Default mode dysfunction underpins suicidal activity in mood disorders

Loudness dependent auditory evoked potentials and suicidality in depression - A meta-analysis with replication in unmedicated patients

OBJECTIVE

Major Depressive Disorder (MDD) is a risk factor for suicide. Loudness-Dependent Auditory Evoked Potentials (LDAEP) is an electroencephalographic biomarker of central serotonergic activity associated with MDD and suicidality. Yet, studies on the matter are conflicting. We therefore: 1) Conducted a meta-analysis to clarify the relation between LDAEP, past suicide attempts and current suicidality in MDD, and 2) replicated the findings in independent data of unmedicated patients with MDD.

METHODOLOGY

1) 10 studies were included in the meta-analysis. The difference in scalp LDAEP between patients with and without past suicide attempts was estimated using Hedge's g. The correlation between scalp LDAEP and suicidality was estimated using Fisher's Zr. The Newcastle-Ottawa Scale was used to assess methodological differences. The review was preregistered (PROSPERO). 2) We examined the associations above within an independent cohort of 88 unmedicated patients with MDD. The analyses were preregistered (AsPredicted.org) and used to update the meta-analysis.

RESULTS

In the initial meta-analysis, scalp LDAEP was not associated with past suicide attempts (g = 0.11 [-0.23, 0.46], p = 0.53) or correlated with suicidality (Zr = 0.06 [-0.15, 0.27], p = 0.60). In the independent cohort, scalp LDAEP was also not associated with past suicide attempts (g = 0.05 [-0.56, 0.65] t(86) = 0.15, p = 0.88) or correlated with suicidality (Zr = 0.11 [-0.1, 0.33] r = 0.11 [-0.10, 0.32], p = 0.30). In the updated meta-analysis, scalp LDAEP continued not to be associated with suicide attempts (g = 0.10 [-0.19, 0.39], p = 0.51) or suicidality (Zr = 0.06 [-0.12, 0.24], p = 0.50).

CONCLUSION

LDAEP is not associated with past suicide attempts or suicidality in MDD, and LDAEP's usefulness in suicide prevention seems limited.

Cortical folding in distinguishing first-episode bipolar and unipolar depression

BACKGROUNDS

Clinical studies to date have yet to establish distinct boundaries between depression in bipolar disorder (BD) and unipolar depression (UD), leading to misdiagnoses and even exacerbation of the conditions. This study aimed to explore the distinctions in the local gyrification index (LGI) between BD and UD, and to evaluate its potential diagnostic value as a biomarker.

METHODS

LGI values across 68 cortical regions were measured from 42 patients with BD, 45 patients with UD, and 45 healthy controls (HCs) based on the Desikan-Killiany atlas. General linear model was performed to compare LGI values among the three groups. XGBoost classifier was implemented to develop a binary classification model for distinguishing BD from UD. Additionally, the correlation between clinical characteristics and LGI values was investigated separately within the BD and UD groups.

RESULTS

Compared to HCs, individuals with BD and UD exhibited significantly reduced LGI values in various cortical regions. Nine LGI regions in the BD group displayed reduced values compared to the UD group, except for a singular increase in the left frontal pole (ηp2 = 0.173; P = 0.006). No significant association was found between LGI values and clinical characteristics within the patient groups. The XGBoost classifier achieved a distinction accuracy of 73.7 % between BD and UD, with the left frontal pole making the most significant contribution to the model.

CONCLUSIONS

The findings suggest that LGI could be a relatively stable neuroimaging biomarker for distinguishing between BD and UD.

Individual suicide risk factors with resting-state brain functional connectivity patterns in bipolar disorder patients based on latent Dirichlet allocation model

BACKGROUND

The widespread problem of suicide and its severe burden in bipolar disorder (BD) necessitate the development of objective risk markers, aiming to enhance individual suicide risk prediction in BD.

METHODS

This study recruited 123 BD patients (61 patients with prior suicide attempted history (PSAs), 62 without (NSAs)) and 68 healthy controls (HEs). The Latent Dirichlet Allocation (LDA) model was used to decompose the resting state functional connectivity (RSFC) into multiple hyper/hypo-RSFC patterns. Thereafter, according to the quantitative results of individual heterogeneity over latent factor dimensions, the correlations were analyzed to test prediction ability.

RESULTS

Model constructed without introducing suicide-related labels yielded three latent factors with dissociable hyper/hypo-RSFC patterns. In the subsequent analysis, significant differences in the factor distributions of PSAs and NSAs showed biases on the default-mode network (DMN) hyper-RSFC factor (factor 3) and the salience network (SN) and central executive network (CEN) hyper-RSFC factor (factor 1), indicating predictive value. Correlation analysis of the individuals' expressions with their Nurses' Global Assessment of Suicide Risk (NGASR) revealed factor 3 positively correlated (r = 0.4180, p < 0.0001) and factor 1 negatively correlated (r = - 0.2492, p = 0.0055) with suicide risk. Therefore, it could be speculated that patterns more associated with suicide reflected hyper-connectivity in DMN and hypo-connectivity in SN, CEN.

