Metabolic dysregulation and late-life depression: a prospective study.

BACKGROUND: Depression is associated with the metabolic syndrome (MS). We examined whether metabolic dysregulation predicted the 2-year course of clinical depression. METHOD: A total of 285 older persons (⩾60 years) suffering from depressive disorder according to DSM-IV-TR criteria was followed up for 2 years. Severity of depression was assessed with the Inventory of Depressive Symptomatology (IDS) at 6-month intervals. Metabolic syndrome was defined according the National Cholesterol Education Programme (NCEP-ATP III). We applied logistic regression and linear mixed models adjusted for age, sex, years of education, smoking, alcohol use, physical activity, somatic co-morbidity, cognitive functioning and drug use (antidepressants, anti-inflammatory drugs) and severity of depression at baseline. RESULTS: MS predicted non-remission at 2 years (odds ratioper component = 1.26, 95% confidence interval 1.00-1.58), p = 0.047), which was driven by the waist circumference and HDL cholesterol. MS was not associated with IDS sum score. Subsequent analyses on its subscales, however, identified an association with the somatic symptom subscale score over time (interaction time × somatic subscale, p = 0.005), driven by higher waist circumference and elevated fasting glucose level. CONCLUSIONS: Metabolic dysregulation predicts a poor course of late-life depression. This finding supports the concept of 'metabolic depression', recently proposed on population-based findings of a protracted course of depressive symptoms in the presence of metabolic dysregulation. Our findings seem to be driven by abdominal obesity (as indicated by the waist circumference) and HDL cholesterol dysregulation.

Cytokine production capacity in depression and anxiety.

Recent studies have suggested that immune function may be dysregulated in persons with depressive and anxiety disorders. Few studies examined the expression of cytokines in response to ex vivo stimulation of blood by lipopolysaccharide (LPS) to study the innate production capacity of cytokines in depression and anxiety. To investigate this, baseline data from the Netherlands Study of Depression and Anxiety (NESDA) were used, including persons (18-65 years; 66% women) with current (that is, past month; N=591) or remitted (N=354) DSM-IV depressive or anxiety disorders and healthy controls (N=297). Depressive and anxiety symptoms were measured by means of the Inventory of Depressive Symptomatology (IDS) and the Beck Anxiety Inventory (BAI). Using Multi-Analyte Profiling technology, plasma levels of 13 cytokines were assayed after whole blood stimulation by addition of LPS. Basal plasma levels of C-reactive protein, interleukin-6 and tumor necrosis factor-α were also available. A basal and a LPS summary index were created. Results show that LPS-stimulated inflammation was associated with increased odds of current depressive/anxiety disorders (odds ratio (OR)=1.28, P=0.009), as was the case for basal inflammation (OR=1.28, P=0.001). These associations were no longer significant after adjustment for lifestyle and health (OR=1.13, P=0.21; OR=1.07, P=0.45, respectively). After adjustment for lifestyle and health, interleukin-8 was associated with both remitted (OR=1.25, P=0.02) and current (OR=1.28, P=0.005) disorders. In addition, LPS-stimulated inflammation was associated with more severe depressive (ß=0.129, P<0.001) and anxiety (ß=0.165, P<0.001) symptoms, as was basal inflammation. Unlike basal inflammation, LPS-stimulated inflammation was still associated with (anxiety) symptom severity after adjustment for lifestyle and health (IDS: interleukin (IL)-8, MCP-1, MMP2; BAI: LPS index, IL-6, IL-8, IL-10, IL-18, MCP-1, MMP2, TNF-ß). To conclude, lifestyle and health factors may partly explain higher levels of basal, as well as LPS-stimulated inflammation in persons with depressive and anxiety disorders. However, production capacity of several cytokines was positively associated with severity of depressive and in particular anxiety symptoms, even while taking lifestyle and health factors into account. Elevated IL-8 production capacity in both previously and currently depressed and anxious persons might indicate a genetic vulnerability for these disorders.

Serum proteomic profiling of major depressive disorder.

