CRH challenge test in anxious depression

An exploratory study of the gut microbiota in major depression with anxious distress

OBJECTIVES

To explore differences in the diversity and composition of the gut microbiome between major depressive disorder (MDD) with and without anxious distress.

METHODS

The study comprised 117 participants (79 female, 36 male, 2 other, mean age 38.2 ± 13.4 years) with a current major depressive episode (MDE) with (n = 63) and without (n = 54) the anxious distress specifier. A clinical psychologist administered the structured clinical interview for the DSM-5-RV to confirm a diagnosis of depression. Participants provided stool samples which were immediately frozen and stored at -80 °C. These samples were analysed using the Illumina 16S Metagenomics sequencing protocol in which the sequencing primers target the V3 and V4 regions of the 16S rRNA gene. Participants also completed mental health questionnaires to assess severity of depression (BDI-II), generalized anxiety (GAD-7), and stress (PSS).

RESULTS

There were no significant group differences in α-diversity (Shannon's diversity Index; Simpson Index), richness (ACE; Chao1), (Pielou's) evenness, or beta diversity (Bray-Curtis dissimilarity index and weighted UniFrac distance) of gut bacteria. Significant group differences in the relative abundance of gut microbiota however were observed at each taxonomical level, including across 15 genera and 18 species.

LIMITATIONS

This was an exploratory study that needs to be replicated across larger samples and compared with a healthy control group.

CONCLUSIONS

The research contributes to knowledge of the depressive gut microbial profile unique to the anxious distress subtype of MDD.

Corticosterone Induced the Increase of proBDNF in Primary Hippocampal Neurons Via Endoplasmic Reticulum Stress

Major depression disorder is one of the most common psychiatric disorders that greatly threaten the mental health of a large population worldwide. Previous studies have shown that endoplasmic reticulum (ER) stress plays an important role in the pathophysiology of depression, and current research suggests that brain-derived neurotrophic factor precursor (proBDNF) is involved in the development of depression. However, the relationship between ER and proBDNF in the pathophysiology of depression is not well elucidated. Here, we treated primary hippocampal neurons of mice with corticosterone (CORT) and evaluated the relationship between proBDNF and ERS. Our results showed that CORT induced ERS and upregulated the expression of proBDNF and its receptor, Follistatin-like protein 4 (FSTL4), which contributed to significantly decreased neuronal viability and expression of synaptic-related proteins including NR2A, PSD95, and SYN. Anti-proBDNF neutralization and ISRIB (an inhibitor of the ERS) treatment, respective ly, protected neuronal viabilities and increased the expression of synaptic-related proteins in corticosterone-exposed neurons. ISRIB treatment reduced the expression of proBDNF and FSTL4, whereas anti-proBDNF treatment did not affect ERS markers (Grp78, p-PERK, ATF4) expression. Our study presented evidence that CORT-induced ERS negatively regulated the neuronal viability and the level of synaptic-related protein of primary neurons via the proBDNF/FSTL4 pathway.

Comorbid Anxiety and Depression: Clinical and Conceptual Consideration and Transdiagnostic Treatment

Although anxiety and depression have been considered as two distinct entities according to the diagnostic criteria, anxious depression (comorbid anxiety and depression) is relatively a common syndrome. According to the DSM-5 criteria, it uses "with anxious distress specifier" to define anxious depression in its MDD section. Anxious depression is known to have different neurobiological profiles compared to non-anxious depression. Several studies have revealed significant differences between anxious depression and non-anxious depression regarding the hypothalamic-pituitary-adrenal (HPA) axis function, structural and functional brain imaging findings, inflammation markers, etc. Patients with anxious depression were significantly more likely to be found in primary care setting and more likely to be associated with female gender, non-single, unemployed, less educated, and more severe depression. Previous reports also showed that patients with anxious depression had more frequent episodes of major depression and a higher risk of suicidal ideation and previous suicide attempts than those with non-anxious depression. Although anxious depression is known to be associated with poor treatment outcomes in several studies, recent researches have sought to find better treatment strategy to improve patients with anxious depression.

