Melancholic and atypical subtypes of depression represent distinct pathophysiological entities: CRH, neural circuits, and the diathesis for anxiety and depression

Depression with immuno-metabolic dysregulation: Testing pragmatic criteria to stratify patients

INTRODUCTION

Inflammatory and metabolic processes are linked to depression, but only 25-30% of depressed patients show low-grade inflammation and metabolic dysregulation associated with atypical, energy-related symptoms (AES). Interventions targeting immuno-metabolic dysregulation could benefit depressed patients, but currently no consensus exists how to best select patients with immuno-metabolic dysregulations. Therefore, we investigated which combinations of circulating C-reactive protein (CRP) and AES could identify those depressed individuals with significant immuno-metabolic dysregulation.

METHODS

Data are from 1,077 persons with a current Major Depressive Disorder (MDD) of the Netherlands Study of Depression and Anxiety. Immuno-metabolic markers were Interleukin-6 (IL-6), Tumor Necrosis Factor alpha (TNF-α), glycoprotein acetyls, body mass index (BMI), waist circumference, triglycerides, high-density-lipoprotein cholesterol (HDL cholesterol), glucose and leptin. Strata for CRP (≤ 1, < 1 CRP ≤ 3, > 3 mg/L) and AES (score of ≤ 3, 4-5, ≥ 6) were compared on immuno-metabolic markers using analyses of covariance.

RESULTS

Across strata of CRP and AES, there was a dose-response pattern with all higher immuno-metabolic marker levels across higher strata of CRP and AES, with the exception for an association between AES and TNF-α. Persons with both elevated CRP (> 1 mg/L) and high AES (≥ 6) showed a more dysregulated inflammatory and metabolic profile compared to persons with lower CRP and/or AES (p < 0.001).

CONCLUSION

Our results show a dose-response relationship between both CRP levels and AES with immuno-metabolic risk biomarkers, indicating that CRP and AES combined can capture immuno-metabolic features of MDD. Combining these available and scalable indexes may be an effective strategy to select a patient sample with immuno-metabolic dysregulation who may benefit from treatments targeting inflammatory or metabolic pathways.

Microbiota-immune-brain interactions: A new vision in the understanding of periodontal health and disease

This review highlights the significance of interactions between the microbiota, immune system, nervous and hormonal systems, and the brain on periodontal health and disease. Microorganisms in the microbiota, immune cells, and neurons communicate via homeostatic nervous and hormonal systems, regulating vital body functions. By modulating pro-inflammatory and anti-inflammatory adaptive immune responses, these systems control the composition and number of microorganisms in the microbiota. The strength of these brain-controlled responses is genetically determined but is sensitive to early childhood stressors, which can permanently alter their responsiveness via epigenetic mechanisms, and to adult stressors, causing temporary changes. Clinical evidence and research with humans and animal models indicate that factors linked to severe periodontitis enhance the responsiveness of these homeostatic systems, leading to persistent hyperactivation. This weakens the immune defense against invasive symbiotic microorganisms (pathobionts) while strengthening the defense against non-invasive symbionts at the gingival margin. The result is an increased gingival tissue load of pathobionts, including Gram-negative bacteria, followed by an excessive innate immune response, which prevents infection but simultaneously destroys gingival and periodontal tissues. Thus, the balance between pro-inflammatory and anti-inflammatory adaptive immunity is crucial in controlling the microbiota, and the responsiveness of brain-controlled homeostatic systems determines periodontal health.

Efficacy of whole system ayurveda management protocol in major depressive disorder- A randomized controlled clinical trial

BACKGROUND

Major Depressive Disorder (MDD) is one of the common depressive disorder. MDD has high comorbidity and has greater implications on quality of life. Whole system Ayurveda management protocol (WSAP) is explored for it's possible role in management of MDD.

OBJECTIVE

To evaluate the efficacy of Whole system Ayurveda management protocol on Major Depressive Disorder.

MATERIAL AND METHODS

Study was a randomized controlled trial. Total 50 patients of MDD meeting the DSM V criteria, age group 20-70 years of either sex participated in the study. They were randomly divided into two groups, control group received Escitalopram 10 mg twice a day and Ayurveda group was on WSAP. Interventions were for 60 days. Assessments were done through various clinical parameters like Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), Brief psychiatric rating scale (BPRS), Pittsburgh Sleep Quality Index (PSQI), WHO Quality of Life- BREF (WHOQOL-BREF), Clinical Global Improvement scale (CGI), UKU Side effect scale. Assessments during intervention was on every 15th day.

RESULTS

Study showed that Ayurveda group produced significant outcome improvement compared to control group in HDRS (p = 0.01), HARS (p = 0.03), PSQI (p = 0.03), WHOQOL-Bref (p < 0.001) and UKU side effect scale (p = 0.02). Both the group showed improvements in all the parameters except in WHOQOL-Bref where Ayurveda group only showed improvements (p < 0.001). Effect size showed large effect in WHOQOL-Bref. Mild side effects were reported in control group and none in Ayurveda group.

CONCLUSION

WSAP was effective in management of MDD and had better side effect profile. Further studies needed.

Changes in Multiple microRNA Levels with Antidepressant Treatment Are Associated with Remission and Interact with Key Pathways: A Comprehensive microRNA Analysis

Individual treatment outcomes to antidepressants varies widely, yet the determinants to this difference remain elusive. MicroRNA (miRNA) gene expression regulation in major depressive disorder (MDD) has attracted interest as a biomarker. This 4-week randomized controlled trial examined changes in the plasma miRNAs that correlated with the treatment outcomes of mirtazapine (MIR) and selective serotonin reuptake inhibitor (SSRI) monotherapy. Pre- and post- treatment, we comprehensively analyzed the miRNA levels in MDD patients, and identified the gene pathways linked to these miRNAs in 46 patients. Overall, 141 miRNA levels significantly demonstrated correlations with treatment remission after 4 weeks of MIR, with miR-1237-5p showing the most robust and significant correlation after Bonferroni correction. These 141 miRNAs displayed a negative correlation with remission, indicating a decreasing trend. These miRNAs were associated with 15 pathways, including TGF-β and MAPK. Through database searches, the genes targeted by these miRNAs with the identified pathways were compared, and it was found that MAPK1, IGF1, IGF1R, and BRAF matched. Alterations in specific miRNAs levels before and after MIR treatment correlated with remission. The miRNAs mentioned in this study have not been previously reported. No other studies have investigated treatment with MIR. The identified miRNAs also correlated with depression-related genes and pathways.

