Associations among serum markers of inflammation, life stress and suicide risk in patients with major depressive disorder

Association between negative life events through mental health and non-suicidal self-injury with young adults: evidence for sex moderate correlation

BACKGROUND

Non-suicidal self-injury (NSSI) has exhibited an increasing trend in recent years and is now globally recognized as a major public health problem among adolescents and young adults. Negative life events (NLEs) are positively associated with NSSI. We sought to explore (1) whether sex plays a role in the risk of NLEs leading to NSSI and (2) the role played by mental health (MH).

METHODS

We adopted a multi-stage cluster sampling method to select college students across four grades from May to June 2022. Generalized linear models were used to evaluate the relationships between NLEs, sex, MH and NSSI, presented as incidence-rate ratios (RRs) with 95% confidence intervals (CIs). We examined the complex relationship between these variables using the PROCESS method for moderation analysis.

RESULTS

Following the exclusion of data that did not meet the study requirements, data from 3,578 students (mean age: 20.53 [± 1.65] years) were included. Poisson regression results indicate that high-level NLEs (RR = 0.110, 95%CI: 0.047-0.173) are associated with increased NSSI. Furthermore, interaction effects were observed among sex, NLEs and NSSI. MH and sex moderated the relationship between NLEs and NSSI.

CONCLUSION

Identifying risk factors for NSSI is also important when exploring the interaction between NLEs and MH given the potential for NSSI to significantly increase the risk of later psychopathological symptoms and substance abuse problems. In addition, the significance of sex differences in risk factors for NSSI should be determined. This study evaluated how the impact of NLEs on NSSI can be reduced among adolescents from multiple perspectives.

Molecular Changes Associated with Suicide

Suicide is a serious global public health problem, with a worrying recent increase in suicide rates in both adolescent and adult populations. However, it is essential to recognize that suicide is preventable. A myriad of factors contributes to an individual's vulnerability to suicide. These factors include various potential causes, from psychiatric disorders to genetic and epigenetic alterations. These changes can induce dysfunctions in crucial systems such as the serotonergic, cannabinoid, and hypothalamic-pituitary-adrenal axes. In addition, early life experiences of abuse can profoundly impact an individual's ability to cope with stress, ultimately leading to changes in the inflammatory system, which is a significant risk factor for suicidal behavior. Thus, it is clear that suicidal behavior may result from a confluence of multiple factors. This review examines the primary risk factors associated with suicidal behavior, including psychiatric disorders, early life adversities, and epigenetic modifications. Our goal is to elucidate the molecular changes at the genetic, epigenetic, and molecular levels in the brains of individuals who have taken their own lives and in the plasma and peripheral mononuclear cells of suicide attempters and how these changes may serve as predisposing factors for suicidal tendencies.

Proinflammatory phenotype in major depressive disorder with adulthood adversity: In line with social signal transduction theory of depression

BACKGROUND

The social signal transduction theory of depression proposes that life stress can be transformed into inflammatory signals, and ultimately lead to the development of major depressive disorder (MDD). The hypotheses of this study were: (1) The pro-inflammatory effect of life stress was only seen in patients with MDD, but not in healthy controls (HCs); (2) Inflammation can mediate the relationship between life stress and depressive symptoms.

METHODS

This study included 170 MDD patients and 196 HCs, and 13 immune-inflammatory biomarkers closely related to MDD were measured, principal component analysis (PCA) was adopted to extract the inflammatory index. Life stress was assessed by Life Event Scale (LES), a total score of >32 points on the LES was considered as adulthood adversity (AA). Path analyses were used to explore the relationship among adulthood stress, inflammatory index, and severity of depression.

RESULTS

Among MDD patients, α2M, CXCL-1, IL-1β, and TLR-1 levels were higher in patients with AA than non-AA group (all FDR-adjusted P values <0.05), meanwhile, the levels of CCL-2 and IL-18 were lower. Path analyses suggested that pro- and anti-inflammatory index could mediate the association between AA and severity of depression in MDD patients.

CONCLUSION

This study found that inflammatory signals can mediate the relationship between adulthood adversity and depression, however, the causal relationship need to be further confirmed. These findings shed light on further understanding the theory of social signal transduction in MDD and provide clues for stress management and controlling inflammation strategies in depression.

