The Food-Specific Serum IgG Reactivity in Major Depressive Disorder Patients, Irritable Bowel Syndrome Patients and Healthy Controls

There is an increasing amount of evidence which links the pathogenesis of irritable bowel syndrome (IBS) with food IgG hyperreactivity. Some authors have suggested that food IgG hyperreactivity could be also involved in the pathophysiology of major depressive disorder (MDD). The aim of this study was to compare levels of serum IgG against 39 selected food antigens between three groups of participants: patients with MDD (MDD group), patients with IBS (IBS group) and healthy controls (HC group). The study included 65 participants (22 in the MDD group, 22 in the IBS group and 21 in the HC group). Serum IgG levels were examined using enzyme-linked immunosorbent assay (ELISA). Medical records, clinical data and laboratory results were collected for the analysis. IgG food hyperreactivity (interpreted as an average of levels of IgG antibodies above 7.5 µg/mL) was detected in 28 (43%) participants, including 14 (64%) from the MDD group, ten (46%) from the IBS group and four (19%) from the HC group. We found differences between extreme IgG levels in MDD versus HC groups and in IBS versus HC groups. Patients with MDD had significantly higher serum levels of total IgG antibodies and IgG against celery, garlic and gluten compared with healthy controls. The MDD group also had higher serum IgG levels against gluten compared with the IBS group. Our results suggest dissimilarity in immune responses against food proteins between the examined groups, with the highest immunoreactivity in the MDD group. Further studies are needed to repeat and confirm these results in bigger cohorts and also examine clinical utility of IgG-based elimination diet in patients with MDD and IBS.

A systematic review of cortisol, thyroid-stimulating hormone, and prolactin in peripartum women with major depression

Pregnancy and postpartum are periods of high susceptibility to major depression (MD) and other mood disorders. The peripartum period is also a time of considerable changes in the levels of hormones, including cortisol, thyroid-stimulating hormone (TSH), prolactin, gonadotropins, and gonadal steroids. To investigate the relationship between mood and hormonal changes during and after pregnancy, we reviewed published reports of hormonal measures during this time frame, searched via PubMed and Web of Science. Studies were included if women in the antepartum or postpartum periods were clinically diagnosed with MD, and if there were repeated measures of cortisol, TSH, or prolactin. For these three hormones, the numbers of human studies that met these criteria were 15, 7, and 3, respectively. Convergent findings suggest that morning cortisol is reduced in pregnant and postpartum women with MD. Evidence did not support changes in TSH as a marker of MD during the peripartum period, and evidence for changes in prolactin in peripartum MD was equivocal. Aside from reduced morning cortisol in peripartum women with MD, definitive evidence for an association between specific hormonal fluctuations and mood disorders in the peripartum period remains elusive.

Mood disorders and circulating levels of inflammatory markers in a longitudinal population-based study

BACKGROUND

There has been increasing evidence that chronic low-grade inflammation is associated with mood disorders. However, the findings have been inconsistent because of heterogeneity across studies and methodological limitations. Our aim is to prospectively evaluate the bi-directional associations between inflammatory markers including interleukin (IL)-6, tumor necrosis factor (TNF)-α and high sensitivity C-reactive protein (hsCRP) with mood disorders.

METHODS

The sample consisted of 3118 participants (53.7% women; mean age: 51.0, s.d. 8.8 years), randomly selected from the general population, who underwent comprehensive somatic and psychiatric evaluations at baseline and follow-up (mean follow-up duration = 5.5 years, s.d. 0.6). Current and remitted mood disorders including bipolar and major depressive disorders (MDD) and its subtypes (atypical, melancholic, combined atypical and melancholic, and unspecified) were based on semi-structured diagnostic interviews. Inflammatory biomarkers were analyzed in fasting blood samples. Associations were tested by multiple linear and logistic regression models.

RESULTS

Current combined MDD [β = 0.29, 95% confidence interval (CI) 0.03-0.55] and current atypical MDD (β = 0.32, 95% CI 0.10-0.55) at baseline were associated with increased levels of hsCRP at follow-up. There was little evidence for inflammation markers at baseline predicting mood disorders at follow-up.

CONCLUSIONS

The prospective unidirectional association between current MDD subtype with atypical features and hsCRP levels at follow-up suggests that inflammation may be a consequence of this condition. The role of inflammation, particularly hsCRP that is critically involved in cardiovascular diseases, warrants further study. Future research that examines potential influences of medications on inflammatory processes is indicated.

