Prefrontal cortex markers of suicidal vulnerability in mood disorders: a model-based structural neuroimaging study with a translational perspective

Cingulate cortex cortical thickness associated with non-suicidal self-injury and suicide risk in youth with mood disorders

BACKGROUND

Non-suicidal self-injury (NSSI) is associated with increased suicide risk and is prevalent among patients with mood disorders, including major depressive disorder (MDD) and bipolar disorder (BD). Structural alterations in cortical regions involved in emotional processing are linked to NSSI as well as suicide risk in mood disorders. Few studies have investigated the neurobiological substrates of NSSI and suicidal thoughts and behaviors (STB), particularly comparing youth with BD to those with MDD. There is a critical need to examine NSSI and STB in the context of MDD and BD separately, as risks differ between these populations.

METHODS

This study investigated the relationship between anterior cingulate cortex (ACC) cortical thickness and volume and NSSI and STB in youth with mood disorders. One-hundred thirty-seven youth (86 with MDD and 51 with BD), ages 13 to 21, completed a diagnostic interview, clinical assessments, and 3 T magnetic resonance imaging. Morphometric analysis of brain images was performed to evaluate differences in cingulate regions of interest.

RESULTS

Seventy-five youth reported a NSSI. Youth with BD were more likely to report NSSI than youth with MDD. In addition, youth with BD and NSSI were more likely to have a suicide attempt and had significantly lower cortical thickness in the right caudal ACC (p = .009, η2 = 0.050) compared to youth with MDD and NSSI.

CONCLUSIONS

These structural alterations in the ACC, which impact emotional regulation and pain processing, may be linked to the increased NSSI and suicide risk observed in BD.

Psychoneuroimmunoendocrinological and neuroanatomical basis of suicidal behavior: potential therapeutic strategies with a focus on transcranial magnetic stimulation (TMS)

Suicidal behavior is a complex phenomenon influenced by psychological, environmental, and biological factors. It affects a significant portion of the global population, with more than 720,000 deaths annually and millions of individuals experiencing suicidal ideation. Among those who attempt suicide, only a fraction progresses to a fatal outcome, emphasizing the importance of understanding individual vulnerabilities. This review explores the neuroanatomical basis of suicidal behavior, focusing on key brain regions and potential pathways for neuromodulation therapies, particularly Transcranial Magnetic Stimulation (TMS). The dorsolateral prefrontal cortex (DLPFC) plays a central role in cognitive control and emotional regulation, with extensive connections to the anterior cingulate cortex, amygdala, orbitofrontal cortex, hippocampus, and thalamus. Dysfunctions in these circuits contribute to heightened impulsivity, impaired decision-making, and emotional dysregulation in individuals with suicidal behavior. Structural and functional abnormalities in the DLPFC, coupled with altered neurotransmitter systems and inflammatory markers, have been consistently linked to suicidality. TMS, targeting the left DLPFC, has shown promise in reducing suicidal ideation by modulating frontostriatal connectivity, enhancing neuroplasticity, and improving cortical excitability. High-frequency TMS and accelerated theta-burst stimulation protocols demonstrate rapid therapeutic effects, though further research is needed to establish standardized treatment guidelines. Understanding the anatomical circuits implicated in suicidal behavior provides valuable insights for early risk assessment and the development of targeted neuromodulation interventions aimed at reducing the burden of suicide across diverse psychiatric populations.

Exploring neural changes associated with suicidal ideation and attempts in major depressive disorder: A multimodal study

Suicidal ideation (SI) and suicide attempts (SA) are highly prevalent in individuals with major depressive disorder (MDD). To explore the structural and functional neural changes associated with SI and SA, we analyzed multimodal Magnetic Resonance Imaging (MRI) data from 159 participants, including those with MDD with suicide attempts (SA group, n = 34), those with MDD with suicidal ideation but not attempts (SI group, n = 53), those with MDD without suicidal ideation (NSI group, n = 14), and healthy controls (HC, n = 59). Voxel-based morphometry (VBM) analysis was performed to estimate and compare gray matter volume (GMV) across groups. Subsequently, a seed-based resting-state functional connectivity (rsFC) analysis was conducted to explore the functional networks associated with the structural brain changes related to suicidal ideation and suicide attempts. Compared with the HC and NSI groups, the SI group showed decreased GMV in the left dorsolateral prefrontal cortex (DLPFC), insula, fusiform gyrus, right posterior cerebellum, and right middle temporal gyrus. Additionally, when compared to the HC and SI groups, the SA group demonstrated smaller GMV in the right superior medial frontal gyrus (SFGmed), left superior and inferior occipital gyri, and superior temporal gyrus (STG), and right cuneus, but larger GMV in the right STG. Moreover, GMV in the insula, cerebellum posterior lobe, and SFGmed was negatively correlated with the scores of the Beck Scale for Suicide Ideation (BSSI). The rsFC analysis revealed weaker rsFC between the left insula and the left SFG as well as between the bilateral middle frontal orbital gyrus and the right SFGmed and the left middle occipital gyrus, but stronger rsFC of the right cerebellum posterior lobe with the left precentral gyrus and right parahippocampal gyrus among the SI group compared to the NSI group and HCs. Additionally, the SA group demonstrated weaker rsFC between the right cerebellum posterior lobe and the left cerebellum posterior lobe as well as the right lingual gyrus, but stronger rsFC between the right SFGmed and the left middle temporal gyrus and right inferior parietal lobule compared to the SI group. Our results indicate that structural and functional changes related to insula, DLPFC and cerebellum posterior lobe are associated with the generation and escalation of SI in MDD, while the structural and functional changes related to SFGmed and STG play a crucial role in the transformation from SI to SA in MDD.

Frontal Pole Neuromodulation for Impulsivity and Suicidality in Veterans With Mild Traumatic Brain Injury and Common Co-Occurring Mental Health Conditions: Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

Suicide remains a leading cause of death among veterans in the United States, and mild traumatic brain injury (mTBI) increases the risk of suicidal ideation (SI) and suicide attempts (SAs). mTBI worsens impulsivity and contributes to poor social and occupational functioning, which further increases the risk of SI and SAs. Repetitive transcranial magnetic stimulation is a neuromodulatory treatment approach that induces neuroplasticity, potentially repairing neurodamage. Intermittent theta burst stimulation (iTBS) is a second-generation form of transcranial magnetic stimulation that is safe, shorter in duration, displays a minimal side effect profile and is a promising treatment approach for impulsivity in mTBI. Our novel proposed treatment protocol uses frontal pole iTBS to target the ventromedial prefrontal cortex, which may reduce impulsivity by strengthening functional connectivity between the limbic system and frontal cortex, allowing for improved top-down control of impulsive reactions, including SI and SAs.

OBJECTIVE

The objectives of this study are to (1) develop an iTBS intervention for veterans with mTBI, impulsivity, and SI; (2) assess the feasibility and tolerability of the intervention; and (3) gather preliminary clinical outcome data on SI, impulsivity, and functions that will guide future studies.

METHODS

This is a pilot, double-blinded, randomized controlled trial. In developing this protocol, we referenced the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. We will enroll 56 participants (28 active iTBS and 28 sham iTBS). The iTBS intervention will be performed daily, 5 days a week, for 2 weeks. We will collect 10 validated, psychometric, quantitative outcome measures before, during, and after the intervention. Measures included will assess functioning, impulsivity, suicidality, posttraumatic stress disorder, and depressive symptoms. We will collect qualitative data through semistructured interviews to elicit feedback on the participants' experiences and symptoms. We will perform quantitative and qualitative analyses to (1) assess the feasibility, tolerability, and acceptability of the treatment; (2) gather advanced neuroimaging data to assess neural changes elicited by treatment; and (3) assess improvements in outcome measures of impulsivity and suicidality in veterans with mTBI.

RESULTS

This study protocol was approved by the Edward Hines, Jr. VA Hospital Institutional Review Board (Hines IRB number 14-003). This novel treatment is a 5-year research project (April 1, 2023, to March 31, 2028) funded by the Veterans Administration Rehabilitation Research and Development service (CDA2 award IK2 RX002938). Study results will be disseminated at or before the project's end date in March 2028.

CONCLUSIONS

We will provide preliminary evidence of the safety, feasibility, and acceptability of a novel frontal pole iTBS treatment for mTBI, impulsivity, SI and SAs, and functional deficits.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05647044; https://clinicaltrials.gov/study/NCT05647044.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/58206.

Synaptophysin and GSK-3beta activity in the prefrontal cortex may underlie the effects of REM sleep deprivation and lithium on behavioral functions and memory performance in male rats

Rapid-eye movement (REM) stage of sleep serves a critical role in processing cognitive and behavioral functions. Evidence shows that REM sleep deprivation (REM SD) strongly affects the mood state and cognitive abilities. However, there are many inconsistent reports. Although the exact molecular mechanisms underlying REM SD effects have not well been discovered, however, molecular factors including those affected synaptic plasticity and mood state may be involved. There are two important molecular factors that have not been well studied: synaptophysin and glycogen synthase kinase-3 beta (GSK-3beta). The present study aimed to investigate the role of synaptophysin and GSK-3beta in the modulation of memory and behavioral changes induced by REM SD and lithium (as a potent GSK-3beta inhibitor and mood stabilizer). Multiple platform apparatus was used to induce REM SD for 48 h. Lithium was injected at the dose of 50 mg/kg, intraperitoneal (i.p.). Locomotor activity, anxiety-like behavior, pain threshold, novel object recognition memory, and synaptophysin and GSK-3beta level in the prefrontal cortex were evaluated. Results showed REM SD increased locomotor activity, decreased pain threshold, impaired novel object recognition memory, decreased synaptophysin and increased GSK-3beta levels. Lithium reversed these effects. Anxiety-like behavior was unaffected. For the first time, the present study showed that GSK-3beta and synaptophysin may be involved in the modulation of behavior and cognition induced by REM SD and lithium. In conclusion, we suggested that GSK-3beta upregulation and synaptophysin downregulation may underlie the deleterious effects of REM SD, while lithium may counteract REM SD effects via restoring the level of both.