Repeated intravenous infusions of ketamine: Neurocognition in patients with anxious and nonanxious treatment-resistant depression

BACKGROUND

Recent studies have suggested that neurocognition is changed after repeated infusions of ketamine in patients with treatment-resistant depression (TRD). The objective of this study was to investigate whether differences existed in the neurocognitive effect of six ketamine infusions in patients with anxious and nonanxious TRD and to determine the association between baseline neurocognition and changes in symptoms after the infusions.

METHOD

Patients with anxious (n = 30) and nonanxious TRD (n = 20) received six intravenous infusions of ketamine (0.5 mg/kg over 40 min) over 12 days. Speed of processing (SOP), working memory (WM), verbal learning and memory (VBM), visual learning and memory (VSM) and the severity of depressive and anxious symptoms were assessed at baseline, one day after the last infusion (day 13) and two weeks after the completion of the serial infusions (day 26). A linear mixed model was used to determine whether the neurocognitive changes differed between the two groups. Pearson correlation analysis was used to determine the relationship between baseline neurocognition and the changes in the symptomatic scores.

RESULTS

Patients with anxious TRD had significant increases in SOP on day 13 and day 26 (both p < 0.001), and in VBM on day 13 (p = 0.028). However, no significant increase in any neurocognitive domain was found in patients with nonanxious TRD. Faster SOP at baseline was associated with greater improvement of anxious symptoms in patients with anxious TRD, and better VSM at baseline was associated with greater improvement of depressive symptoms in patients with nonanxious TRD.

LIMITATION

The major limitation of this study is the open-label design.

CONCLUSION

After six ketamine infusions, neurocognitive improvement was observed in patients with anxious TRD but not in patients with nonanxious TRD.

Fast Feedback Inhibition of Adrenocorticotropic Hormone Secretion by Endogenous Cortisol in Humans

BACKGROUND

Using high-frequency blood sampling, we demonstrate glucocorticoid fast feedback (FF) mediated by endogenous cortisol in 6 normal humans.

METHODS

We stimulated adrenocorticotropic hormone (ACTH) secretion by ovine corticotropin-releasing hormone (oCRH) with the experimental paradigm in which a high-frequency blood sampling was designed for plasma ACTH and cortisol determinations.

RESULTS

We saw previously unrecognized variability in the timing of key events such as onsets of ACTH and cortisol secretion, onset and offset of FF, and in FF duration. This variability mandated analyses referenced to case-wise event times rather than referenced simply to time since oCRH administration. The mean time of FF onset was 4.0 min (range 0-9; median 3) after cortisol secretion began, and the mean FF duration was 7.5 min (range 3-18; median 6.0). The FF effect was rate-sensitive and does not reflect level-sensitive cortisol feedback. In agreement with previous estimates using hydrocortisone infusions, the rate of rise of cortisol that triggered FF was approximately 44 nmol/L/min or 1.6 µg/dL/min. FF onset followed the trigger cortisol slope with an average lag of 1 min (range 0-3; median 0). Unexpectedly, this trigger cortisol slope quickly declined within the FF period.

CONCLUSIONS

This experimental design may enable new physiological studies of human FF that is mediated by endogenous cortisol, including mechanisms, reproducibility, and generalizability to other activating stimuli.

Childhood trauma dependent anxious depression sensitizes HPA axis function

Anxious depression is a common subtype of major depressive disorder (MDD) and is associated with greater severity and poorer outcome. Alterations of the hypothalamic-pituitary-adrenal (HPA) axis, especially of the glucocorticoid receptor (GR) function, are often observed in MDD, but evidence lacks for anxious depression. Childhood adversity is known to influence both the HPA axis and risk of MDD. Therefore, we investigated GR-function in anxious depression dependent on childhood adversity. We enrolled 144 depressed in-patients (49.3% females). Anxious depression was defined using the Hamilton Depression Rating Scale (HAM-D) anxiety/somatization factor score ≥7. Blood draws were performed at 6 pm before and 3 h after 1.5 mg dexamethasone ingestion for measurement of cortisol, ACTH and blood count to assess GR-function and the immune system. In a subgroup of n = 60 FKBP5 mRNA controlled for FKBP5 genotype was measured before and after dexamethasone. Childhood adversity was evaluated using the Childhood Trauma Questionnaire (CTQ). We identified 78 patients (54.2%) with anxious depression who showed a greater severity and worse outcome. These patients were more often exposed to sexual abuse (30% vs. 16%/p = 0.04) and emotional neglect (76% vs. 58%/p = 0.02) than patients with non-anxious depression. Anxious depressed patients showed an enhanced GR-induced FKBP5 mRNA expression (F = 5.128; p = 0.03) and reduced cortisol levels, partly dependent on sexual abuse (F = 7.730; p = 0.006). Additionally, the GR-induced leukocyte response was enhanced in patients with sexual abuse (F = 7.176; p = 0.008). Anxious depression in dependence of childhood trauma is associated with heightened sensitivity of the HPA axis and the immune system which should be considered for treatment algorithms and targets.

