc chloride (ZnCl2) was given alone or in combination with different classes of antidepressants by oral route (p.o.) to mice and the behavioral response in the tail suspension test (TST), a predictive test of antidepressant action, was investigated. ZnCl2 at a dose of 10 and 30 mg/kg, p.o., reduced the immobility time in the TST, without affecting the locomotor activity in open-field test. The antidepressants fluoxetine, paroxetine, imipramine, desipramine and bupropion produced a significant reduction in the immobility time in TST at the doses of 10, 1, 1, 1 and 10 mg/kg, p.o., respectively. The combined treatment of sub-effective doses of ZnCl2 (1 mg/kg) with sub-effective doses of fluoxetine (5 mg/kg), paroxetine (0.1 mg/kg), desipramine (0.1 mg/kg), imipramine (0.1 mg/kg) or bupropion (1 mg/kg) induced a significant reduction in the immobility time in the TST when compared with the groups treated with ZnCl2 or with antidepressants alone. The treatment with sub-effective doses of ZnCl2 and antidepressants alone or in combination did not affect the locomotion in open-field test, except that desipramine alone reduced the ambulation. The results first indicate that ZnCl2 administered by p.o. route produces an antidepressant-like effect in the TST. Moreover, synergistic effects of zinc with antidepressants were shown in the TST, suggesting that an improvement in the response to the antidepressant therapy occurs when zinc is combined with different classes of antidepressants.

Involvement of the adenosine A1 and A2A receptors in the antidepressant-like effect of zinc in the forced swimming test

It was previously shown that the acute administration of zinc chloride elicits an antidepressant-like effect in the mouse forced swimming test (FST). We have also shown that the activation of adenosine A(1) and A(2A) receptors produces an antidepressant-like effect in FST. Thus, this study investigated the involvement of adenosine receptors in the antidepressant-like effect of zinc in the FST. The antidepressant-like effect of ZnCl(2) (30 mg/kg, i.p.) in the FST was prevented by the pretreatment of animals with caffeine (3 mg/kg, i.p., a non-selective adenosine receptor antagonist), DPCPX (2 mg/kg, i.p., a selective adenosine A(1) receptor antagonist) or ZM241385 (1 mg/kg, i.p., a selective adenosine A(2A) receptor antagonist), administered at doses that per se produced no anti-immobility effect. Moreover, the treatment of mice with CHA (0.05 mg/kg, i.p., a selective adenosine A(1) receptor agonist), DPMA (0.1 mg/kg, i.p., a selective adenosine A(2A) receptor agonist) or dipyridamole (0.1 microg/site, i.c.v., an adenosine transporter inhibitor) was able to potentiate the action of sub-effective doses of ZnCl(2). Taken together, the results suggest that the antidepressant-like effect of zinc in the mouse FST might involve a direct or indirect activation of adenosine A(1) and A(2A) receptors.

Serum cortisol, immunoglobulins and some complements among depressed patients

Psychiatric disorders especially depression are associated with a variety of changes in immunity parameters. In this work, an attempt was carried out to make estimation about the correlation between immunity and depression through the measuring of IgG, IgA, and IgM and complements (C3 and C4) levels in the serum of patients and comparing them with the corresponding levels of healthy control group. The results showed a significant increase in serum level of C3, C4, cortisol, IgG and no significant differences were noticed in the level of IgA and IgM in the depressed patients group as compared with control group. A slight positive correlation was observed between cortisol versus IgG in depressed patients that is not found in normal subjects. Thus in depression, human body defenses psychologically and sometimes this defense transformed into immunological resistance that is expressed as different measurable changes in immunological parameters.