Genetic underpinnings of affective temperaments: a pilot GWAS investigation identifies a new genome-wide significant SNP for anxious temperament in ADGRB3 gene

Although recently a large-sample GWASs identified significant loci in the background of depression, the heterogeneity of the depressive phenotype and the lack of accurate phenotyping hinders applicability of findings. We carried out a pilot GWAS with in-depth phenotyping of affective temperaments, considered as subclinical manifestations and high-risk states for affective disorders, in a general population sample of European origin. Affective temperaments were measured by TEMPS-A. SNP-level association was assessed by linear regression models, assuming an additive genetic effect, using PLINK1.9. Gender, age, the first ten principal components (PCs) and the other four temperaments were included in the regression models as covariates. SNP-level relevances (p-values) were aggregated to gene level using the PEGASUS method¹. In SNP-based tests, a Bonferroni-corrected significance threshold of p ≤ 5.0 × 10^-8 and a suggestive significance threshold of p ≤ 1.0 × 10^-5, whereas in gene-based tests a Bonferroni-corrected significance of 2.0 × 10^-6 and a suggestive significance of p ≤ 4.0 × 10^-4 was established. To explore known functional effects of the most significant SNPs, FUMA v1.3.5 was used. We identified 1 significant and 21 suggestively significant SNPs in ADGRB3, expressed in the brain, for anxious temperament. Several other brain-relevant SNPs and genes emerged at suggestive significance for the other temperaments. Functional analyses reflecting effect on gene expression and participation in chromatin interactions also pointed to several genes expressed in the brain with potentially relevant phenotypes regulated by our top SNPs. Our findings need to be tested in larger GWA studies and candidate gene analyses in well-phenotyped samples in relation to affective disorders and related phenotypes.

Elucidating the Possible Role of FoxO in Depression

Forkhead box-O (FoxO) transcriptional factors perform essential functions in several physiological and biological processes. Recent studies have shown that FoxO is implicated in the pathophysiology of depression. Changes in the upstream mediators of FoxOs including brain-derived neurotrophic factor (BDNF) and protein kinase B have been associated with depressive disorder and the antidepressant agents are known to alter the phosphorylation of FoxOs. Moreover, FoxOs might be regulated by serotonin or noradrenaline signaling and the hypothalamic-pituitary-adrenal (HPA)-axis,both of them are associated with the development of the depressive disorder. FoxO also regulates neural morphology, synaptogenesis, and neurogenesis in the hippocampus, which accounts for the pathogenesis of the depressive disorder. The current article underlined the potential functions of FoxOs in the etiology of depressive disorder and formulate few essential proposals for further investigation. The review also proposes that FoxO and its signal pathway might establish possible therapeutic mediators for the management of depressive disorder.

Endocrine Factors in Key Structural and Intracellular Changes in Depression

Endocrine disturbances play predominant roles in recently discovered, clinically relevant abnormalities in depression. These affect multiple sites in the prefrontal cortex, amygdala, hippocampus, nucleus accumbens, and habenula. Deficits consist of changes in volume, neuroplasticity, neural connectivity, synapse composition, and neurogenesis. Depression is associated with endocrine-related, premature systemic disease, that results in a loss of approximately 7 years of life. CRH, glucocorticoids, somatostatin, gonadal steroids, and thyroid hormones all contribute to the deficits that largely define the pathophysiologic presentation of depression. The World Health Organization ranks depression as the second greatest cause of disability worldwide. The response rate to current antidepressants is below 60%. It is important that new knowledge about the endocrine-mediated pathophysiology of depression be communicated to provide targets for new agents.

Is there a relation between major depression and hair cortisol? A systematic review and meta-analysis

Literature supports a causal role of stress in major depressive disorder (MDD). Hair cortisol concentration (HCC) has been widely used as a measure of long-term stress. Although elevated HCC has been observed in healthy people experiencing chronic stress, findings regarding individuals with mental disorders have been complicated. This review attempts to systematically present all the published research on major depression and HCC. An extensive search of databases was performed to identify articles that investigated this question. The initial search retrieved 142 studies, of which, 16 original articles were included in this review. Results were contradictory; most of the studies showed no significant HCC differences between MDD patients and controls, while others indicated either higher or lower HCC in MDD patients than controls. Higher HCC was reported in first depressive episode compared to recurrent MDD and controls; patients with comorbid MDD and anxiety disorder had higher HCC than controls. No significant HCC difference was found between patients with melancholic or atypical depression and controls. Findings concerning HCC in postpartum depression were inconsistent. A meta-analysis of the data extracted from seven studies of the sample was performed to quantify the degree of cortisol change in MDD patients vs. controls. A random effects model revealed no significant hair cortisol concentrations difference between depressed patients and healthy controls (SMD: -0.02, 95% CI: -0.36 to 0.32). Significant heterogeneity was identified across included studies (P = 0.002, I² = 71%). The disagreement among studies' results indicates that there is room for improvement in this research field. Confounding factors independent of depression should be taken into consideration.

The effects of ketamine on typical and atypical depressive symptoms

OBJECTIVE

Ketamine's effects on different dimensions of depressive symptomatology, including typical/melancholic and atypical depression, remain largely unknown. This study examined the effects of a single intravenous dose of ketamine on general depressive symptoms (measured using the Montgomery-Asberg Depression Rating Scale (MADRS), typical/melancholic symptoms (measured using the MADRS5), and atypical symptoms (measured using the Scale for Atypical Symptoms (SAS)).

METHODS

Data from 68 participants with treatment-resistant major depressive disorder (MDD) or bipolar depression were pooled from three separate, double-blind, placebo-controlled, crossover studies investigating ketamine's efficacy in depression. MDD participants were unmedicated; bipolar participants received therapeutic-dose lithium or valproate. Clinical symptoms were collected preinfusion and up to 14 days postinfusion. Effect sizes were calculated for days 1 and 3 postinfusion. The primary measures of interest for this exploratory analysis were total MADRS, MADRS5, and SAS scores. Individual symptoms were also analyzed in an exploratory manner.

RESULTS

Scores improved significantly at Day 1 postinfusion (MADRS: Cohen's d = 0.64; MADRS5: Cohen's d = 0.61; SAS: Cohen's d = 0.41) and continued to be significantly improved over placebo at Day 3 (MADRS: Cohen's d = 0.49; MADRS5: Cohen's d = 0.43; SAS: Cohen's d = 0.39). Effect sizes were greater for typical/melancholic than atypical symptoms at Day 1 postinfusion.

CONCLUSION

Ketamine appears to effectively treat both the typical/melancholic and atypical symptoms of depression, but may have early preferential effects for the former.

Systemic neuro-dysregulation in depression: Evidence from genome-wide association

Depression is the world's leading cause of disability. Greater understanding of the neurobiological basis of depression is necessary for developing novel treatments with improved efficacy and acceptance. Recently, major advances have been made in the search for genetic variants associated with depression which may help to elucidate etiological mechanisms. The present review has two major objectives. First, we offer a brief review of two major biological systems with strong evidence for involvement in depression pathology: neurotransmitter systems and the stress response. Secondly, we provide a synthesis of the functions of the 269 genes implicated by the most recent genome-wide meta-analysis, supporting the importance of these systems in depression and providing insights into other possible mechanisms involving neurodevelopment, neurogenesis, and neurodegeneration. Our goal is to undertake a broad, preliminary stock-taking of the most recent hypothesis-free findings and examine the weight of the evidence supporting these existing theories and highlighting novel directions. This qualitative review and accompanying gene function table provides a valuable resource and guide for basic and translational researchers, with suggestions for future mechanistic research, leveraging genetics to prioritize studies on the neurobiological processes involved in depression etiology and treatment.

Fatigue in Cancer and Neuroinflammatory and Autoimmune Disease: CNS Arousal Matters

The term fatigue is not only used to describe a sleepy state with a lack of drive, as observed in patients with chronic physical illnesses, but also a state with an inhibition of drive and central nervous system (CNS) hyperarousal, as frequently observed in patients with major depression. An electroencephalogram (EEG)-based algorithm has been developed to objectively assess CNS arousal and to disentangle these pathophysiologically heterogeneous forms of fatigue. The aim of this study was to test the hypothesis that fatigued patients with CNS hyperarousal score higher on depressive symptoms than those without this neurophysiological pattern.