Patients with anxious depression: overview of prevalence, pathophysiology and impact on course and treatment outcome

PURPOSE OF REVIEW

Major depressive disorder with a comorbid anxiety disorder or with significant anxiety symptoms (here called anxious depression) is common and has been associated with poor clinical course trajectories. However, various dichotomous as well as dimensional definitions have been used to label anxious depression and it remains unclear to which extent these result in inconsistent findings. This review provides an overview of recent literature on the impact of anxiety in depressed patients on clinical course trajectories, treatment outcomes, and underlying neurobiological dysregulations.

RECENT FINDINGS

Anxious depression seems associated with poorer clinical course trajectories and treatment nonresponse as compared with 'pure' depression, regardless of which definition is used. Recent studies have attempted to determine specific efficacy of novel pharmacological treatments for anxious depressed patients, but have not been conclusive because of the insufficient number of studies and differences in definitions and assessment of anxious depression. Neurobiology studies suggest that anxious depression is associated with increased immune dysregulation, more cortical thinning, and corticolimbic dysfunctions as compared with 'pure' depression.

SUMMARY

Anxious depression appears to be a common and clinically relevant subtype of depression as it predicts poorer course trajectories. As populations with anxious depression may benefit from specific treatment regimens, further research is necessary to better delineate its definition and neurobiology. The relatively new Diagnostic and Statistical Manual of Mental Disorders-5 anxious distress specifier is a welcome development and should be further investigated and compared against other anxiety constructs.

The role of anxious distress in immune dysregulation in patients with major depressive disorder

Although depression with anxious distress appears to be a clinically relevant subtype of major depressive disorder (MDD), whether it involves specific pathophysiology remains unclear. Inflammation has been implicated, but not comprehensively studied. We examined within a large MDD sample whether anxious distress and related anxiety features are associated with differential basal inflammation and innate cytokine production capacity. Data are from 1078 MDD patients from the Netherlands Study of Depression and Anxiety. In addition to the DSM-5 anxious distress specifier, we studied various dimensional anxiety scales (e.g. Inventory of Depressive Symptomatology anxiety arousal subscale [IDS-AA], Beck Anxiety Inventory [BAI], Mood and Anxiety Symptoms Questionnaire Anxious Arousal scale [MASQ-AA]). The specifier was constructed using five self-report items from the IDS and BAI. Basal inflammatory markers included C-reactive protein (CRP), interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Innate production capacity was assessed by 13 lipopolysaccharide (LPS)-stimulated inflammatory markers. Basal and LPS-stimulated inflammation index scores were created. Basal inflammation was not associated with anxious distress (prevalence = 54.3%) in MDD patients, except for a modest positive association for BAI score. However, anxious distress was associated with higher LPS-stimulated levels (interferon-γ, IL-6, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, matrix metalloproteinase (MMP)-2, TNF-α, LPS-stimulated index). Other anxiety indicators (anxious distress specifier score, BAI, MASQ-AA) were also associated with increased innate production capacity. Within a large MDD sample, the anxious distress specifier was associated with increased innate cytokine production capacity but not with basal inflammation. Results from dimensional anxiety indicators largely confirm these results. These findings provide new insight into the pathophysiology of anxious depression.