The hygiene hypothesis and psychiatric disorders

The hygiene hypothesis proposes that several chronic inflammatory disorders (allergies, autoimmunity, inflammatory bowel disease) are increasing in prevalence in developed countries because a changing microbial environment has perturbed immunoregulatory circuits which normally terminate inflammatory responses. Some stress-related psychiatric disorders, particularly depression and anxiety, are associated with markers of ongoing inflammation, even without any accompanying inflammatory disorder. Moreover, pro-inflammatory cytokines can induce depression, which is commonly seen in patients treated with interleukin-2 or interferon-alpha. Therefore, some psychiatric disorders in developed countries might be attributable to failure of immunoregulatory circuits to terminate ongoing inflammatory responses. This is discussed in relation to the effects of the immune system on a specific group of brain serotonergic neurons involved in the pathophysiology of mood disorders.

Low serum albumin and high ferritin levels in chronic hemodialysis patients with major depression

We investigated the relationships between serum albumin and ferritin levels in chronic hemodialysis patients with or without major depression. During a 1-year period, a total of 107 chronic hemodialysis patients were recruited. The diagnosis of major depression in patients was made by one psychiatrist. The data showed that patients with major depression (n=15) had significantly lower albumin and higher ferritin levels than patients without major depression (n=92). Chronic hemodialysis patients with major depression might have a more severe inflammation reaction and greater oxidative damage than patients without major depression.

Zinc status, psychological and nutritional assessment in old people recruited in five European countries: Zincage study

The paper shows the results on the relationship between zinc status, psychological dimensions (cognitive functions, mood, perceived stress) and nutritional aspects in European healthy old subjects recruited for ZINCAGE Project (supported by the European Commission in the Sixth Framework Programme). The old healthy subjects were recruited in Italy, Greece, Germany, France, Poland taking into account the different dietary habits between Northern and Southern European Countries and the pivotal role played by zinc for psychological functions. Measures of the cognitive status, mood and perceived stress level were obtained at baseline, using the "Mini Mental State Examination (MMSE)"; the "Geriatric Depression Scale (GDS - 15 items)" and the "Perceived Stress Scale (PSS)", respectively. Nutritional status was assessed using "Frequency Food Questionnaire". The sample included 853 old subjects, classified in 4 groups of age: 60-69-years-old (n = 359); 70-74-years-old (n = 225); 75-79-years-old (n = 153); 80-84-years-old (n = 116). Subjects were studied on the basis of plasma zinc, in which zinc </=11 microM means marginal zinc deficiency. The total samples showed that the 82% had no cognitive decline, whereas 76% presented a low GDS value indicating no depression. However, all psychological variables were related to plasma zinc values and nutritional assessment. In particular, a relationship between marginal zinc deficiency and impaired psychological dimensions occurred in Greece than in other European countries due to low intake and less variety of foods rich of zinc. This phenomenon was independent by the age, suggesting that a correct zinc intake from a wide range of foods may be useful to maintain a satisfactory plasma zinc levels as well as psychological status in elderly with subsequent achievement of healthy ageing.

T-helper 1/T-helper 2 cytokine imbalance and clinical phenotypes of acute-phase major depression

Several studies have discussed the relationships between T-helper 1 (Th1) or Th2 cytokines and major depression. The aim of the present study was to investigate the relationships between Th1/Th2 cytokine balance and clinical phenotypes of acute-phase major depression. A total of 82 subjects including 42 patients with major depressive disorder and 40 healthy controls were recruited. Serum cytokine levels of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and IL-10 were examined. Using ancova with age and body mass index (BMI) adjustments, there were no significant differences in serum IL-1beta, TNF-alpha, and IL-10 levels between patients with major depressive disorder and healthy controls. However, using ANCOVA with BMI adjustment only, the results showed that patients with major depressive disorder had significantly higher TNF-alpha levels than control subjects. In addition, using ANCOVA with age and BMI adjustments, significantly higher serum IL-1beta level and IL-1beta/IL-10 ratio were noted in patients with melancholic features than patients with non-melancholic features. However, there were no significant differences in serum IL-1beta, TNF-alpha and IL-10 levels between patients with and without suicide attempt. In conclusion, serum TNF-alpha, IL-1beta level and IL-1beta/IL-10 ratio might play an important role in the psychopathology of acute-phase major depressive disorder.