METHODS

Subjects with fatigue (Multidimensional Fatigue Inventory sum-score > 40) in the context of cancer, neuroinflammatory, or autoimmune diseases were drawn from the 60+ cohort of the Leipzig Research Center for Civilization Diseases. CNS arousal was assessed by automatic EEG-vigilance stage classification using the Vigilance Algorithm Leipzig (VIGALL 2.1) based on 20 min EEG recordings at rest with eyes closed. Depression was assessed by the Inventory of Depressive Symptomatology (IDS-SR).

RESULTS

Sixty participants (33 female; median age: 67.5 years) were included in the analysis. As hypothesized, fatigued patients with CNS hyperarousal had higher IDS-SR scores than those without hyperarousal (F_1,58 = 18.34; p < 0.0001, η² = 0.240).

CONCLUSION

hyperaroused fatigue in patients with chronic physical illness may be a sign of comorbid depression.

Appetite changes reveal depression subgroups with distinct endocrine, metabolic, and immune states

There exists little human neuroscience research to explain why some individuals lose their appetite when they become depressed, while others eat more. Answering this question may reveal much about the various pathophysiologies underlying depression. The present study combined neuroimaging, salivary cortisol, and blood markers of inflammation and metabolism collected prior to scanning. We compared the relationships between peripheral endocrine, metabolic, and immune signaling and brain activity to food cues between depressed participants experiencing increased (N = 23) or decreased (N = 31) appetite and weight in their current depressive episode and healthy control participants (N = 42). The two depression subgroups were unmedicated and did not differ in depression severity, anxiety, anhedonia, or body mass index. Depressed participants experiencing decreased appetite had higher cortisol levels than subjects in the other two groups, and their cortisol values correlated inversely with the ventral striatal response to food cues. In contrast, depressed participants experiencing increased appetite exhibited marked immunometabolic dysregulation, with higher insulin, insulin resistance, leptin, CRP, IL-1RA, and IL-6, and lower ghrelin than subjects in other groups, and the magnitude of their insulin resistance correlated positively with the insula response to food cues. These findings provide novel evidence linking aberrations in homeostatic signaling pathways within depression subtypes to the activity of neural systems that respond to food cues and select when, what, and how much to eat. In conjunction with prior work, the present findings strongly support the existence of pathophysiologically distinct depression subtypes for which the direction of appetite change may be an easily measured behavioral marker.

Comparison of short-term (saliva) and long-term (hair) cortisol levels in out-patients with melancholic and non-melancholic major depression

BACKGROUND

Major depressive episodes (MDEs) show diverse cortisol level alterations. Heterogeneity in symptom profiles, symptom severity and cortisol specimens may explain these heterogeneous results. Less severely ill out-patients with a non-melancholic MDE (NM-MDE) may have a variation in the rhythm of cortisol secretion rather than in its concentration.

METHOD

Cortisol measures were taken (a) over a short-term period (12 h) by measuring daily salivary output using the area under the curve with respect to the ground (AUCg) and (b) over a long-term period (3 months) in hair. Additionally, cortisol reactivity measures in saliva - the cortisol awakening response and the 30 min delta cortisol secretion after awakening (DELTA) - were investigated in 19 patients with a melancholic MDE (M-MDE) and 52 with a NM-MDE, and in 40 matched controls who were recruited from the UK and Chile. Depression severity scores were correlated with different cortisol measures.

RESULTS

The NM-MDE group showed a decreased AUCg in comparison with controls (P = 0.02), but normal cortisol reactivity and long-term cortisol levels. The M-MDE group did not exhibit any significant cortisol alterations nor an association with depression severity scores. Higher Hamilton Rating Scale for Depression score was linked with decreased hair cortisol concentration (HCC, P = 0.05) and higher DELTA (P = 0.04) in NM-MDEs, whereas decreased HCC was the sole alteration associated with out-patients with severe M-MDEs.

CONCLUSIONS

The contrasting short- and long-term cortisol output results are compatible with an alteration in the rhythm of cortisol secretion in NM-MDEs. This alteration may consist of large and/or intense episodes of hypercortisolaemia in moderate NM-MDEs and frequent, but brief and sharp early-morning DELTAs in its severe form. These changes may reflect the effects of environmental factors or episodes of nocturnal hypercortisolaemia that were not measured by the short-term samples used in this study.

Genetic variation of the mineralocorticoid receptor gene (MR, NR3C2) is associated with a conceptual endophenotype of "CRF-hypoactivity"

Recently, the "conceptual endophenotype" approach has been proposed as a means to identify subgroups of patients affected by stress-related psychiatric disorders. Conceptual endophenotypes consist of patterns of psychological, biological, and symptomatic elements. We studied a sample of patients seeking help for psychosomatic and stress-related disorders (total N = 469), who were evaluated with a diagnostic instrument that integrates psychological and biological data to derive 13 endophenotypes, or Neuropattern. The goal of this study was to explore associations between common variations of the mineralocorticoid receptor gene (MR, NR3C2), and the 13 conceptual endophenotypes of Neuropattern, as well as with the respective biological and symptom measures. A common haplotype of the MR, comprised of two functional single nucleotide polymorphism (rs2070951 G/C & rs5522 A/G), was associated with the conceptual endophenotype CRF-hypoactivity, characterized by low cortisol levels at awakening and a symptom constellation often observed in atypical depression. Homozygous carriers of the G-A haplotype (haplotype 1), previously associated with reduced dispositional optimism, increased levels of rumination and higher risk for depression, more frequently endorsed this Neuropattern. In addition to the overall association between MR variation and CRF hypoactivity, we observed in the whole sample significant associations between MR haplotypes and cortisol awakening response patterns, as well as with symptoms that characterize the CRF hypoactivity endophenotype. If replicated, MR haplotype 1 might serve as a vulnerability marker for a disorder class characterized in biological terms by reduced cortisol levels, and in terms of symptom constellation by features often observed in atypical depression.

Prevalence and clinical features of atypical depression among patients with major depressive disorder in China

BACKGROUND

Little is known about the demographic and clinical features of the atypical subtype of major depressive disorder (MDD) patients in China. This study set out to investigate the prevalence of atypical depression in MDD patients in China, and identify its demographic and clinical features.

METHODS

The study was conducted in 13 major psychiatric hospitals or in the psychiatric units of general hospitals in China, and recruited a sample of 1172 patients diagnosed with MDD. The patients' demographic and clinical features and prescriptions of psychotropic drugs were collected using a standardized questionnaire designed for the study.

RESULTS

The prevalence of atypical depression was 15.3%. In multiple logistic regression analyses, compared to the non-atypical depression patients, the atypical depression patients were more likely to have depressive episodes with suicide ideation and attempts (OR = 1.49, 95% CI = 1.06, 2.10, P = 0.023), depressive episodes with psychotic features (OR = 2.15, 95% CI = 1.43, 3.22, P < 0.001), seasonal depressive episodes (OR = 1.77, 95% CI = 1.12, 2.78, P = 0.014), an earlier age of onset (OR = 0.98, 95% CI = 0.96, 0.99, P = 0.001), and lifetime depressive episodes (OR = 1.07, 95% CI = 1.01, 1.13, P = 0.020).

