Interest of neuroimaging of social exclusion in suicide

Social isolation, loneliness, death stress and life satisfaction in older adults: A serial mediation study

This study aims to examine the mediating role of loneliness on the relationship between social isolation and life satisfaction among older adults and tests a mechanism through which social isolation exerts its menacing effects through a sequential model of loneliness and death distress. Data came from 548 community-dwelling older adults in rural settings in Turkey. They completed some demographic information including sex, age and measures of social isolation, loneliness, death distress, and life satisfaction. The results showed that loneliness and death distress exacerbated the negative effects of social isolation on life satisfaction. Loneliness and death distress served as a sequential mediating role in the association between social isolation and life satisfaction. Older adults with higher social isolation experience heightened loneliness and death distress, and worsening levels of life satisfaction. Greater experience of loneliness in sequence with greater levels of death distress mediated the relationship between life satisfaction and social isolation.

Alterations in orbitofrontal cortex communication relate to suicidal attempts in patients with major depressive disorder

BACKGROUND

Investigating how the interaction between the orbitofrontal cortex (OFC) and various brain regions/functional networks in major depressive disorder (MDD) patients with a history of suicide attempt (SA) holds importance for understanding the neurobiology of this population.

METHODS

We employed resting-state functional magnetic resonance imaging (rs-fMRI) to analyze the OFC's functional segregation in 586 healthy individuals. A network analysis framework was then applied to rs-fMRI data from 86 MDD-SA patients and 85 MDD-Control patients, utilizing seed mappings of OFC subregions and a multi-connectivity-indicator strategy involving cross-correlation, total interdependencies, Granger causality, and machine learning.

RESULTS

Four functional subregions of left and right OFC, were designated as seed regions of interest. Relative to the MDD-Control group, the MDD-SA group exhibited enhanced functional connectivity (FC) and attenuated interaction between the OFC and the sensorimotor network, imbalanced communication between the OFC and the default mode network, enhanced FC and interaction between the OFC and the ventral attention network, enhanced interaction between the OFC and the salience network, and attenuated FC between the OFC and the frontoparietal network.

LIMITATIONS

The medication and treatment condition of patients with MDD was not controlled, so the medication effect on the alteration model cannot be affirmed.

CONCLUSION

The findings suggest an imbalanced interaction pattern between the OFC subregions and a set of cognition- and emotion-related functional networks/regions in the MDD-SA group.

Correlations between Dementia and Loneliness

This review describes associations between dementia and loneliness on the neurobiological and epidemiological levels according to the recent body of literature. The aim of this study was to highlight major lines of research in this field. Sociocognitive skills and social interactions present complex interdependencies with dementia which may be explained by two theories. According to the first one, not sufficiently engaging in social or cognitive activities results in brain atrophy. The second one claims that brain neurogenesis and synaptic density are being increased by social connections. The relationship between loneliness and dementia could be mediated by sensory loss, including hearing and visual impairment, as well as depression and psychotic symptoms. Loneliness itself might cause a depletion in sensory and cognitive stimulation which results in a decrease in neural reserve. Certain changes in the structures of the brain caused by loneliness were found in imaging examination. Loneliness appears to be a crucial risk factor for dementia in recent times due to the modern lifestyle and consequences of the outbreak of COVID-19. Additional studies are required to understand more completely the key tenets of this topic and therefore to improve the prevention and treatment of dementia.

Neuroimaging alterations of the suicidal brain and its relevance to practice: an updated review of MRI studies

Suicide is a leading cause of death in the United States. Historically, scientific inquiry has focused on psychological theory. However, more recent studies have started to shed light on complex biosignatures using MRI techniques, including task-based and resting-state functional MRI, brain morphometry, and diffusion tensor imaging. Here, we review recent research across these modalities, with a focus on participants with depression and Suicidal Thoughts and Behavior (STB). A PubMed search identified 149 articles specific to our population of study, and this was further refined to rule out more diffuse pathologies such as psychotic disorders and organic brain injury and illness. This left 69 articles which are reviewed in the current study. The collated articles reviewed point to a complex impairment showing atypical functional activation in areas associated with perception of reward, social/affective stimuli, top-down control, and reward-based learning. This is broadly supported by the atypical morphometric and diffusion-weighted alterations and, most significantly, in the network-based resting-state functional connectivity data that extrapolates network functions from well validated psychological paradigms using functional MRI analysis. We see an emerging picture of cognitive dysfunction evident in task-based and resting state fMRI and network neuroscience studies, likely preceded by structural changes best demonstrated in morphometric and diffusion-weighted studies. We propose a clinically-oriented chronology of the diathesis-stress model of suicide and link other areas of research that may be useful to the practicing clinician, while helping to advance the translational study of the neurobiology of suicide.

Risk factors for suicide attempts among U.S. military veterans: A 7-year population-based, longitudinal cohort study

BACKGROUND

Population-based data on risk factors for suicide attempts among veterans remains limited.

METHODS

A national probability sample of 2307 veterans was followed over the course of four timepoints spanning seven years to examine how a range of baseline risk factors predict incident suicide attempt. Suicide attempt data were aggregated into a single follow-up timepoint.

