Depressive disorders and suicide: Epidemiology, risk factors, and burden

Macrophages and depression - a misalliance or well-arranged marriage?

Depression is a severe medical condition with multiple manifestations and diverse, largely unknown etiologies. The immune system, particularly macrophages, plays an important role in the pathology of the illness. Macrophages represent a heterogeneous population of immune cells that is dispersed throughout the body. The central nervous system is populated by several types of macrophages, including microglia, perivascular cells, meningeal and choroid plexus macrophages and pericytes. These cells occupy different brain compartments and have various functions. Under basal conditions, brain macrophages support the proper function of neural cells, organize and preserve the neuronal network and maintain homeostasis. As cells of the innate immune system, they recognize and react to any disturbances in homeostasis, eliminating pathogens or damaged cells, terminating inflammation and proceeding to initiate tissue reconstruction. Disturbances in these processes result in diverse pathologies. In particular, tissue stress or malfunction, both in the brain and in the periphery, produce sustained inflammatory states, which may cause depression. Excessive release of proinflammatory mediators is responsible for alterations of neurotransmitter systems and the occurrence of depressive symptoms. Almost all antidepressive drugs target monoamine or serotonin neurotransmission and also have anti-inflammatory or immunosuppressive properties. In addition, non-pharmacological treatments, such as electroconvulsive shock, can also exert anti-inflammatory effects. Recent studies have shown that antidepressive therapies can affect the functional properties of peripheral and brain macrophages and skew them toward the anti-inflammatory M2 phenotype. Because macrophages can affect outcome of inflammatory diseases, alleviate sickness behavior and improve cognitive function, it is possible that the effects of antidepressive treatments may be, at least in part, mediated by changes in macrophage activity.

Influence of 5-HTR2A genetic polymorphisms on the efficacy of antidepressants in the treatment of major depressive disorder: a meta-analysis

OBJECTIVE

The aim of the current meta-analysis was to assess the influence of common genetic polymorphisms in the 5-HTR2A gene on the efficacy of antidepressants in the treatment of major depressive disorder (MDD).

METHOD

MEDLINE (1966-2013), Cochrane Library Database (Issue 12, 2013), EMBASE (1980-2013), CINAHL (1982-2013), Web of Science (1945-2013) and Chinese Biomedical Database (CBM) (1982-2013) were searched without language restrictions. Meta-analysis was performed using the STATA statistical software. We calculated the odds ratio (OR) and its 95% confidence interval (95% CI) to estimate the efficacy of antidepressants in the treatment of MDD.

RESULTS

Eleven studies with a total of 1775 MDD patients met the inclusion criteria of this meta-analysis. Three common polymorphisms in the 5-HTR2A gene were assessed, including rs6311 C>T, rs7997012 G>A, and rs6313 T>C. Our findings suggested that the 5-HTR2A rs6313 T>C polymorphism was significantly correlated with a higher response rate to antidepressants in MDD patients (allele model: OR=1.33, 95% CI=1.05-1.68, P=0.020; dominant model: OR=1.62, 95% CI=1.21-2.18, P=0.001; homozygous model: OR=1.85, 95% CI=1.18-2.90, P=0.008). The rs7997012 G>A polymorphism was also associated with a higher response rate to antidepressants in MDD patients under the dominant model (OR=1.92, 95% CI=1.02-3.61, P=0.044). However, no significant correlation was found for the 5-HTR2A rs6311 C>T polymorphism under five genetic models (all P>0.05).

CONCLUSION

Our findings provide empirical evidence that the 5-HTR2A rs6313 T>C and rs7997012 G>A polymorphism may be correlated with the efficacy of antidepressants in the treatment of MDD.

Anhedonia predicts suicidal ideation in a large psychiatric inpatient sample

This study examined the relationship among symptoms of anhedonia and suicidal ideation at baseline, at termination, and over time in 1529 adult psychiatric inpatients. Anhedonia was associated with suicidality cross-sectionally at baseline and at termination. In addition, change in anhedonia from baseline to termination predicted change in suicidality from baseline to termination, as well as level of suicidality at termination; moreover, anhedonia remained a robust predictor of suicidal ideation independent of cognitive/affective symptoms of depression. Symptom-level analyses also revealed that, even after accounting for the physical aspect of anhedonia (e.g., loss of energy), loss of interest and loss of pleasure were independently associated with higher levels of suicidal ideation at baseline, over time, and at discharge. Loss of interest was most highly predictive of suicidal ideation, providing support for recent differential conceptualizations of anhedonia. Taken together, these findings indicate that the manner in which anhedonia is conceptualized is important in predicting suicidal ideation, and that anhedonia symptoms warrant particular clinical attention in the treatment of suicidal patients.