LIMITATIONS

The assessment of atypical features was not based on a validated rating scale.

CONCLUSION

Our results indicate that atypical depression is common in Chinese patients with MDD. MDD with atypical features may be more severe and debilitating than patients with non-atypical features.

Mapping depression rating scale phenotypes onto research domain criteria (RDoC) to inform biological research in mood disorders

BACKGROUND

Substantial research progress can be achieved if available clinical datasets can be mapped to the National Institute of Mental Health Research-Domain-Criteria (RDoC) constructs. This mapping would allow investigators to both explore more narrowly defined clinical phenotypes and the relationship of these phenotypes to biological markers and clinical outcomes approximating RDoC criteria.

METHODS

Using expert review and consensus, we defined four major depression phenotypes based on specific RDoC constructs. Having matched these constructs to individual items from the Hamilton Depression Rating Scale and Quick Inventory of Depressive Symptomatology, we identified subjects meeting criteria for each of these phenotypes from two large clinical trials of patients treated for major depression. In a post hoc analysis, we evaluated the overall treatment response based on the phenotypes: Core Depression (CD), Anxiety (ANX), and Neurovegetative Symptoms of Melancholia (NVSM) and Atypical Depression (NVSAD).

RESULTS

The phenotypes were prevalent (range 10.5-52.4%, 50% reduction range 51.9-82.9%) and tracked with overall treatment response. Although the CD phenotype was associated with lower rates of remission in both cohorts, this was mainly driven by baseline symptom severity. However, when controlling for baseline severity, patients with the ANX phenotype had a significantly lower rate of remission.

LIMITATIONS

The lack of replication between the studies of the phenotypes' treatment prediction value reflects important variability across studies that may limit generalizability.

CONCLUSION

Further work evaluating biological markers associated with these phenotypes is needed for further RDoC concept development.

Stress and cortisol responses in men: differences according to facial symmetry

Stress response is associated with increased activity in the hypothalamic-pituitary-adrenocortical axis. Chronic stress-induced elevation in cortisol may alter its own negative regulation with multiple long-term consequences for physical and psychological health. One of the most reliable physical traits associated with mental, apparent physical health, and competitiveness is the degree of facial fluctuating asymmetry. However, to our knowledge there are no studies regarding the relationship between cortisol levels, facial symmetry and male competitiveness, and how cortisol changes after a stressful test depending on these traits. Here, a group of 100 college men were photographed to obtain their facial asymmetry levels. They then, answered the perceived stress scale and the intrasexual competition test and donated two saliva samples (pre-and post-test sample) to measure the change in their cortisol levels after a stressful test. We found that basal cortisol levels were positively correlated with both perceived stress and competitiveness, but not with facial fluctuating asymmetry. Cortisol levels increased in most symmetrical men after a short stressful test, but it decreased in most asymmetrical men. The results suggest differences in endocrine responses according to facial fluctuating asymmetry in men and how these responses could be related to the maintenance of social status.

The cortisol:C-reactive protein ratio and negative affect reactivity in depressed adults

OBJECTIVE

We evaluated the effect of the cortisol (CORT) to high sensitivity C-reactive protein (hsCRP) ratio on stress-induced negative affect (NA) reactivity and whether the association was moderated by depressive symptom severity and gender. The CORT/CRP ratio was used to evaluate the integrity of the negative feedback loop between the hypothalamic-pituitary-adrenal axis and inflammatory response system.

METHOD

Basal CORT and hsCRP levels were measured in fasting blood samples from 198 medication-free and nonsmoking healthy men and women. Depressive symptom severity was assessed using the Hamilton Rating Scale for Depression (HAMD). NA ratings were collected at baseline and at the completion of the laboratory stressors, the Anger Recall Interview (ARI) and reading.

RESULTS

Adjusting for potential confounders and baseline NA, analysis revealed a significant relationship between CORT/CRP ratio and NA reactivity to ARI as a function of depressive symptom severity. Simple effects revealed that for participants with high HAMD, decreasing CORT/CRP ratio, suggestive of an insufficient CORT release relative to higher hsCRP, predicted increasing stress-induced NA reactivity. For participants with low HAMD, the CORT/CRP ratio failed to predict NA reactivity. Gender did not moderate the joint effect of depressive symptom severity and the CORT/CRP ratio on stress-induced NA reactivity.

CONCLUSIONS

This is the first study to document that a premorbid dysregulation of the neuro-immune relationship, characterized by an insufficient release of CORT in conjunction with higher CRP, plays a role in stress sensitivity, and specifically NA reactivity, in individuals with elevated levels of depression symptoms. (PsycINFO Database Record

The role of adipokines in the rapid antidepressant effects of ketamine

We previously found that body mass index (BMI) strongly predicted response to ketamine. Adipokines have a key role in metabolism (including BMI). They directly regulate inflammation and neuroplasticity pathways and also influence insulin sensitivity, bone metabolism and sympathetic outflow; all of these have been implicated in mood disorders. Here, we sought to examine the role of three key adipokines-adiponectin, resistin and leptin-as potential predictors of response to ketamine or as possible transducers of its therapeutic effects. Eighty treatment-resistant subjects who met DSM-IV criteria for either major depressive disorder (MDD) or bipolar disorder I/II and who were currently experiencing a major depressive episode received a single ketamine infusion (0.5 mg kg-1 for 40 min). Plasma adipokine levels were measured at three time points (pre-infusion baseline, 230 min post infusion and day 1 post infusion). Overall improvement and response were assessed using percent change from baseline on the Montgomery-Asberg Depression Rating Scale and the Hamilton Depression Rating Scale. Lower baseline levels of adiponectin significantly predicted ketamine's antidepressant efficacy, suggesting an adverse metabolic state. Because adiponectin significantly improves insulin sensitivity and has potent anti-inflammatory effects, this finding suggests that specific systemic abnormalities might predict positive response to ketamine. A ketamine-induced decrease in resistin was also observed; because resistin is a potent pro-inflammatory compound, this decrease suggests that ketamine's anti-inflammatory effects may be transduced, in part, by its impact on resistin. Overall, the findings suggest that adipokines may either predict response to ketamine or have a role in its possible therapeutic effects.

Familial aggregation and heritability of the melancholic and atypical subtypes of depression

BACKGROUND

The heterogeneity of mood disorders has been a challenge to our understanding of their underlying biologic and genetic pathways. This report examines the specificity of the familial aggregation of atypical and melancholic subtypes of depression and their clinical correlates in a large community based family study of affective spectrum disorders.

METHODS

The sample includes 457 probands and their directly interviewed adult first degree relatives from the National Institute of Mental Health (NIMH) Family Study of Affective Spectrum Disorder. Depression subtypes were based on best estimate diagnoses using information from semi-structured diagnostic interviews by experienced clinical interviews and multiple family history reports.

RESULTS

Atypical depression in probands was significantly associated with the atypical subtype of depression in relatives (OR 1.75 [95%CI 1.02-3.02], p=0.04), independent of proband and relative comorbid disorders. Melancholic depression in probands was not associated with melancholic depression in relatives (OR 1.25 [95%CI 0.62-2.55], p=.53). The familial heritability of the atypical subtype was 0.46 (95%CI 0.21-0.71), whereas that of the melancholic subtype was 0.33 (95%CI 0.21-0.45). Melancholic depression was associated with greater severity in terms of treatment, global functioning, suicide attempts, comorbid disorders, and an earlier age at onset of depression.