13C-phenylalanine breath test and serum biopterin in schizophrenia, bipolar disorder and major depressive disorder

Phenylalanine is required for the synthesis of the neurotransmitters dopamine, noradrenaline, and adrenaline. The rate-limiting step for phenylalanine metabolism is catalyzed by phenylalanine hydroxylase (PAH) and its cofactor tetrahydrobiopterin. We aimed to detect altered phenylalanine metabolism in major psychiatric disorders using the l-[1-13C]phenylalanine breath test (13C-PBT) and serum biopterin levels. We also investigated association of PAH mutations with schizophrenia and phenylalanine metabolism. 13C-phenylalanine (100 mg) was orally administered, and the breath 13CO2/12CO2 ratio was monitored for 120 min in four groups: 103 patients with schizophrenia (DSM-IV), 39 with bipolar disorder, 116 with major depressive disorder (MDD), and 241 healthy controls. Serum biopterin levels were measured by high performance liquid chromatography. Mutation screening of PAH exons was performed by direct sequencing in 46 schizophrenia patients. Association analysis was performed using six tag single nucleotide polymorphisms and the PAH Arg53His mutation by TaqMan assays in 616 schizophrenia patients and 1194 healthy controls. Analyses of covariance controlling for age, sex, and body weight showed that the index for the amount of exhaled 13CO2 was significantly lower in the schizophrenia group than in the other three groups (all p < 0.05). Biopterin levels in schizophrenia and MDD were significantly lower than those in controls. Biopterin levels correlated with 13C-PBT indices in controls. PAH polymorphisms were not associated with schizophrenia or 13C-PBT indices. 13C-PBT revealed reduced phenylalanine metabolism in schizophrenia, though we obtained no evidence of involvement of PAH polymorphism. Serum biopterin levels were lower in schizophrenia and MDD, warranting further investigation.

Global arginine bioavailability ratio is decreased in patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is characterized by increased oxidative and nitrosative stress. We compared nitric oxide metabolism, i.e., the global arginine bioavailability ratio (GABR) and related serum amino acids, between MDD patients and non-depressed controls, and between remitted and non-remitted MDD patients.

METHODS

Ninety-nine MDD patients and 253 non-depressed controls, aged 20-71 years, provided background data via questionnaires. Fasting serum samples were analyzed using ultra-performance liquid chromatography coupled to mass spectrometry to determine the serum levels of ornithine, arginine, citrulline, and symmetric and asymmetric dimethylarginine. GABR was calculated as arginine divided by the sum of ornithine plus citrulline. We compared the above measures between: 1) MDD patients and controls, 2) remitted (n=33) and non-remitted (n = 45) MDD patients, and 3) baseline and follow-up within the remitted and non-remitted groups.

RESULTS

Lower arginine levels (OR 0.98, 95% CI 0.97-0.99) and lower GABR (OR 0.13, 95% CI 0.03-0.50) were associated with the MDD vs. the non-depressed group after adjustments for potential confounders. The remitted group showed a decrease in GABR, arginine, and symmetric dimethylarginine, and an increase in ornithine after the follow-up compared with within-group baseline values. The non-remitted group displayed an increase in arginine and ornithine levels and a decrease in GABR. No significant differences were recorded between the remitted and non-remitted groups.

LIMITATIONS

The MDD group was not medication-free.

CONCLUSIONS

Arginine bioavailability may be decreased in MDD. This could impair the production of nitric oxide, and thus add to oxidative stress in the central nervous system.

Major Depressive Disorder Following Dermatomyositis: A Case Linking Depression with Inflammation

Major depressive disorder (MDD) is one of the most common psychiatric disorders. Recent studies have shown a strong association between MDD and peripheral inflammation, shown by a higher incidence of depression in patients with inflammatory diseases including rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis and systemic lupus erythematosus. Dermatomyositis (DM), an idiopathic inflammatory connective tissue disease that is associated with inflammation, predominantly affects the skin and skeletal muscle. The association between DM and MDD in the context of inflammation has seldom been reported. Here we report a 30- year- old Caucasian female with symptoms of depression dating back to 2 years. These symptoms started after cutaneous manifestations of DM. In the past two years, her DM symptoms have worsened that paralleled an increase of depressive symptoms. Also, during the course of the patient's DM, we tracked elevated inflammatory markers including creatine kinase and aldolase, whereas C-reactive protein, C3, and C4 were in a high normal range which correlated with worsening of depression. Hence, a temporal relationship between the onset of MDD and DM symptoms suggests that inflammation may be a common mechanism linking these two conditions.