CONCLUSIONS

This study provided individual suicide-associated risk factors that could reflect the abnormal RSFC patterns, and explored the suicide related brain mechanisms, which is expected to provide supports for clinical decision-making and timely screening and intervention for individuals at high risks of suicide.

The neural connectome of suicidality in adults with mood and anxiety disorders

Although suicide risk is a major public health issue, attempts to understand the neural basis of suicidality have been limited by small sample sizes and a focus on specific psychiatric disorders. This sample comprised 579 participants, of whom 428 had a psychiatric disorder (depression, anxiety or stress-related disorder) and 151 were non-psychiatric controls. All participants underwent structured clinical interviews, including an assessment of suicidality in the past month, and completed a functional magnetic resonance imaging scan. There were 238 (41.1%) participants who met criteria for suicidality and 341 (58.9%) were non-suicidal. Task-derived functional connectivity was calculated for 436 brain regions, comprising 8 intrinsic connectivity networks. Participants who were suicidal had decreased connectivity in a network of 143 connections across 86 brain regions. This pattern was characterized primarily by decreased connectivity within the visual, somatomotor and salience networks, between these networks, and also with the default mode and limbic networks. By adopting a transdiagnostic approach with a very large sample of individuals with mood disorders, anxiety and stress and non-psychiatric participants, this study highlights the hypoconnectivity that characterizes suicidality and points to altered connectivity within and between key networks involved in emotional, sensory and cognitive processes that are implicated in suicidal risk.

Causal role of immune cells in major depressive disorder and bipolar disorder: Mendelian randomization (MR) study

BACKGROUND

Major depressive disorder (MDD) and bipolar disorder (BD) are prevalent psychiatric conditions linked to inflammatory processes. However, it is unclear whether associations of immune cells with these disorders are likely to be causal.

METHODS

We used two-sample Mendelian randomization (MR) approach to investigate the relationship between 731 immune cells and the risk of MDD and BD. Rigorous sensitivity analyses are conducted to assess the reliability, heterogeneity, and horizontal pleiotropy of the findings.

RESULTS

Genetically-predicted CD27 on IgD+ CD38- unswitched memory B cell (inverse variance weighting (IVW): odds ratio (OR) [95 %]: 1.017 [1.007 to 1.027], p = 0.001), CD27 on IgD+ CD24+ B cell (IVW: OR [95 %]: 1.021 [1.011 to 1.031], p = 4.821E-05) and other 12 immune cells were associated with increased risk of MDD in MR, while HLA DR++ monocyte %leukocyte (IVW: OR [95 %]: 0.973 [0.948 to 0.998], p = 0.038), CD4 on Central Memory CD4+ T cell (IVW: OR [95 %]: 0.979 [0.963 to 0.995], p = 0.011) and other 13 immune cells were associated with decreased risk of MDD in MR. Additionally, CD33+ HLA DR+ Absolute Count (IVW: OR [95 %]: 1.022[1.007 to 1.036], p = 0.007), CD28+ CD45RA- CD8+ T cell %T cell (IVW: OR [95 %]: 1.024 [1.008 to 1.041], p = 0.004) and other 18 immune cells were associated with increased risk of BD in MR, while CD62L on CD62L+ myeloid Dendritic Cell (IVW: OR [95 %]: 0.926 [0.871 to 0.985], p = 0.014), IgD- CD27- B cell %lymphocyte (IVW: OR [95 %]: 0.918 [0.880 to 0.956], p = 4.654E-05) and other 13 immune cells were associated with decreased risk of BD in MR.

CONCLUSIONS

This MR study provides robust evidence supporting a causal relationship between immune cells and the susceptibility to MDD and BD, offering valuable insights for future clinical investigations. Experimental studies are also required to further examine causality, mechanisms, and treatment potential for these immune cells for MDD and BD.

Differentiation between suicide attempt and suicidal ideation in patients with major depressive disorder using cortical functional network

Studies exploring the neurophysiology of suicide are scarce and the neuropathology of related disorders is poorly understood. This study investigated source-level cortical functional networks using resting-state electroencephalography (EEG) in drug-naïve depressed patients with suicide attempt (SA) and suicidal ideation (SI). EEG was recorded in 55 patients with SA and in 54 patients with SI. Particularly, all patients with SA were evaluated using EEG immediately after their SA (within 7 days). Graph-theory-based source-level weighted functional networks were assessed using strength, clustering coefficient (CC), and path length (PL) in seven frequency bands. Finally, we applied machine learning to differentiate between the two groups using source-level network features. At the global level, patients with SA showed lower strength and CC and higher PL in the high alpha band than those with SI. At the nodal level, compared with patients with SI, patients with SA showed lower high alpha band nodal CCs in most brain regions. The best classification performances for SA and SI showed an accuracy of 73.39%, a sensitivity of 76.36%, and a specificity of 70.37% based on high alpha band network features. Our findings suggest that abnormal high alpha band functional network may reflect the pathophysiological characteristics of suicide and serve as a clinical biomarker for suicide.