Much has still to be learned about the molecular mechanisms of depression. This study aims to gain insight into contributing mechanisms by identifying serum proteins related to major depressive disorder (MDD) in a large psychiatric cohort study. Our sample consisted of 1589 participants of the Netherlands Study of Depression and Anxiety, comprising 687 individuals with current MDD (cMDD), 482 individuals with remitted MDD (rMDD) and 420 controls. We studied the relationship between MDD status and the levels of 171 serum proteins detected on a multi-analyte profiling platform using adjusted linear regression models. Pooled analyses of two independent validation cohorts (totaling 78 MDD cases and 156 controls) was carried out to validate our top markers. Twenty-eight analytes differed significantly between cMDD cases and controls (P < 0.05), whereas 10 partly overlapping markers differed significantly between rMDD cases and controls. Antidepressant medication use and comorbid anxiety status did not substantially impact on these findings. Sixteen of the cMDD-related markers had been assayed in the pooled validation cohorts, of which seven were associated with MDD. The analytes prominently associated with cMDD related to diverse cell communication and signal transduction processes (pancreatic polypeptide, macrophage migration inhibitory factor, ENRAGE, interleukin-1 receptor antagonist and tenascin-C), immune response (growth-regulated alpha protein) and protein metabolism (von Willebrand factor). Several proteins were implicated in depression. Changes were more prominent in cMDD, suggesting that molecular alterations in serum are associated with acute depression symptomatology. These findings may help to establish serum-based biomarkers of depression and could improve our understanding of its pathophysiology.

Sex-specific effects of naturally occurring variants in the dopamine receptor D2 locus on insulin secretion and type 2 diabetes susceptibility.

AIMS: Modulation of dopamine receptor D2 (DRD2) activity affects insulin secretion in both rodents and isolated pancreatic ß-cells. We hypothesized that single nucleotide polymorphisms in the DRD2/ANKK1 locus may affect susceptibility to type 2 diabetes in humans. METHODS: Four potentially functional variants in the coding region of the DRD2/ANKK1 locus (rs1079597, rs6275, rs6277, rs1800497) were genotyped and analysed for type 2 diabetes susceptibility in up to 25 000 people (8148 with type 2 diabetes and 17687 control subjects) from two large independent Dutch cohorts and one Danish cohort. In addition, 340 Dutch subjects underwent a 2-h hyperglycaemic clamp to investigate insulin secretion. Since sexual dimorphic associations related to DRD2 polymorphisms have been previously reported, we also performed a gender-stratified analysis. RESULTS: rs1800497 at the DRD2/ANKK1 locus was associated with a significantly increased risk for type 2 diabetes in women (odds ratio 1.14 (1.06-1.23); P = 4.1*104) but not in men (odds ratio 1.00 (95% CI 0.93-1.07); P = 0.92) or the combined group. Although rs1800497 was not associated with insulin secretion, we did find another single nucleotide polymorphism in this locus, rs6275, to be associated with increased first-phase glucose-stimulated insulin secretion in women (P = 5.5*104) but again not in men (P = 0.34). CONCLUSION: The present data identify DRD2/ANKK1 as a potential sex-specific type 2 diabetes susceptibility gene.

The association between immune activation and manic symptoms in patients with a depressive disorder.

Although recent studies have shown that immunological processes play an important role in the pathophysiology of mood disorders, immune activation may only be present in specific subgroups of patients. Our study aimed to examine whether immune activation was associated with (a) the presence of manic symptoms and (b) the onset of manic symptoms during 2 years of follow-up in depressed patients. Patients with a depressive disorder at baseline (N=957) and healthy controls (N=430) were selected from the Netherlands Study of Depression and Anxiety. Assessments included lifetime manic symptoms at baseline and two-year follow up, as well as C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) at baseline. Within depressed patients, immune activation was not related to the presence or absence of lifetime manic symptoms at baseline. However, CRP levels were strongly elevated in depressed men who developed manic symptoms compared with those who did not develop manic symptoms over 2 years (P<0.001, Cohen's d=0.89). IL-6 and TNF-α were also higher in depressed men with an onset of manic symptoms, but this association was not significant. However, we found that the onset of manic symptoms was particularly high in men with multiple elevated levels of inflammatory markers. Depressed men who developed manic symptoms during follow-up had increased immunological activity (especially CRP) compared with depressed men who did not develop manic symptoms. Further research should explore whether a treatment approach focusing on inflammatory processes may be more effective in this specific subgroup of depressed patients.