Clinical and Neuropsychological Features of Suicide Attempters in Tehran, Iran: A Comparative Study

Background

Identifying suicide risk factors and understanding the variations among different clinical groups can play a crucial role in preventing suicide. The objective of this study is to examine the distinctions in clinical and neuropsychological features among suicidal attempters, who have attempted in the last four weeks.

Methods

The design of the study was a case-control study. This study consisted of 62 participants who were assigned to the suicide attempters group (SA+MDD), non-suicidal depressed group (MDD), and healthy control group (HC). Clinical and neuropsychological evaluations were conducted for all participants. The Kolmogorov-Smirnov test was used to evaluate the normality of distribution. To compare the quantitative variables among the three groups, we employed Analysis of Variance (ANOVA), and Kruskal-Wallis. Post hoc analysis was conducted using Dunnett's test. A correlation analysis was conducted between clinical and neuropsychological variables.

Results

The results showed that there was no significant difference in neuropsychological functions among the three groups except Scaled Score Similarities (P=0.007). However, there were significant mean differences observed across the SA+MDD and HC groups for BHS (P<0.001), SSI (P<0.001), RFL (P<0.001), BPAQ (P=0.037), Anxiety-springer-1 (P<0.001), Anxiety-springer-2 (P<0.001), and BDI (P<0.001). Specifically, this difference was significant just for SSI (P<0.001), and RFL (P<0.001) when comparing the SA+MDD and MDD groups. Some significant correlations were seen between clinical and neuropsychological features among suicide attempters. Among neuropsychological features, Motor screening with BIS (P<0.001), Gambling test with SIS (P=0.04), Digit span with BPAQ (P=0.04), anxiety-springer-1 (P=0.07), and BDI (P=0.005), arithmetic task with SIS (P=0.004), BPAQ (P=0.004), anxiety-springer-1 (P=0.03), and anxiety-springer-2 (P=0.008), block design task with SIS (P=0.002), and BPAQ (P=0.03), Rapid Visual Information with BIS (P=0.01), anxiety-springer-2 (P=0.04), and BDI (P=0.003), digital symbol task with BIS (P=0.02), and BDI (P=0.008), and the Picture Completion task with BHS (P= 0.04), had more negative/positive correlation with clinical features.

Conclusion

Some clinical features such as hopelessness should be deemed serious among individuals with suicide attempt particularly among those who were discharged recently. neuropsychological findings revealed functional disturbances in the frontal, parietal and temporal areas of the subjects who are at risk of suicide attempt. The findings can inform the design and implementation of suicide prevention programs. Targeted interventions can be developed to address the identified risk factors and protective factors associated with suicide, such as increasing reasons for living, improving social connectedness, and building resilience.

The Effect of Forkhead Box O1 Single Nucleotide Polymorphisms on Cortical Thickness and White Matter Integrity in High Suicide Risk Patients

OBJECTIVE

Neuroinflammation's role is increasingly emphasized in the pathology of major depressive disorder (MDD), and its close association with the risk of suicide is being reported. The Forkhead Box O1 (FoxO1) gene is known to play a role in regulating mood and emotion and is associated with susceptibility to suicidality in relation to environmental stress. This research aims to explore the relationship between FoxO1 and the risk of suicide in individuals with MDD.

METHODS

We enrolled 127 healthy controls (HC) and 231 patients diagnosed with MDD, including 119 individuals with high suicide risk (HSR). All participants underwent the Hamilton Rating Scale for Depression Assessment and magnetic resonance imaging. Cortical thickness and white matter integrity were evaluated.

RESULTS

In the HSR group, cortical thinning was observed in the left triangular part of the inferior frontal gyrus and right transverse frontopolar gyrus compared to HC. Additionally, fractional anisotropy (FA) values were decreased in the left posterior thalamic radiation, sagittal stratum, and uncinate fasciculus. Although no differences were observed based on allele variations for the two FoxO1 single nucleotide polymorphisms (SNPs), those with the minor allele of FoxO1 rs34733279, especially in the HSR group, displayed increased cortical thinning and reduced FA values in the left cingulum.

CONCLUSION

Our study reveals close association between the minor allele of the FoxO1 gene rs34733279 and suicide risk in the left cingulum highlights the potential key role of the FoxO1 gene rs34733279 in the context of suicidal vulnerability. Further investigations are warranted to elucidate the underlying biological mechanisms.

Transcriptional Patterns of Brain Structural Covariance Network Abnormalities Associated With Suicidal Thoughts and Behaviors in Major Depressive Disorder

BACKGROUND

Although brain structural covariance network (SCN) abnormalities have been associated with suicidal thoughts and behaviors (STBs) in individuals with major depressive disorder (MDD), previous studies have reported inconsistent findings based on small sample sizes, and underlying transcriptional patterns remain poorly understood.

METHODS

Using a multicenter magnetic resonance imaging dataset including 218 MDD patients with STBs, 230 MDD patients without STBs, and 263 healthy control participants, we established individualized SCNs based on regional morphometric measures and assessed network topological metrics using graph theoretical analysis. Machine learning methods were applied to explore and compare the diagnostic value of morphometric and topological features in identifying MDD and STBs at the individual level. Brainwide relationships between STBs-related connectomic alterations and gene expression were examined using partial least squares regression.

RESULTS

Group comparisons revealed that SCN topological deficits associated with STBs were identified in the prefrontal, anterior cingulate, and lateral temporal cortices. Combining morphometric and topological features allowed for individual-level characterization of MDD and STBs. Topological features made a greater contribution to distinguishing between patients with and without STBs. STBs-related connectomic alterations were spatially correlated with the expression of genes enriched for cellular metabolism and synaptic signaling.

CONCLUSIONS

These findings revealed robust brain structural deficits at the network level, highlighting the importance of SCN topological measures in characterizing individual suicidality and demonstrating its linkage to molecular function and cell types, providing novel insights into the neurobiological underpinnings and potential markers for prediction and prevention of suicide.

Disrupted small-world white matter networks in patients with major depression and recent suicide plans or attempts

Suicide is a major concern for health, and depression is an established proximal risk factor for suicide. This study aimed to investigate white matter features associated with suicide. We constructed white matter structural networks by deterministic tractography via diffusion tensor imaging in 51 healthy controls, 47 depressed patients without suicide plans or attempts and 56 depressed patients with suicide plans or attempts. Then, graph theory analysis was used to measure global and nodal network properties. We found that local efficiency was decreased and path length was increased in suicidal depressed patients compared to healthy controls and non-suicidal depressed patients; moreover, the clustering coefficient was decreased in depressed patients compared to healthy controls; and the global efficiency and normalized characteristic path length was increased in suicidal depressed patients compared to healthy controls. Similarly, compared with those in non-suicidal depressed patients, nodal efficiency in the thalamus, caudate, medial orbitofrontal cortex, hippocampus, olfactory cortex, supplementary motor area and Rolandic operculum was decreased. In summary, compared with those of non-suicidal depressed patients, the structural connectome of suicidal depressed patients exhibited weakened integration and segregation and decreased nodal efficiency in the fronto-limbic-basal ganglia-thalamic circuitry. These alterations in the structural networks of depressed suicidal brains provide insights into the underlying neurobiology of brain features associated with suicide.

Distinct effects of first-episode and recurrent major depressive disorder on brain changes related to suicidal ideation: Evidence from the REST-meta-MDD Project

BACKGROUND

Significant differences in clinical manifestations between first-episode and recurrent major depression disorder (FE-MDD/R-MDD) have been demonstrated in previous studies, including the degree of suicide attempt. However, the potential brain mechanism underlying the effect of depressive episode frequency on suicidal ideation (SI) remains unclear.

METHODS

In this study, 102 patients with FE-MDD (SI/non-SI: N = 70/32) and 71 matched normal controls (NCs), as well as 75 patients with R-MDD (SI/non-SI: N = 37/38) and 49 matched NCs were screened from the Chinese REST-meta-MDD consortium. T1-weighted and resting-state fMRI images were used to calculate gray matter volume (GMV) and fractional amplitude of low-frequency fluctuations (fALFF), respectively.

RESULTS

Group comparisons revealed that FE-MDD showed changes only in GMV, while R-MDD showed changes in both GMV and fALFF compared to NCs. SI-specific GMV decreases were observed in the right cerebellum, superior marginal gyrus, and left middle temporal gyrus in FE-MDD patients, while SI-specific fALFF decreases in bilateral superior frontal gyrus and increases in bilateral cerebellum and left parahippocampal gyrus were obserevd in R-MDD patients. Moreover, a negative correlation was found between GMV value in right cerebellum and HAMD score.

CONCLUSIONS

These findings suggest that first-episode and recurrent MDD show different effects on brain structure and function in patients with SI, providing a potential explanation for the distinct clinical manifestations of MDD patients from a brain mechanisms perspective.