MicroRNA132 associated multimodal neuroimaging patterns in unmedicated major depressive disorder

There is compelling evidence that epigenetic factors contribute to the manifestation of depression, in which microRNA132 (miR-132) is suggested to play a pivotal role in the pathogenesis and neuronal mechanisms underlying the symptoms of depression. Additionally, several depression-associated genes [MECP2, ARHGAP32 (p250GAP), CREB, and period genes] were experimentally validated as miR-132 targets. However, most studies regarding miR-132 in major depressive disorder are based on post-mortem, animal models or genetic comparisons. This work will be the first attempt to investigate how miR-132 dysregulation may impact covariation of multimodal brain imaging data in 81 unmedicated major depressive patients and 123 demographically-matched healthy controls, as well as in a medication-naïve subset of major depressive patients. MiR-132 values in blood (patients > controls) was used as a prior reference to guide fusion of three MRI features: fractional amplitude of low frequency fluctuations, grey matter volume, and fractional anisotropy. The multimodal components correlated with miR-132 also show significant group difference in loadings. Results indicate that (i) higher miR-132 levels in major depressive disorder are associated with both lower fractional amplitude of low frequency fluctuations and lower grey matter volume in fronto-limbic network; and (ii) the identified brain regions linked with increased miR-132 levels were also associated with poorer cognitive performance in attention and executive function. Using a data-driven, supervised-learning method, we determined that miR-132 dysregulation in major depressive disorder is associated with multi-facets of brain function and structure in fronto-limbic network (the key network for emotional regulation and memory), which deepens our understanding of how miR-132 dysregulation in major depressive disorders contribute to the loss of specific brain areas and is linked to relevant cognitive impairments.

Correlation between allopregnanolone levels and depressive symptoms during late menopausal transition and early postmenopause

OBJECTIVES

This observational, cross-sectional study included 140 women with climacteric symptoms. The aim of the study was to evaluate the correlation between the presence and severity of depressive symptoms and allopregnanolone levels in women during late menopausal transition and early postmenopause.

METHODS

The study group was divided into two groups: 45 women in late menopausal transition and 95 early postmenopausal women. We evaluated Kupperman index, Hamilton scale and serum follicle-stimulating hormone, luteinizing hormone, 17β-estradiol, prolactin, total testosterone, dehydroepiandrosterone sulfate and allopregnanolone levels.

RESULTS

We found that serum allopregnanolone concentration was lower in early postmenopausal women compared to women in late menopausal transition; that there was a correlation between serum allopregnanolone levels in early postmenopausal women and time since last menstruation, intensity of climacteric symptoms, and intensity of depression symptoms and that there was a correlation between serum allopregnanolone levels and several depression symptoms presence (shallow sleep and symptoms of the digestive tract in women during late menopause transition; feelings of guilt, sleep disorders and general somatic symptoms in early postmenopausal women).

CONCLUSION

We concluded that reproductive aging is characterized by a reduction of allopregnanolone circulating levels that correlate to Hamilton depression index in early postmenopause and presence of specific depressive symptoms during late menopausal transition and early postmenopause.

Youth Depression Alleviation-Augmentation with an anti-inflammatory agent (YoDA-A): protocol and rationale for a placebo-controlled randomized trial of rosuvastatin and aspirin

AIM

There is growing support for the role of inflammation and oxidative stress in the pathophysiology of major depressive disorder (MDD). This has led to the development of novel strategies targeting inflammation in the treatment of depression. Rosuvastatin and aspirin have well-documented, anti-inflammatory and antioxidant properties. The aim of the Youth Depression Alleviation: Augmentation with an anti-inflammatory agent (YoDA-A) study is to determine whether individuals receiving adjunctive anti-inflammatory agents, aspirin and rosuvastatin experience a reduction in the severity of MDD compared with individuals receiving placebo.

METHODS

YoDA-A is a 12-week triple-blind, randomized controlled trial funded by the National Health and Medical Research Council, Australia. Participants aged 15-25, with moderate-to-severe MDD, are allocated to receive either 10 mg/day rosuvastatin, 100 mg/day aspirin, or placebo, in addition to treatment as usual. Participants are assessed at baseline and at weeks 4, 8, 12 and 26. The primary outcome is change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to week 12.

RESULTS

The study is planned to be completed in 2017. At date of publication, 85 participants have been recruited.

CONCLUSION

Timely and targeted intervention for youth MDD is crucial. Given the paucity of new agents to treat youth MDD, adjunctive trials are not only pragmatic and 'real-world', but additionally aim to target shortfalls in conventional medications. This study has the potential to first provide two new adjunctive treatment options for youth MDD; aspirin and rosuvastatin. Second, this study will serve as proof of principle of the role of inflammation in MDD.

Changes in miRNA-132 and miR-124 levels in non-treated and citalopram-treated patients with depression

BACKGROUND

Neurotrophins including brain-derived neurotropic factor (BDNF) are implicated in the pathogenesis of major depressive disorder (MDD). Yet, the roles of brain-specific BDNF-related miRNAs miR-132 and miR-124 are unclear.