The Role of Chronic Stress in Anxious Depression

Depression is a heterogeneous disease with many different subtypes. Patients with the anxious depression-a common subtype of major depression-are at an increased risk for treatment-resistance to standard antidepressants, with resultant increases in morbidity. However, the underlying pathophysiology of anxious depression remains unknown. Without such knowledge, the development of targeted treatments towards this specific depression subtype will likely remain elusive. One method by which research into the neurobiology of anxious depression may prove fruitful is with the research domain criteria (RDoC). RDoC provides a framework for investigation into the underlying pathophysiology of mental illness. By studying disorders in terms of RDoC constructs-such as the sustained threat construct of the negative valence system-new insights may be gained into neurobiological mechanisms of disease. These mechanisms may be useful for the development of novel antidepressants that are based on specific brain targets. Specifically, we review the impact that sustained threat-or chronic stress-has on the eventual development of depression (especially anxious depression) through pathological changes to molecules, cells, neurocircuitry, physiology, and behavior.

Anxious distress predicts subsequent treatment outcome and side effects in depressed patients starting antidepressant treatment

Evidence has shown that the DSM-5 anxious distress specifier captures a clinically valid construct that predicts a worse clinical course. Although of importance for treatment planning and monitoring, however, the specifier's ability to predict treatment outcome is unknown. This is the first study to examine the ability of the DSM-5 anxious distress specifier to predict treatment response and side effects in depressed patients who recently initiated antidepressant treatment. Patients were from the Netherlands Study of Depression and Anxiety, an ongoing longitudinal cohort study. Baseline, 1-year and 2-year follow-up data were used from 149 patients (18-65 years) with current Major Depressive Disorder (MDD) who recently started adequately dosed antidepressant medication. Five self-report items were used to construct the DSM-5 anxious distress specifier. Treatment outcomes were depression severity after 1 year and 2 years, remission of MDD after 2 years and antidepressant side effects during treatment. For comparison, analyses were repeated for comorbid DSM-IV-based anxiety disorders as a predictor. In depressed patients who received antidepressant treatment, the anxious distress specifier (prevalence = 59.1%) significantly predicted higher severity (1 year: B = 1.94, P = 0.001; 2 years: B = 1.63, P = 0.001), lower remission rates (OR = 0.44, P = 0.0496) and greater frequency of side effects (≥4 vs. 0: OR = 2.74, P = 0.061). In contrast, the presence of comorbid anxiety disorders did not predict these treatment outcomes. The anxious distress specifier significantly predicts poorer treatment outcomes as shown by higher depression severity, lower remission rates, and greater frequency of antidepressant side effects in patients with MDD on adequate antidepressant treatment. Therefore, this simple 5-item specifier is of potential great clinical usefulness for treatment planning and monitoring in depressed patients.

Anxious and non-anxious forms of major depression: familial, personality and symptom characteristics

BACKGROUND

Earlier clinical studies have suggested consistent differences between anxious and non-anxious depression. The aim of this study was to compare parental pathology, personality and symptom characteristics in three groups of probands from the general population: depression with and without generalized anxiety disorder (GAD) and with other anxiety disorders. Because patients without GAD may have experienced anxious symptoms for up to 5 months, we also considered GAD with a duration of only 1 month to produce a group of depressions largely unaffected by anxiety.

METHOD

Depressive and anxiety disorders were assessed in a 10-year prospective longitudinal community and family study using the DSM-IV/M-CIDI. Regression analyses were used to reveal associations between these variables and with personality using two durations of GAD: 6 months (GAD-6) and 1 month (GAD-1).

RESULTS

Non-anxious depressives had fewer and less severe depressive symptoms, and higher odds for parents with depression alone, whereas those with anxious depression were associated with higher harm avoidance and had parents with a wider range of disorders, including mania.

CONCLUSIONS

Anxious depression is a more severe form of depression than the non-anxious form; this is true even when the symptoms required for an anxiety diagnosis are ignored. Patients with non-anxious depression are different from those with anxious depression in terms of illness severity, family pathology and personality. The association between major depression and bipolar disorder is seen only in anxious forms of depression. Improved knowledge on different forms of depression may provide clues to their differential aetiology, and guide research into the types of treatment that are best suited to each form.