LIMITATIONS

The subsample of interviewed relatives necessary to assess specific subtypes of depression reduced the power to detect the specificity of mood disorder subtypes.

CONCLUSION

The results indicate that the atypical subtype should be incorporated in future treatment, genetic and other etiologic studies of major depression. Findings further suggest that melancholic subtype may be an indicator of clinical severity of depression.

Role of neuroinflammation and sex hormones in war-related PTSD

The susceptibility to develop posttraumatic stress disorder (PTSD) is greatly influenced by both innate and environmental risk factors. One of these factors is gender, with women showing higher incidence of trauma-related mental health disorders than their male counterparts. The evidence so far links these differences in susceptibility or resilience to trauma to the neuroprotective actions of sex hormones in reducing neuroinflammation after severe stress exposure. In this review, we discuss the impact of war-related trauma on the incidence of PTSD in civilian and military populations as well as differences associated to gender in the incidence and recovery from PTSD. In addition, the mutually influencing role of inflammation, genetic, and sex hormones in modulating the consequences derived from exposure to traumatic events are discussed in light of current evidence.

Association of pain intensity, pain-related disability, and depression with hypothalamus-pituitary-adrenal axis function in female patients with chronic temporomandibular disorders

Patients with temporomandibular disorders (TMD) commonly experience myofascial and joint pain, pain-related disability, and other pain conditions including depression. The present study was carried out to explore the function of the hypothalamus-pituitary-adrenal (HPA) axis in relation to variables of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II and comorbid depression in female patients with TMD. Cortisol and dehydroepiandrosterone (DHEA) levels were determined in saliva samples that had been collected at various periods after waking (0, 30, and 60min) and at nighttime (2100-2200h) from 52 female patients with chronic TMD pain and age- and gender-matched controls (n=54, 20-40 years old). There were no significant differences in the levels and diurnal patterns of cortisol and DHEA secretion between groups of patients with TMD and controls. In patients, the cortisol awakening response (CAR) or diurnal cortisol rhythm were not associated with any variables of the RDC/TMD Axis II or the Beck Depression Inventory (BDI)-II total scores. However, the ratio of overall cortisol secretion within the first hour after waking (CARauc) to overall DHEA secretion during the post-waking period (Daucawk), defined as CARauc/Daucawk, was significantly associated with pain-related RDC/TMD variables (pain intensity and pain-related disability) and BDI-II total scores. Pain intensity and pain-related disability scores were also significantly associated with BDI-II total scores. These results indicated that an increase in molar cortisol/DHEA ratio due to the dissociation between cortisol and DHEA secretion was associated with pain intensity, pain-related disability, and depression in female patients with TMD.

Polygenic dissection of major depression clinical heterogeneity

The molecular mechanisms underlying major depressive disorder (MDD) are largely unknown. Limited success of previous genetics studies may be attributable to heterogeneity of MDD, aggregating biologically different subtypes. We examined the polygenic features of MDD and two common clinical subtypes (typical and atypical) defined by symptom profiles in a large sample of adults with established diagnoses. Data were from 1530 patients of the Netherlands Study of Depression and Anxiety (NESDA) and 1700 controls mainly from the Netherlands Twin Register (NTR). Diagnoses of MDD and its subtypes were based on DSM-IV symptoms. Genetic overlap of MDD and subtypes with psychiatric (MDD, bipolar disorder, schizophrenia) and metabolic (body mass index (BMI), C-reactive protein, triglycerides) traits was evaluated via genomic profile risk scores (GPRS) generated from meta-analysis results of large international consortia. Single nucleotide polymorphism (SNP)-heritability of MDD and subtypes was also estimated. MDD was associated with psychiatric GPRS, while no association was found for GPRS of metabolic traits. MDD subtypes had differential polygenic signatures: typical was strongly associated with schizophrenia GPRS (odds ratio (OR)=1.54, P=7.8e-9), while atypical was additionally associated with BMI (OR=1.29, P=2.7e-4) and triglycerides (OR=1.21, P=0.006) GPRS. Similar results were found when only the highly discriminatory symptoms of appetite/weight were used to define subtypes. SNP-heritability was 32% for MDD, 38% and 43% for subtypes with, respectively, decreased (typical) and increased (atypical) appetite/weight. In conclusion, MDD subtypes are characterized by partially distinct polygenic liabilities and may represent more homogeneous phenotypes. Disentangling MDD heterogeneity may help the psychiatric field moving forward in the search for molecular roots of depression.

Effects of Acupuncture, RU-486 on the Hypothalamic-Pituitary-Adrenal Axis in Chronically Stressed Adult Male Rats

We have recently reported that pretreatment with electroacupuncture (EA) at stomach meridian point 36 (St36) prevents the chronic cold-stress increase in the hypothalamus-pituitary-adrenal axis (HPA), an action that may be under central control. Given that treatment for stress-related symptoms usually begins after onset of the stress responses, the objectives of the present study were to determine the efficacy of EA St36 on HPA hormones when EA St36 is given after stress was initiated, if the results are long lasting, and if blocking the glucocorticoid receptor (GR) using RU-486 had the same effects as EA St36. Adult male rats were placed in 4 groups of animals, 3 of which were exposed to cold and 1 of which was a nontreatment control group. After exposure to the cold stress, 2 groups were treated with either EA St36 or sham-EA, repeated over 10 days. The increase in ACTH and corticosterone observed in stress-only rats was prevented in EA St36 animals, and the effects remained intact 4 days after withdrawal of EA but continuation of cold stress. When the GR was blocked with RU-486, the efficacy of EA St36 remained unchanged. GR blockade did significantly elevate ACTH, which is not seen with EA St36, suggesting that EA St36 does act centrally. The elevated HPA hormones in stress-only rats were associated with a significant increase in depressive and anxious behavior; this was not observed in the stressed EA St36 animals. The results indicate that EA specifically at St36 vs sham-EA is effective in treating chronic poststress exposure.

Mood and anxiety disorders as early manifestations of medical illness: a systematic review

BACKGROUND

Affective disturbances involving alterations of mood, anxiety and irritability may be early symptoms of medical illnesses. The aim of this paper was to provide a systematic review of the literature with qualitative data synthesis.

METHODS

MEDLINE, PsycINFO, EMBASE, Cochrane, and ISI Web of Science were systematically searched from inception to February 2014. Search terms were 'prodrome/early symptom', combined using the Boolean 'AND' operator with 'anxiety/depression/mania/hypomania/irritability/irritable mood/hostility', combined with the Boolean 'AND' operator with 'medical illness/medical disorder'. PRISMA guidelines were followed.

RESULTS

A total of 21 studies met the inclusion criteria and were analyzed. Depression was found to be the most common affective prodrome of medical disorders and was consistently reported in Cushing's syndrome, hypothyroidism, hyperparathyroidism, pancreatic and lung cancer, myocardial infarction, Wilson's disease, and AIDS. Mania, anxiety and irritability were less frequent.