Anxiety disorders and inflammation in a large adult cohort.

Although anxiety disorders, like depression, are increasingly being associated with metabolic and cardiovascular burden, in contrast with depression, the role of inflammation in anxiety has sparsely been examined. This large cohort study examines the association between anxiety disorders and anxiety characteristics with several inflammatory markers. For this purpose, persons (18-65 years) with a current (N=1273) or remitted (N=459) anxiety disorder (generalized anxiety disorder, social phobia, panic disorder, agoraphobia) according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and healthy controls (N=556) were selected from the Netherlands Study of Depression and Anxiety. In addition, severity, duration, age of onset, anxiety subtype and co-morbid depression were assessed. Inflammatory markers included C-reactive protein (CRP), interleukin (IL)-6 and tumor-necrosis factor (TNF)-α. Results show that after adjustment for sociodemographics, lifestyle and disease, elevated levels of CRP were found in men, but not in women, with a current anxiety disorder compared with controls (1.18 (s.e.=1.05) versus 0.98 (s.e.=1.07) mg l(-1), P=0.04, Cohen's d=0.18). No associations were found with IL-6 or TNF-α. Among persons with a current anxiety disorder, those with social phobia, in particular women, had lower levels of CRP and IL-6, whereas highest CRP levels were found in those with an older age of anxiety disorder onset. Especially in persons with an age of onset after 50 years, CRP levels were increased compared with controls (1.95 (s.e.=1.18) versus 1.27 (s.e.=1.05) mg l(-1), P=0.01, Cohen's d=0.37). In conclusion, elevated inflammation is present in men with current anxiety disorders. Immune dysregulation is especially found in persons with a late-onset anxiety disorder, suggesting the existence of a specific late-onset anxiety subtype with a distinct etiology, which could possibly benefit from alternative treatments.

Evidence for a differential role of HPA-axis function, inflammation and metabolic syndrome in melancholic versus atypical depression.

The hypothalamic-pituitary-adrenal (HPA) axis and the inflammatory response system have been suggested as pathophysiological mechanisms implicated in the etiology of major depressive disorder (MDD). Although meta-analyses do confirm associations between depression and these biological systems, effect sizes vary greatly among individual studies. A potentially important factor explaining variability is heterogeneity of MDD. Aim of this study was to evaluate the association between depressive subtypes (based on latent class analysis) and biological measures. Data from 776 persons from the Netherlands Study of Depression and Anxiety, including 111 chronic depressed persons with melancholic depression, 122 with atypical depression and 543 controls were analyzed. Inflammatory markers (C-reactive protein, interleukin-6, tumor necrosis factor-α), metabolic syndrome components, body mass index (BMI), saliva cortisol awakening curves (area under the curve with respect to the ground (AUCg) and with respect to the increase (AUCi)), and diurnal cortisol slope were compared among groups. Persons with melancholic depression had a higher AUCg and higher diurnal slope compared with persons with atypical depression and with controls. Persons with atypical depression had significantly higher levels of inflammatory markers, BMI, waist circumference and triglycerides, and lower high-density lipid cholesterol than persons with melancholic depression and controls. This study confirms that chronic forms of the two major subtypes of depression are associated with different biological correlates with inflammatory and metabolic dysregulation in atypical depression and HPA-axis hyperactivity in melancholic depression. The data provide further evidence that chronic forms of depressive subtypes differ not only in their symptom presentation, but also in their biological correlates. These findings have important implications for future research on pathophysiological pathways of depression and treatment.

The role of negative emotionality and impulsivity in depressive/anxiety disorders and alcohol dependence.