The altered temporal properties of dynamic functional connectivity associated with suicide attempt in bipolar disorders

OBJECTIVE

The suicide risk in bipolar disorder (BD) is the highest among psychiatric disorders, and the neurobiological mechanism of suicide in BD remains unclear. The study aimed to investigate the underlying relevance between the implicated abnormalities of dynamic functional connectivity (FC) and suicide attempt (SA) in BD.

METHODS

We used the sliding window method to analyze the dynamic FC patterns from resting-state functional MRI data in 81 healthy controls (HC) and 114 BD patients (50 with SA and 64 with none SA). Then, the temporal properties of dynamic FC and the relationship between altered measures and clinical variables were explored.

RESULTS

We found that one of the five captured brain functional states was more associated with SA. The SA patients showed significantly increased fractional window and dwell time in the suicide-related state, along with increased number of state transitions compared with none SA (NSA). In addition, the connections within subcortical network-subcortical network (SubC-SubC), default mode network-subcortical network (DMN-SubC), and attention network-subcortical network (AN-SubC) were significantly changed in SA patients relative to NSA and HC in the suicide-related state. Crucially, the above-altered measures were significantly correlated with suicide risk.

CONCLUSIONS

Our findings suggested that the impaired dynamic FC within SubC-SubC, DMN-SubC, and AN-SubC were the important underlying mechanism in understanding SA for BD patients. It highlights the temporal properties of whole-brain dynamic FC could serve as the valuable biomarker for suicide risk assessment in BD.

Improvement of astrocytic gap junction involves the anti-depressive effect of celecoxib through inhibition of NF-κB

CONTEXT

Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, has been shown to exhibit anti-depressive effects in clinical trials. However, the direct mechanism underlying its effect on neuroinflammation remains unclear. Neuroinflammatory reaction from astrocytes leads to depression, and our previous study found that gap junction disorder between astrocytes aggravated neuroinflammatory reaction in depressed mice.

OBJECTIVE

To investigate the potential mechanism of celecoxib's effects on astrocytic gap junctions during the central nervous inflammation-induced depression.

MATERIALS & METHODS

Stereotaxic injection of lipopolysaccharide (LPS) into the prefrontal cortex (PFC) to establish a model of major depressive disorder (MDD). Celecoxib was administrated into PFC 15 min after LPS injection. The depressive performance was tested by tail suspension test and forced swimming test, and the levels of proinflammation cytokines were determined at mRNA and protein levels. Resting-state functional connection (rsFC) was employed to assess changes in the default mode network (DMN). Additionally, astrocytic gap junctions were also determined by lucifer yellow (LY) diffusion and transmission electron microscope (TEM), and the expression of connexin 43 (Cx43) was measured by western blotting, quantitative polymerase chain reaction, and immunofluorescence.

RESULTS

LPS injection induced significant depressive performance, which was ameliorated by celecoxib treatment. Celecoxib also improved rsFC in the DMN. Furthermore, celecoxib improved astrocytic gap junctions as evidenced by increased LY diffusion, shortened gap junction width, and normalized levels of phosphorylated Cx43. Celecoxib also blocked the phosphorylation of p65, and inhibition of p65 abolished the improvement of Cx43.

DISCUSSION & CONCLUSION

Anti-depressive effects of celecoxib are mediated, at least in part, by the inhibition of nuclear factor- kappa B (NF-κB) and the subsequent improvement of astrocytic gap junction function.

Correlation between low frequency fluctuation and cognitive performance in bipolar disorder patients with suicidal ideation

BACKGROUND

Patients with bipolar disorder (BD) are at high risk of suicidal ideation (SI), and BD patients with suicidal ideation (BDSI) have shown marked abnormalities in spontaneous brain function. Cognitive impairment, on the other hand, is considered to be one of the core symptoms of BD. However, few studies have addressed the association between cognitive performance and abnormal spontaneous brain function in BDSI.

METHODS

In the current study, the MATRICS Consensus Cognitive Battery (MCCB) was used to assess cognitive performance in BDSI (n = 20), BD subjects without suicidal ideation (BDNSI) (n = 24) and healthy controls (HC) (n = 30). Their cognitive performance was then correlated with amplitude of low frequency fluctuation (ALFF) values obtained by resting-state functional magnetic resonance imaging (rs-fMRI).