CLINICAL TRIALS

NCT02023567.

Major depressive disorder with suicidal ideation or behavior in Chinese population: A scoping review of current evidence on disease assessment, burden, treatment and risk factors

BACKGROUND

Identifying and managing major depressive disorder (MDD) patients with suicidal ideation or behavior (MDSI) is critical for reducing the disease burden. This scoping review aims to map the existing evidence related to MDSI in the Chinese population.

METHOD

A scoping review was conducted to summarize the published evidence regarding epidemiology or disease burden, evaluation, diagnosis, management, and prognosis of MDSI. The search strategy imposed restriction on English or Chinese publications between 1 January 2011 and 28 February 2022.

RESULTS

Of the 14,005 identified records, 133 met the eligibility criteria and were included for analysis. The included studies were characterized as high heterogeneity in evaluation of suicidal ideation or behavior. Compared with MDD patients without suicidal ideation or behavior, MDSI patients were more likely to suffer from psychological and somatic symptoms, social function impairment, and lower quality of life. Younger age, female gender, longer disease course, and comorbid psychological or physical symptoms were consistently found to be risk factors of suicidal ideation or behavior. Relevant research gaps remain regarding comprehensive evaluation of standard clinical diagnosis, disease burden, social-cultural risk factors, and effectiveness of interventions targeting MDSI. Studies with large sample size, representative population are warranted to provide high-quality evidence.

CONCLUSIONS

MDD patients with suicidal ideation or behavior should be prioritized in treatment and resource allocation. Heterogeneity exists in the definition and evaluation of MDSI in different studies. To better inform clinical practice, it is imperative to establish a unified standard for evaluation and diagnosis of suicidal ideation or behavior among MDD population.

Potential Inflammatory Biomarkers for Major Depressive Disorder Related to Suicidal Behaviors: A Systematic Review

Major depressive disorder (MDD) is a highly prevalent psychiatric condition affecting an estimated 280 million individuals globally. Despite the occurrence of suicidal behaviors across various psychiatric conditions, MDD is distinctly associated with the highest risk of suicide attempts and death within this population. In this study, we focused on MDD to identify potential inflammatory biomarkers associated with suicidal risk, given the relationship between depressive states and suicidal ideation. Articles published before June 2023 were searched in PubMed, Embase, Web of Science, and the Cochrane Library to identify all relevant studies reporting blood inflammatory biomarkers in patients with MDD with suicide-related behaviors. Of 571 articles, 24 were included in this study. Overall, 43 significant biomarkers associated with MDD and suicide-related behaviors were identified. Our study provided compelling evidence of significant alterations in peripheral inflammatory factors in MDD patients with suicide-related behaviors, demonstrating the potential roles of interleukin (IL)-1β, IL-6, C-reactive protein, C-C motif chemokine ligand 2, and tumor necrosis factor-α as biomarkers. These findings underscore the intricate relationship between the inflammatory processes of these biomarkers and their interactions in MDD with suicidal risk.

Suicidality in civilian women with PTSD: Possible link to childhood maltreatment, proinflammatory molecules, and their genetic variations

Background

Posttraumatic stress disorder (PTSD) is a robust risk factor for suicide. Studies have suggested an association between suicide and elevated inflammatory markers, although such evidence in PTSD is scarce. Suicide risk, PTSD, and inflammatory molecules are all shown to be associated with childhood maltreatment and genetic factors.

Methods

We examined the association between suicidal ideation/risk and inflammatory markers in 83 civilian women with PTSD, and explored the possible influence of childhood maltreatment and inflammatory genes. Suicidal ideation and risk were assessed using the Beck Depression Inventory-II and the Mini-International Neuropsychiatric Interview. Childhood maltreatment history was assessed with the Childhood Trauma Questionnaire (CTQ). Blood levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and high-sensitivity tumor necrosis factor-α were measured. Genetic polymorphisms of CRP rs2794520 and IL6 rs1800796 were genotyped.