Psychosocial and biochemical interactions in aging: preliminary results from an Italian old sample of "Zincage" project

The study of the interactions among biological factors and psychosocial conditions is a very innovative field, because data are lacking in the scientific literature. Among biological aspects, zinc is an essential element in the elderly, especially in relation to one of the proteins, such as albumin, involved in zinc transport into the cells. In this study, the aim is the assessment of the interrelationship between albumin value (used as an index of the body zinc status) and some psychosocial dimensions in elderly Italian sample recruited for ZINCAGE project, supported by the European Commission in the "Sixth Framework Programme". Some tests and questionnaires were administered to older people included in the trial: the "life-style questionnaire"; the mini mental state examination (MMSE); the geriatric depression scale (GDS-15 items). On the basis of the Senieur Protocol for gerontological studies, a sample of 291 Italian healthy old subjects has been recruited in Central Italy and divided into 3 age groups: (a) 125 subjects aged from 65 to 74 years, (b) 89 subjects aged from 75 to 84 years, (c) 77 subjects aged >or=85 years (classified like successful old people). No cognitive impairment assessed by MMSE was observed in 67.5% of the sample; 64.0% had GDS score less than 5, indicating no depression, whereas the prevalence of biological albumin deficiency (<3.5 g/dl) found in Italian old people was 21.0%. Sixty one percent of subjects with albumin deficiency displayed higher values of GDS (>or=5). These preliminary results showed an interrelationship among serum albumin value and psychosocial aspects in Italian old population, suggesting that low albumin values may be involved in impaired psychological dimensions.

High-sensitivity C-reactive protein levels in patients with major depressive disorder and bipolar mania

The serum high-sensitivity C-reactive protein (hsCRP) levels in patients with major depressive disorder and bipolar I disorder in acute phases were investigated. During a 1-year period, a total of 67 participants including 23 patients with major depressive disorder, 13 patients with bipolar I disorder (manic episode) and 31 healthy controls were recruited in this study. The diagnoses of mental disorders in participants were made by one psychiatrist according to the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID). Both patient groups with major depression and bipolar disorder had higher mean serum hsCRP levels than the healthy control group. Using analysis of covariance with age adjustment, patients with bipolar I disorders still had significantly higher hsCRP levels than healthy controls (P=0.043). However, patients with major depression did not have significantly higher hsCRP levels than healthy controls (P=0.172). These results suggest that patients with bipolar I disorder might have a more severe inflammation reaction than patients without major depression. However, larger samples and adequate statistical methods are needed to prove these results.

Psychosocial aspects and zinc status: is there a relationship with successful aging?

It is very interesting and innovative to study the interrelationships between biological characteristics, particularly zinc status, and psychosocial conditions in old age, because there are few and fragmentary data in the literature. The aim of this study was to examine the interrelationship between serum albumin value (an indicator of zinc status) and some psychosocial characteristics in elderly Italian volunteers recruited for the ZINCAGE project, which is supported by the European Commission in the Sixth Framework Programme (Food-CT-2003- 506850). A protocol of tests and questionnaires was used: the Lifestyle Questionnaire, the Mini-Mental Status Examination (MMSE), the Geriatric Depression Scale (GDS, 15 items), and the Perceived Stress Scale. A sample of 174 old subjects were recruited in Region Marche (Central Italy), and classified into three age groups: 65 to 74 years old, 75 to 84 years old, and >85 years old (including some nonagenarians). The preliminary results show that 69.7% of the subjects have no cognitive impairment; 66.5% have a value of the GDS scale indicating no depression; and 17% have an albumin deficiency. The majority of these are >85 years old and women. A relationship between level of albumin (used as indicator of zinc status) and depression has been found: 71% of subjects with albumin deficiency displayed a higher value on the depression test against 29% of subjects with a normal value (p < 0.01). These preliminary results show a relationship between serum albumin and psychological characteristics, in particular depression in an old Italian population. This further suggests that a zinc deficiency, via hypoalbumin values, is involved in impaired psychological characteristics in the elderly.