Classification of fNIRS signals from adolescents with MDD in suicide high- and low-risk groups using machine learning

Prefrontal cortex activation is attenuated during cognitive tasks in patients with suicidal ideation or major depressive disorder (MDD). However, the apparent relationship between patients with MDD, especially suicide high-risk (SHR) adolescents, and the characteristics of their hemodynamic responses has not yet been elucidated. To investigate this relationship, we recruited 30 patients with MDD aged 13-19. Functional near-infrared spectroscopy (fNIRS) data were collected for all patients during a Stroop test. Through a ten-time iterative leave-one-out cross-validation via 1000 iterative random search-based feature selections, we achieved a generalized classification accuracy of 70.3±5.0 % (from min. 63.3 % to max. 76.7 %). From the results of random search-based feature selection, Ch08oxy and Ch09deoxy were identified as the two most relevant fNIRS channels. This finding implies that these fNIRS channels can be used as neurological biomarkers to distinguish SHR adolescents with MDD from suicide low-risk (SLR) adolescents. In addition, we determined the oxy-Hb channels of the SHR group, except for Ch01oxy, Ch02oxy, Ch11oxy, and Ch14oxy, were hyperactivated compared to the SLR group.

Pathways from threat exposure to psychotic symptoms in youth: The role of emotion recognition bias and brain structure

BACKGROUND

Research supports an association between threatening experiences in childhood and psychosis. It is possible that early threat exposure disrupts the development of emotion recognition (specifically, producing a bias for facial expressions relating to threat) and the brain structures subserving it, contributing to psychosis development.

METHODS

Using data from the Philadelphia Neurodevelopmental Cohort, we examined associations between threat exposure and both the misattribution of facial expressions to fear/anger in an emotion recognition task, and gray matter volumes in key emotion processing regions. Our sample comprised youth with psychosis spectrum symptoms (N = 304), control youth (N = 787), and to evaluate specificity, youth with internalizing symptoms (N = 92). The moderating effects of group and sex were examined.

RESULTS

Both the psychosis spectrum and internalizing groups had higher levels of threat exposure than controls. In the total sample, threat exposure was associated with lower left medial prefrontal cortex (mPFC) volume but not misattributions to fear/anger. The effects of threat exposure did not significantly differ by group or sex.

CONCLUSIONS

The findings of this study provide evidence for an effect of threat exposure on mPFC morphology, but do not support an association between threat exposure and a recognition bias for threat-related expressions, that is particularly pronounced in psychosis. Future research should investigate factors linking transdiagnostic alterations related to threat exposure with psychotic symptoms, and attempt to clarify the mechanisms underpinning emotion recognition misattributions in threat-exposed youth.

Hippocampal Dynamic Functional Connectivity, HPA Axis Activity, and Personality Trait in Bipolar Disorder with Suicidal Attempt

INTRODUCTION

Suicide in bipolar disorder (BD) is a multifaceted behavior, involving specific neuroendocrine and psychological mechanisms. According to previous studies, we hypothesized that suicidal BD patients may exhibit impaired dynamic functional connectivity (dFC) variability of hippocampal subregions and hypothalamic-pituitary-adrenal (HPA) axis activity, which may be associated with suicide-related personality traits. The objective of our study was to clarify this.

METHODS

Resting-state functional magnetic resonance imaging data were obtained from 79 patients with BD, 39 with suicidal attempt (SA), and 40 without SA, and 35 healthy controls (HCs). The activity of the HPA axis was assessed by measuring morning plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) levels. All participants underwent personality assessment using Minnesota Multiphasic Personality Inventory-2 (MMPI-2).

RESULTS

BD patients with SA exhibited increased dFC variability between the right caudal hippocampus and the left superior temporal gyrus (STG) when compared with non-SA BD patients and HCs. BD with SA also showed significantly lower ACTH levels in comparison with HCs, which was positively correlated with increased dFC variability between the right caudal hippocampus and the left STG. BD with SA had significantly higher scores of Hypochondriasis, Depression, and Schizophrenia than non-SA BD. Additionally, multivariable regression analysis revealed the interaction of ACTH × dFC variability between the right caudal hippocampus and the left STG independently predicted MMPI-2 score (depression evaluation) in suicidal BD patients.

CONCLUSION

These results suggested that suicidal BD exhibited increased dFC variability of hippocampal-temporal cortex and less HPA axis hyperactivity, which may affect their personality traits.

Suicidality and homelessness: prevalence and associated factors of suicidal behaviour among homeless young adults in Southern Ethiopia

BACKGROUND

Research indicates that homelessness is associated with an increased risk of suicide. While street homelessness is a global problem, it is a disproportionately serious concern in low- and middle-income countries such as Ethiopia. Despite their high risk of suicidal thoughts and attempts, there has been limited research on this subject among homeless young people in Ethiopia. Therefore, we assessed the prevalence and factors contributing to suicidal behaviour among homeless young people in the southern region of this country.

METHODS

We conducted a community-based cross-sectional study from 15 June to 15 August 2020 involving 798 homeless young adults in four southern Ethiopian towns and cities. The Suicide Behaviour Questionnaire-Revised (SBQ-R) was used to assess suicidal behaviour. Data were coded and entered into Epi-Data version 7 and analysed using SPSS version 20. We conducted a multivariable logistic regression analysis to identify factors associated with suicidal behaviour. Variables with a p-value of < 0.05 were considered statistically significant. An adjusted odds ratio with a 95% confidence interval was determined to indicate the association's strength.

RESULTS

The overall prevalence of suicidal behaviour among young homeless individuals was 38.2% (95% CI: 34.8%, 41.5%). The lifetime prevalence of suicidal ideation, planning and attempt was 10.7% (95% CI: 8.6-12.9%), 5.1% (95% CI: 3.6-6.6%) and 3% (95% CI: 1.9-4.3%), respectively. A longer duration of homelessness (1-2 years) (AOR = 2.244, 95% CI: 1.447-3.481), stressful life events (AOR = 1.655, 95% CI: 1.132-2.418) and the stigma associated with homelessness (AOR = 1.629, 95% CI: 1.149-1.505) were significantly associated with suicidal behaviour.

CONCLUSION

The results of our study indicate that suicide is a serious public health problem among homeless young people in southern Ethiopia. We have found associations between suicidal behaviour and stressful events, homelessness lasting for one to two years and stigma. Our study suggests that policymakers and programme planners need to develop a strategy for preventing, detecting and managing suicidal behaviour among street-dwelling homeless young adults, a vulnerable and understudied population. A community-based suicide prevention campaign is also essential for street-dwelling homeless young people in Ethiopia.

Machine learning based identification of structural brain alterations underlying suicide risk in adolescents

Suicide is the third leading cause of death for individuals between 15 and 19 years of age. The high suicide mortality rate and limited prior success in identifying neuroimaging biomarkers indicate that it is crucial to improve the accuracy of clinical neural signatures underlying suicide risk. The current study implements machine-learning (ML) algorithms to examine structural brain alterations in adolescents that can discriminate individuals with suicide risk from typically developing (TD) adolescents at the individual level. Structural MRI data were collected from 79 adolescents who demonstrated clinical levels of suicide risk and 79 demographically matched TD adolescents. Region-specific cortical/subcortical volume (CV/SCV) was evaluated following whole-brain parcellation into 1000 cortical and 12 subcortical regions. CV/SCV parameters were used as inputs for feature selection and three ML algorithms (i.e., support vector machine [SVM], K-nearest neighbors, and ensemble) to classify adolescents at suicide risk from TD adolescents. The highest classification accuracy of 74.79% (with sensitivity = 75.90%, specificity = 74.07%, and area under the receiver operating characteristic curve = 87.18%) was obtained for CV/SCV data using the SVM classifier. Identified bilateral regions that contributed to the classification mainly included reduced CV within the frontal and temporal cortices but increased volume within the cuneus/precuneus for adolescents at suicide risk relative to TD adolescents. The current data demonstrate an unbiased region-specific ML framework to effectively assess the structural biomarkers of suicide risk. Future studies with larger sample sizes and the inclusion of clinical controls and independent validation data sets are needed to confirm our findings.

Smaller rostral cingulate volume and psychosocial correlates in veterans at risk for suicide

Suicide research/clinical work remain in dire need of effective tools that can better predict suicidal behavior. A growing body of literature has started to focus on the role that neuroimaging may play in helping explain the path towards suicide. Specifically, structural alterations of rostral anterior cingulate cortex (rost-ACC) may represent a biological marker and/or indicator of suicide risk in Major Depressive Disorder (MDD). Furthermore, the construct of "grit," defined as perseverance for goal-attainment and shown to be associated with suicidality, is modulated by rost-ACC. The aim was to examine relationships among rost-ACC gray matter volume, grit, and suicidality in U.S. Military Veterans. Participants were age-and-sex-matched Veterans with MDD: with suicide attempt (MDD+SA:n = 23) and without (MDD-SA:n = 37). Groups did not differ in depression symptomatology. Participants underwent diagnostic interview, clinical symptom assessment, and 3T-MRI-scan. A Group (SA-vs.-No-SA) x Cingulate-region (rostral-caudal-posterior) x Hemisphere (left-right) mixed-model-multivariate-ANOVA was conducted. Left-rost-ACC was significantly smaller in MDD+SA, Group x Cingulate-region x Hemisphere-interaction. Lower grit and less left-rost-ACC gray matter each predicted suicide attempt history, but grit level was a more robust predictor of SA. Both structural alterations of rost-ACC and grit level represent potentially valuable tools for suicide risk assessment.