BACKGROUND: Much is still unclear about the role of personality in the structure of common psychiatric disorders such as depressive/anxiety disorders and alcohol dependence. This study will therefore examine whether various traits of negative emotionality and impulsivity showed shared or specific associations with these disorders. Method Cross-sectional data were used from the Netherlands Study of Depression and Anxiety (NESDA), including individuals with no DSM-IV psychiatric disorder (n = 460), depressive/anxiety disorder only (i.e. depressive and/or anxiety disorder; n = 1398), alcohol dependence only (n = 32) and co-morbid depressive/anxiety disorder plus alcohol dependence (n = 358). Aspects of negative emotionality were neuroticism, hopelessness, rumination, worry and anxiety sensitivity, whereas aspects of impulsivity included disinhibition, thrill/adventure seeking, experience seeking and boredom susceptibility. RESULTS: Aspects of negative emotionality formed a homogeneous dimension, which was unrelated to the more heterogeneous construct of impulsivity. Although all aspects of negative emotionality were associated with alcohol dependence only, associations were much stronger for depressive/anxiety disorder only and co-morbid depressive/anxiety disorder with alcohol dependence. The results for impulsivity traits were less profound and more variable, with disinhibition and boredom susceptibility showing modest associations with both depressive/anxiety disorder and alcohol dependence, whereas low thrill/adventure seeking and high disinhibition were more strongly related with the first and the latter, respectively. CONCLUSIONS: Our results suggest that depressive/anxiety disorder and alcohol dependence result from shared as well as specific aetiological pathways as they showed the same associations with all aspects of negative emotionality, disinhibition and boredom susceptibility as well as specific associations with thrill/adventure seeking and disinhibition.

A K(ATP) channel gene effect on sleep duration: from genome-wide association studies to function in Drosophila.

Humans sleep approximately a third of their lifetime. The observation that individuals with either long or short sleep duration show associations with metabolic syndrome and psychiatric disorders suggests that the length of sleep is adaptive. Although sleep duration can be influenced by photoperiod (season) and phase of entrainment (chronotype), human familial sleep disorders indicate that there is a strong genetic modulation of sleep. Therefore, we conducted high-density genome-wide association studies for sleep duration in seven European populations (N=4251). We identified an intronic variant (rs11046205; P=3.99 × 10(-8)) in the ABCC9 gene that explains ≈5% of the variation in sleep duration. An influence of season and chronotype on sleep duration was solely observed in the replication sample (N=5949). Meta-analysis of the associations found in a subgroup of the replication sample, chosen for season of entry and chronotype, together with the discovery results showed genome-wide significance. RNA interference knockdown experiments of the conserved ABCC9 homologue in Drosophila neurons renders flies sleepless during the first 3 h of the night. ABCC9 encodes an ATP-sensitive potassium channel subunit (SUR2), serving as a sensor of intracellular energy metabolism.

Association of depressive disorders, depression characteristics and antidepressant medication with inflammation.

Growing evidence suggests that immune dysregulation may be involved in depressive disorders, but the exact nature of this association is still unknown and may be restricted to specific subgroups. This study examines the association between depressive disorders, depression characteristics and antidepressant medication with inflammation in a large cohort of controls and depressed persons, taking possible sex differences and important confounding factors into account. Persons (18-65 years) with a current (N = 1132) or remitted (N = 789) depressive disorder according to DSM-IV criteria and healthy controls (N = 494) were selected from the Netherlands Study of Depression and Anxiety. Assessments included clinical characteristics (severity, duration and age of onset), use of antidepressant medication and inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α)). After adjustment for sociodemographics, currently depressed men, but not women, had higher levels of CRP (1.33 versus 0.92 mg l(-1), P<0.001, Cohen's d = 0.32) and IL-6 (0.88 versus 0.72 pg ml(-1), P = 0.01, Cohen's d = 0.23) than non-depressed peers. Associations reduced after considering lifestyle and disease indicators--especially body mass index--but remained significant for CRP. After full adjustment, highest inflammation levels were found in depressed men with an older age of depression onset (CRP, TNF-α). Furthermore, inflammation was increased in men using serotonin-norepinephrine reuptake inhibitors (CRP, IL-6) and in men and women using tri- or tetracyclic antidepressants (CRP), but decreased among men using selective serotonin reuptake inhibitors (IL-6). In conclusion, elevated inflammation was confirmed in depressed men, especially those with a late-onset depression. Specific antidepressants may differ in their effects on inflammation.

