Suicidal behaviors are associated with loneliness and decrease during inpatient CBASP treatment for persistent depressive disorder

Association between loneliness and suicidality among general populations and persons with depressive and bipolar disorders: A systematic review

BACKGROUND

Loneliness and suicidality are interrelated phenomena. Several studies suggest that they often co-exist, but the magnitude is unclear. This systematic review aims to analyze this association in general population samples of varying age groups and persons with depressive and bipolar disorders.

METHODS

Search terms in this review included words related to loneliness and suicidality among general populations and depressive and bipolar disorders. Databases included PubMed, PsychINFO, and Web of Science. The search occurred up until May 27, 2024. Screening and data extraction were performed independently. Studies were categorized by age group or clinical diagnosis. Quality assessments were conducted using NIH tools.

RESULTS

Fifty-six studies met eligibility criteria: 52 involved general population samples and 4 involved patients with depressive or bipolar disorders. In healthy adults aged 18 to 64, loneliness mainly showed a moderate positive correlation with suicidality (r = 0.26 to 0.59), while correlations in older adults (aged 65+) (r = 0.498) and in adolescents aged 13-17 were weaker. In depressive and bipolar disorders, correlations ranged from weak to moderate (r = -0.06 to 0.40), with associations stronger in unadjusted models (UOR = 2.8 to 7.07). Furthermore, some studies suggested that depressive symptoms mediate the association between loneliness and suicidality.

CONCLUSION

A moderate and positive association was observed between loneliness and suicidality in healthy adults and patients with depressive disorders. However, the role of bipolar disorders in the association remains unclear. Practitioners should routinely evaluate persons living with depressive or bipolar disorders for loneliness as part of a comprehensive assessment.

Temporal interaction of suicidal ideations and behaviors with loneliness in persistent depressive disorder - a feasibility study using ecological momentary assessment

Individuals with persistent depressive disorder (PDD) are at increased risk for suicidality. Suicidality may be precipitated by loneliness. However, their temporal interplay in PDD has not been studied. We conducted a feasibility study using ecological momentary assessment (EMA) to measure short-term courses of suicidality and loneliness in 20 inpatients with PDD and current suicidality. EMA adherence of 13 completers was 81.3%. Suicidal ideations and loneliness varied with one standard deviation over three to six hours. This pilot study confirmed the feasibility of EMA in PDD and provided new insights in dynamics of suicidality and loneliness informing future study designs.

Socioeconomic Correlates of Suicidal Ideation in Military Veterans: Examining the Interaction Between Homelessness and Financial Debt

Studies in veterans have yet to examine interconnections between homelessness, financial debt, and suicidal ideation. We analyzed data from a nationally-representative study conducted in 2021 of low-income U.S. veterans (N = 1,004). Analyses revealed veterans who were younger, male, had a history of criminal arrests, met criteria for posttraumatic stress disorder (PTSD), reported greater loneliness, or had both a history of homelessness and higher debt were more likely to endorse suicidal ideation. We found an interaction between a history of homelessness and current debt: 40% of veterans with both past homelessness and higher debt reported suicidal ideation, whereas only 10% of veterans with either past homelessness or higher debt reported suicidal ideation. As past homelessness and current debt interacted to increase the odds of suicidal ideation in a national sample of veterans, these results inform policy and clinical decision-making for suicide prevention and in programs serving veterans experiencing homelessness.

Gut dysbiosis induces the development of depression-like behavior through abnormal synapse pruning in microglia-mediated by complement C3

BACKGROUND

Remodeling eubiosis of the gut microenvironment may contribute to preventing the occurrence and development of depression. Mounting experimental evidence has shown that complement C3 signaling is associated with the pathogenesis of depression, and disruption of the gut microbiota may be an underlying cause of complement system activation. However, the mechanism by which complement C3 participates in gut-brain crosstalk in the pathogenesis of depression remains unknown.

RESULTS

In the present study, we found that chronic unpredictable mild stress (CUMS)-induced mice exhibited obvious depression-like behavior as well as cognitive impairment, which was associated with significant gut dysbiosis, especially enrichment of Proteobacteria and elevation of microbiota-derived lipopolysaccharides (LPS). In addition, peripheral and central complement C3 activation and central C3/CR3-mediated aberrant synaptic pruning in microglia have also been observed. Transplantation of gut microbiota from CUMS-induced depression model mice into specific pathogen-free and germ-free mice induced depression-like behavior and concomitant cognitive impairment in the recipient mice, accompanied by increased activation of the complement C3/CR3 pathway in the prefrontal cortex and abnormalities in microglia-mediated synaptic pruning. Conversely, antidepressants and fecal microbiota transplantation from antidepressant-treated donors improved depression-like behaviors and restored gut microbiome disturbances in depressed mice. Concurrently, inhibition of the complement C3/CR3 pathway, amelioration of abnormal microglia-mediated synaptic pruning, and increased expression of the synapsin and postsynaptic density protein 95 were observed. Collectively, our results revealed that gut dysbiosis induces the development of depression-like behaviors through abnormal synapse pruning in microglia-mediated by complement C3, and the inhibition of abnormal synaptic pruning is the key to targeting microbes to treat depression.