RESULTS

We found that ALFF was significantly higher in the left precuneus and right posterior cingulate cortex in the BDSI group and significantly lower in the right precuneus in the BDNSI group than in the HC group. In addition, in the BDSI group, visual learning performance was positively correlated with ALFF values in the left precuneus.

CONCLUSIONS

Our findings support the notion that BD patients present with ALFF abnormalities, which are associated with cognitive performance in BDSI.

Association of hospitalization for suicide attempts in adolescent girls with subsequent hospitalization for eating disorders

OBJECTIVE

To determine the association between adolescent hospitalization for suicide attempts and the subsequent risk of eating disorder hospitalization.

METHOD

This was a cohort study of 162,398 adolescent girls in Quebec, Canada, including 7741 with suicide attempts before 20 years of age, matched to 154,657 adolescents with no attempt between 1989 and 2019. The main exposure measure was suicide attempt hospitalization. The main outcome measure was hospitalization for an eating disorder up to 31 years later, including anorexia nervosa, bulimia nervosa, and other eating disorders. We used adjusted Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between adolescent suicide attempts and eating disorder hospitalization.

RESULTS

Adolescent girls admitted for a suicide attempt had 5.55 times the risk of eating disorder hospitalization over time (95% CI 3.74-8.23), compared with matched controls. Suicide attempt was associated with anorexia nervosa (HR 3.57, 95% CI 1.78-7.17) and bulimia nervosa and other eating disorders (HR 8.55, 95% CI 5.48-13.32). Associations were pronounced in girls with repeated suicide attempts. Girls who attempted suicide through self-poisoning had an elevated risk of anorexia nervosa, whereas girls who used violent methods such as cutting or piercing had a greater risk of bulimia nervosa and other eating disorders. Suicide attempt was strongly associated with eating disorder hospitalization in the year following the attempt, but associations persisted throughout follow-up.

DISCUSSION

Suicide attempt admission is associated with the long-term risk of eating disorder hospitalization in adolescent girls.

PUBLIC SIGNIFICANCE

This study of adolescent girls suggests that suicide attempt admission is associated with the long-term risk of hospitalization for eating disorders. The risk is greatest in the year after the attempt, but persists over time. Adolescents who present with a suicide attempt may benefit from screening for eating disorders and long-term follow-up to help prevent the exacerbation or development of eating disorders.

Resting-state network analysis of suicide attempt history in the UK Biobank

BACKGROUND

Prior research has identified altered brain structure and function in individuals at risk for self-directed violence thoughts and behaviors. However, these studies have largely utilized healthy controls and findings have been inconsistent. Thus, this study examined differences in resting-state functional network connectivity among individuals with lifetime suicide attempt(s) v. lifetime self-directed violence thoughts alone.

METHODS

Using data from the UK Biobank, this study utilized a series of linear regressions to compare individuals with lifetime suicide attempt(s) (n = 566) v. lifetime self-directed violence thoughts alone (n = 3447) on within- and between- network resting-state functional connectivity subnetworks.

RESULTS

There were no significant between-group differences for between-network, within-network, or whole-brain functional connectivity after adjusting for age, sex, ethnicity, and body mass index and performing statistical corrections for multiple comparisons. Resting-state network measures may not differentiate between individuals with lifetime suicide attempt(s) and lifetime self-directed violence thoughts alone.

CONCLUSIONS

Null findings diverge from results reported in smaller neuroimaging studies of suicide risk, but are consistent with null findings in other large-scale studies and meta-analyses. Strengths of the study include its large sample size and stringent control group. Future research on a wider array of imaging, genetic, and psychosocial risk factors can clarify relative contributions of individual and combined variables to suicide risk and inform scientific understanding of ideation-to-action framework.

Association of executive function with suicidality based on resting-state functional connectivity in young adults with subthreshold depression

Subthreshold depression (StD) is associated an increased risk of developing major depressive disorder (MDD) and suicidality. Suicidality could be linked to distress intolerance and use of context-dependent strategies. We identified neural correlates of executive functioning among the hubs in the resting-state functional connectome (rs-FCN) and examined associations with recent suicidality in StD and MDD. In total, 79 young adults [27 StD, 30 MDD, and 23 healthy controls (HC)] were scanned using magnetic resonance imaging. Neurocognitive measures of the mean latency to correct five moves in the One Touch Stockings of Cambridge (OTSMLC5), spatial working memory between errors (SWMBE), rapid visual information processing A' (RVPA'), and the stop signal reaction time in the stop signal test (SSTSSRT) were obtained. Global graph metrics were calculated to measure the network integration, segregation, and their balance in the rs-FCN. Regional graph metrics reflecting the number of neighbors (degree centrality; DC), participation in the shortcuts (betweenness centrality; BC), and accessibility to intersections (eigenvector centrality; EC) in the rs-FCN defined group-level hubs for StD, HC, and MDD, separately. Global network metrics were comparable among the groups (all P > 0.05). Among the group-level hubs, regional graph metrics of left dorsal anterior insula (dAI), right dorsomedial prefrontal cortex (dmPFC), right rostral temporal thalamus, right precuneus, and left postcentral/middle temporal/anterior subgenual cingulate cortices were different among the groups. Further, significant associations with neurocognitive measures were found in the right dmPFC with SWMBE, and left dAI with SSTSSRT and RVPA'. Shorter OTSMLC5 was related to the lower centralities of right thalamus and suffer of recent 1-year suicidal ideation (all Ps < 0.05 in ≥ 2 centralities out of DC, BC, and EC). Collectively, salience and thalamic networks underlie spatial strategy and planning, response inhibition, and suicidality in StD and MDD. Anti-suicidal therapies targeting executive function and modulation of salience-thalamic network in StD and MDD are required.