CONCLUSIONS

Physicians may not pursue medical workup of cases that appear to be psychiatric in nature. They should be alerted that disturbances in mood, anxiety and irritability may antedate the appearance of a medical disorder.

IL-1β and BDNF are associated with improvement in hypersomnia but not insomnia following exercise in major depressive disorder

Given the role of sleep in the development and treatment of major depressive disorder (MDD), it is becoming increasingly clear that elucidation of the biological mechanisms underlying sleep disturbances in MDD is crucial to improve treatment outcomes. Sleep disturbances are varied and can present as insomnia and/or hypersomnia. Though research has examined the biological underpinnings of insomnia in MDD, little is known about the role of biomarkers in hypersomnia associated with MDD. This paper examines biomarkers associated with changes in hypersomnia and insomnia and as predictors of improvements in sleep quality following exercise augmentation in persons with MDD. Subjects with non-remitted MDD were randomized to augmentation with one of two doses of aerobic exercise: 16 kilocalories per kilogram of body weight per week (KKW) or 4 KKW for 12 weeks. The four sleep-related items on the clinician-rated Inventory of Depressive Symptomatology (sleep onset insomnia, mid-nocturnal insomnia, early morning insomnia and hypersomnia) assessed self-reported sleep quality. Inflammatory cytokines (tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6) and brain-derived neurotrophic factor (BDNF) were assessed in blood samples collected before and following the 12-week intervention. Reduction in hypersomnia was correlated with reductions in BDNF (ρ = 0.26, P = 0.029) and IL-1β (ρ = 0.37, P = 0.002). Changes in these biomarkers were not associated with changes in insomnia; however, lower baseline levels of IL-1β were predictive of greater improvements in insomnia (F = 3.87, P = 0.050). In conclusion, improvement in hypersomnia is related to reductions in inflammatory markers and BDNF in persons with non-remitted MDD. Distinct biological mechanisms may explain reductions in insomnia.

Excessive Sugar Consumption May Be a Difficult Habit to Break: A View From the Brain and Body

CONTEXT

Sugar overconsumption and chronic stress are growing health concerns because they both may increase the risk for obesity and its related diseases. Rodent studies suggest that sugar consumption may activate a glucocorticoid-metabolic-brain-negative feedback pathway, which may turn off the stress response and thereby reinforce habitual sugar overconsumption.

OBJECTIVE

The objective of the study was to test our hypothesized glucocorticoid-metabolic-brain model in women consuming beverages sweetened with either aspartame of sucrose.

DESIGN

This was a parallel-arm, double-masked diet intervention study.

SETTING

The study was conducted at the University of California, Davis, Clinical and Translational Science Center's Clinical Research Center and the University of California, Davis, Medical Center Imaging Research Center.

PARTICIPANTS

Nineteen women (age range 18-40 y) with a body mass index (range 20-34 kg/m(2)) who were a subgroup from a National Institutes of Health-funded investigation of 188 participants assigned to eight experimental groups.

INTERVENTION

The intervention consisted of sucrose- or aspartame-sweetened beverage consumption three times per day for 2 weeks.

MAIN OUTCOME MEASURES

Salivary cortisol and regional brain responses to the Montreal Imaging Stress Task were measured.

RESULTS

Compared with aspartame, sucrose consumption was associated with significantly higher activity in the left hippocampus (P = .001). Sucrose, but not aspartame, consumption associated with reduced (P = .024) stress-induced cortisol. The sucrose group also had a lower reactivity to naltrexone, significantly (P = .041) lower nausea, and a trend (P = .080) toward lower cortisol.

CONCLUSION

These experimental findings support a metabolic-brain-negative feedback pathway that is affected by sugar and may make some people under stress more hooked on sugar and possibly more vulnerable to obesity and its related conditions.

Depressogenic vulnerability and gender-specific patterns of neuro-immune dysregulation: What the ratio of cortisol to C-reactive protein can tell us about loss of normal regulatory control

We examined whether the ratio of cortisol (CORT) to high-sensitivity C-reactive protein (hsCRP), an index that captures the integrity of homeostatic regulation between the hypothalamic-pituitary-adrenal (HPA) axis and inflammatory processes, is associated with vulnerability to depression in a gender specific manner and whether glucocorticoid receptor (GR) sensitivity plays a role in these associations. Fasting blood samples were collected between 08:45 and 09:15 and assayed for CORT, hsCRP, and leukocyte count in 213 healthy, medication-free men and women. The NEO-Personality Inventory was used to assess neuroticism, extraversion and anxiety. We used the Hamilton Depression Interview to assess depressive symptoms, the Buss-Perry anger subscale to measure anger, and the Pittsburgh Sleep Quality Index to evaluate subjective sleep quality and its components. Log-transformed CORT/CRP values were analyzed using multiple regression with Holms' adjusted p-values and age, body mass index (BMI), and race as covariates. GR sensitivity was estimated using the log-transformed ratio of neutrophils (N)-to-monocytes (M). The log-transformed ratio of CORT/CRP did not differ between men and women but was significantly and negatively associated with age and BMI. Severity of depressive symptoms, extraversion, anxiety, and sleep quality were associated with the CORT/CRP ratio in a gender-specific manner. For women, decreasing CORT/CRP ratios, suggestive of an insufficient release of CORT coupled with a heightened inflammatory state, were associated with increasing severity of depressive symptoms, decreasing quality of sleep, increasing frequency of sleep disturbance, and decreasing extraversion. For men, increasing frequency of daytime disturbance and levels of anxiety were associated with increasing CORT/CRP ratio, suggestive of an enhanced release of CORT relative to attenuated levels of hsCRP. For both genders, increasing anger was associated with decreasing CORT/CRP ratios. Although results suggested GR downregulation in women but not men, such differences did not mediate the observed associations. With the use of the CORT/CRP ratio, we showed that vulnerability factors for depression are associated with a loss of normal regulatory controls resulting in gender-specific patterns of neuro-immune dysregulation. That GR downregulation did not influence these associations suggests that the loss of regulatory controls in at risk individuals is primarily at the level of the hormone. Beyond the individual contribution of each component of the CORT/CRP ratio, disruption of normal neuroimmune regulatory feedback provides a plausible biological framework useful in understanding biobehavioral vulnerabilities to depression in a gender specific manner. The CORT/CRP ratio may be a viable biomarker not only for delineating risk for MDD but also progression and treatment responses among patients with MDD; possibilities that are testable in future studies.