The effect of early trauma on suicidal vulnerability depends on fronto-insular sulcation

Improving our understanding of pathophysiology of suicidal behavior (SB) is an important step for prevention. Assessment of suicide risk is based on socio-demographic and clinical risk factors with a poor predictivity. Current understanding of SB is based on a stress-vulnerability model, whereby early-life adversities are predominant. SB may thus result from a cascade of developmental processes stemming from early-life abuse and/or neglect. Some cerebral abnormalities, particularly in fronto-limbic regions, might also provide vulnerability to develop maladaptive responses to stress, leading to SB. We hypothesized that SB is associated with interactions between early trauma and neurodevelopmental deviations of the frontal and insular cortices. We recruited 86 euthymic women, including 44 suicide attempters (history of depression and SB) and 42 affective controls (history of depression without SB). The early development of prefrontal cortex (PFC) and insula was inferred using 3D magnetic resonance imaging-derived regional sulcation indices, which are indirect markers of early neurodevelopment. The insula sulcation index was higher in emotional abused subjects; among those patients, PFC sulcation index was reduced in suicide attempters, but not in affective controls. Such findings provide evidence that SB likely traced back to early stages of brain development in interaction with later environmental factors experienced early in life.

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.

[Morphofunctional cerebral changes associated with development of suicidal behavior]

THE AIM OF THE STUDY

Was to identify the cerebral areas, which demonstrate the most significant structural changes and damaged functional activity in patients with suicidal behavior. The original studies, presented in PubMed database, were used to analyze the literature. Additional literature in the form of atlases, review articles and publications, written in related spheres, was used to interpret the results. The study identified the 69 cerebral regions, demonstrating significant changes and the structures with the most significant deviations among them were selected. The regions of cerebral grey matter, in particular basal ganglia (structures of striatum and limbic system), as well as selected regions of cerebral cortex, specifically frontal, insularis, singulate and parietal mostly were included in the list. The decrease in grey matter volume, changes of neuronal and glial density, special patterns of activity and variations of functional association with other cerebral regions are described within mentioned structures. The literature review found that there was a lack of postmortem examinations in suicidal cases. Advanced study of the described structures is required in cases of completed suicide using new research methods.

Addressing Emotional Dysregulation and Potential Pharmacogenetic Implication of 5-HTTLPR Genotype in Attention Deficit Hyperactivity Disorder

Background

This review unpacks the emotional presentation of externalizing behaviors in attention deficit hyperactivity disorder (ADHD), by diving into the psychophysiology, neurophysiology, and neurogenetics in relation to executive function. The correlations among these three variables are identified, showing that standard assessments for ADHD leave out the emotional dysregulation element. This may lead to suboptimal management outcomes during the developmental progression into adolescence and adulthood.

Summary

The emotional impulsivity manifestation in adolescence and adulthood related to the under-managed emotional dysregulation in childhood is found to be associated with subtle confounding impact of 5-HTTLPR (serotonin-transporter-linked promoter region) genotype. The genotype of interest affects the neurochemistry, neurophysiology, and psychophysiology of the cognition for executive function. The established practice of using methylphenidate in treating ADHD surprisingly has a neurogenetic effect in targeting the genotype of interest. Methylphenidate provides neuroprotective effects throughout the neurodevelopment timeline from childhood to adulthood.

Key Messages

The emotional dysregulation element in ADHD which is often overlooked should be addressed to improve the prognostic outcomes in adolescence and adulthood.

Aberrant resting-state functional connectivity of major depressive disorder with higher risk of suicide

Aim

Suicide prevention for depressive patients is an important clinical issue in psychiatry. However, not all depressive patients plan or attempt suicide. In this study, we investigated the differences of functional brain networks between a high-risk group and a low-risk group for suicide by comparing resting-state functional connectivity (rsFC).

Methods

The subjects were 29 patients with major depressive disorder, nine of whom had attempted suicide. The suicidal ideation of all subjects was assessed with the Columbia-Suicide Severity Rating Scale, then the subjects were divided into two groups based on the most severe suicidal ideation (MSI) in their lifetime. We compared rsFC between the two groups.

Results

Of the 29 subjects, 16 were in the severe MSI group. We found that the severe MSI group members had significantly smaller rsFC in two networks: one comprised the right dorsolateral prefrontal cortex and the default-mode network, and the other comprised the left rostrolateral prefrontal cortex and the striatum, amygdala, and hippocampus. These regions are reported to be associated with rumination, retrieval suppression, and delay discounting (DD).

Conclusion

Our results suggest that functional networks related to rumination, retrieval suppression, and DD might be impaired in depressive patients with severe suicidal ideation. It might be beneficial for psychiatrists to assess these characteristics in terms of suicide prevention for depressive patients.

Diminished frontal pole size and functional connectivity in young adults with high suicidality

BACKGROUND

Suicide rates among young people have been increasing in recent years, yet no validated methods are available for identifying those who are at greatest risk for suicide. Abnormalities in the medial prefrontal cortex have been previously observed in suicidal individuals, but confounding factors such as treatment and chronic illness may have contributed to these findings. Thus, in this study we tested whether the size of the medial prefrontal cortex is altered in suicidal young adults who have received no treatment with psychotropic medications.

METHODS

Suicidality was evaluated using the Suicide Behaviors Questionnaire-Revised (SBQ-R) and surface areas of four regions-of-interest (ROIs) within the medial prefrontal cortex were measured using magnetic resonance imaging (MRI) in a cohort of college students (n = 102). In addition, a secondary seed-based functional connectivity analysis was conducted using resting-state functional MRI data. Areas and functional connectivity of the medial prefrontal cortex of young adults with high suicidality (HS; SBQ-R score > 7; n = 20) were compared to those with low suicidality (LS; SBQ-R score = 3, n = 37).

RESULTS

Compared to the LS group, the HS group had a significantly lower surface area of the right frontal pole (p < 0.05, Bonferroni-corrected) and significantly lower functional connectivity of the right frontal pole with the bilateral inferior frontal cortex (p < 0.001, Monte-Carlo corrected).

LIMITATION

These findings require replication in a larger sample and extension in younger (adolescent) populations.

CONCLUSION

Diminished frontal pole surface area and functional connectivity may be linked to elevated levels of suicidality in young people.

A diathesis-stress rat model induced suicide-implicated endophenotypes and prefrontal cortex abnormalities in the PKA and GABA receptor signaling pathways

Suicide is one of the leading causes of death and represents a significant public health problem worldwide; however, the underlying mechanism of suicide remains unclear, and there is no animal model with suicide-implicated endophenotypes for investigating the etiology, course and potential treatment targets of suicide. Thus, we generated a diathesis-stress rat model to simulate suicide-implicated endophenotypes. First, two hundred rats were screened in two rounds of learned helplessness (LH) tests and selected as learned helplessness-sensitive (LHS) rats (n = 37) and learned helplessness-resistant (LHR) rats (n = 39). Then, all LHS rats and half of the rats (randomly selected) in the LHR group were exposed to four weeks of social defeat stress (SDS) (LHS + SDS group, n = 37 and LHR + SDS group, n = 20, respectively). The remainder of the LHR rats were handled as controls (LHR + CON group, n = 19). The LHS + SDS group showed significantly more suicide-implicated endophenotypes than the LHR + CON group, including longer immobile times in the forced swim test (hopelessness), higher scores in the irritability test (irritability), shorter latencies to attack (impulsivity), longer total attack times in the resident-intruder test (aggression), and lower sucrose preference indices (anhedonia). Proteomic analyses revealed that the canonical pathways that were the most common between the LHS + SDS and LHR + CON groups were the PKA and GABA receptor pathways in the prefrontal cortex. A diathesis-stress paradigm would be a useful way to establish a rat model with suicide-implicated endophenotypes, providing novel perspectives for revealing the potential mechanism of suicide.

The Indirect Effect of Prefrontal Gray Matter Volume on Suicide Attempts among Individuals with Major Depressive Disorder

Trait impulsivity is a known risk factor for suicidality, and the prefrontal cortex plays a key role in impulsivity and its regulation. However, the relationship between trait impulsivity, neural basis, and suicidality has been inconsistent. Therefore, this study aimed to explore the relationship between impulsivity and its structural correlates (prefrontal gray matter volume), suicidal ideation, and actual suicide attempts. A total of 87 individuals with major depressive disorder participated in study, and the gray matter volume of the prefrontal regions was extracted from T1 images based on region of interest masks. The variables for the mediation models were selected based on correlation analysis and tested for their ability to predict suicide attempts, with impulsivity and suicidal ideation as the mediation variables and gray matter volume as the independent variable. A significant correlation was observed between suicidal ideation and the left dorsolateral prefrontal cortex and right dorsomedial prefrontal cortex. The dual-mediation model revealed a significant indirect relationship between gray matter volume in both regions and suicide attempts mediated by motor impulsivity and suicidal ideation. The counterintuitive positive relationship between gray matter volume and suicidality was also discussed.

