Inflammatory depression is associated with selective glomerular hypofiltration

BACKGROUND

Systemic low-grade inflammation may be a pathophysiological mechanism in a subtype of depression. In this study we investigate a novel candidate mechanism of inflammatory depression - Selective Glomerular Hypofiltration Syndromes (SGHS) - which are characterized by a reduced estimated glomerular filtration rate (eGFR) based on cystatin C (cysC) relative to eGFR based on creatinine (crea). SGHS have been associated with increased blood levels of pro-inflammatory markers, but have never been investigated in a sample of depressed individuals.

METHOD

The prevalence of SGHS was compared between 313 patients with difficult-to-treat depression and 73 controls. Since there is no single established eGFRcysC/eGFRcrea-ratio cut-off to define SGHS, several cut-offs were investigated in relation to a depression diagnosis, inflammation, and symptom severity. Plasma inflammatory markers tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-6, IL-8, and IL-10 were available from 276 depressed patients. We examined mediation effects of IL-6 on the relationship between SGHS and depression.

RESULTS

Depressed patients were more likely to have SGHS compared to controls defining SGHS as either eGFRcysC/eGFRcrea-ratio < 0.9 (33.2 % vs 20.5 %, p = 0.035) or < 0.8 (15.7 % vs 5.5 %, p = 0.023). Lower eGFRcysC/eGFRcrea-ratio was associated with higher levels of inflammatory markers in depressed patients. IL-6 partly mediated the relationship between SGHS and depression.

CONCLUSION

This is the first study to demonstrate a link between SGHS and inflammatory depression. If replicated in independent and longitudinal cohorts, this may prove to be a relevant pathophysiological mechanism in some cases of depression that could be targeted in future intervention and prevention studies.

Omega-3 fatty acids for inflamed depression - A match/mismatch study

Despite decades of research on the pathophysiology of depression, the development of new therapeutic interventions has been slow, and no biomarkers of treatment response have been clinically implemented. Several lines of evidence suggest that the clinical and biological heterogeneity among patients with major depressive disorder (MDD) has hampered progress in this field. MDD with low-grade inflammation - "inflamed depression" - is a subtype of depression that may be associated with a superior antidepressant treatment response to anti-inflammatory compounds. Omega-3 fatty acid eicosapentaenoic acid (EPA) has anti-inflammatory properties, and preliminary data suggest that it may be particularly efficacious in inflamed depression. In this study we tested the hypothesis that add-on EPA has greater antidepressant efficacy in MDD patients with high baseline high-sensitivity C-reactive protein (hs-CRP) compared to MDD patients with low hs-CRP. All subjects received 2.2 g EPA, 400 mg docosahexaenoic acid and 800 mg of other fatty acids daily for 8 weeks, added to stable ongoing antidepressant treatment. The primary outcome was change in the 17-item Hamilton Depression Rating Scale (HAMD-17). Patients and raters were blind to baseline hs-CRP status. In an intention-to-treat analysis including all subjects with at least one post baseline visit (n = 101), ahs-CRPcut-off of ≥1 mg/L, but not ≥3 mg/L, was associated with a greater improvement in HAMD-17 total score. In addition to a general antidepressant effect among patients with hs-CRP ≥ 1 mg/L, adjuvant EPA treatment improved symptoms putatively related to inflamed depression such as fatigue and sleep difficulties. This adds to the mounting evidence that delineation of MDD subgroups based on inflammation may be clinically relevant to predict treatment response to anti-inflammatory interventions.

An inflamed subtype of difficult-to-treat depression

BACKGROUND

Chronic low-grade inflammation may play a role in the pathophysiology of depression, at least in a subset of patients. High-sensitivity C-reactive protein (hs-CRP) has been used to define an inflamed subgroup of depression with specific clinical characteristics and symptoms. In this study we investigated biochemical and clinical characteristics in patients with difficult-to-treat depression with and without chronic low-grade inflammation.

METHOD

We assayed plasma levels of interferon-gamma, tumor necrosis factor-alpha, Interleukin (IL)-10, IL-6, IL-8, and vitamin D in a clinically well-characterized sample of patients with difficult-to-treat depression (n = 263) and healthy controls (n = 46). Serum hs-CRP levels were available in the patient group and were used to define "inflamed depression" (hs-CRP > 3 mg/L). Based on previous studies correlating specific depressive symptoms to inflammatory markers, we calculated a composite score of inflammatory depressive symptoms (Infl-Dep score). A principal component analysis (PCA) was performed to identify patterns of variance in cytokines and vitamin D among patients.