EEG source functional connectivity in patients after a recent suicide attempt

OBJECTIVE

Electroencephalogram (EEG) based frequency measures within the alpha frequency range (AFR), including functional connectivity, show potential in assessing the underlying pathophysiology of depression and suicide-related outcomes. We investigated the association between AFR connectivity, suicidal thoughts and behaviors, and depression in a transdiagnostic sample of patients after a recent suicide attempt (SA).

METHODS

Lagged source-based measures of linear and nonlinear whole-brain connectivity within the standard AFR ([sAFR], 8-12 Hz) and the individually referenced AFR (iAFR) were applied to 70 15-minute resting-state EEGs from patients after a SA and 70 age- and gender-matched healthy controls (HC). Hypotheses were tested using network-based statistics and multiple regression models.

RESULTS

Results showed no significant differences between patients after a SA and HC in any of the assessed connectivity modalities. However, a subgroup analysis revealed significantly increased nonlinear connectivity within the sAFR for patients after a SA with a depressive disorder or episode ([DD], n = 53) compared to matched HC. Furthermore, a multiple regression model, including significant main effects for group and global nonlinear connectivity within the sAFR outperformed all other models in explaining variance in depressive symptom severity.

CONCLUSIONS

Our study further supports the importance of the AFR in pathomechanisms of suicidality and depression. The iAFR does not seem to improve validity of phase-based connectivity.

SIGNIFICANCE

Our results implicate distinct neurophysiological patterns in suicidal subgroups. Exploring the potential of these patterns for treatment stratification might advance targeted interventions for suicidal thoughts and behaviors.

Common and distinct patterns of task-related neural activation abnormalities in patients with remitted and current major depressive disorder: A systematic review and coordinate-based meta-analysis

Whether remitted major depressive disorder (rMDD) and MDD present common or distinct neuropathological mechanisms remains unclear. We performed a meta-analysis of task-related whole-brain functional magnetic resonance imaging (fMRI) using anisotropic effect-size signed differential mapping software to compare brain activation between rMDD/MDD patients and healthy controls (HCs). We included 18 rMDD studies (458 patients and 476 HCs) and 120 MDD studies (3746 patients and 3863 HCs). The results showed that MDD and rMDD patients shared increased neural activation in the right temporal pole and right superior temporal gyrus. Several brain regions, including the right middle temporal gyrus, left inferior parietal, prefrontal cortex, left superior frontal gyrus and striatum, differed significantly between MDD and rMDD. Meta-regression analyses revealed that the percentage of females with MDD was positively associated with brain activity in the right lenticular nucleus/putamen. Our results provide valuable insights into the underlying neuropathology of brain dysfunction in MDD, developing more targeted and efficacious treatment and intervention strategies, and more importantly, providing potential neuroimaging targets for the early screening of MDD.

Sex-specific risk and resilience correlates of suicidal ideation in U.S. military veterans

OBJECTIVES

To estimate the prevalence and identify gender-specific risk factors associated with suicidal ideation (SI) in a nationally representative sample of U.S. military veterans.

METHODS

Data were analyzed from the 2019-2020 National Health and Resilience in Veterans Study, which surveyed a nationally representative sample of 4069 veterans. Bivariate and multivariable analyses were conducted to identify factors associated with SI in male and female veterans.

RESULTS

The prevalence of SI was significantly higher in female than male veterans (18.1 % vs. 11.2 %). In female veterans, results of a relative importance analysis revealed that the majority of explained variance in SI (Nagelkerke R² = 0.54) was accounted for by lower psychological resilience (44.4 %), and history of non-suicidal self-injury (24.4 %) and alcohol use disorder (20.6 %). In male veterans, the majority of explained variance in SI (Nagelkerke R² = 0.32) was accounted for by higher loneliness (19.5 %) and hostility (19.1 %), and lower purpose in life (16.3 %).