The organization of the stress system and its dysregulation in depressive illness

Stressors are imminent or perceived challenges to homeostasis. The stress response is an innate, stereotypic, adaptive response to stressors that has evolved in the service of restoring the nonstressed homeostatic set point. It is encoded in specific neuroanatomical sites that activate a specific repertoire of cognitive, behavioral and physiologic phenomena. Adaptive responses, though essential for survival, can become dysregulated and result in disease. A clear example is autoimmune disease. I postulate that depression, like autoimmunity, represents a dysregulated adaptive response: a stress response that has gone awry. The cardinal manifestation of the normal stress response is anxiety. Cognitive programs shift from complex associative operations to rapid retrieval of unconscious emotional memories acquired during prior threatening situations. These emerge automatically to promote survival. To prevent distraction during stressful situations, the capacity to seek and experience pleasure is reduced, food intake is diminished and sexual activity and sleep are held in abeyance. Monoamines, cytokines, glutamate, GABA and other central mediators have key roles in the normal stress response. Many central loci are involved. The subgenual prefrontal cortex restrains the amygdala, the corticotropin-releasing hormone/hypothalamic-pituitary-adrenal (CRH/HPA) axis and the sympathomedullary system. The function of the subgenual prefrontal cortex is moderately diminished during normal stress to disinhibit these loci. This disinhibition promotes anxiety and physiological hyperarousal, while diminishing appetite and sleep. The dorsolateral prefrontal cortex is downregulated, diminishing cognitive regulation of anxiety. The nucleus accumbens is also downregulated, to reduce the propensity for distraction by pleasurable stimuli or the capacity to experience pleasure. Insulin resistance, inflammation and a prothrombotic state acutely emerge. These provide increased glucose for the brain and establish premonitory, proinflammatory and prothrombotic states in anticipation of either injury or hemorrhage during a threatening situation. Essential adaptive intracellular changes include increased neurogenesis, enhancement of neuroplasticity and deployment of a successful endoplasmic reticulum stress response. In melancholic depression, the activities of the central glutamate, norepinephrine and central cytokine systems are significantly and persistently increased. The subgenual prefrontal cortex is functionally impaired, and its size is reduced by as much as 40%. This leads to sustained anxiety and activations of the amygdala, CRH/HPA axis, the sympathomedullary system and their sequella, including early morning awakening and loss of appetite. The sustained activation of the amygdala, in turn, further activates stress system neuroendocrine and autonomic functions. The activity of the nucleus accumbens is further decreased and anhedonia emerges. Concomitantly, neurogenesis and neuroplasticity fall significantly. Antidepressants ameliorate many of these processes. The processes that lead to the behavioral and physiological manifestations of depressive illness produce a significant decrease in lifespan, and a doubling of the incidence of premature coronary artery disease. The incidences of premature diabetes and osteoporosis are also substantially increased. Six physiological processes that occur during stress and that are markedly increased in melancholia set into motion six different mechanisms to produce inflammation, as well as sustained insulin resistance and a prothrombotic state. Clinically, melancholic and atypical depression seem to be antithesis of one another. In melancholia, depressive systems are at their worst in the morning when arousal systems, such as the CRH/HPA axis and the noradrenergic systems, are at their maxima. In atypical depression, depressive symptoms are at their worst in the evening, when these arousal systems are at their minima. Melancholic patients experience anorexia and insomnia, whereas atypical patients experience hyperphagia and hypersomnia. Melancholia seems like an activation and persistence of the normal stress response, whereas atypical depression resembles a stress response that has been excessively inhibited. It is important that we stratify clinical studies of depressed patients to compare melancholic and atypical subtypes and establish their differential pathophysiology. Overall, it is important to note that many of the major mediators of the stress response and melancholic depression, such as the subgenual prefrontal cortex, the amygdala, the noradrenergic system and the CRH/HPA axis participate in multiple reinforcing positive feedback loops. This organization permits the establishment of the markedly exaggerated, persistent elevation of the stress response seen in melancholia. Given their pronounced interrelatedness, it may not matter where in this cascade the first abnormality arises. It will spread to the other loci and initiate each of their activations in a pernicious vicious cycle.

Mineralocorticoid receptor stimulation improves cognitive function and decreases cortisol secretion in depressed patients and healthy individuals

Memory and executive function are often impaired in patients with major depression, while cortisol secretion is increased. Mineralocorticoid receptors (MR) are abundantly expressed in the hippocampus and in the prefrontal cortex, brain areas critical for memory, executive function, and cortisol inhibition. Here, we investigated whether MR stimulation with fludrocortisone (1) improves memory and executive function and (2) decreases cortisol secretion in depressed patients and healthy individuals. Twenty-four depressed patients without medication and 24 age-, sex-, and education-matched healthy participants received fludrocortisone (0.4 mg) or placebo in a randomized, double-blind, within-subject cross-over design. We measured verbal memory, visuospatial memory, executive function, psychomotor speed, and salivary cortisol secretion during cognitive testing between 1400 and 1700 hours. For verbal memory and executive function, we found better performance after fludrocortisone compared with placebo across groups. No treatment effect on other cognitive domains emerged. Depressed patients performed worse than healthy individuals in psychomotor speed and executive function. No group effect or group × treatment interaction emerged on other cognitive domains. Fludrocortisone decreased cortisol secretion across groups and there was a significant correlation between cortisol inhibition and verbal memory performance. Our data suggest a crucial role of MR in verbal memory and executive function and demonstrate the possibility to improve cognition in depressed patients and healthy individuals through MR stimulation.

The missing link between clinical states and biomarkers in mental disorders

Current diagnostic definitions of psychiatric disorders based on collections of symptoms encompass very heterogeneous populations and are thus likely to yield spurious results when exploring biological correlates of mental disturbances. It has been suggested that large studies of biomarkers across diagnostic entities may yield improved clinical information. Such a view is based on the concept of assessment as a collection of symptoms devoid of any clinical judgment and interpretation. Yet, important advances have been made in recent years in clinimetrics, the science of clinical judgment. The current clinical taxonomy in psychiatry, which emphasizes reliability at the cost of clinical validity, does not include effects of comorbid conditions, timing of phenomena, rate of progression of an illness, responses to previous treatments, and other clinical distinctions that demarcate major prognostic and therapeutic differences among patients who otherwise seem to be deceptively similar since they share the same psychiatric diagnosis. Clinimetrics may provide the missing link between clinical states and biomarkers in psychiatry, building pathophysiological bridges from clinical manifestations to their neurobiological counterparts.

Adipokines as emerging depression biomarkers: a systematic review and meta-analysis

Adiponectin, leptin and resistin may play a role in the pathophysiology of major depressive disorder (MDD). However, differences in peripheral levels of these hormones are inconsistent across diagnostic and intervention studies. Therefore, we performed meta-analyses of diagnostic studies (i.e., MDD subjects versus healthy controls) and intervention investigations (i.e., pre-vs. post-antidepressant treatment) in MDD. Adiponectin (N = 1278; Hedge's g = -0.35; P = 0.16) and leptin (N = 893; Hedge's g = -0.018; P = 0.93) did not differ across diagnostic studies. Meta-regression analyses revealed that gender and depression severity explained the heterogeneity observed in adiponectin diagnostic studies, while BMI and the difference in BMI between MDD individuals and controls explained the heterogeneity of leptin diagnostic studies. Subgroup analyses revealed that adiponectin peripheral levels were significantly lower in MDD participants compared to controls when assayed with RIA, but not ELISA. Leptin levels were significantly higher in individuals with mild/moderate depression versus controls. Resistin serum levels were lower in MDD individuals compared to healthy controls (N = 298; Hedge's g = -0.25; P = 0.03). Leptin serum levels did not change after antidepressant treatment. However, heterogeneity was significant and sample size was low (N = 108); consequently meta-regression analysis could not be performed. Intervention meta-analyses could not be performed for adiponectin and resistin (i.e., few studies met inclusion criteria). In conclusion, this systematic review and meta-analysis underscored that relevant moderators/confounders (e.g., BMI, depression severity and type of assay) should be controlled for when considering the role of leptin and adiponectin as putative MDD diagnostic biomarkers.