RESULTS

Mean levels of IL-6 and IL-8 were significantly higher in depressed patients compared to controls, also after adjusting for sex, smoking, BMI, and age. None of the other inflammatory markers differed significantly between depressed patients and controls. Two components were extracted using PCA; one showed general cytokine elevations and one represented a pattern where IL-6 and IL-8 were inversely related to vitamin D (IL6-IL8-VitD component). The inflamed subgroup (hs-CRP > 3, n = 51) exhibited significantly higher BMI, higher Infl-Dep scores and higher IL6-IL8-VitD component scores than uninflamed patients (hs-CRP ≤ 3, n = 212). There were no significant differences in overall depression severity or suicidality between the inflamed and uninflamed groups.

CONCLUSION

Our results support the hypothesis of an inflamed subgroup of depression as a meaningful construct. This subgroup may have certain biological and clinical characteristics and more studies are needed to determine potential clinical implications.

Efficacy of eicosapentaenoic acid in inflammatory depression: study protocol for a match-mismatch trial

BACKGROUND

Most antidepressant treatment studies have included patients strictly based on the Diagnostic and Statistical Manual of Mental Disorders definition of Major Depressive Disorder (MDD). Given the heterogeneity of MDD, this approach may have obscured inter-patient differences and hampered the development of novel and targeted treatment strategies. An alternative strategy is ​​to use biomarkers to delineate endophenotypes of depression and test if these can be targeted via mechanism-based interventions. Several lines of evidence suggest that "inflammatory depression" is a clinically meaningful subtype of depression. Preliminary data indicate that omega-3 fatty acids, with their anti-inflammatory and neuroprotective properties, may be efficacious in this subtype of depression, and this study aims to test this hypothesis.

METHOD

We conduct a match-mismatch-trial to test if add-on omega-3 fatty acid eicosapentaenoic acid (EPA) reduces depressive symptoms in patients with MDD and systemic low-grade inflammation. MDD patients on a stable antidepressant treatment are stratified at baseline on high sensitivity-C-reactive protein (hs-CRP) levels to a high-inflammation group (hs-CRP ≥ 3 mg/L) or a low-inflammation group (hs-CRP < 3 mg/L). Both groups receive add-on EPA (2 g per day) for 8 weeks with three study visits, all including blood draws. Patients and raters are blind to inflammation status. Primary outcome measure is change in Hamilton Depression Rating Scale score between baseline and week 8. We hypothesize that the inflammation group has a superior antidepressant response to EPA compared to the non-inflammation group. Secondary outcomes include a composite score of "inflammatory depressive symptoms", quality of life, anxiety, anhedonia, sleep disturbances, fatigue, cognitive performance and change in biomarkers relating to inflammation, oxidative stress, metabolomics and cellular aging.

DISCUSSION

In this study we will, for the first time using a match-mismatch trial design, test if omega-3 is an efficacious treatment for inflammatory depression. If our study is successful, it could add to the field of precision psychiatry.

TRIAL REGISTRATION

This trial was registered May 8, 2017 on clinicaltrials.gov under the reference number NCT03143075.

Growth patterns and their contributing factors among HIV-exposed uninfected infants

With expanded HIV treatment and prevention programmes, most infants born to HIV‐positive women are uninfected, but the patterns and determinants of their growth are not well described. This study aimed to assess growth patterns in a cohort of HIV‐exposed uninfected (HEU) infants who participated in an experimental HIV vaccine trial and to test for associations with maternal and infant factors, including in‐utero exposure to antiretroviral therapy (ART), mode of delivery, exclusive breastfeeding, mother's education and receipt of the vaccine. Infants in the trial were seen at regular clinic visits from birth to 48 weeks of age. From the anthropometric measurements at these visits, weight‐for‐age z‐scores (WAZ), weight‐for‐length z‐scores (WLZ) and length‐for‐age z‐scores (LAZ) were computed using World Health Organization (WHO) software and reference tables. Growth patterns were investigated with respect to maternal and infant factors, using linear mixed regression models. From 94 infants included at birth, growth data were available for 75.5% at 48 weeks. The determinants of infant growth in this population are multifactorial: infant LAZ during the first year was significantly lower among infants delivered by caesarean section (p = 0.043); both WAZ and LAZ were depressed among infants with longer exposure to maternal ART (WAZ: p = 0.015; LAZ: p < 0.0001) and among infants of mothers with lower educational level (WAZ: p = 0.038; LAZ: p < 0.0001); the effect of maternal education was modified by breastfeeding practice, with no differences seen in exclusively breastfed infants. These findings inform intervention strategies to preserve growth in this vulnerable infant population.