METHODS

We enrolled 45 treatment-free patients with MDD, 32 citalopram-treated patients with MDD, and 32 healthy control subjects. Participants were assessed with the Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA). In a case-control sub-study, we followed 14 treatment-free patients who were subsequently treated with citalopram for 2 months. Enzyme-linked immunosorbent assay was used to detect plasma BDNF, and real-time polymerase chain reaction was used to quantify relative plasma miR-132 and miR-124 expression.

RESULTS

Patients with MDD had significantly higher HAMA and HAMD scores than the control group, with the highest scores in the treatment-free MDD group. Plasma miR-132 in the treatment-free MDD group was 2.4-fold that in the control group and significantly higher than that in the citalopram-treated MDD group. Plasma miR-124 in the treatment-free MDD and citalopram-treated MDD groups was 1.8-fold and 4-fold that in the control group, respectively. Compared to the control group, plasma BDNF levels were increased in both MDD groups, but not significantly different between them. There was a positive correlation between miR-132 and HAMD and HAMA scores, whereas no significant correlations were identified for plasma miR-124 or BDNF.

LIMITATIONS

The range of neurotrophin-related MiRNAs and the number of follow-up cases were limited.

CONCLUSIONS

BDNF and miR-124 in plasma increase with depression and antidepressants. Plasma MiR-132 might be an indication for depression status.

Associations between Proportion of Plasma Phospholipid Fatty Acids, Depressive Symptoms and Major Depressive Disorder. Cross-Sectional Analyses from the AGES Reykjavik Study

BACKGROUND

Deficits in n-3 fatty acids may be associated with depression. However, data are scarce from older adults who are at greater risk of poor dietary intake and of developing depression.

OBJECTIVE

To investigate proportion of plasma phospholipid fatty acids with respect to depressive symptoms and major depressive disorder in community dwelling older adults.

METHODS

Cross-sectional analyses of 1571 participants in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study aged 67-93 years. Depressive symptoms were measured using the 15-item Geriatric Depression Scale (GDS-15). Major depressive disorder was assessed according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria using the Mini-International Neuropsychiatric Interview (MINI).

RESULTS

Depressive symptoms were observed in 195 (12.4%) subjects and there were 27 (1.7%) cases of major depressive disorder. Participants with depressive symptoms were less educated, more likely to be smokers, less physically active and consumed cod liver oil less frequently. Difference in GDS-15 scores by tertiles of n-3 fatty acid proportion was not significant. Proportion of long chain n-3 fatty acids (Eicosapentaenoic- + Docosahexaenoic acid) were inversely related to major depressive disorder, (tertile 2 vs. tertile 1) OR: 0.31 (95% CI: 0.11, 0.86); tertile 3 vs. tertile 1, OR: 0.45 (95% CI: 0.17, 1.21).

CONCLUSION

In our cross sectional analyses low proportions of long chain n-3 fatty acids in plasma phospholipids appear to be associated with increased risk of major depressive disorder. However, the results from this study warrant further investigation in prospective setting with sufficiently long follow-up.

Stability of Cellular Immune Parameters over 12 Weeks in Patients with Major Depression or Somatoform Disorder and in Healthy Controls

OBJECTIVE

Cellular immune status in major depression (MD) patients differs from that in somatoform disorder (SFD) patients and healthy controls (HC). It is still questionable whether the patterns of immune parameters remain stable over time. Therefore, we studied lymphocyte and monocyte cell counts and neopterin levels in peripheral blood of MD and SFD patients and HC over 12 weeks and tested for correlations between biochemical and psychometric parameters.

METHODS

Thirty-nine patients with MD, 27 with SFD, and 51 HC were recruited. Peripheral blood was drawn at four visits, at 4-week intervals. We assessed the total cell count of B lymphocytes, natural killer (NK) cells, T lymphocyte subpopu-lations, and monocytes by flow cytometry, and neopterin serum levels by ELISA. Psychometric parameters were measured with questionnaires.

RESULTS

Counts of lymphocytes, monocytes, and neopterin were stable in the SFD and HC groups. In the MD group, total CD3+, CD3+CD8+, NK cells, and CD3+CD25+ T cells showed inhomogeneous variances in Friedman tests, particularly in females. Neopterin correlated with depressed mood in MD patients, and with body mass index in HC.

CONCLUSIONS

Cellular immune parameters are stable in HC and SFD. Our results may indicate influences of MD and gender on some cellular immune parameters. This may need to be considered in future immunological studies.