Effectiveness of community facilitator training in improving knowledge, attitudes, and confidence in relation to depression and suicidal behavior: results of the OSPI-Europe intervention in four European countries

BACKGROUND

Community facilitators (CFs), such as teachers, nurses and social workers, are well placed as gatekeepers for depression and suicidal behavior, but not properly prepared to provide preventive and supportive services. The current study aimed: (1) to improve CFs' attitudes toward depression, knowledge on suicide, and confidence to detect suicidal behavior in four European countries and (2) to identify specific training needs across regions and CF groups.

METHODS

A standardized training program was provided to 1276 CFs in Germany, Hungary, Ireland, and Portugal. Attitudes toward depression, knowledge about suicide, and confidence in identifying suicidal persons were assessed before training, after training, and at three to six months follow-up. Additionally, several participants' characteristics were registered.

RESULTS

At baseline, CFs showed relatively favorable attitudes toward depression, but limited knowledge on suicide, and little confidence to identify suicidal behavior. Basic skills strongly differed across CF groups and countries. For example, in Germany, carers for the elderly, nurses, teachers, and managers were most in need of training, while in Portugal pharmacists and the clergy appeared to be important target groups. Most importantly, the training program improved the competencies of CF groups across countries and these improvements were sustained after three to six months. CFs with low basic skills benefited most of the training.

LIMITATIONS

The observed training effects could be influenced by other external factors as our results are based upon a pre-post comparison with no control group.

CONCLUSIONS

Gatekeeper trainings in community settings are successful in improving knowledge, reshaping attitudes, and boosting the confidence of gatekeepers. The most effective strategy to achieve the preferred objectives is to target those CF groups that are most in need of training and to tailor the content of the training program to the individual needs of the target group.

Suicidal ideation in prostate cancer survivors: understanding the role of physical and psychological health outcomes

BACKGROUND

Epidemiological studies have shown prostate cancer (PC) survivors are at an increased risk of suicide compared with the general population, but to the authors' knowledge very little is known regarding what factors are associated with this increased risk. The current study examined the prevalence of suicidal ideation (SI) and its association with cancer treatment and posttreatment physical and emotional health in a cohort of long-term PC survivors.

METHODS

A total of 693 PC survivors (3-8 years after diagnosis) completed a mailed survey on physical and psychological functioning, including cancer treatments, the Short Form-12 (SF-12), the Expanded Prostate Cancer Index Composite Instrument (EPIC-26), a depression rating scale, and 8 items regarding recent suicidal thoughts and behaviors.

RESULTS

A total of 86 PC survivors (12.4%) endorsed SI, with 10 individuals (1.4%) reporting serious SI. Serious SI was more common in this sample compared with age-adjusted and sex-adjusted normative data. SI was not associated with most demographic variables, or with PC stage or treatments. However, SI was found to be significantly associated with employment status, poor physical and emotional functioning, greater symptom burden on the EPIC-26, higher frequency of significant pain, and clinically significant depression (P < .01). In an adjusted logistic model, poor physical and emotional function, including disability status and pain, were found to be associated with SI (P < .05), even after adjusting for depression.

CONCLUSIONS

A significant percentage of PC survivors report recent SI, which is associated with both physical and psychological dysfunction, but not PC treatments. The results of the current study help to explain the increased risk of suicide previously reported in PC survivors and have important implications for identifying and treating those survivors at greatest risk of suicidality.

Gender differences in the association between adiposity and probable major depression: a cross-sectional study of 140,564 UK Biobank participants

BACKGROUND

Previous studies on the association between adiposity and mood disorder have produced contradictory results, and few have used measurements other than body mass index (BMI). We examined the association between probable major depression and several measurements of adiposity: BMI, waist circumference (WC), waist-hip-ratio (WHR), and body fat percentage (BF%).

METHODS

We conducted a cross-sectional study using baseline data on the sub-group of UK Biobank participants who were assessed for mood disorder. Multivariate logistic regression models were used, adjusting for potential confounders including: demographic and life-style factors, comorbidity and psychotropic medication.

RESULTS

Of the 140,564 eligible participants, evidence of probable major depression was reported by 30,145 (21.5%). The fully adjusted odds ratios (OR) for obese participants were 1.16 (95% confidence interval (CI) 1.12, 1.20) using BMI, 1.15 (95% CI 1.11, 1.19) using WC, 1.09 (95% CI 1.05, 1.13) using WHR and 1.18 (95% CI 1.12, 1.25) using BF% (all p < 0.001). There was a significant interaction between adiposity and gender (p = 0.001). Overweight women were at increased risk of depression with a dose response relationship across the overweight (25.0-29.9 kg/m2), obese I (30.0-34.9 kg/m2), II (35.0-39.9 kg/m2) and III (≥40.0 kg/m2) categories; fully adjusted ORs 1.14, 1.20, 1.29 and 1.48, respectively (all p < 0.001). In contrast, only obese III men had significantly increased risk of depression (OR 1.29, 95% CI 1.08, 1.54, p = 0.006).