A Computational Model of Hopelessness and Active-Escape Bias in Suicidality

Currently, psychiatric practice lacks reliable predictive tools and a sufficiently detailed mechanistic understanding of suicidal thoughts and behaviors (STB) to provide timely and personalized interventions. Developing computational models of STB that integrate across behavioral, cognitive and neural levels of analysis could help better understand STB vulnerabilities and guide personalized interventions. To that end, we present a computational model based on the active inference framework. With this model, we show that several STB risk markers - hopelessness, Pavlovian bias and active-escape bias - are interrelated via the drive to maximize one's model evidence. We propose four ways in which these effects can arise: (1) increased learning from aversive outcomes, (2) reduced belief decay in response to unexpected outcomes, (3) increased stress sensitivity and (4) reduced sense of stressor controllability. These proposals stem from considering the neurocircuits implicated in STB: how the locus coeruleus - norepinephrine (LC-NE) system together with the amygdala (Amy), the dorsal prefrontal cortex (dPFC) and the anterior cingulate cortex (ACC) mediate learning in response to acute stress and volatility as well as how the dorsal raphe nucleus - serotonin (DRN-5-HT) system together with the ventromedial prefrontal cortex (vmPFC) mediate stress reactivity based on perceived stressor controllability. We validate the model by simulating performance in an Avoid/Escape Go/No-Go task replicating recent behavioral findings. This serves as a proof of concept and provides a computational hypothesis space that can be tested empirically and be used to distinguish planful versus impulsive STB subtypes. We discuss the relevance of the proposed model for treatment response prediction, including pharmacotherapy and psychotherapy, as well as sex differences as it relates to stress reactivity and suicide risk.

Detecting Suicide Ideation in the Era of Social Media: The Population Neuroscience Perspective

Social media platforms are increasingly used across many population groups not only to communicate and consume information, but also to express symptoms of psychological distress and suicidal thoughts. The detection of suicidal ideation (SI) can contribute to suicide prevention. Twitter data suggesting SI have been associated with negative emotions (e.g., shame, sadness) and a number of geographical and ecological variables (e.g., geographic location, environmental stress). Other important research contributions on SI come from studies in neuroscience. To date, very few research studies have been conducted that combine different disciplines (epidemiology, health geography, neurosciences, psychology, and social media big data science), to build innovative research directions on this topic. This article aims to offer a new interdisciplinary perspective, that is, a Population Neuroscience perspective on SI in order to highlight new ways in which multiple scientific fields interact to successfully investigate emotions and stress in social media to detect SI in the population. We argue that a Population Neuroscience perspective may help to better understand the mechanisms underpinning SI and to promote more effective strategies to prevent suicide timely and at scale.

Effects of polygenic risk for suicide attempt and risky behavior on brain structure in young people with familial risk of bipolar disorder

Bipolar disorder (BD) is associated with a 20-30-fold increased suicide risk compared to the general population. First-degree relatives of BD patients show inflated rates of psychopathology including suicidal behaviors. As reliable biomarkers of suicide attempts (SA) are lacking, we examined associations between suicide-related polygenic risk scores (PRSs)-a quantitative index of genomic risk-and variability in brain structures implicated in SA. Participants (n = 206; aged 12-30 years) were unrelated individuals of European ancestry and comprised three groups: 41 BD cases, 96 BD relatives ("high risk"), and 69 controls. Genotyping employed PsychArray, followed by imputation. Three PRSs were computed using genome-wide association data for SA in BD (SA-in-BD), SA in major depressive disorder (SA-in-MDD) (Mullins et al., 2019, The American Journal of Psychiatry, 176(8), 651-660), and risky behavior (Karlsson Linnér et al., 2019, Nature Genetics, 51(2), 245-257). Structural magnetic resonance imaging processing employed FreeSurfer v5.3.0. General linear models were constructed using 32 regions-of-interest identified from suicide neuroimaging literature, with false-discovery-rate correction. SA-in-MDD and SA-in-BD PRSs negatively predicted parahippocampal thickness, with the latter association modified by group membership. SA-in-BD and Risky Behavior PRSs inversely predicted rostral and caudal anterior cingulate structure, respectively, with the latter effect driven by the "high risk" group. SA-in-MDD and SA-in-BD PRSs positively predicted cuneus structure, irrespective of group. This study demonstrated associations between PRSs for suicide-related phenotypes and structural variability in brain regions implicated in SA. Future exploration of extended PRSs, in conjunction with a range of biological, phenotypic, environmental, and experiential data in high risk populations, may inform predictive models for suicidal behaviors.

Abnormal brain activity in fronto-central regions in mental disorders with suicide: An EEG Study

Suicide is a global health problem, and early and accurate identification of suicide attempt individuals has very important clinical significance. Thus the exploration of neurobiological mechanisms underlying suicidal behavior is crucial for systematically preventing suicide. However, the neurophysiological biomarkers for identifying affective disorders with suicidal attempt are remain unknown. Here, we recruited 28 patients with mental disorders from Tianjin Anding Hospital, and the subjects were divided into suicide attempt group (SA=14) and non suicide attempt group (NSA=14) according to whether they had attempted suicide. We also recruited 14 healthy subjects matched with age and sex ratio as healthy control group (HC=14). By recording the electroencephalogram(EEG) data of 60 electrodes in resting state for eight minutes (four minutes with open eyes and four minutes with close eyes), the absolute power of five frequency bands( delta(0.5-4Hz), theta(4-8Hz), alpha(8-13Hz), beta (13-30Hz), gamma(30-65Hz)) were analyzed to explore the changes of brain rhythm. And then the Modulation index (MI) was calculated to quantify the intensity of phase amplitude coupling (PAC) between different frequency bands in different brain regions, so as to observe the mechanism of neuronal synchronization in different frequency bands. We found that the absolute power of SA group was significantly higher than NSA group and HC group in delta (P<0.05), beta (P<0.05) and gamma (P<0.05) bands. The PAC strength between beta and gamma was calculated and it showed that the PAC strength of SA group was significantly weaker than NSA group in fronto-central regions, indicating that decreased synchronization between neurons could bring about brain function impairment. These findings suggest that the brain electrical activity in the fronto-central regions of the SA group may be damaged, which may lead to an increased suicidal risk in mental disoders. The EEG activity in delta, beta, gamma band and PAC in fronto-central regions may be used as a potential clinical biomarker for preventing suicide.

Reduced left ventrolateral prefrontal cortex activation during verbal fluency tasks is associated with suicidal ideation severity in medication-naïve young adults with major depressive disorder: A functional near-infrared spectroscopy study

The reduction in the oxygenation dynamics in the prefrontal cortex (PFC) during cognitive tasks is a well-known occurrence in major depressive disorders (MDD). Studies focusing on oxygenation changes in the PFC in individuals with suicidal ideation are limited. Therefore, this study investigated and confirmed the presence of prefrontal dysfunction depending on the intensity of suicidal ideation among 77 young adults (45 patients with MDD and 32 healthy controls) using near-infrared spectroscopy (NIRS). All participants underwent assessment with the Beck Depression Inventory-II, Beck Anxiety Inventory, and Beck Scale for Suicidal ideation. NIRS revealed relative hypofunction in the left dorsolateral PFC, left ventrolateral PFC (LVLPFC), and both orbitofrontal cortices in young adults with MDD compared to that in the healthy controls during verbal fluency tasks. Furthermore, the oxyhaemoglobin changes in the LVLPFC mediated the indirect effect of depression severity on suicidal ideation intensity. Our results confirmed that functional NIRS is a useful auxiliary tool for objectively assessing the risk of suicidal ideation.

Translating Interventional Neuroscience to Suicide: It's About Time

Despite significant advances in psychiatric and psychological treatment over the last 30 years, suicide deaths have increased. Unfortunately, neuroscience insights have yielded few translational interventions that specifically target suicidal thoughts and behaviors. In our view, this is attributable to two factors. The first factor is our limited integration of neurocircuitry models with contemporary suicide theory. The second challenge is inherent to the variable nature of suicide risk over time. Few interventional neuroscience studies evaluate how temporal fluctuations in risk affect treatment, despite evidence that temporality is a key component distinguishing suicide phenotypes. To wit, individual variability in risk trajectories may provide different treatment targets to engage as a patient moves between suicidal ideation and attempt. Here, we first review contemporary ideation-to-action theories of suicide from a neurobiological perspective, focusing on valence and executive function circuits and the key role of state-induced (e.g., within stressful contexts) functional modulation on longitudinal risk trajectories. We then describe neural correlates of suicide reduction following various interventions, ranging from circuit specific (i.e., transcranial magnetic stimulation) to broader pharmacological (i.e., ketamine, lithium) to psychological (i.e., brief cognitive therapy). We then introduce novel strategies for tracking risk in naturalistic settings and real time using ecological momentary interventions. We provide a critical integration of the literature focusing on the intersection between targets and temporality, and we conclude by proposing novel research designs integrating real-time and biologically based interventions to generate novel strategies for future suicide reduction research.

Atrophy of right inferior frontal orbital gyrus and frontoparietal functional connectivity abnormality in depressed suicide attempters

Although structural and functional brain abnormalities have been observed in depressed suicide attempters (DS), structural deficits and functional impairments together with their relationship in DS remain unclear. To clarify this issue, we aimed to examine the differences in gray matter (GM) alteration, corresponding functional connectivity (FC) change, and their relationship between DS and depressed non-suicide attempters (NDS). Sixty-eight DS, 119 NDS and 103 healthy controls were enrolled and subjected to magnetic resonance imaging scans. The patients were evaluated using the 17-item Hamilton Rating Scale for Depression (HRSD) and Nurses' Global Assessment of Suicide Risk (NGASR) scale. Both voxel-based morphometry and resting-state FC analyses were performed based on functional and structural imaging data. Compared with NDS, the DS group showed reduced GM volume in the right inferior frontal orbital gyrus (IFOG) and left caudate (CAU) but increased GM volume in the left calcarine fissure, weaker negative right IFOG-left rectus gyrus (REG) FC, and weaker positive right IFOG-left inferior parietal lobule (IPL) FC. In DS, the GM volume of the right IFOG and left CAU was negatively correlated with NGASR and HRSD scores, respectively; the right IFOG-left IPL FC was negatively correlated with cognitive factor scores; and the GM volume of the right IFOG was positively correlated with IFOG-REG and IFOG-IPL FC. Our findings indicate that structural deficit with its related functional alterations in brain circuits converged in right IFOG centralized pathways and may play a central role in suicidal behaviors in depression.