Increase in synaptic hippocampal zinc concentration following chronic but not acute zinc treatment in rats

Electroconvulsive seizures (ECS), one of the most effective treatments of depression, induce mossy fiber sprouting (when assayed by means of synaptic zinc method), and this indicates an increase in the synaptic zinc level in the hippocampus following such therapy. The aim of the present study was to investigate the influence of acute and chronic zinc hydroaspartate administration on the synaptic and total zinc level in the rat hippocampus. We used two methods of zinc determination: (1) zinc-selenium method, which images the pool of synaptic zinc, and (2) flame atomic absorption spectrometry, which assays the total concentration of zinc. Our results indicate that chronic (14 x 65 mg/kg), but not acute, zinc hydroaspartate administration intraperitoneally (i.p.) increases the pool of synaptic zinc in the majority of rat hippocampal layers (by 72-190%), except for the stratum moleculare and stratum radiatum CA, and perforant path DG. On the other hand, no changes were found in total hippocampal zinc level, measured by flame atomic absorption spectrometry. These data suggest that chronic zinc treatment increases the pool of synaptic zinc in the hippocampus, and this effect is similar to that observed following chronic ECS treatment. The measurement of zinc concentration in the whole hippocampus by the flame atomic absorption spectrometry method is not sensitive enough to detect such subtle alteration.

Zinc: the new antidepressant?

Low serum zinc levels have been linked to major depression. Furthermore, zinc treatment has been shown to have an antidepressant effect. With the hope of understanding the role of zinc in mood disorders, recent work has begun to explore possible mechanisms of zinc action on serotonin uptake in the brain.

Opposite effects of Zn on the in vitro binding of [3H]LY354740 to recombinant and native metabotropic glutamate 2 and 3 receptors

We investigated the effect of Zn on agonist binding to both recombinant and native mGlu2 and mGlu3 receptors. Zn had a biphasic inhibitory effect on recombinant mGlu2 with IC(50) values for the high- and low-affinity components of 60 +/- 10 microM and 2 +/- 0.7 mM, respectively. Zn induced a complex biphasic effect of inhibition and enhancement of [(3)H]LY354740 binding to mGlu3. Observations with a series of chimeric mGlu2/3 receptors suggest that the Zn effect resides in the N-terminal domain of mGlu2 and mGlu3. We observed that the His56 of mGlu2, which corresponds to Asp63 in mGlu3 was largely accountable for the second phase of the Zn effect. As revealed by quantitative receptor radioautography, the addition of up to 100 microm Zn to brain sections of wild-type mice resulted in significant decreases in binding density in most brain regions. In particular, the mid-molecular layer of the dentate gyrus (DGmol) and the CA1 lacunosum moleculare of hippocampus (CA1-LMol) showed reductions of 62 and 67%, respectively. In contrast, the addition of 300 microM Zn to brain sections of mGlu2(-/-) mice caused large increases in binding density of 289 and 242% in DGmol and CA1-LMol, respectively. Therefore, Zn might play a role as a physiological modulator of group II mGlu receptor function.