Results

Suicidal ideation was significantly positively correlated with hsCRP (p = 0.002) and IL-6 (p = 0.015) levels. Suicide risk weighted score was significantly positively correlated with hsCRP (p = 0.016) levels. The risk alleles of CRP rs2794520 and IL6 rs1800796 leading to increased respective protein levels were dose-dependently associated with higher risk of suicide (p = 0.007 and p = 0.029, respectively). The CTQ total score was significantly correlated with suicidal ideation and risk, but not with inflammatory marker levels. Furthermore, a multivariate regression analysis controlling for PTSD severity and potential confounders revealed that rs2794520 and rs1800796, but not hsCRP or IL-6 levels, significantly predicted suicidal ideation (p < 0.001) and risk (p = 0.007), respectively.

Conclusion

Genetic variations within inflammatory genes might be useful in detecting PTSD patients at high risk of suicide.

Fight the Fire: Association of Cytokine Genomic Markers and Suicidal Behavior May Pave the Way for Future Therapies

The fight against suicide is highly challenging as it may be one of the most complex and, at the same time, most threatening among all psychiatric phenomena. In spite of its huge impact, and despite advances in neurobiology research, understanding and predicting suicide remains a major challenge for both researchers and clinicians. To be able to identify those patients who are likely to engage in suicidal behaviors and identify suicide risk in a reliable and timely manner, we need more specific, novel biological and genetic markers/indicators to develop better screening and diagnostic methods, and in the next step to utilize these molecules as intervention targets. One such potential novel approach is offered by our increasing understanding of the involvement of neuroinflammation based on multiple observations of increased proinflammatory states underlying various psychiatric disorders, including suicidal behavior. The present paper overviews our existing understanding of the association between suicide and inflammation, including peripheral and central biomarkers, genetic and genomic markers, and our current knowledge of intervention in suicide risk using treatments influencing inflammation; also overviewing the next steps to be taken and obstacles to be overcome before we can utilize cytokines in the treatment of suicidal behavior.

Suicide Biomarkers to Predict Risk, Classify Diagnostic Subtypes, and Identify Novel Therapeutic Targets: 5 Years of Promising Research

BACKGROUND

Suicide is a global health crisis. However, no objective biomarkers of suicide risk currently exist, and self-reported data can be unreliable, which limits prediction, diagnostic, and treatment efforts. Reliable biomarkers that can differentiate between diagnostic subgroups, predict worsening symptoms, or suggest novel therapeutic targets would be extremely valuable for patients, researchers, and clinicians.

METHODS

MEDLINE was searched for reports published between 2016 and 2021 using search terms (suicid*) AND (biomarker*) OR (indicat*). Reports that compared biomarkers between suicidal ideation, suicide attempt, death from suicide, or any suicide subgroup against other neuropsychiatric disorders were included. Studies exclusively comparing suicidal behavior or death from suicide with healthy controls were not included to ensure that biomarkers were specific to suicide and not other psychopathology.

RESULTS

This review summarizes the last 5 years of research into suicide-associated biomarkers and provides a comprehensive guide for promising and novel biomarkers that encompass varying presentations of suicidal ideation, suicide attempt, and death by suicide. The serotonergic system, inflammation, hypothalamic-pituitary-adrenal axis, lipids, and endocannabinoids emerged as the most promising diagnostic, predictive, and therapeutic indicators.

CONCLUSIONS

The utility of diagnostic and predictive biomarkers is evident, particularly for suicide prevention. While larger-scale studies and further in-depth research are required, the last 5 years of research has uncovered essential biomarkers that could ultimately improve predictive strategies, aid diagnostics, and help develop future therapeutic targets.

Inflammation biomarkers in suicide attempts and their relation to abuse, global functioning and cognition

OBJECTIVES

To explore the link between cytokines and suicide attempts and their relationship with the psychological aspects of this complex multifactorial phenomenon.

METHODS

96 participants, including 20 patients with a recent suicide attempt and diagnosis of Major Depression Disorder (MDD), 33 MDD patients with a lifetime history of suicide attempt, 23 non-attempter MDD patients, and 20 healthy controls underwent an assessment on depressive symptoms, global functioning, aggressive behaviour, presence of abuse and attention performance. Additionally, all participants had a blood extraction for IL-2, IL2-R, IL-4, IL-6, and TNF-α plasma levels analysis.