Fear of dying in panic attacks predicts suicide attempt in comorbid depressive illness: prospective evidence from the National Epidemiological Survey on Alcohol and Related Conditions

CONTEXT

As a group, comorbid anxiety disorders among depressed persons have consistently been found to increase risk of suicide attempt (SA). Growing evidence supports the link between panic attacks (PAs) and suicidality, but prospective evidence is limited and the nature of the linkage remains unclear. The positive-feedback model of suicide suggests that PAs eliciting catastrophic cognitions may drive SA.

OBJECTIVE

To prospectively examine the relationship between PAs, panic symptoms and suicidality in individuals meeting DSM-IV criteria for past-year major depressive episodes in a large epidemiological study.

METHODS

In data on 2,864 participants of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) wave 1 and 2 surveys with depressive disorders, the associations of PAs and panic symptoms with subsequent suicidal ideation (SI) and SAs were assessed using logistic regression.

RESULTS

Past-year PAs in wave 1 significantly increased odds for subsequent SI and attempt in the 3-year follow-up interval; however, in multivariate analyses, PAs were not a significant predictor, but PAs featuring fear of dying were. Further, among subjects with PAs, fear of dying during a PA increased the odds of subsequent SA sevenfold, even after controlling for comorbid disorders, demographic factors, and other PA symptoms.

CONCLUSION

PAs characterized by prominent morbid catastrophic cognitions may mediate the transition to SIs and SAs in subjects with depressive episodes. Presence of these symptoms in clinical settings may serve as a warning sign for future suicidality.

Neurobiology of anxious depression: a review

Anxious depression is a common, distinct clinical subtype of major depressive disorder (MDD). This review summarizes current neurobiological knowledge regarding anxious depression. Peer-reviewed articles, published January 1970 through September 2012, were identified via PUBMED, EMBASE, and Cochrane Library, using the following key words: anxious depression electroencephalography (EEG), anxious depression functional magnetic resonance imaging (fMRI), anxious depression genetics, anxious depression neurobiology, and anxious melancholia neurobiology. Despite a general dearth of neurobiological research, the results suggest that anxious depression-when defined either syndromally or dimensionally-has distinct neurobiological findings that separate it from nonanxious depression. Structural neuroimaging, EEG, genetics, and neuropsychiatric studies revealed differences in subjects with anxious depression compared to other groups. Endocrine differences between individuals with anxious depression and those with nonanxious depression have also been noted, as evidenced by abnormal responses elicited by exogenous stimulation of the system. Despite these findings, heterogeneity in the definition of anxious depression complicates the results. Because exploring the neurobiology of this depressive subtype is important for improving diagnosis, prognosis, and treatment, enrichment strategies to decrease heterogeneity within the field should be employed for future research.

The combined T3/TRH test in depressed patients and healthy controls

It is well established that depressed patients show a blunted TSH response in the TRH-stimulation test. However, it has not been investigated so far whether pre-treatment with 3,5,3'-triiodothyronine (T3) is able to further suppress the TRH-induced TSH response in depressed patients or whether it may cause an escape-phenomenon with paradoxically enhanced TSH stimulation in a subsequent TRH test. In 20 drug-free depressed patients (eight men, 12 women) suffering from a major depressive episode according to DSM-IV criteria and in 20 age- and sex-matched healthy controls, the single TRH-stimulation test (administration of 200 microg TRH at 09:00 h) was carried out followed by a combined T3/TRH test (pre-treatment with 40 microg T3 at 23:00 h the night before; administration of 200 microg TRH at 09:00 h the next day). Compared to the controls, the depressed patients showed a significantly blunted TSH response in the single TRH test. However, the percentage suppression of TRH-induced TSH stimulation after pre-treatment with 40 microg T3 was comparable in the depressive patients (61.07%) and the healthy volunteers (64.20%). Prolactin secretion did not differ between patients and controls either in the single TRH test or in the combined T3/TRH test. Apparently, in contrast to the hypothalamo-pituitary-adrenocortical (HPA) system, no disturbance of feedback control in regulation of the hypothalamo-pituitary-thyroid (HPT) axis secretion can be demonstrated in depressed patients when using the combined T3/TRH test.

Are SSRIs really more effective for anxious depression?