Glucocorticoid may influence amyloid β metabolism in patients with depression

Epidemiological studies have demonstrated that depression may be a risk factor for Alzheimer's disease (AD); however, the biological mechanisms of the transition from depression to AD are still not clear. Changes of amyloid β protein (Aβ) metabolism and increased glucocorticoid (GC) levels have been found in both depression and AD. Moreover, several studies in animal models have demonstrated that GC administration changes Aβ metabolism. To reveal whether GC affects amyloid metabolism in patients with depression, we evaluated serum levels of Aβ40, Aβ42 and cortisol at admission in 187 inpatients with major depressive disorder (MDD) and 224 healthy comparisons. Additionally, we re-evaluated the serum levels of Aβs in 27 patients with MDD 1 year later. The results of multiple regression analyses revealed that serum cortisol and Aβ levels are not correlated at the time of admission. However, serum cortisol levels at admission correlated with serum Aβ42 levels and Aβ40/Aβ42 ratio 1 year later. These findings suggest that increased cortisol in patients with MDD may influence the metabolism of Aβ over prolonged periods of time.

Antidepressants Improve Negative Regulation of Toll-Like Receptor Signaling in Monocytes from Patients with Major Depression

OBJECTIVE

Changes in the brain's inflammatory status can lead to psychopathological responses, especially depression. Using animal models, recent studies have revealed that this pathology is due, in part, to innate immune responses of monocytes.

METHODS

We focus on the involvement of Toll-like receptors (TLRs) and expression of genes encoding their negative regulators, SOCS1, TOLLIP, SIGIRR, MyD88s, NOD2, and TNFAIP3, in CD14+ monocytes from 34 patients with major depressive disorder (MDD) and 33 healthy controls before and after treatment with antidepressants. We also seek to investigate their association with depression severity, measured by the 17-item Hamilton Depression Rating Scale (HAMD-17).

RESULTS

mRNA expression of all TLRs, except TLR3 and -5, was significantly higher in monocytes from patients with MDD than in those from controls. Conversely, the "brakes" in TLR signaling, including TOLLIP, MyD88s, NOD2, and TNFAIP3, were downregulated. In clinical findings, the remission group showed higher baseline TLR4 and lower baseline IRAK3 mRNA levels but only baseline elevated SOCS1 mRNA levels, which were inversely correlated with HAMD-17 scores, predicting worsened outcome in MDD patients. In addition, TNFAIP3 mRNA levels were increased by antidepressant treatment.

CONCLUSION

Collectively, our findings suggest a role for dysregulation of TLR signaling in monocytes in MDD and identify a balancing effect of antidepressants on this dysregulation.

[SERUM CYTOKINE CONCENTRATIONS ASSOCIATION WITH THE SEVERITY OF SYMPTOMS IN MAJOR DEPRESSION]

BACKGROUND

Mounting data are indicating that major depression is related to diverse functions of the immune system. Several observations indicate that cytokine concentrations might also relate to the intensity of depressive manifestations. In this study we assessed whether inflammatory and anti-inflammatory cytokine concentrations are associated with the intensity of the depressive features in a cohort of patients with major depression and in healthy normal controls.

METHODS

A group of 25 patients with major depression all suffering from an acute deterioration of their mental status and all hospitalized in a psychiatric ward were assessed for the intensity of their depressive manifestations according to the Hamilton rating scale for depression and by the clinical global impression scale (CGI). In parallel, concentrations of serum IL-2R, IL-6, IL-8, IL-10 were analyzed by commercial ELISA kits. As comparators, a group of 25 healthy controls was analyzed.

RESULTS

The levels of IL-6 were higher among patients with depression. A high degree of correlation was found between the scores measured by the Hamilton and CGI scales by which the intensity of depressive symptoms were ranked. Interestingly, within the group of patients with depression a negative correlation was detected between the IL-6 concentrations and the CGI scores while a positive correlation was found between the IL-10 concentration and IL-6 concentration.

CONCLUSIONS

Our data indicate that the patients with depression differ from healthy individuals by their cytokine profile. Within this group of patients depressive features have a specific pattern and linkage to inflammatory and anti-inflammatory scores.

Are adverse childhood experiences and depression associated with impaired glucose tolerance in females? An experimental study

Adverse childhood experiences (ACE) enhance the risk for mental disorders, e.g. major depressive disorder (MDD). Increasing evidence suggests an association between ACE and impaired physical health, e.g. metabolic syndrome. The aim of this study was to assess several metabolic risk markers in healthy individuals with and without ACE and depressed patients with and without ACE. We examined glucose and insulin release in the oGTT in 33 women with MDD and ACE, 47 women with MDD without ACE, 21 women with ACE but no current or lifetime MDD and 36 healthy women without either MDD or ACE. Several metabolic markers such as triglycerides, cholesterol, LDL, HDL, HbA1c, BMI and waist to hip ratio were assessed. The four groups did neither differ in insulin release and glucose concentrations in the oGTT nor with respect to other metabolic variables. Depressed patients with and without psychotropic medication did not differ in any outcome variable, but there was a trend towards higher glucose concentrations in the oGTT in patients with current psychotropic medication. In this physically healthy sample neither ACE nor MDD were associated with metabolic risk factors. Thus, metabolic alterations might not directly be linked to ACE and depression.