CONCLUSIONS

Suicidal ideation is prevalent among U.S. veterans, particularly in female veterans. Different risk factors emerged as strong correlates of SI in female and male veterans, which may be used to inform gender-specific suicide prevention and treatment efforts in this population.

Resting-state neural mechanisms of capability for suicide and their interaction with pain - A CAN-BIND-05 Study

BACKGROUND

Suicidal ideation is highly prevalent in Major Depressive Disorder (MDD). However, the factors determining who will transition from ideation to attempt are not established. Emerging research points to suicide capability (SC), which reflects fearlessness of death and increased pain tolerance, as a construct mediating this transition. This Canadian Biomarker Integration Network in Depression study (CANBIND-5) aimed to identify the neural basis of SC and its interaction with pain as a marker of suicide attempt.

METHODS

MDD patients (n = 20) with suicide risk and healthy controls (n = 21) completed a self-report SC scale and a cold pressor task measuring pain threshold, tolerance, endurance, and intensity at threshold and tolerance. All participants underwent a resting-state brain scan and functional connectivity was examined for 4 regions: anterior insula (aIC), posterior insula (pIC), anterior mid-cingulate cortex (aMCC) and subgenual anterior cingulate cortex (sgACC).

RESULTS

In MDD, SC correlated positively with pain endurance and negatively with threshold intensity. Furthermore, SC correlated with the connectivity of aIC to the supramarginal gyrus, pIC to the paracingulate gyrus, aMCC to the paracingulate gyrus, and sgACC to the dorsolateral prefrontal cortex. These correlations were stronger in MDD compared to controls. Only threshold intensity mediated the correlation between SC and connectivity strength.

LIMITATIONS

Resting-state scans provided an indirect assessment of SC and the pain network.

CONCLUSIONS

These findings highlight point to a neural network underlying SC that is associated with pain processing. This supports the potential clinical utility of pain response measurement as a method to investigate markers of suicide risk.

Alcohol use is associated with affective and interoceptive network alterations in bipolar disorder

INTRODUCTION

Alcohol use in bipolar disorder (BD) is associated with mood lability and negative illness trajectory, while also impacting functional networks related to emotion, cognition, and introspection. The adverse impact of alcohol use in BD may be explained by its additive effects on these networks, thereby contributing to a poorer clinical outcome.

METHODS

Forty BD-I (DSM-IV-TR) and 46 psychiatrically healthy controls underwent T1 and resting state functional MRI scanning and the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) to assess alcohol use. Functional images were decomposed using spatial independent component analysis into 14 resting state networks (RSN), which were examined for effect of alcohol use and diagnosis-by-alcohol use accounting for age, sex, and diagnosis.

RESULTS

Despite the groups consuming similar amounts of alcohol (BD: mean score ± SD 3.63 ± 3; HC 4.72 ± 3, U = 713, p = .07), for BD participants, greater alcohol use was associated with increased connectivity of the paracingulate gyrus within a default mode network (DMN) and reduced connectivity within an executive control network (ECN) relative to controls. Independently, greater alcohol use was associated with increased connectivity within an ECN and reduced connectivity within a DMN. A diagnosis of BD was associated with increased connectivity of a DMN and reduced connectivity of an ECN.

CONCLUSION

Affective symptomatology in BD is suggested to arise from the aberrant functionality of networks subserving emotive, cognitive, and introspective processes. Taken together, our results suggest that during euthymic periods, alcohol can contribute to the weakening of emotional regulation and response, potentially explaining the increased lability of mood and vulnerability to relapse within the disorder.

An fMRI examination of the neural basis of suicide attempts: The role of mentalizing in the context of mood

OBJECTIVES

Facial emotion recognition (FER) deficits in depressed mood disorder patients contribute to suicidality. Prior research shows that intrinsic brain activity patterns are altered by attempting suicide. Therefore, we investigated in depressed patients whether differences in FER contribute to their clinical symptoms of suicide.

METHODS

Neural activity in response to an FER task was compared across three groups: healthy controls (HCs, N = 66), suicide non-attempter (SNA, N = 50), suicide attempter (SA, N = 25). Modulation of brain networks by the task and functional connectivity (FC) within (using spatial map, spectral power) and between (using functional network connectivity; FNC) were examined. The contribution of these differences to suicidal symptoms in each group was also examined.

RESULTS

Patient groups displayed impaired FC both within and between networks but differed in nature and networks involved. They also showed differential modulation of networks by task, such that compared with both HC and SNA, SA displayed impaired FC within the default-mode network (DMN) and also its task modulation. In the SA group, FC within the DMN and FNC between two lateral prefrontal networks, and its interaction with the basal ganglia network contributed significantly to the clinical symptoms of suicide.