BACKGROUND

Selective Serotonin Reuptake Inhibitors (SSRIs) are well-established first-line agents for Anxiety Disorders. Anxiety is also a frequent manifestation of major depression. Many psychiatrists assume that anxious depression is more responsive to SSRIs than to other antidepressants. The purpose of this literature review was to determine if SSRIs or any other antidepressants are superior.

METHODS

A computerized search was conducted of double-blind, English-language studies comparing antidepressants available in the United States. Databases searched included Medline and PsycINFO.

RESULTS

SSRIs were not found to be superior to other antidepressants in the treatment of anxious depression.

CONCLUSIONS

The above assumption is not supported. Treatment implications are discussed.

Comment: the corticotropin-releasing hormone stimulation test in white coat hypertension

This study was undertaken to clarify the status of the ACTH and cortisol responses to CRH in patients with white coat hypertension. White coat hypertension was defined as a difference between clinic blood pressure and ambulatory blood pressure of at least 20 mm Hg for systolic blood pressure and/or 10 mm Hg for diastolic blood pressure. CRH stimulation tests were performed between 1400 and 1700 h in 11 patients with white coat hypertension (4 males and 7 females) and 11 normal subjects (4 males and 7 females). Blood pressure and heart rate were measured 15 min before, at time zero, and 15, 30, 60, and 120 min after initiation of the CRH stimulation tests. In white coat hypertension, both the mean systolic blood pressure (162 +/- 15 mm Hg) and diastolic blood pressure (97 +/- 10 mm Hg) were higher than in controls (P < 0.01) on 3 occasions. The mean ambulatory blood pressure for the 24-h period of the test did not differ between patients with white coat hypertension and normal subjects. Basal levels of ACTH and cortisol did not differ between patients with white coat hypertension and control subjects. However, challenge with CRH elevated ACTH (30 min) and cortisol (30, 60, and 120 min) to levels higher than those in controls, with the net increase in both ACTH and cortisol being higher than that in controls over the study period (P < 0.01). These significant responses suggest that white coat hypertension is associated with hypothalamic-pituitary-adrenal hypersensitivity to stressors.

Recognizing the anxious face of depression

"Anxious depression" is used variably both by researchers and clinicians to describe admixtures of anxiety and depressive symptoms. The authors sought to determine the best model for conceptualizing anxious depression by studying a sample of depressed patients referred to a tertiary referral unit. Anxiety and depression were assessed using a comprehensive set of mixed symptoms that were subsequently refined to provide separate anxiety and depressive factors, and patients were trichotomized into groups of low, medium, and high anxiety on the basis of their total anxiety factor scores. Associations between the constructs of anxiety and depression in different depressive subgroups were explored, and the severity of depressive symptoms and other clinical variables across the three anxiety groupings was assessed. Depression variables were not linearly associated in a consistent pattern with anxiety-defined groups, arguing against a simple interdependence model driven by a higher-order variable such as depression severity. By contrast, the state anxiety categories were linked strongly with lifetime anxiety disorder prevalence, with some associations linear and with others evidencing a trend break association. The authors found support for a model of anxious depression, whereby anxiety both predisposes to nonmelancholic depression and contributes to its presentation by shaping its clinical features. Such a model and its definition assist in clarifying the cause of anxious depression and its treatment.

Faulty cortisol/serotonin interplay. Psychopathological and biological characterisation of a new, hypothetical depression subtype (SeCA depression)

The hypothesis is proposed of a new subtype of depression named: stressor-precipitated, cortisol-induced, serotonin-related, anxiety/aggression-driven depression (SeCA depression). Biologically, these patients are characterized by impaired 5-HT synthesis and reduced 5-HT1A receptor sensitivity. Under normal conditions these functions proceed marginally; in times of stress they easily fail, due to sustained overproduction of cortisol. Psychopathologically this depression type shows the following characteristics: anxiety and aggression, not mood lowering, heralding a depressive episode; the personality structure shows 'character neurotic' impairments and tolerance for (certain) traumatic life events is low. As specific therapeutic agents selective 5-HT1A agonists and cortisol or CRH antagonists are proposed. Prophylactically, maintenance treatment with 5-HT1A agonists seems indicated as well as psychological interventions to increase the stressor threshold.