Decreased serum L-arginine and L-citrulline levels in major depression

RATIONALE

It has been suggested that endothelial dysfunction caused by a decreased endothelial production of nitric oxide (NO) may contribute to the consistently observed increased risk of developing cardiovascular disease (CVD) in physically healthy patients suffering from major depression (MD). NO is a gas synthesized from Larginine (a conditionally essential amino acid) and oxygen by endothelial nitric oxide synthase (eNOS). The end products of NO production include both NO and L-citrulline. NO is rapidly reduced to the anions nitrite and nitrate, classically referred to as NO metabolites. Their measurement has been used as a surrogate measurement for endothelial NO production. We and others have shown decreased levels of NO metabolites in the serum of MD patients. The mechanism of this decreased production of NO by the endothelium has not yet been elucidated.

OBJECTIVES

The purpose of this study is to assess serum levels of L-arginine and L-citrulline in patients with MD.

METHODS

Levels of L-arginine and L-citrulline were measured in 35 unmedicated physically healthy MD patients and 36 healthy controls (HCs).

RESULTS

L-arginine and L-citrulline concentrations were significantly lower in MD patients than in healthy controls (L-arginine, 73.54 + 21.53 μmol/L and 84.89 + 25.16, p = 0.04 μmol/L and L-citrulline 31.58 + 6.05 μmol/L and 35.19 + 6.85 μmol/L, p = 0.03, respectively).

CONCLUSIONS

The decrease in L-arginine levels in MD patients is a possible explanation for the decrease in NO metabolites in MD patients and therefore may contribute, through endothelial dysfunction, to the increased CV risk associated with MD.

The association between the hypothalamic pituitary adrenal axis and tryptophan metabolism in persons with recurrent major depressive disorder and healthy controls

OBJECTIVES

Persistent changes in serotonergic and hypothalamic pituitary adrenal (HPA) axis functioning are implicated in recurrent types of major depressive disorder (MDD). Systemic tryptophan levels, which influence the rate of serotonin synthesis, are regulated by glucocorticoids produced along the HPA axis. We investigated tryptophan metabolism and its association with HPA axis functioning in single episode MDD, recurrent MDD and non-depressed individuals.

METHODS

We included depressed individuals (n = 1320) and controls (n = 406) from the Netherlands Study of Depression and Anxiety (NESDA). The kynurenine to tryptophan ratio (kyn/trp ratio) was established using serum kynurenine and tryptophan levels. Several HPA axis parameters were calculated using salivary cortisol samples. We adjusted the regression analyses for a wide range of potential confounders and differentiated between single episode MDD, recurrent MDD and control.

RESULTS

Tryptophan, kynurenine and the kyn/trp ratio did not differ between controls and depressed individuals. Increased evening cortisol levels were associated with a decreased kyn/trp ratio in the total sample (Crude: β = -.102, p < .001; Adjusted: β = -.083, p < .001). This association was found to be restricted to recurrently depressed individuals (Crude: β = -.196, p < .001; Adjusted: β = -.145, p = .001). Antidepressant treatment did not affect this association.

CONCLUSIONS

Our results suggest that an imbalance between HPA axis function and tryptophan metabolism could be involved in recurrent depression.

Proteomics profiling reveals inflammatory biomarkers of antidepressant treatment response: Findings from the CO-MED trial

Animal and human studies suggest an association between depression and aberrant immune response. Further, common inflammatory markers may change during the course of antidepressant treatment in patients. The objective of this study was to evaluate changes in inflammatory markers and clinical outcomes from subjects enrolled in the Combining Medications to Enhance Depression Outcome (CO-MED) trial. At baseline and week 12 (treatment completion), plasma samples of 102 participants were analyzed via a multiplex assay comprised of inflammatory markers using a 27-plex standard assay panel plus a 4-plex human acute phase xMAP technology based platform. We carried out analyses in two steps. First, t-tests were used to identify inflammatory marker levels that changed between baseline and week 12. For markers that were altered, logistic regression models were then conducted to look for associated changes in remission at week 12. Among the 31 inflammatory markers analyzed, several cytokines (IL-5, IFN-γ, IL-13), two chemokines (Eotaxin-1/CCL11, RANTES) and an acute-phase reactant (serum amyloid P component) showed change from baseline to week 12. However, only two indicated differential remission responses. Interestingly, increased levels of Eotaxin-1/CCL11 correlated with remission at week 12, whereas decreased levels of IFN-γ correlated with non-remission at week 12. Results suggest that these inflammatory proteins may serve as predictors of treatment response.