CONCLUSIONS

This study affirms differences between SA and SNA brain activity patterns and suggests that suicidal activity probably emanates via different mechanisms in these patient groups. Perhaps, over-attribution of emotion impairs one's self-referential thought processes and coupled with diminished emotional control this makes depressed individuals vulnerable to suicide.

The characterization of static and dynamic brain functional networks in suicide attempters with major depressive disorder and its relation to psychological pain

Psychological pain is a robust predictor of suicide attempts in patients with major depressive disorder (MDD). However, whether suicide and psychological pain share a common neural basis remains unclear. Patients with MDD (n = 64) and healthy controls (HC) (n = 35) were recruited and patients were allocated to two groups: those with a history of suicide attempts (MDD-SA) (n = 25) and those without such a history (MDD-NSA) (n = 39). All participants completed the measurements and underwent functional magnetic resonance imaging to investigate the resting-state static and dynamic brain functional networks in default mode (DMN), central executive (CEN), salience (SN), and basal ganglia (BGN) networks. The MDD-SA group scored higher in pain avoidance than the MDD-NSA and HC groups. Functional connectivity within the dorsal DMN in the MDD-SA group was greater than that in the MDD-NSA and HC groups, and was significantly correlated with pain avoidance and suicide attempts. Dynamic functional connectivity analysis revealed that the proportion of State I in the fraction windows in the MDD-SA group was higher than those in the MDD-NSA and HC groups. Therefore, the increased functional connectivity within the dorsal DMN and segregation of networks may represent potential biological markers for suicide attempts related to psychological pain processing.

Suicide Attempt and Risk of Substance Use Disorders Among Female Youths

IMPORTANCE

Suicide attempts are prevalent among female youths, yet little is known about the subsequent development of substance use disorders.

OBJECTIVE

To assess the association between suicide attempts among females before 20 years of age and future risk of substance use disorders.

DESIGN, SETTING, AND PARTICIPANTS

In this longitudinal cohort study, females aged 8 to 19 years (hereafter referred to as youths) who attempted suicide were matched with female youths with no attempt between April 1, 1989, and March 31, 2019, in Quebec, Canada. The cohort was followed up for 31 years, for a total of 2 409 396 person-years, to identify subsequent substance use disorders.

EXPOSURES

Confirmed suicide attempts among females 8 to 19 years of age.

MAIN OUTCOMES AND MEASURES

The main outcome measure was hospitalization for a substance use disorder later in life. Hazard ratios (HRs) and 95% CIs for the association of suicide attempt with substance use disorders were estimated using Cox proportional hazards regression models adjusted for baseline age, mental illness, resource-limited socioeconomic status, and year at start of follow-up.

RESULTS

Among 122 234 female youths (mean [SD] age, 15.6 [1.9] years), 5840 (4.8%) attempted suicide and 4341 (3.6%) developed a substance use disorder. Compared with the 116 394 matched female youths who did not attempt suicide (95.2%), those who attempted suicide had a greater risk of hospitalization for any substance use disorder during the follow-up period (HR, 6.03; 95% CI, 5.39-6.77), especially sedative or hypnotic use disorders (HR, 32.24; 95% CI, 23.29-44.64). Suicide attempt was associated with the development of sedative or hypnotic use disorders up to 5 years (HR, 66.69; 95% CI, 34.72-128.09), although risks remained elevated up to 3 decades later for all substances. Compared with those without suicide attempt, female youths with 3 or more suicide attempts had 21.20 (95% CI, 13.53-32.90) times the risk of substance use disorders, whereas female youths with 1 attempt had 5.70 (95% CI, 5.08-6.41) times the risk of these disorders.

CONCLUSIONS AND RELEVANCE

In this cohort study, female youths who attempted suicide had increased risk of subsequent substance use disorders compared with female youths who did not attempt suicide. These findings suggest that closer management and prevention of substance use among female youths who attempt suicide may be beneficial.

Transcriptome Profiling of the Dorsomedial Prefrontal Cortex in Suicide Victims

The default mode network (DMN) plays an outstanding role in psychiatric disorders. Still, gene expressional changes in its major component, the dorsomedial prefrontal cortex (DMPFC), have not been characterized. We used RNA sequencing in postmortem DMPFC samples to investigate suicide victims compared to control subjects. 1400 genes differed using log2FC > ±1 and adjusted p-value < 0.05 criteria between groups. Genes associated with depressive disorder, schizophrenia and impaired cognition were strongly overexpressed in top differentially expressed genes. Protein−protein interaction and co-expressional networks coupled with gene set enrichment analysis revealed that pathways related to cytokine receptor signaling were enriched in downregulated, while glutamatergic synaptic signaling upregulated genes in suicidal individuals. A validated differentially expressed gene, which is known to be associated with mGluR5, was the N-terminal EF-hand calcium-binding protein 2 (NECAB2). In situ hybridization histochemistry and immunohistochemistry proved that NECAB2 is expressed in two different types of inhibitory neurons located in layers II-IV and VI, respectively. Our results imply extensive gene expressional alterations in the DMPFC related to suicidal behavior. Some of these genes may contribute to the altered mental state and behavior of suicide victims.