[Depressive symptoms, cortisol, visceral fat and metabolic syndrome]. / Depressieve klachten, cortisol, visceraal vet en metabool syndroom.

BACKGROUND: Metabolic syndrome might explain the relationship between depression and cardiovascular disease. AIM: To examine the (longitudinal) relationship between depressive symptoms, cortisol and metabolic syndrome, especially visceral fat. METHODS: Our study derives data on depressive symptoms, cortisol, visceral fat and metabolic syndrome obtained from three different cohorts of older persons (Inchianti, lasa, Health abc). RESULTS: Metabolic dysregulation, especially in relation to fat occurs mainly in depressed persons with hypercortisolemia. There seems to be a vicious cycle between depressive symptoms and visceral fat. CONCLUSION: Early detection of metabolic disturbances in depressed patients might prevent cardiovascular outcomes. Future research should investigate whether the treatment of depression could positively influence metabolic syndrome, and whether, conversely, the treatment of metabolic syndrome could relieve depression.

The educational patterning of health-related adversities in individuals with major depression.

BACKGROUND: Major depressive disorder and depression severity are socially patterned, disfavouring individuals from lower socioeconomic groups. Depressive disorders are associated with several adverse health-related outcomes. We examined the educational patterning of somatic health, lifestyles, psychological function and treatment modalities in individuals suffering from major depressive disorder. METHODS: We used cross-sectional medical and psychiatric data from 992 participants of The Netherlands Study of Depression and Anxiety (NESDA) with a diagnosed current major depressive disorder. Associations of education with somatic, lifestyle-related, and psychological outcomes, and with treatment modalities, adjusted for depression severity, were examined by means of (multinomial and binary) logistic and linear regression analyses. RESULTS: In addition to and independent of major depressions being more severe in the less educated patients, metabolic syndrome, current smoking, low alcohol consumption, hopelessness and low control were more prevalent in a group of less educated individuals suffering from major depression, compared with their more highly educated peers. The less educated persons were more likely to be treated with antidepressant medication and less likely to receive psychotherapy treatment. None of these observations were explained by a higher depression severity in the less educated group. LIMITATIONS: The cross-sectional design does not allow us to make direct causal inferences regarding the mutual influences of the different health-related outcomes. CONCLUSIONS: Further research should explore the necessity and feasibility of routine screening for additional health risk, particularly among less educated depressed individuals.

Increasing blood oxygen increases an index of 5-HT synthesis in human brain as measured using alpha-[(11)C]methyl-L-tryptophan and positron emission tomography.

The main objective of this investigation was to test the hypothesis that brain serotonin (5-HT) synthesis, as measured by trapping of alpha-[(11)C]methyl-L-tryptophan (alpha-MTrp) using positron emission tomography (PET), can be modulated by changes in blood oxygen. The study involved six healthy participants (three male and three female), who breathed a 15% or 60% oxygen mixture starting 15 min before the injection of tracer and continuing during the entire acquisition period. Participants were injected with up to 12m Ci of alpha-MTrp. Two sets of PET images were acquired while the participants were breathing each of the oxygen mixtures and, after reconstruction, all images were converted into brain functional images illustrating the brain trapping constant K(*) (microL/g/min). The K(*) values were obtained for 12 regions of interest outlined on the magnetic resonance images. The K(*) values obtained at high and low blood oxygen content were compared by paired statistics using Tukey's post hoc correction. As there were no difference in plasma tryptophan concentrations, these K(*) values are directly related to regional 5-HT synthesis. The results showed highly significant increases (50% on average) in brain serotonin synthesis (K(*) values) at high (mean value of 223+/-41 mmHg) relative to low (mean value 77.1+/-7.7 mmHg) blood oxygen levels. This suggests that tryptophan hydroxylase is not saturated with oxygen in the living human brain and that increases in blood oxygen can elevate brain serotonin synthesis.