Prefrontal activity during experimental ostracism and daily psychache in suicide attempters

BACKGROUND

Suicidal behaviors can result from a complex interaction between social stressors and individual vulnerability. Evidence suggests a specific neural processing of social cues in suicide attempters without knowledge of how it relates to real-world experiences.

OBJECTIVE

To investigate the association between brain activity during experimental social exclusion (measured by functional MRI) and psychological pain in daily life (assessed by Ecological Momentary Assessment) in patients with a lifetime history of suicide attempt.

METHODS

Thirty-three euthymic females with a history of a major depressive episode were recruited: 13 suicide attempters and 20 affective controls (no history of suicide attempt). Functional MRI scans were acquired while participants played the Cyberball game, a validated social exclusion paradigm. After fMRI, participants completed EMA for a one-week period. Five times per day, they were asked to rate their psychological pain, hopelessness and the negativity of daily events. EMA indices (psychological pain, hopelessness and their interaction with negative events) were correlated with cerebral activations using a ROI approach (orbitofrontal, dorsal and ventrolateral prefrontal cortices, anterior cingulate cortex and insula) in each group.

RESULTS

We found a negative correlation between daily ratings of psychological pain and orbitofrontal activation for exclusion versus inclusion during the Cyberball game in suicide attempters but not in affective controls. We did not find correlations between cerebral activation and daily hopelessness ratings.

LIMITATIONS

Small sample size CONCLUSION: Scanner-based orbitofrontal activity during social exclusion relates to psychological pain in daily life which participates in suicide risk among vulnerable individuals.

Volumetric MRI Analysis of Brain Structures in Patients with History of First and Repeated Suicide Attempts: A Cross Sectional Study

Structural brain changes are found in suicide attempters and in patients with mental disorders. It remains unclear whether the suicidal behaviors are related to atrophy of brain regions and how the morphology of specific brain areas is changing with each suicide attempt. The sample consisted of 56 patients hospitalized after first suicide attempt (first SA) (n = 29), more than one suicide attempt (SA > 1) (n = 27) and 54 healthy controls (HC). Brain volume was measured using FreeSurfer 6.0 automatic segmentation technique. In comparison to HC, patients with first SA had significantly lower cortical thickness of the superior and rostral middle frontal areas, the inferior, middle and superior temporal areas of the left hemisphere and superior frontal area of the right hemisphere. In comparison to HC, patients after SA > 1 had a significantly lower cortical thickness in ten areas of frontal cortex of the left hemisphere and seven areas of the right hemisphere. The comparison of hippocampus volume showed a significantly lower mean volume of left and right parts in patients with SA > 1, but not in patients with first SA. The atrophy of frontal, temporal cortex and hippocampus parts was significantly higher in repeated suicide attempters than in patients with first suicide attempt.

Altered cortical morphology in major depression disorder patients with suicidality

Background

Major depressive disorder (MDD) is associated with high risk of suicide, but the biological underpinnings of suicidality in MDD patients are far from conclusive. Previous neuroimaging studies using voxel-based morphometry (VBM) demonstrated that depressed individuals with suicidal thoughts or behaviors exhibit specific cortical structure alterations. To complement VBM findings, surface-based morphometry (SBM) can provide more details into gray matter structure, including the cortical complexity, cortical thickness and sulcal depth for brain images.

Objective

This study aims to use SBM to investigate cortical morphology alterations to obtain evidence for neuroanatomical alterations in depressed patients with suicidality.

Methods

Here, 3D T1-weighted MR images of brain from 39 healthy controls, 40 depressed patients without suicidality (patient controls), and 39 with suicidality (suicidal groups) were analyzed based on SBM to estimate the fractal dimension, gyrification index, sulcal depth, and cortical thickness using the Computational Anatomy Toolbox. Correlation analyses were performed between clinical data and cortical surface measurements from patients.

Results

Surface-based morphometry showed decreased sulcal depth in the parietal, frontal, limbic, occipital and temporal regions and decreased fractal dimension in the frontal regions in depressed patients with suicidality compared to both healthy and patient controls. Additionally, in patients with depression, the sulcal depth of the left caudal anterior cingulate cortex was negatively correlated with Hamilton Depression Rating Scale scores.

Conclusions

Depressed patients with suicidality had abnormal cortical morphology in some brain regions within the default mode network, frontolimbic circuitry and temporal regions. These structural deficits may be associated with the dysfunction of emotional processing and impulsivity control. This study provides insights into the underlying neurobiology of the suicidal brain.

Functional network alterations differently associated with suicidal ideas and acts in depressed patients: an indirect support to the transition model

The transition from suicidal ideas to a suicide act is an important topic of research for the identification of those patients at risk of acting out. We investigated here whether specific brain activity and connectivity measures at rest may be differently associated with suicidal thoughts and behaviors. A large sample of acutely depressed patients with major depressive disorder was recruited in three different centers (Montreal/Canada, Stanford/USA, and Jena/Germany), covering four different phenotypes: patients with a past history of suicide attempt (n = 53), patients with current suicidal ideas but no past history of suicide attempt (n = 40), patients without current suicidal ideation nor past suicide attempts (n = 42), and healthy comparison subjects (n = 107). 3-T resting-state functional magnetic resonance imaging (fMRI) measures of the amplitude of low-frequency fluctuation (ALFF) and degree centrality (DC) were obtained and examined in a whole-brain data-driven analysis. Past suicide attempt was associated with a double cortico-subcortical dissociation in ALFF values. Decreased ALFF and DC values mainly in a frontoparietal network and increased ALFF values in some subcortical regions (hippocampus and thalamus) distinguished suicide attempters from suicide ideators, patient controls, and healthy controls. No clear neural differences were identified in relation to suicidal ideas. Suicide attempters appear to be a distinct subgroup of patients with widespread brain alterations in functional activity and connectivity that could represent factors of vulnerability. Our results also indirectly support at the neurobiological level the relevance of the transition model described at the psychological and clinical levels. The brain bases of suicidal ideas occurrence in depressed individuals needs further investigations.

Identification of suicidality in adolescent major depressive disorder patients using sMRI: A machine learning approach

BACKGROUND

Suicidal behavior is a major concern for patients who suffer from major depressive disorder (MDD), especially among adolescents and young adults. Machine learning models with the capability of suicide risk identification at an individual level could improve suicide prevention among high-risk patient population.

METHODS

A cross-sectional assessment was conducted on a sample of 66 adolescents/young adults diagnosed with MDD. The structural T1-weighted MRI scan of each subject was processed using the FreeSurfer software. The classification model was conducted using the Support Vector Machine - Recursive Feature Elimination (SVM-RFE) algorithm to distinguish suicide attempters and patients with suicidal ideation but without attempts.

RESULTS

The SVM model was able to correctly identify suicide attempters and patients with suicidal ideation but without attempts with a cross-validated prediction balanced accuracy of 78.59%, the sensitivity was 73.17% and the specificity was 84.0%. The positive predictive value of suicide attempt was 88.24%, and the negative predictive value was 65.63%. Right lateral orbitofrontal thickness, left caudal anterior cingulate thickness, left fusiform thickness, left temporal pole volume, right rostral anterior cingulate volume, left lateral orbitofrontal thickness, left posterior cingulate thickness, right pars orbitalis thickness, right posterior cingulate thickness, and left medial orbitofrontal thickness were the 10 top-ranked classifiers for suicide attempt.

CONCLUSIONS

The findings indicated that structural MRI data can be useful for the classification of suicide risk. The algorithm developed in current study may lead to identify suicide attempt risk among MDD patients.

Alterations in gray matter volumes and intrinsic activity in the prefrontal cortex are associated with suicide attempts in patients with bipolar disorder

Bipolar disorder (BD) is associated with increased suicidal behavior. Understanding the neural features of suicide attempts (SA) in patients with BD is critical to preventing suicidal behavior. The prefrontal cortex (PFC) is a key region related to SA. In this study, forty BD patients with a history of SA (BD+SA), 70 BD patients without a history of SA (BD-SA), and 110 individuals in a healthy control (HC) group underwent structural magnetic resonance imaging (MRI) and resting-state functional MRI. We used voxel-based morphometry (VBM) and amplitude of low frequency fluctuations (ALFF) techniques to examine the gray matter volumes (GMVs) and ALFF values in the PFC. Compared with the HC group, both the BD+SA and BD-SA groups had lower GMVs and higher ALFF values in the medial PFC (MPFC), ventral PFC (VPFC), and dorsolateral PFC (DLPFC). The ALFF values in the MPFC, VPFC, and DLPFC in the BD+SA group were significantly higher than those in the BD-SA group. These findings suggest that BD patients with SA have intrinsic activity abnormalities in PFC regions. This provides potentially identifiable neuroimaging markers in BD patients with SA that could be used to increase our understanding of suicidal behavior.