Hypoalbuminemia in drug-free patients with major depressive disorder compared with a dietary matched control group: a clinical meaning beyond malnutrition

Serum albumin (sALB) is routinely determined in blood tests and is an excellent predictor of risk for many medical illnesses. Hypoalbuminemia has been sporadically reported in patients with psychiatric disorders, such as major depressive disorder and schizophrenia. We compared sALB levels between 19 drug-free patients of major depressive disorder with a control group of matching diets. We conducted this study by controlling the nutrition factor by assessing patient's diets, as well as other possible confounding factors such as sex, age, body mass index (BMI), liver function, and exercise, while focusing on hypoalbuminemia in patients with major depressive disorder. There is no difference in age, gender distribution, and dietary frequency on protein and albumin intake between the patient and control group. The sALB levels of the group with major depressive disorder were significantly reduced (p=0.049). The severity of depression is negatively correlated to the sALB level (r=-0.46, p=0.04). Hypoalbuminemia has clinical meanings on severity of depression and is independent of malnutrition. However, our results can only be seen as very preliminary and should be confirmed by larger studies.

Involvement of NMDA receptors and L-arginine-nitric oxide pathway in the antidepressant-like effects of zinc in mice

This study investigated the involvement of NMDA receptors and the L-arginine-nitric oxide (NO) pathway in the antidepressant-like effects of zinc in the forced swimming test (FST). The immobility times in the FST and in the tail suspension test (TST) were reduced by zinc chloride (ZnCl(2), 30 and 10-30 mg/kg intraperitoneal (i.p.), respectively). The doses active in the FST and TST reduced locomotor activity in an open-field. The antidepressant-like effect of ZnCl(2) in the FST was prevented by pre-treatment of animals with guanosine 5'-monophosphate (GMP), ascorbic acid, L-arginine, or S-nitroso-N-acetyl-penicillamine (SNAP), but not with D-arginine, administered at doses that per se produced no anti-immobility effect. The immobility time of mice treated with ZnCl(2)+MK-801 was not different from the result obtained with ZnCl(2) or MK-801 alone, but ZnCl(2)+imipramine had a greater effect in the FST than administration of either drug alone. Pre-treatment of animals with a sub-threshold dose of ZnCl(2) prevented the anti-immobility effect of MK-801, ketamine, GMP, L-arginine or N(G)-nitro-L-arginine (L-NNA), but did not alter the effect of imipramine or fluoxetine. Taken together, the results demonstrate that zinc produced an antidepressant-like effect that seems to be mediated through its interaction with NMDA receptors and the L-arginine-NO pathway.

Inhibition of glycogen synthase kinase-3beta by bivalent zinc ions: insight into the insulin-mimetic action of zinc

Zinc is an important trace element found in most body tissues as bivalent cations and has essential roles in human health. The insulin-like effect of zinc cations raises the possibility that they inhibit glycogen synthase kinase-3beta (GSK-3beta), a serine/threonine protein kinase linked with insulin resistance and type 2 diabetes. Here we show that physiological concentrations of zinc ions directly inhibit GSK-3beta in vitro in an uncompetitive manner. Treatment of HEK-293 cells with zinc enhanced glycogen synthase activity and increased the intracellular levels of beta-catenin, providing evidence for inhibition of endogenous GSK-3beta by zinc. Moreover, zinc ions enhanced glucose uptake 3-fold in isolated mouse adipocytes, an increase similar to activation with saturated concentrations of insulin. We propose that the in vivo insulin-mimetic actions of zinc are mediated via direct inhibition of endogenous GSK-3beta.

Serological observations in patients suffering from acute manic episodes

Although abnormalities of the immune system have been described in depression, information on serological alteration in acutely manic patients has been scarce. The present study undertook to investigate the levels of C-reactive proteins, circulating immune complexes, total immunoglobulins and immunoglobulin subclasses, complement proteins C3, C4, C6 and Factor B in the sera of 45 patients suffering from an acute manic episode. The findings were compared with assessments on the sera of 45 controls. The results demonstrate a number of significant differences between patients and controls. Whilst levels of immunoglobulin D were significantly lower, the levels of total immunoglobulin and immunoglobulin G1, complement proteins C3, C6 and Factor B were raised in the patient group when compared with the controls. Our results suggest a relationship between acute mania and immunological parameters associated with acute phase responses.