Gene expression in blood of children and adolescents: Mediation between childhood maltreatment and major depressive disorder

Investigating major depressive disorder (MDD) in childhood and adolescence can help reveal the relative contributions of genetic and environmental factors to MDD, since early stages of disease have less influence of illness exposure. Thus, we investigated the mRNA expression of 12 genes related to the hypothalamic-pituitary-adrenal (HPA) axis, inflammation, neurodevelopment and neurotransmission in the blood of children and adolescents with MDD and tested whether a history of childhood maltreatment (CM) affects MDD through gene expression. Whole-blood mRNA levels of 12 genes were compared among 20 children and adolescents with MDD diagnosis (MDD group), 49 participants without MDD diagnosis but with high levels of depressive symptoms (DS group), and 61 healthy controls (HC group). The differentially expressed genes were inserted in a mediation model in which CM, MDD, and gene expression were, respectively, the independent variable, outcome, and intermediary variable. NR3C1, TNF, TNFR1 and IL1B were expressed at significantly lower levels in the MDD group than in the other groups. CM history did not exert a significant direct effect on MDD. However, an indirect effect of the aggregate expression of the 4 genes mediated the relationship between CM and MDD. In the largest study investigating gene expression in children with MDD, we demonstrated that NR3C1, TNF, TNFR1 and IL1B expression levels are related to MDD and conjunctly mediate the effect of CM history on the risk of developing MDD. This supports a role of glucocorticoids and inflammation as potential effectors of environmental stress in MDD.

Plasma and cerebrospinal fluid G72 protein levels in schizophrenia and major depressive disorder

G72 is a modulator of D-amino acid oxidase, the enzyme that degrades D-serine, an amino acid that plays a critical role in glutamate neurotransmission, and has been implicated in psychiatric disorders. The aim of this study was to examine whether plasma or cerebrospinal fluid (CSF) G72 protein levels were altered in either schizophrenia or major depressive disorder (MDD) and whether any correlation between G72 levels and disease severity existed. Initially, 27 schizophrenic patients, 26 MDD patients, and 27 healthy controls matched for age, sex, and ethnicity were enrolled. Compared to those of controls, plasma or CSF G72 levels were not significantly different in patients with schizophrenia or MDD. Although we found a significant positive correlation between plasma G72 levels and a positive symptoms score on the positive and negative syndrome scale (PANSS), this was not replicated in the second study (40 schizophrenic patients). CSF G72 levels showed no significant correlation with PANSS scores. In MDD, neither plasma nor CSF G72 levels correlated significantly with depression severity. Since severity of our patients were relatively mild, further investigations in a large number of subjects including drug-free patients, younger patients, and more severely affected patients are warranted.

Inflammation and internalizing disorders in adolescents

Serum inflammatory markers have been studied in adults with anxiety and depression, but little is known about cytokine levels in young adolescents with emotional disorders. The objective of this study is to compare serum levels of interleukin-6 (IL-6) and interleukin-10 (IL-10) between adolescents with internalizing disorders and adolescents from the same community without internalizing disorders. A total of 134 non-medicated subjects (n=76 with internalizing disorders) were recruited from a larger sample of 2457 individuals. Serum levels of IL-6 and IL-10 were quantified and psychiatric diagnosis was evaluated using structured clinical interviews. Adolescents with internalizing disorders presented significantly higher levels of IL-6 as compared to youngsters without internalizing disorders. Differences between groups in IL-10 levels were not statistically significant. This study points out that IL-6 levels may be associated with internalizing disorders in youths and suggests that inflammation might be an early biomarker of emotional distress. High levels of cytokines may adversely affect general health in the long-term, which raise broader issues in terms of public health if results are replicated.

The relationship between major depressive disorder and glucose parameters: A cross-sectional study in a Chinese population

BACKGROUND

Depressive symptoms have been linked with insulin resistance in middle-aged and elderly populations. A strong relationship between peripheral insulin resistance and glucose homeostasis imbalance has been well established in previous studies. The role of serum fructosamine and fasting blood glucose (FBG) in elevating glucose homeostasis has been documented in the literature.

OBJECTIVES

The aim of the study was to examine the association of serum fructosamine and FBG with major depressive disorder (MDD).

MATERIAL AND METHODS

The study analyzed the clinical characteristics and biochemical parameters of 305 patients with MDD and 312 healthy individuals.