CONCLUSION

Adiposity was associated with probable major depression, irrespective of the measurement used. The association was stronger in women than men. Physicians managing overweight and obese women should be alert to this increased risk.

Association between norepinephrine transporter gene (SLC6A2) polymorphisms and suicide in patients with major depressive disorder

BACKGROUND

Although several studies have investigated possible associations between norepinephrine neurotransmitter transporter gene (SLC6A2) polymorphisms and depression, few studies have examined associations between SLC6A2 polymorphisms and suicide.

METHODS

Three single-nucleotide polymorphisms (rs2242446, rs28386840, and rs5569) were measured in 550 patients: 201 with major depressive disorder (MDD) and suicide attempt/s, 160 with MDD without suicide attempts, and 189 healthy controls. Analysis of single-nucleotide polymorphisms (SNPs) and haplotype was conducted for the three groups. Subsequently, multivariate logistic regression analysis adjusting for age and gender was conducted to identify independent influences of each SNP. A possible association between suicide lethality and SLC6A2 polymorphisms was also investigated.

RESULTS

In the genotype and allele frequency analysis, there were significant differences in rs28386840 between suicidal MDD patients and healthy controls. In the haplotype analysis, TAA (rs2242446-rs28386840-rs5569, from left to right) was associated with suicide attempts in MDD, although the significance (p=0.043) disappeared after Bonferroni correction. There were no relationships between lethality scores and SLC6A2 polymorphisms in suicidal MDD.

LIMITATIONS

Modest sample size and a single type of neurotransmitter analyzed (norepinephrine) are the primary limitations.

CONCLUSION

Our results suggest that SLC6A2 polymorphisms were associated with suicide risk in patients with MDD. Future studies are warranted to elucidate possible mechanisms by which SLC6A2 polymorphisms influence suicide risk.

Sleep Organisation in Depression and Schizophrenia: Index of Endogenous Periodicity of Sleep as a State Marker [Retracted]

Background: Sleep disorders are frequent symptoms described in psychiatric patients with major depression or schizophrenia. These patients also exhibit changes in the sleep architecture measured by polysomnography (PSG) during sleep. The aim of the present study was to identify potential biomarkers that would facilitate the diagnosis based on polysomnography (PSG) measurements.Subjects and Methods: 30 patients with schizophrenia, 30 patients with major depression and 30 healthy control subjects were investigated in the present study. The mean age in the group with schizophrenia was 36.73 (SD 6.43), in the group of patients with depression 40.77 (SD 7.66), in the healthy controls group 34.40 (SD 5.70). The gender distribution was as follows: 18 male, 12 female in the group with schizophrenia; in the group of patients with depression 11 male, 19 female; in the control group 16 male and 14 female. All subjects underwent polysomnography (PSG) for a minimum time of 8 hours according to the criteria of Rechtschaffen & Kales (1968). The following polysomnographic (PSG) parameters were analyzed: sleep latency (SL), total sleep time (TST), waking time after sleep onset (WTASO), number of awakenings (NAW), slow wave sleep (SWS), rapid eye movement sleep (REM), rapid eye movement sleep latency (REML), first REM period (REM 1), and first NREM period (NREM 1). We tested the potential of multiple sleep variables to predict diagnosis in different groups by using linear discriminate analysis (LDA).Results: There were significant differences in polysomnography (PSG) variables between healthy control subjects and psychiatric patients (total sleep time, sleep latency, number of awakenings, time of awakening after sleep onset, REM 1 latency, REM 1 and index of endogenous periodicity). Importantly, LDA was able to predict the correct diagnosis in 88% of all cases.Conclusions: The presented analysis showed commonalities and differences in polysomnography (PSG) changes in patients with major depressive disorder and in patients with schizophrenia. Our results underline the potential of polysomnography (PSG) measurements to facilitate diagnostic processes.