Examination of structural brain changes in recent suicidal behavior

We aimed to identify brain structural changes in cortical and subcortical regions linked to recent suicidal behavior. We performed secondary analyses of structural MRI data of two independent studies, namely the Establishing Moderators/Biosignatures of Antidepressant Response - Clinical Care (EMBARC) study and a Little Rock study on acute suicidal behavior. Study 1 (EMBARC, N = 187), compared individuals with remote suicide attempts (Remote-SA), individuals with lifetime suicide ideation but no attempts (Lifetime-SI only), and depressed individuals without lifetime suicide ideation or attempts (non-suicidal depressed). Study 2 (Little Rock data, N = 34) included patients recently hospitalized for suicide ideation or attempt constituted by: patients who recently attempted suicide (Recent-SA), individuals with remote suicide attempts (Remote-SA), and Lifetime-SI only. Study 3 combined the EMBARC and Little Rock datasets including Recent-SA, Remote-SA, Lifetime-SI only and non-suicidal depressed individuals. In Study 1 and Study 2, no significant differences were observed between groups. In Study 3, significantly lower middle temporal gyrus thickness, insular surface area, and thalamic volume and higher volume in the nucleus accumbens were observed in Recent-SA. This pattern of structural abnormalities may underlie pain and emotion dysregulation, which have been linked to the transition from suicidal thoughts to action.

The Correlation of Reduced Fractional Anisotropy in the Cingulum With Suicide Risk in Bipolar Disorder

Objective: This study aims to investigate the significant alterations in brain white matter integrity in individuals with bipolar disorder (BD) who had attempted suicide by applying a tract-based spatial statistics (TBSS) approach with tensor-based spatial normalization. Methods: A TBSS approach with novel tensor-based registration was used to compare the white matter fractional anisotropy (FA) between 51 individuals with BD, of whom 19 had attempted suicide, and 43 healthy controls (HC). The suicide attempt was assessed with the Columbia-Suicide Severity Rating Scale (C-SSRS). In addition, we also investigated the correlations of FA values with clinical measures in BD, including illness duration, and the severity of depression and anxiety measured by the Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Rating Scale (HAMA), respectively. Results: A significant reduction of FA value in the hippocampal cingulum was observed in BD individuals who had attempted suicide compared with those who had not. For the genu/body of the corpus callosum, inferior fronto-occipital fasciculus, uncinate fasciculus, and anterior thalamic radiation, the reductions in FA values were significantly greater in both BD subgroups who attempted suicide and who did not, compared to HC. The correlation analysis showed that the illness duration of attempters was correlated to the FA value of the genu of the corpus callosum, while the HAMD and HAMA scores of non-attempters were relevant to the FA of the superior longitudinal fasciculus. Conclusion: The observation that white matter integrity was altered in the hippocampal cingulum in BD individuals who attempted suicide suggested that this brain area may be the neurobiological basis of suicide attempts. Our findings also support the involvement of white matter (WM) microstructure of frontal-subcortical circuits in the neurobiological mechanism of BD. In addition, the illness duration of patients with attempted suicide may have an effect on the altered integrity of the corpus callosum.

The Association Between Resting State Functional Connectivity and the Trait of Impulsivity and Suicidal Ideation in Young Depressed Patients With Suicide Attempts

Suicide is a leading cause of death among youth and is strongly associated with major depressive disorder (MDD). However, the neurobiological underpinnings of suicidal behaviour and the identification of risk for suicide in young depressed patients are not yet well-understood. In this study, we used a seed-based correlation analysis to investigate the differences in resting-state functional connectivity (RSFC) in depressed youth with or without a history of suicide attempts and healthy controls (HCs). Suicidal attempters (ATT group, n = 35), non-suicide attempters (NAT group, n = 18), and HCs exhibited significantly different RSFC patterns with the left superior prefrontal gyrus (L-SFG) and left middle prefrontal gyrus (L-MFG) serving as the regions of interest (ROIs). The ATT group showed decreased RSFC of the left middle frontal gyrus with the left superior parietal gyrus compared to the NAT and HC groups. Decreased RSFC between the left superior frontal gyrus and the right anterior cingulate cortex (rACC) was found in the ATT group compared to the NAT and HC groups. Furthermore, the left prefrontal-parietal connectivity was associated with suicidal ideation and levels of impulsivity, but RSFC of the left prefrontal cortex with the rACC was correlated exclusively with impulsivity levels and was not related to suicidal ideation in the ATT group. Our results demonstrated that altered RSFC of the prefrontal-parietal and prefrontal-rACC regions was associated with suicide attempts in depressed youth, and state-related deficits in their interconnectivity may contribute to traits, such as cognitive impairments and impulsivity to facilitate suicidal acts. Our findings suggest that the neural correlates of suicidal behaviours might be dissociable from those related to the severity of current suicidal ideation. Neural circuits underlying suicide attempts differ from those that underlie suicidal ideation.

Exploring the Evidence Implicating the Renin-Angiotensin System (RAS) in the Physiopathology of Mood Disorders

Mood disorders include Major Depressive Disorder (MDD), Bipolar Disorder (BD) and variations of both. Mood disorders has a public health significance with high comorbidity, suicidal mortality and economic burden on the health system. Research related to mood disorders has evolved over the years to relate it with systemic conditions. The Renin Angiotensin System (RAS) has been noticed to play major physiological roles beyond renal and cardiovascular systems. Recent studies have linked RAS not only with neuro-immunological processes, but also with psychiatric conditions like mood and anxiety disorders. In this comprehensive review, we integrated basic and clinical studies showing the associations between RAS and mood disorders. Animal studies on mood disorders models - either depression or mania - were focused on the reversal of behavioral and/or cognitive symptoms through the inhibition of RAS components like the Angiotensin- Converting Enzyme (ACE), Angiotensin II Type 1 receptor (AT1) or Mas receptors. ACE polymorphisms, namely insertion-deletion (I/D), were linked to mood disorders and suicidal behavior. Hypertension was associated with neurocognitive deficits in mood disorders, which reversed with RAS inhibition. Low levels of RAS components (renin activity or aldosterone) and mood symptoms improvement with ACE inhibitors or AT1 blockers were also observed in mood disorders. Overall, this review reiterates the strong and under-researched connection between RAS and mood disorders.

The Role of Sociodemographic, Clinical and Neuropsychological Variables in Suicide Attempts in Depressed Adolescents

INTRODUCTION

In this study, we aimed to evaluate the relationship between sociodemographic, clinical and neuropsychological variables and suicide attempts by comparing adolescents with Major Depressive Disorder (MDD) with and without suicide attempt.

METHOD

30 adolescents with and without suicide attempt were included in this study. Sociodemographic and Clinical Data Form, Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime Version (K-SADS-PL), The Children Depression Inventory (CDI), Beck Hopelessness Scale (BHS), Barratt Impulsivity Scale (BIS) and neuropsychological tests (Go/NoGo test, Stroop test Wisconsin Card Sorting Test) was applied to participants.

RESULTS

Depressed adolescents with suicide attempt compared to adolescents without suicide attempt; motor and total impulsivity scores in BIS-11, commission errors in Go/NoGo test which measure motor inhibition, completion time and errors in Stroop 5 which measure interference inhibition and scores of perseveration in Winsconsin Card Sorting Test (WCST) which measure cognitive inhibition were found to be higher. Family history of suicide attempt (OR: 5.87), commission errors (OR: 1.37), perseverative errors (OR: 1.09) ve total impulsivity (OR: 1.05) were remained in the logistic regression model.

CONCLUSION

Results of this study suggested that family history of suicide attempt was the most important factor predicting suicide attempt in adolescents with depression. Other factors predicting suicide attempt were executive dysfunction and impulsivity.

Source-based morphometry reveals gray matter differences related to suicidal behavior in criminal offenders

Relative to the general population, criminal offenders have a higher risk of suicide. Neurobiological deficits related to suicidal behavior have been identified in the general population, but unexamined in offenders to date. We examined the association between brain morphology and suicidal behavior in adult male criminal offenders. Brain morphology was examined using voxel-based morphometry (VBM) and source-based morphometry (SBM), a multivariate alternative to VBM which analyzes brain volume in between-subject spatially independent networks. Results showed that offenders with past suicide attempts (n = 19), relative to offenders without past suicide attempts (n = 19) and non-offenders (n = 26), had reduced gray matter in an SBM component that comprised the posterior cingulate, dorsal prefrontal cortex, and amygdala. The SBM source weights were significantly associated with suicide attempts independent of other suicide risk variables (e.g., depression). VBM results were similar to the SBM results but less robust. The results reveal a potential neurobiological marker of vulnerability to suicidal behavior among criminal offenders and illustrate the utility of multivariate methods of gray matter analyses.

Aberrant functional connectivity and graph properties in bipolar II disorder with suicide attempts

OBJECTIVE

The physiological mechanism of suicide attempt (SA) in bipolar II disorder (BD-II) remains only partially understood. The study seeks to identify the dysfunction pattern in suicide brain for BD-II patients.

METHODS

Graph theory was utilized to explore topological properties at whole-brain, module and region levels based on resting-state functional MRI (rs-fMRI) data, which acquired from 38 un-medicated BD-II patients with at least one SA, 60 none SA (NSA) patients and 69 healthy controls (HCs). Finally, the correlation relationship between graph metrics and clinical variables were estimated.