CONCLUSIONS

Our findings provide novel insights into the involvement of complement C3/CR3 signaling and aberrant synaptic pruning of chemotactic microglia in gut-brain crosstalk in the pathogenesis of depression. Video Abstract.

Suicidal behaviors and adverse childhood experiences: A cross-diagnostic study in persistent depressive disorder and borderline personality disorder

Adverse childhood experiences (ACE) constitute a known risk factor for suicidality. There is a research gap regarding differential patterns of associations between variants of suicidal ideations and behaviors (SIB) and characteristics of ACE in severe mental disorders. This cross-diagnostic study investigates whether SIB are related to ACE subtypes in two high-risk conditions, i.e., persistent depressive disorder (PDD) and borderline personality disorder (BPD). Inpatients with PDD (n = 117; age 40.2 years ± 12.3) and BPD (n = 74; age 26.2 ± 7.9) were assessed with the Columbia-Suicide Severity Rating Scale for suicidal ideations (SI), suicidal behaviors (SB) and actual suicide attempts (SA); ACE were recorded with the Childhood Trauma Questionnaire. In PDD, SI and SA were associated with childhood physical abuse (ORs 7.2 and 2.3, respectively). In BPD, SA were associated with severe experiences of physical abuse (OR 6.5). Weaker yet significant associations were found for childhood emotional abuse in PDD with SB (including SA), and in BPD with SA. Recall of childhood physical abuse may be clinically relevant information for identifying particular risks of SIB. Future studies should investigate these differential patterns in more depth and in terms of causality.

Suicide Risk in Personality Disorders: A Systematic Review

PURPOSE OF REVIEW

This systematic review aimed to distil recent literature investigating psychosocial factors which may account for the association between personality disorder (PD) and suicide attempt or suicide death.

RECENT FINDINGS

Suicide risk is particularly elevated in people with PD compared to those with no, or many other, mental health diagnoses. Despite this, suicide prevention strategies for PD populations have not progressed markedly in recent years. It is critical, therefore, to identify additional factors associated with suicide in PD populations. Of the 34 studies included in this review, most identified a relationship between personality disorder and suicide attempt and/or death. Historical interpersonal factors (e.g., childhood trauma), drug and alcohol use, and ideation-to-enaction factors were commonly associated with suicide-related outcomes. Interventions that provide interpersonal support may reduce suicide attempts. Limitations of the review include the heterogeneity of studies and small sample sizes.

High Serum Levels of IL-6 Are Associated with Suicide Attempt but Not with High Lethality Suicide Attempts: A Preliminary Case-Control Study

Suicide attempts are an emerging health problem around the world. Increased levels of IL-6 have been associated with suicidal behavior. Therefore, the aims of this study were to evaluate the serum levels of IL-6 in individuals with suicide attempts and a comparison group and to associate the IL-6 levels with the lethality of the suicide attempt. Additionally, we associated the rs2228145 polymorphism of the IL6R gene with suicide attempts or with the IL-6 serum levels. Suicide attempts and their lethality were evaluated using the Columbia Suicide Severity Rating Scale. The serum concentrations of IL-6 were measured by the ELISA technique in individuals with suicide attempts and then compared to a control group. The rs2228145 polymorphism of the IL6R gene was analyzed by real-time polymerase chain reaction. We found elevated serum levels of IL-6 in the suicide attempt group when compared to the control group (F = 10.37, p = 0.002). However, we found no differences of the IL-6 levels between high and low lethality. The IL6R gene polymorphism rs2479409 was not associated with suicide attempts. Our data suggest that IL-6 serum is increased in individuals with suicide attempts.

Aggressive intentions after social exclusion and their association with loneliness

Both social exclusion and loneliness are aversive experiences that can lead to hostile behavioral reactions, including aggressive behavior. This study aimed to assess whether a social exclusion scenario in the subject's imagination elicits aggressive reactions towards an excluding person as measured with the hot sauce paradigm. Furthermore, we studied the effect of loneliness on such reactions. In total, 251 subjects (67.7% female; mean age 27.3 ± 9.3 years) participated in this study which was based on an online survey. After trait loneliness was assessed with the UCLA Loneliness scale at baseline, two imaginary scenarios were presented in randomized order, i.e., an exclusion condition (with one of two working colleagues excluding the participant from a social activity) and an inclusion condition (without exclusion). Following each scenario, participants had the task to allocate the amount of hot sauce to each colleague that they find appropriate. Participants distributed significantly more hot sauce to the excluder than to the includers. The amount of hot sauce was significantly correlated with loneliness for all includer interactions (i.e., after the inclusion as well as the exclusion scenario), but not for the interaction with the excluder. Our results support the hypothesis that social exclusion elicits aggressive behavior. Interestingly, the experience of loneliness seems to be associated with an increase in aggressive behavioral tendencies or a lack of their inhibition. The cognitive and/or emotional processes underlying the interplay between social exclusion, loneliness and aggression should be a focus of future research.