RESULTS

Sixty-two veterans (3.1%) reported attempting suicide during the 7-year period. The strongest risk factors for suicide attempts were higher baseline levels of loneliness, lower baseline levels of adaptive psychosocial traits (e.g., dispositional gratitude), baseline thoughts of self-harm, and greater post-baseline trauma exposures (12.3%-41.3% of explained variance). Veterans with multiple co-occurring risk factors were at greatest risk for attempts; of veterans with 0, 1, 2, 3, and all 4 of these factors, the predicted probability of suicide attempt was 2.0%, 5.3%, 13.5%, 30.4%, and 55.0%, respectively.

CONCLUSIONS

Baseline loneliness, dispositional gratitude, thoughts of self-harm, and new-onset traumas emerged as the strongest risk factors for suicide attempts among veterans, underscoring the potential importance of targeting these factors in prevention efforts. Veterans with multiple co-occurring risk factors have substantially greater risk for suicide attempts, suggesting that examination of multiple coinciding vulnerability factors may help improve suicide risk prediction models.

Emotional Loneliness Is Associated With a Risk of Dementia in a General Japanese Older Population: The Hisayama Study

OBJECTIVES

To investigate the association of loneliness and its component subscales with the risk of dementia in a general Japanese older population.

METHOD

A total of 1,141 community-dwelling Japanese residents aged ≥65 years without dementia were prospectively followed up for a median 5.0 years. We evaluated any loneliness and its component subscales-namely, social and emotional loneliness-by using the 6-item de Jong Gierveld Loneliness Scale. Cox proportional hazards models were used to estimate hazard ratios (HRs) of each loneliness type on the risk of dementia controlling for demographic factors, lifestyle factors, physical factors, social isolation factors, and depression.

RESULTS

During the follow-up, 114 participants developed dementia. The age- and sex-adjusted incidence rate of dementia was significantly greater in participants with any loneliness and emotional loneliness than those without. The multivariable-adjusted HRs (95% confidence intervals) of participants with any loneliness and emotional loneliness on incident dementia were 1.61 (1.08-2.40) and 1.65 (1.07-2.54), respectively, as compared to those without. However, there was no significant association between social loneliness and dementia risk. In subgroup analyses of social isolation factors, excess risks of dementia associated with emotional loneliness were observed in participants who had a partner, lived with someone, or rarely communicated with relatives or friends, but such association was not significant in participants who had no partner, lived alone, or frequently communicated with friends or relatives.

DISCUSSION

The present study suggested that loneliness, especially emotional loneliness, was a significant risk factor for the development of dementia in the general older population in Japan.

Thwarted belongingness predicts greater neural reactivity to a novel social exclusion image set: Evidence from the late positive potential

INTRODUCTION

Thwarted belongingness (TB) is among the most well-researched risk factors for suicidal ideation (SI). Yet, there is little research examining neural mechanisms underlying this construct. The present study used a novel social exclusion image set in concert with the late positive potential (LPP) to test the role of neural reactivity social exclusion in TB and SI.

METHODS

Participants (n = 243) were recruited based on elevated suicide risk and completed an emotional picture viewing task. The LPP was used to index neural reactivity to a novel set of social exclusion images and international affective picture system (IAPS) neutral, positive, and negative images.

RESULTS

Greater TB predicted a larger social exclusion ΔLPP (social exclusion LPP relative to neutral LPP) and social exclusion LPP even when accounting for SI, biological sex, age, negative affect, and perceived burdensomeness. Moreover, the social exclusion LPP was uniquely related to TB beyond the LPP to other images. Last, a larger social exclusion LPP predicted greater SI via elevations in TB.

CONCLUSION

Reactivity to social exclusion stimuli may play an important role in SI via elevated TB, but not perceived burdensomeness. Future research should further explore the neural mechanisms underlying other IPT constructs.

Suicidality among young adults: Unique and cumulative roles of 14 different adverse childhood experiences

BACKGROUND

College students with suicidal ideation (SI) are at high risk of suicide. Adverse childhood experiences (ACEs) are important risk factors for suicidal behavior. Most research in this area has been restricted to 10 conventional ACEs and suggests negative long-term developmental effects from other common childhood adversities such as peer victimization, peer isolation/rejection, exposure to community violence, and low socioeconomic status.

OBJECTIVE

To test the unique and cumulative associations of 14 different ACEs with SI among young adults.

PARTICIPANTS AND SETTING

Participants were 989 college students from two universities in China's provincial-leveled Hui Autonomous Region.

METHODS

Associations between ACEs and SI were analyzed by logistic regression. A Chi-square trend test was used to examine the association between cumulative ACEs and SI.

RESULTS

The rates of suicidal ideation, plans, and attempts among the cohort were 11.9%, 3.7%, and 1.6%, respectively; 43.9% had experienced at least one ACE. The strongest predictor of SI in adulthood was peer isolation/rejection, followed by emotional neglect, then low socioeconomic status. There was a cumulative effect of ACEs and SI, whereby the greater the number of ACEs, the greater the likelihood of SI.

CONCLUSION

Peer isolation/rejection, emotional neglect, and low socioeconomic status were associated with increased risk of SI in adulthood. Two (peer isolation/rejection and low socioeconomic status) of the three factors that emerged from the analysis are not typically included in ACEs research. There was a cumulative effect of 14 kinds of ACEs on SI among young adults. Early recognition of risk factors is therefore important.