Low total cholesterol and low-density lipoprotein associated with aggression and hostility in recent suicide attempters

Low cholesterol levels have been correlated with both suicidal and aggressive behavior in psychiatric patients. Few studies have investigated associations between serum lipid profiles and both aggressive state and trait. Fifty-two psychiatric medication-free inpatients were included in this study after a suicide attempt. Composite scores of "State Aggression" and "Trait Aggression" were calculated using relevant items from the Comprehensive Psychopathological Rating Scale and the Karolinska Scales of Personality. State Aggression was significantly and negatively correlated with total cholesterol (TC) and low-density lipoprotein (LDL). Trait Aggression was also significantly and negatively correlated with LDL, but not TC. There were small but significant mediation effects of severity of anxiety symptoms on the relationship between State Aggression and TC as well as LDL. In exploratory analyses we found that low cholesterol was also associated with personality traits of hostility. Moreover, low cholesterol was more robustly associated with personality trait items related to interpersonal aggression, as opposed to items related to irritability or more indirect, non-overt aggression. Our findings suggest that low cholesterol is associated with both state and trait aggression in suicide attempters. Future mechanistic studies are warranted to better understand the relationship between low cholesterol and high aggression in suicide attempters.

Leaky gut biomarkers in depression and suicidal behavior

OBJECTIVE

Inflammation is associated with major depressive disorder (MDD) and suicidal behavior. According to the 'leaky gut hypothesis', increased intestinal permeability may contribute to this relationship via bacterial translocation across enterocytes. We measured plasma levels of gut permeability markers, in patients with a recent suicide attempt (rSA), MDD subjects with no history of a suicide attempt (nsMDD), and healthy controls (HC), and related these markers to symptom severity and inflammation.

METHOD

We enrolled rSA (n = 54), nsMDD (n = 13), and HC (n = 17). Zonulin, intestinal fatty acid binding protein (I-FABP), soluble CD14, and interleukin-6 (IL-6) were quantified in plasma. Montgomery-Åsberg Depression Rating Scale (MADRS) and Suicide Assessment Scale (SUAS) were used for symptom assessments.

RESULTS

The rSA group displayed higher I-FABP and lower zonulin levels compared with both the nsMDD and the HC groups (all P < 0.001). IL-6 correlated positively with I-FABP (r = 0.24, P < 0.05) and negatively with zonulin (r = -0.25, P < 0.05). In all subjects, I-FABP levels correlated positively with MADRS (r = 0.25, P < 0.05) and SUAS scores (r = 0.38, P < 0.001), and the latter correlation was significant also in the nsMDD group (r = 0.60, P < 0.05).

CONCLUSION

The 'leaky gut hypothesis' may improve our understanding of the link between inflammation and suicidal behavior. These findings should be considered preliminary until replicated in larger cohorts.

Electroconvulsive therapy for manic state with mixed and psychotic features in a teenager with bipolar disorder and comorbid episodic obsessive-compulsive disorder: a case report

BACKGROUND

Comorbidity of bipolar disorder and obsessive-compulsive disorder is common in adolescence. Obsessive-compulsive disorder symptoms may be episodic and secondary to alterations in mood, and display specific features. Management of pediatric bipolar disorder-obsessive-compulsive disorder is challenging, as pharmacotherapy of obsessive-compulsive disorder may induce or exacerbate manic episodes and there is limited evidence of treatment efficacy. Electroconvulsive therapy is sparsely used in children and adolescents, but is documented to be a safe and efficacious intervention in adults with bipolar disorder. In view of the severity of symptoms in juvenile mania, studies on treatment strategies are warranted. We report a case of an adolescent with bipolar disorder-obsessive-compulsive disorder who was successfully treated with electroconvulsive therapy during an episode of severe mania.

CASE PRESENTATION

A 16-year-old girl of Middle East origin first presented to us with depressed mood, irritability, and increased obsessive-compulsive disorder symptoms, which were initially interpreted in the context of acute stress secondary to migration. She had been diagnosed with bipolar disorder and obsessive-compulsive disorder in her previous home country, but had difficulties in accounting for earlier psychiatric history. During hospitalization her mood switched to a manic state with mixed and psychotic features, at times showing aggression toward others. Interruption in her lithium treatment for a short period and possibly the introduction of an atypical antipsychotic could in part have been triggering factors. After 8 weeks of in-patient care and psychotropic drug trials, electroconvulsive therapy was initiated and administered every second or third day for 4 weeks, with marked positive response. No apparent side effects were reported.

CONCLUSIONS

This case demonstrates the need for a detailed medical history, taking special note of periodicity and character of obsessive-compulsive disorder symptoms, in adolescents with mood disorders. When treating culturally diverse patients, extra consideration should be taken. Special concerns in the pharmacological treatment to avoid the patient's condition from worsening must be addressed, including giving priority to mood stabilization before obsessive-compulsive disorder symptoms. There are potential benefits in considering electroconvulsive therapy in young patients with severe mania where first-line treatment options have failed.