RESULTS

Serum concentrations of lipoprotein-cholesterol (HDL-C), total protein (TP) and creatinine (Cr) were found to be significantly different between the two groups. Serum fructosamine and fasting blood glucose (FBG) concentrations were high in patients with MDD compared with healthy individuals (2.3 ± 0.26 vs. 2.1 ± 0.27, p = 0.018; 4.7 ± 0.45 vs. 4.5 ± 0.45, p < 0.001). The levels of serum fructosamine and FBG were also significantly higher in patients with MDD when all participants were stratified by gender. Age was found to be positively correlated with FBG, serum fructosamine and Cr (r = 0.203, p < 0.001; r = 0.129, p = 0.025; r = 0.129, p = 0.024), and negatively correlated with TP (r = -0.114, p = 0.047) in patients with MDD. However, there were no correlations between age and FBG, serum fructosamine or Cr in the healthy controls. In a multivariate logistic regression analysis, increased serum fructosamine and FBG concentrations were positively associated with MDD independently of age and gender, after adjustment for age and potential confounding factors (OR = 6.313, CI95 %:2.953-13.393, p < 0.001; OR = 2.251, CI95 %: 1.464-3.462, p < 0.001).

CONCLUSIONS

The study results suggest that increased serum fructosamine and FBG concentrations are associated with depressive conditions, which may influence glucose metabolism and impair glucose homeostasis in patients with MDD.

Neuroactive steroid levels and psychiatric and andrological features in post-finasteride patients

Recent reports show that, in patients treated with finasteride for male pattern hair loss, persistent side effects including sexual side effects, depression, anxiety and cognitive complaints may occur. We here explored the psychiatric and andrological features of patients affected by post-finasteride syndrome (PFS) and verified whether the cerebrospinal fluid (CSF) and plasma levels of neuroactive steroids (i.e., important regulators of nervous function) are modified. We found that eight out of sixteen PFS male patients considered suffered from a DSM-IV major depressive disorder (MDD). In addition, all PFS patients showed erectile dysfunction (ED); in particular, ten patients showed a severe and six a mild-moderate ED. We also reported abnormal somatosensory evoked potentials of the pudendal nerve in PFS patients with severe ED, the first objective evidence of a neuropathy involving peripheral neurogenic control of erection. Testicular volume by ultrasonography was normal in PFS patients. Data obtained on neuroactive steroid levels also indicate interesting features. Indeed, decreased levels of pregnenolone, progesterone and its metabolite (i.e., dihydroprogesterone), dihydrotestosterone and 17beta-estradiol and increased levels of dehydroepiandrosterone, testosterone and 5alpha-androstane-3alpha,17beta-diol were observed in CSF of PFS patients. Neuroactive steroid levels were also altered in plasma of PFS patients, however these changes did not reflect exactly what occurs in CSF. Finally, finasteride did not only affect, as expected, the levels of 5alpha-reduced metabolites of progesterone and testosterone, but also the further metabolites and precursors suggesting that this drug has broad consequence on neuroactive steroid levels of PFS patients.

Altered soluble epoxide hydrolase-derived oxylipins in patients with seasonal major depression: An exploratory study

Many cytochrome p450-derived lipids promote resolution of inflammation, in contrast to their soluble epoxide hydrolase(sEH)-derived oxylipin breakdown products. Here we compare plasma oxylipins and precursor fatty acids between seasons in participants with major depressive disorder with seasonal pattern (MDD-s). Euthymic participants with a history of MDD-s recruited in summer-fall were followed-up in winter. At both visits, a structured clinical interview (DSM-5 criteria) and the Beck Depression Inventory II (BDI-II) were administered. Unesterified and total oxylipin pools were assayed by liquid chromatography tandem mass-spectrometry (LC-MS/MS). Precursor fatty acids were measured by gas chromatography. In nine unmedicated participants euthymic at baseline who met depression criteria in winter, BDI-II scores increased from 4.9±4.4 to 19.9±7.7. Four sEH-derived oxylipins increased in winter compared to summer-fall with moderate to large effect sizes. An auto-oxidation product (unesterified epoxyketooctadecadienoic acid) and lipoxygenase-derived 13-hydroxyoctadecadienoic acid also increased in winter. The cytochrome p450-derived 20-COOH-leukotriene B4 (unesterified) and total 14(15)-epoxyeicosatetraenoic acid, and the sEH-derived 14,15-dihydroxyeicostrienoic acid (unesterified), decreased in winter. We conclude that winter depression was associated with changes in cytochrome p450- and sEH-derived oxylipins, suggesting that seasonal shifts in omega-6 and omega-3 fatty acid metabolism mediated by sEH may underlie inflammatory states in symptomatic MDD-s.