Evidence-based definitions of bipolar-I and bipolar-II disorders among 5,635 patients with major depressive episodes in the Bridge Study: validity and comorbidity

The definitions of bipolar-I (BP-I) and bipolar-II (BP-II) disorders are currently under revision by the APA and by the WHO. We provide evidence of a revised set of criteria for bipolar disorders and major depressive disorder (MDD) which could serve to strengthen the construct and predictive validity of both disorders and enable more incisive studies of treatments and courses of both disorders. In the diagnostic Bridge Study of 5,635 patients with major depressive episodes from 18 countries (Europe, North Africa, Near East and Far East) leading psychiatrists in each country assessed a pre-specified group of symptoms, illness course, family history and duration of episodes; these data allowed tests of several definitions of bipolarity. The primary revised specifier diagnosis of BP-I disorder included manic episodes based on an additional category A criterion (increased activity/energy) and did not apply any exclusion criteria. The revised BP-II disorders included hypomanic episodes of 1-3 days. Family history and illness course validators (history of mania/hypomania among first degree relatives, 2 or more lifetime episodes and first symptoms having occurred before age 30) discriminated clearly between patients with bipolar-I or bipolar-II disorders meeting bipolarity specifier criteria and those with MDD. Specifier definitions provided better discrimination between MDD and the two bipolar subgroups. Patterns of concurrent comorbidities also differed significantly between patients meeting criteria for MDD compared with those meeting bipolar specifier criteria. Comorbidity patterns differed between bipolar-I and bipolar-II patients. This study provides evidence for the validity of modified (specifier) BP-I and BP-II definitions that incorporate illness course and family history which reduce ambiguities of major depressive episodes between bipolar-I and bipolar-II disorders and MDD.

A systematic literature review of resting state network--functional MRI in bipolar disorder

BACKGROUND

Several studies using functional magnetic resonance imaging (fMRI) in bipolar disorder (BD) have been performed in the last decade. Some of them have applied novel neuroimaging techniques such as resting-state functional connectivity magnetic resonance imaging (rs-fcMRI).

METHODS

We reviewed the top-quality rs-fcMRI studies in BD available in the PubMed and Embase databases up to November, 2012 to identify brain activation networks and research techniques that may benefit future research.

RESULTS

We present and discuss the methods and findings of eight articles. Most of these studies used the regions-of-interest (ROI) and independent component analysis (ICA) methods, and some used approaches such as amplitude of low-frequency fluctuation (ALFF), restricted global brain connectivity (rGBC) and regional homogeneity (ReHO). The largest differences in their results were found in the connectivity of the medial prefrontal cortex (mPFC) and the anterior cingulated cortex with limbic-striatal structures, and in spatial extent in ReHo when studying the default mode network (DMN).

LIMITATIONS

The heterogeneity of the analytical methods used to explore the resting-state network (RSN) and the characteristics of the sample of each study limit the conclusions.

CONCLUSIONS

Despite the variation among the results of the reviewed papers, they all support the cortico-limbic hypothesis and suggest that connectivity can be more complex and that intra-regional disturbances should also be studied. Recommendations for future studies include consideration of intra-regional disturbances, better control of confounding factors, use of larger scale methods, and a consensus regarding how to approach the study of resting-state networks and interpret the results obtained.

Pooled analysis of sustained response rates for extended release quetiapine fumarate as monotherapy or adjunct to antidepressant therapy in patients with major depressive disorder

BACKGROUND

Clinical trials are not generally powered to analyze outcomes such as sustained response. We evaluated sustained response rates for patients with major depressive disorder receiving quetiapine XR as monotherapy or adjunct therapy.

METHOD

Post hoc analyses of pooled data from four previously reported randomized, placebo-controlled studies of quetiapine XR 150 and 300 mg/day as monotherapy or adjunct therapy to ongoing antidepressant. Sustained response rates (≥50% reduction in MADRS total score at specific timepoint and each subsequent visit until Week 6) were calculated at Weeks 1, 2, and 4; rates were compared using a Cochran-Mantel-Haenszel analysis.

RESULTS

In the monotherapy studies, the proportion of patients experiencing sustained response was greater with quetiapine XR 150 mg/day versus placebo at Week 2 (20.0% vs. 13.3%; p<0.05) and Week 4 (33.3% vs. 23.3%; p<0.01) (observed cases [OC]). The corresponding sustained response rates for quetiapine XR 300 mg/day were 18.0% (p=0.104) and 29.7% (p=0.063), respectively (OC). The proportion of patients experiencing sustained response was greater in the adjunct studies versus placebo at Weeks 2 and 4 for quetiapine XR 150 (Week 2, 30.1% vs. 15.2%, p<0.001; Week 4, 40.1% vs. 32.0%, p<0.05) and 300 mg/day (Week 2, 29.0% vs. 15.2%, p<0.001; Week 4, 42.0% vs. 32.0%, p<0.05) (OC).

LIMITATIONS

Post hoc analyses, acute treatment period; no active comparator.

CONCLUSIONS

Quetiapine XR as monotherapy (150 mg/day at Weeks 2 and 4) or adjunct to ongoing antidepressant therapy (150 and 300 mg/day at Weeks 2 and 4) increased sustained response rates versus placebo.