Alternative treatments for adults with attention-deficit hyperactivity disorder (ADHD)

A previous review of alternative treatments (Tx) of ADHD--those other than psychoactive medication and behavioral/psychosocial Tx--was supplemented with an additional literature search focused on adults with ADHD. Twenty-four alternative Tx were identified, ranging in scientific documentation from discrediting controlled studies through mere hypotheses to positive controlled double-blind clinical trials. Many of them are applicable only to a specific subgroup. Although oligoantigenic (few-foods) diets have convincing double-blind evidence of efficacy for a properly selected subgroup of children, they do not appear promising for adults. Enzyme-potentiated desensitization, relaxation/EMG biofeedback, and deleading also have controlled evidence of efficacy. Iron supplementation, magnesium supplementation, Chinese herbals, EEG biofeedback, massage, meditation, mirror feedback, channel-specific perceptual training, and vestibular stimulation all have promising prospective pilot data, many of these tests reasonably controlled. Single-vitamin megadosage has some intriguing pilot trial data. Zinc supplementation is hypothetically supported by systematic case-control data, but no systematic clinical trial. Laser acupuncture has promising unpublished pilot data and may be more applicable to adults than children. Essential fatty acid supplementation has promising systematic case-control data, but clinical trials are equivocal. RDA vitamin supplementation, non-Chinese herbals, homeopathic remedies, and antifungal therapy have no systematic data in ADHD. Megadose multivitamin combinations are probably ineffective for most patients and are possibly dangerous. Simple sugar restriction seems ineffective. Amino acid supplementation is mildly effective in the short term, but not beyond 2-3 months. Thyroid treatment is effective in the presence of documented thyroid abnormality. Some alternative Tx of ADHD are effective or probably effective, but mainly for certain patients. In some cases, they are the Tx of choice, and initial evaluation should consider the relevant etiologies. A few have failed to prove effective in controlled trials. Most need research to determine whether they are effective and/or to define the applicable subgroup. Some of them, although not safer than standard Tx, may be preferable for an etiologic subgroup.

Serum trace elements in animal models and human depression: Part III. Magnesium. Relationship with copper

In the present study we report the results of investigations into the serum magnesium levels in a clinical study of 19 patients with unipolar depression; 16 normal controls and in three animal models of depression: chronic severe stress (CSS), chronic mild stress (CMS) and olfactory bulbectomy (OB) in rats. There was no alteration in the values found in the rat models of depression. Unipolar depressed patients exhibit significantly lower serum magnesium levels than the appropriate controls (depression 19.1+/-2.2 mg/l; control 21.0 mg/l). There is no correlation between serum magnesium levels and the severity of depression. A significant positive correlation between serum magnesium/copper ratio and the severity of depression indicates a clear relationship between alterations of the homeostasis of these two ions in human depression. Copyright 2000 John Wiley & Sons, Ltd.

Effect of antidepressant drugs on veratridine-evoked glutamate and aspartate release in rat prefrontal cortex

In vivo microdialysis in conscious rats was used to evaluate the effect of local application, through a microdialysis probe, of desipramine (DMI), imipramine and citalopram (CIT), on veratridine-evoked glutamate and aspartate release in rat prefrontal cortex (PFCx). All antidepressant drugs (ADs), given at a concentration of 0.1 mM, significantly inhibited glutamate release, while aspartate release was affected only by DMI and CIT. In contrast, local administration of ADs markedly potentiated veratridine-evoked dopamine and noradrenaline release. Perfusion of clonidine, quinpirole and 1-[3-(trifluoro-methyl)phenyl]-piperazine (TFMPP) at 0.1 mM concentration also diminished, evoked release of glutamate and aspartate. The regulation of amino acid release in rat PFCx may be achieved by direct effect of ADs on Na+ channels or indirectly, by involvement of D2/D3, alpha 2 or 5-HT1B heteroceptors activated by the increased level of monoamines in response to the blockade of respective transporters.