RESULTS

IL-6 levels were significantly different across groups (F(3,89)=3.690; p = 0.015), with higher concentrations in both recent (p = 0.04) and distant (p = 0.015) attempt in comparison to MDD non-attempters. IL-6 was associated with adult physical abuse (B = 2.591; p = 0.021), lower global functioning score (B = -0.512; p = 0.011), and poorer performance on attention (B = -0.897; p = 0.011).

CONCLUSIONS

Recent and distant suicidal behaviour is associated with elevated IL-6 levels, which may be influenced by stressful and traumatic experiences. Elevated concentrations of IL-6 could have a negative impact on attention, increasing suicide risk. More research is needed to clarify the role of cytokines in suicide-related features to explore novel treatments and more effective preventive interventions.

Highlighting Immune System and Stress in Major Depressive Disorder, Parkinson's, and Alzheimer's Diseases, with a Connection with Serotonin

There is recognition that both stress and immune responses are important factors in a variety of neurological disorders. Moreover, there is an important role of several neurotransmitters that connect these factors to several neurological diseases, with a special focus in this paper on serotonin. Accordingly, it is known that imbalances in stressors can promote a variety of neuropsychiatric or neurodegenerative pathologies. Here, we discuss some facts that link major depressive disorder, Alzheimer’s, and Parkinson’s to the stress and immune responses, as well as the connection between these responses and serotonergic signaling. These are important topics of investigation which may lead to new or better treatments, improving the life quality of patients that suffer from these conditions.

Suicidal Ideation and Attempt among North Korean Refugee Women in South Korea: Factors that Distinguish Suicide Attempt from Suicidal Ideation

BACKGROUND

North Korean Refugee Women (NKRW) are at a high risk for suicide. However, few studies have examined risk factors for suicide among NKRW in South Korea. This study aimed to examine factors increasing risk for suicidal ideation and to identify factors differentiating suicide attempt from ideation among NKRW in South Korea.

METHODS

A sample of 140 NKRW was analyzed; multinomial logistic regression was conducted to identify factors distinguishing respondents with (1) no suicidal ideation, (2) isolated suicidal ideation (without attempts), and (3) ideation with attempts.

RESULTS

About 46% of the sample reported suicidal ideation, and about 18% attempted suicide during the past year. NKRW without any suicidal risk had significantly lower levels of social isolation (OR = 0.86, p = 0.02) and less exposure to traumatic events (OR = 0.89, p = 0.02) than those with suicidal ideation. NKRW who attempted suicide were more likely to have higher levels of stress than those with only suicidal ideation (OR = 1.40, p = 0.03).

CONCLUSION

This study provides insights into suicide prevention among refugees and emphasized that post-migration life stress significantly differentiates suicidal ideation from attempt among NKRW. Intervening to address current life stress, traumatic experiences, and social isolation may help prevent refugee suicidal ideation and further attempt.

Association of serum uric acid levels with suicide risk in female patients with major depressive disorder: a comparative cross-sectional study

BACKGROUND

Individuals with major depressive disorder (MDD) have a high suicide risk. Some evidence suggests that uric acid (UA) may be involved in the pathophysiology of MDD. The purpose of this study was to evaluate whether serum UA levels were associated with suicide risk in MDD patients.

METHODS

One hundred four female patients with MDD (52 patients with suicide risk and 52 patients without suicide risk) and 52 healthy individuals were included in this study. The suicide risk was evaluated by Mini International Neuropsychiatric Interview (M.I.N.I.). Fasting serum levels of UA, as well as glucose, lipid and renal function indicators were measured.

RESULTS

Serum UA levels in MDD patients with suicide risk (245.01 ± 55.44 μmol/L) were significantly lower than those in MDD patients without suicide risk (274.17 ± 72.65 μmol/L) (p = 0.017) and healthy controls (271.42 ± 55.25 μmol/L) (p = 0.030). There was no difference in serum UA levels between the MDD patients without suicide risk and healthy controls (p = 0.821). Binary logistic regression analysis revealed a significant relationship between suicide risk and decreased serum UA levels (OR = 0.989, p = 0.010) in MDD patients.

CONCLUSION

Decreased serum UA levels were associated with suicide risk in MDD patients. Purinergic system dysfunction may be involved in the neurobiological basis of suicide risk in these patients.