Journal of Affective Disorders Special Issue on Suicide-Related Research: Hopeful progress but much research urgently needed

Resting-State Functional Connectivity of the Anterior Cingulate Cortex Among Persons With Mood Disorders and Suicidal Behaviors

OBJECTIVE

To assess whether anterior cingulate cortex (ACC) abnormalities contribute to suicide risk in major depressive disorder and bipolar disorder, the investigators compared resting-state functional connectivity (rsFC) of ACC subdivisions between individuals with major depressive or bipolar disorder with and without a lifetime history of suicidal behavior.

METHODS

Forty-two inpatients with and 26 inpatients without a history of suicidal behavior (SB+ and SB-, respectively) associated with major depressive or bipolar disorder and 40 healthy control (HC) participants underwent rsFC neuroimaging. RsFC of the subgenual, perigenual, rostral, dorsal, and caudal subdivisions of the ACC was calculated. Possible confounders, such as psychosis and severity of depression, were controlled for, seed-to-voxel and post hoc region of interest (ROI)-to-ROI analyses were performed, and the accuracy of rsFC in classifying suicidal behavior was studied.

RESULTS

Compared with individuals in the SB- and HC groups, patients in the SB+ group had higher rsFC between the left rostral and right dorsal ACC seeds and visual cortex clusters. Conversely, rsFC between the left rostral and right dorsal ACC seeds and cingulate and frontal clusters was lower in the SB+ group than in the HC group. Left rostral ACC to left Brodmann's area 18 connectivity showed up to 75% discriminative accuracy in distinguishing SB+ from SB- patients.

CONCLUSIONS

A history of suicidal behavior among individuals with major depressive disorder or bipolar disorder was associated with altered rsFC of the rostral and caudal ACC, regions involved in conflict detection and error monitoring. Replication of these findings is needed to further explore the involvement of the ACC in the neurobiology of suicidal behavior and suicidal ideation.

Suicide and economic uncertainty: New findings in a global setting

This study extends the previous literature on the association between country-level economic uncertainty and suicide rate to 141 countries by introducing the World Uncertainty Index. We first examine the role of economic uncertainty on the suicide rates in a global setting for the period 2000-2019 and then analyze if the association varied across different income groups. Our primary findings suggest that a rise in economic uncertainty is related to an increased suicide rate. According to the estimates based on various income levels, higher economic uncertainty is associated with increased suicide risk in high-income countries. For middle- and low-income countries, we find no such impact. Overall, we conclude that contemporaneous and lagged economic uncertainty is a concern for the increased risk of suicide, especially in high-income countries. The results highlight the need for proactive suicide-prevention strategies in uncertain times.

Elevated cognitive rumination and adverse life events are associated with lower cortical surface area and suicidal ideation in adolescents with major depressive disorder

INTRODUCTION

Suicide is the second most common cause of death among young people. Structural brain alterations, rumination, and recent stressful experiences contribute to suicidal thoughts and behaviors (STBs).

METHODS

Here, we employed structural equation modeling (SEM) to examine the unique and combined relationships of these risk factors with STBs in a sample of young people with major depressive disorder (MDD) from the Magnetic Resonance-Improving Mood with Psychoanalytic and Cognitive Therapies (MR-IMPACT) study (N = 67, mean age = 15.90; standard deviation ± 1.32).

RESULTS

Whereas increased rumination and lower surface area of brain regions, that have been previously reported to be involved in both STBs and rumination, were associated with each other (Beta = -0.268, standard error (SE) = 0.114, Z = -2.346, p = 0.019), only increased rumination was related to greater severity of suicidal ideation (Beta = 0.281, SE = 0.132, Z = 2.134, p = 0.033). In addition, we observed that recent stress was associated with lower surface area in the suicidal ideation model without covariate only (Beta = -0.312, SE = 0.149, Z = -2.089, p = 0.037). For the attempt models, no associations were found between any of the risk factors and suicide attempts.

LIMITATIONS

We emphasize that these findings from this secondary analysis are hypothesis-forming and preliminary in nature given the small sample size for SEM analyses.

CONCLUSION

Our findings suggest that neither lower surface area nor recent stress are directly associated with youth suicidal ideation or attempt. However, lower surface area is related to recent stress and increased rumination, which predicted greater severity of suicidal ideation in young people with MDD.

The role of psychiatric symptoms and environmental vulnerability factors in explaining the relationship between child maltreatment and suicidality: A prospective investigation

BACKGROUND

Childhood maltreatment has been associated with suicide thoughts and attempts; however, few longitudinal studies have assessed risk of suicidality into adulthood. Fewer have examined potential mediators (psychiatric symptoms and environmental vulnerability factors).

METHODS

Prospective cohort design. Children with documented cases of maltreatment (N = 495, ages 0-11) were matched with non-maltreated children (N = 395) and followed up into adulthood. Psychiatric symptoms (depression, anxiety, dysthymia, post-traumatic stress,antisocial personality,and substance use) and environmental vulnerability (social isolation, physical disability/illness, and homelessness) were assessed at mean age 29 and suicide thoughts and attempts at 39. Structural equation models tested for mediation, controlling for age, sex, race, and IQ.

RESULTS

Childhood maltreatment predicted suicide attempts (Beta = 0.44, p<0.001), but not suicide thoughts only.Individuals with only suicide thoughts differed significantly from those with suicide attempts in psychiatric symptoms, physical disability/ illness, and homelessness. There were significant paths from child maltreatment to suicide attempts through psychiatric symptoms (0.18, p<0.001), ASPD (0.13, p<0.001), substance use (0.07, p<0.01), and homelessness (0.10, p<0.05).

LIMITATIONS

Court cases of child maltreatment may not generalize to middle- or upper- class and non-reported cases.Effect sizes were small but significant.

CONCLUSIONS

Psychiatric risk factors for suicide are well recognized. These new results provide strong evidence that environmental vulnerability factors, particularly homelessness, are associated with increased risk for suicide attempts and warrant attention.Although many people report suicide thoughts, maltreated children with more psychiatric symptoms and experience homelessness are more likely to attempt suicide and warrant targeted interventions.