A functional polymorphism in the HTR2C gene associated with stress responses: a validation study

Previously we have shown that a functional nonsynonymous single nucleotide polymorphism (SNP), rs6318 on the HTR2C gene located on the X-chromosome, is associated with hypothalamic-pituitary-adrenal axis response to a laboratory stress recall task. The present paper reports a validation of the cortisol response to stress in a second, independent sample. The study population consisted of 60 adult participants (73.3% males). Consistent with our prior findings, compared to Cys23 G allele carriers, persons homozygous for the Ser23C allele had a significantly greater average cortisol response (p=0.007) and area under the curve (p=0.021) over the course of an emotional stress recall protocol. Also parallel to our prior report, the change in cortisol from baseline to the average during the stress protocol was roughly twice as large among Ser23C homozygotes than among persons with Cys23 G. These findings validate our initial observation of association between rs6318 and cortisol response to an acute stressor, and extend the results to include females.

Childhood depression subscales using repeated sessions on Children's Depression Rating Scale - revised (CDRS-R) scores

BACKGROUND

Although acute treatments have been shown to be effective in treating early-onset depression, only one-third or thereabouts reach a remission within 3 months. Unfortunately, delayed time to remission in early-onset depression leads to poorer therapeutic outcomes. Clearly, there is a need to identify, diagnose, and provide effective treatment of a depressed patient quickly. A sophisticated understanding of depression subscales and their change over time with treatment could enhance pathways to individualized treatment approaches for childhood depression.

OBJECTIVE

Previous studies have found that the clinician-measured instrument, Children's Depression Rating Scale-Revised (CDRS-R) measures multiple subscales (or components) of depression. The aim of this study was to see how these subscales may change over the course of a 12-week study. This knowledge will help determine if dimensions/subscales of childhood depression (paralleling the adult literature) using the subscales derived from factor analysis procedure is useful.

METHODS

We examined two clinical trials in which youth (n=234) with major depressive disorder (MDD) were treated openly with fluoxetine for eight sessions spread over 12 weeks. The CDRS-R was completed based on clinician interviews with parent and child at each session. Classical test theory and component analysis with associated parallel analysis (oblique rotation) were conducted on each week's scores.

RESULTS

Although more factors were needed for the baseline and first two therapy sessions, a two-factor solution sufficed thereafter. Depressed facial affect, listless speech, and hypoactivity best defined Factor I, whereas sleep problems, appetite disturbance, physical symptoms, irritability, guilt, and weeping best defined Factor II. All other symptoms cross-loaded almost equally on the two factors. The scale's reliability (internal consistency) improved from baseline to exit sessions (α=0.65-0.91). As a result, the clinicians' assessments of the various symptoms became more highly related to one another. This caused the first eigenvalue to increase from 3.24 to 7.38 and the variance explained to increase (%) from 19% to 43% over sessions. These two factors may reflect 1) clinician-observed signs and 2) reported symptoms of depression.

CONCLUSIONS

Factor analysis of CDRS-R data in a single session consistently generates a complex and difficult to interpret structure of at least three factors. This makes it very difficult to understand what these factors measure. However, when gathered over additional sessions, the CDRS-R structure tends to simplify to two factors. The reasons for this simplification are as yet unclear and in need of further study.

Minireview: Gut microbiota: the neglected endocrine organ

The concept that the gut microbiota serves as a virtual endocrine organ arises from a number of important observations. Evidence for a direct role arises from its metabolic capacity to produce and regulate multiple compounds that reach the circulation and act to influence the function of distal organs and systems. For example, metabolism of carbohydrates results in the production of short-chain fatty acids, such as butyrate and propionate, which provide an important source of nutrients as well as regulatory control of the host digestive system. This influence over host metabolism is also seen in the ability of the prebiotic inulin to influence production of relevant hormones such as glucagon-like peptide-1, peptide YY, ghrelin, and leptin. Moreover, the probiotic Lactobacillus rhamnosus PL60, which produces conjugated linoleic acid, has been shown to reduce body-weight gain and white adipose tissue without effects on food intake. Manipulating the microbial composition of the gastrointestinal tract modulates plasma concentrations of tryptophan, an essential amino acid and precursor to serotonin, a key neurotransmitter within both the enteric and central nervous systems. Indirectly and through as yet unknown mechanisms, the gut microbiota exerts control over the hypothalamic-pituitary-adrenal axis. This is clear from studies on animals raised in a germ-free environment, who show exaggerated responses to psychological stress, which normalizes after monocolonization by certain bacterial species including Bifidobacterium infantis. It is tempting to speculate that therapeutic targeting of the gut microbiota may be useful in treating stress-related disorders and metabolic diseases.

Dietary patterns and the risk of depression in adults: a systematic review of observational studies

PURPOSE

Diet, a modifiable lifestyle factor, may influence the development of depression. We performed a systematic review of observational studies examining the relationship between dietary patterns and depression in healthy adults.

METHODS

A literature research was conducted searching various electronic databases up to May 2013. Study selection was based on predefined inclusion and exclusion criteria. Included studies were reviewed, and relevant data were extracted by two independent researchers. Due to a high level of heterogeneity, no meta-analysis was conducted. Therefore, main results are presented in a descriptive way.

RESULTS

In total, 16 studies met the inclusion criteria and are part of this review. Dietary patterns most commonly found were traditional/healthy patterns, Western/unhealthy patterns and Mediterranean patterns. The available literature suggests a protective effect of healthy and Mediterranean patterns, as well as a potential positive association of Western patterns and depression. However, comparison of the included studies was difficult, due to differences in relevant study characteristics and methodological limitations.

CONCLUSIONS

There are indications that dietary patterns may have influence on the onset of depression, but no firm conclusion can be drawn at this point. Further research is needed to clarify the diet-depression relationship, preferably in the form of methodological strong prospective studies using more homogeneous methods.

Biological differences between melancholic and nonmelancholic depression subtyped by the CORE measure

BACKGROUND

The purpose of this study was to compare melancholic patients rated by the CORE measure of observable psychomotor disturbance with nonmelancholic and control subjects across a set of biomarkers.

METHODS

Depressed patients were classified as melancholic or nonmelancholic by using the CORE measure. Both groups of patients, as well as control subjects, were compared for a set of clinical and laboratory measures. Serum levels of brain-derived neurotrophic factor, of two markers of oxidative stress (protein carbonyl content [PCC] and thiobarbituric acid reactive substances [TBARS]), and of several immunity markers (interleukin [IL]-2, IL-4, IL-6, IL-10, IL-17, tumor necrosis factor-alpha, and interferon-gamma) were analyzed.

RESULTS

Thirty-three depressed patients and 54 healthy controls were studied. Depressive patients showed higher IL-4, IL-6, and PCC values than healthy controls. Thirteen (39%) of the depressed patients were assigned as melancholic by the CORE measure. They generated lower interferon-gamma (compared with nonmelancholic depressed patients) and TBARS (compared with both the nonmelancholic subset and controls) and returned higher IL-6 levels than controls. Both depressive groups generated higher PCC scores than controls, with no difference between melancholic and nonmelancholic subsets.

CONCLUSION

A sign-based measure to rate melancholia was able to replicate and extend biological findings discriminating melancholic depression. Signs of psychomotor disturbance may be a useful diagnostic measure of melancholia.