RESULTS

Compared with NSA patients and HCs, the functional connectivity strength between limbic/sub-cortical (LIMB/SubC) and frontoparietal network (FPN) were significantly weakened. Nodal strength in left head of caudate nucleus (HCN), raphe nucleus (RN), right nucleus accumbens (NAcc), right subgenual anterior cingulate cortex (sgACC) and nodal efficiency in right sgACC, right HCN for SA patients were significantly reduced relative to NSA and HCs. In particular, nodal strength in RN and nodal efficiency in right sgACC showed a significant negative correlation with Nurses' Global Assessment of Suicide Risk (NGASR) scores.

LIMITATIONS

This is a single-mode cross-sectional study, the results were not verified by multi-center data.

CONCLUSIONS

The abnormal disrupted FC between LIMB/SubC and FPN is associated with SA in BD-II patients, which increased the susceptibility of suicide. Especially, the dysfunction in RN and right sgACC predict a higher suicide risk in BD-II patients.The results can help us to understand the suicide mechanism and early judgment of suicidal behaviors for BD-II patients.

Association between cognition and suicidal ideation in patients with major depressive disorder: A longitudinal study

BACKGROUND

Suicidal ideation (SI) is common in patients with major depressive disorder (MDD) and often related to cognitive deficits. Limited longitudinal study has shown that cognitive improvement is associated with reduced SI. However, the comparatively study in Chinese depressed patients is still absent. The objective of this study was to explore the specific cognitive deficits in Chinese MDD with SI and investigate the relationship between changes in cognition and change in SI across antidepressant treatment.

METHODS

Three hundred and five patients with MDD received four weeks of antidepressant treatment. The 17-item Hamilton Depression Rating Scale (HAMD-17) and four domains of the MATRICS Consensus Cognitive Battery (MCCB), including speed of processing, working memory, visual learning and verbal learning were measured at baseline and four-week follow-up.

RESULTS

One hundred and thirty patients (42.6%) expressed suicidal ideation. Suicidal patients performed worse on verbal learning than non-suicidal patients. Change in speed of processing domain was negatively associated with change in suicidal scores over time. Logistic regression analysis showed that reduction of SI was associated with improvement of speed of processing.

LIMITATION

The major limitation was that there was no healthy control group in the current study, which might limit the interpretation of cognitive deficits in depressed patients with SI.

CONCLUSIONS

Our findings suggest that suicidal patients performed worse on verbal learning which can potentially serve as a cognitive biomarker of suicide risk in MDD. Moreover, reduced suicidal ideation was associated with improved speed of processing.

Socioeconomic disadvantage, brain morphometry, and attentional bias to threat in middle childhood

Socioeconomic disadvantage is associated with higher rates of psychopathology as well as hippocampus, amygdala and prefrontal cortex structure. However, little is known about how variations in brain morphometry are associated with socio-emotional risks for mood disorders in children growing up in families experiencing low income. In the current study, using structural magnetic resonance imaging, we examined the relationship between socioeconomic disadvantage and gray matter volume in the hippocampus, amygdala, and ventrolateral prefrontal cortex in a sample of children (n = 34) in middle childhood. Using an affective dot probe paradigm, we examined the association between gray matter volume in these regions and attentional bias to threat, a risk marker for mood disorders including anxiety disorders. We found that lower income-to-needs ratio was associated with lower bilateral hippocampal and right amygdala volume, but not prefrontal cortex volumes. Moreover, lower attentional bias to threat was associated with greater left hippocampal volume. We provide evidence of a relationship between income-related variations in brain structure and attentional bias to threat, a risk for mood disorders. Therefore, these findings support an environment-morphometry-behavior relationship that contributes to the understanding of income-related mental health disparities in childhood.

Alterations in functional brain networks in depressed patients with a suicide attempt history

Suicide is a major challenge in public health and is strongly associated with major depressive disorder (MDD). Despite recent neuroimaging developments, the neural correlates of suicide behavior in patients with MDD remain unclear. Independent component analysis (ICA) for neuroimaging data allows the identification of functional brain networks without prior regions of interest and may help to identify neurobiological markers of specific disorders. Using ICA, we investigated the differences in resting-state brain networks in patients with MDD who had or did not have a history of suicide attempts and in healthy controls (HCs). Suicidal depressed (SD) patients, non-suicidal depressed (NSD) patients, and HCs significantly differed from each other in the pattern of connectivity of multiple functional networks, network synchronization, and functional network connectivity (FNC). The patient groups had a decreased network synchronization in the insular, cerebellum, basal ganglia, thalamus, operculum, frontoparietal cortices, and sensory cortices relative to the HCs. The decreased FNC between these networks (insular-default mode network and insular-cerebellum) was found in the SD group compared to the NSD and HC groups. These differences were not related to illness duration and medication status differences between SD and NSD. Furthermore, the degree of FNC in these networks was associated with the suicide ideation and stress level. Our results demonstrated that widespread but discrete network changes in brain networks and their interconnectivity was associated with suicide attempts in patients with MDD. Our results suggest that the neural basis underlying the psychopathology of attempted suicide in patients with MDD involves multiple brain networks and their interaction.

Dorsolateral and ventrolateral prefrontal cortex structural changes relative to suicidal ideation in patients with depression

The prefrontal cortex (PFC) is enormously important in suicide and major depressive disorder (MDD). However, little is known about the structural alterations in the brains of people with MDD and suicidal ideation. We examined the gray matter volume (GMV) of the PFC of individuals with MDD and suicidal ideation to determine if PFC volumetric differences contribute to suicidal ideation in patients with MDD. Thirty-five subjects with MDD and suicidal ideation, 38 subjects with MDD but without suicidal ideation, and 43 age- and gender-matched healthy control (HC) subjects underwent T1-weighted imaging. A voxel-based morphometric analysis was conducted to compare the PFC GMVs of the three groups. Further GMV reductions in the left and right dorsolateral PFC (DLPFC) and right ventrolateral PFC (VLPFC) were detected in the MDD with suicidal ideation group compared with those in the HC group and the MDD without suicidal ideation group, whereas the MDD without suicidal ideation group only exhibited significant differences in the left DLPFC relative to the HC group. Our findings demonstrated that left DLPFC reductions were associated with MDD and suicidal ideation, and diminished GMV reductions in the right DLPFC and right VLPFC were only associated with suicidal ideation. These results help us better understand the neuropathological changes in MDD with suicidal ideation.

Accelerated extrinsic epigenetic aging and increased natural killer cells in blood of suicide completers

BACKGROUND

Studies suggest aberrant DNA methylation in victims of suicide. Recently, DNA methylation profiles have been developed for determining "epigenetic age," which is the most accurate estimate of biological age. Subsequently, two refined measures of epigenetic age acceleration have been expanded for blood samples as intrinsic and extrinsic epigenetic age acceleration (IEAA and EEAA, respectively). IEAA involves pure epigenetic aging independent of blood cell composition, whereas EEAA involves immunosenescence in association with blood cell composition.

METHODS

We investigated epigenetic age acceleration using two independent DNA methylation datasets: a brain dataset from 16 suicide completers and 15 non-psychiatric controls and a blood dataset compiled using economical DNA pooling technique from 56 suicide completers and 60 living healthy controls. In the blood dataset, we considered IEAA and EEAA, as well as DNA methylation-based blood cell composition.

RESULTS

There was no significant difference in universal epigenetic age acceleration between suicide completers and controls in both brain and blood datasets. Blood of suicide completers exhibited an increase in EEAA, but not in IEAA. We additionally found that suicide completers had more natural killer cells but fewer granulocytes compared to controls.

CONCLUSION

This study provides novel evidence for accelerated extrinsic epigenetic aging in suicide completers and for the potential application of natural killer cells as a biomarker for suicidal behavior.

Understanding the Complex of Suicide in Depression: from Research to Clinics

OBJECTIVE

Amongst psychiatric disorders, major depressive disorder (MDD) is the most prevalent, by affecting approximately 15-17% of the population and showing a high suicide risk rate equivalent to around 15%. The present comprehensive overview aims at evaluating main research studies in the field of MDD at suicide risk, by proposing as well as a schematic suicide risk stratification and useful flow-chart for planning suicide preventive and therapeutic interventions for clinicians.

METHODS

A broad and comprehensive overview has been here conducted by using PubMed/Medline, combining the search strategy of free text terms and exploded MESH headings for the topics of 'Major Depressive Disorder' and 'Suicide' as following: ((suicide [Title/Abstract]) AND (major depressive disorder [Title/Abstract])). All articles published in English through May 31, 2019 were summarized in a comprehensive way.

RESULTS

Despite possible pathophysiological factors which may explain the complexity of suicide in MDD, scientific evidence supposed the synergic role of genetics, exogenous and endogenous stressors (i.e., interpersonal, professional, financial, as well as psychiatric disorders), epigenetic, the hypothalamic-pituitary-adrenal stress-response system, the involvement of the monoaminergic neurotransmitter systems, particularly the serotonergic ones, the lipid profile, neuro-immunological biomarkers, the Brain-derived neurotrophic factor and other neuromodulators.

CONCLUSION

The present overview reported that suicide is a highly complex and multifaceted phenomenon in which a large plethora of mechanisms could be variable implicated, particularly amongst MDD subjects. Beyond these consideration, modern psychiatry needs a better interpretation of suicide risk with a more careful assessment of suicide risk stratification and planning of clinical and treatment interventions.