Graph theory analysis of whole brain functional connectivity to assess disturbances associated with suicide attempts in bipolar disorder

Brain targets to lower the high risk of suicide in Bipolar Disorder (BD) are needed. Neuroimaging studies employing analyses dependent on regional assumptions could miss hubs of dysfunction critical to the pathophysiology of suicide behaviors and their prevention. This study applied intrinsic connectivity distribution (ICD), a whole brain graph-theoretical approach, to identify hubs of functional connectivity (FC) disturbances associated with suicide attempts in BD. ICD, from functional magnetic resonance imaging data acquired while performing a task involving implicit emotion regulation processes important in BD and suicide behaviors, was compared across 40 adults with BD with prior suicide attempts (SAs), 49 with BD with no prior attempts (NSAs) and 51 healthy volunteers (HVs). Areas of significant group differences were used as seeds to identify regional FC differences and explore associations with suicide risk-related measures. ICD was significantly lower in SAs than in NSAs and HVs in bilateral ventromedial prefrontal cortex (vmPFC) and right anterior insula (RaIns). Seed connectivity revealed altered FC from vmPFC to bilateral anteromedial orbitofrontal cortex, left ventrolateral PFC (vlPFC) and cerebellum, and from RaIns to right vlPFC and temporopolar cortices. VmPFC and RaIns ICD were negatively associated with suicidal ideation severity, and vmPFC ICD with hopelessness and attempt lethality severity. The findings suggest that SAs with BD have vmPFC and RaIns hubs of dysfunction associated with altered FC to other ventral frontal, temporopolar and cerebellar cortices, and with suicidal ideation, hopelessness, and attempt lethality. These hubs may be targets for novel therapeutics to reduce suicide risk in BD.

Alterations of Plasma Lipids in Adult Women With Major Depressive Disorder and Bipolar Depression

Lipidomics has been established as a potential tool for the investigation of mental diseases. However, the composition analysis and the comparison of the peripheral lipids regarding adult women with major depressive depression (MDD) or bipolar depression (BPD) has been poorly addressed. In the present study, age-matched female individuals with MDD (n = 28), BPD (n = 22) and healthy controls (HC, n = 25) were enrolled. Clinical symptoms were assessed and the plasma samples were analyzed by comprehensive lipid profiling based on liquid chromatography-mass spectrometry (LC/MS). We found that the composition of lipids was remarkably changed in the patients with MDD and BPD when compared to HC or compared to each other. Moreover, we identified diagnostic potential biomarkers comprising 20 lipids that can distinguish MDD from HC (area under the curve, AUC = 0.897) and 8 lipids that can distinguish BPD from HC (AUC = 0.784), as well as 13 lipids were identified to distinguish MDD from BPD with moderate reliability (AUC = 0.860). This study provides further understanding of abnormal lipid metabolism in adult women with MDD and BPD and may develop lipid classifiers able to effectively discriminate MDD from BPD and HC.

Is it time to put rest to rest?

The so-called resting state, in which participants lie quietly with no particular inputs or outputs, represented a paradigm shift from conventional task-based studies in human neuroimaging. Our foray into rest was fruitful from both a scientific and methodological perspective, but at this point, how much more can we learn from rest on its own? While rest still dominates in many subfields, data from tasks have empirically demonstrated benefits, as well as the potential to provide insights about the mind in addition to the brain. I argue that we can accelerate progress in human neuroscience by de-emphasizing rest in favor of more grounded experiments, including promising integrated designs that respect the prominence of self-generated activity while offering enhanced control and interpretability.

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.

White matter integrity, suicidal ideation, and cognitive dysfunction in combat-exposed Iraq and Afghanistan Veterans

White matter alterations in frontolimbic circuits and poorer cognitive functioning have been observed in individuals endorsing suicidality across numerous psychiatric conditions. However, relationships between white matter integrity, cognition, and suicidality in Veterans are poorly understood, particularly for those at increased risk for suicide due to mental health conditions (e.g., posttraumatic stress disorder, depression) and traumatic brain injury history. We (1) examined white matter alterations in combat-exposed Iraq/Afghanistan Veterans with and without suicidal ideation (SI) and (2) investigated relationships between white matter integrity and neuropsychological functioning in regions that differed between SI groups. No group differences were found regarding psychiatric diagnoses. Participants with SI had lower fractional anisotropy (FA) in the posterior corona radiata, superior corona radiata, and superior longitudinal fasciculus relative to those without SI. Worse processing speed/attention performance was associated with lower FA in the superior longitudinal fasciculus, while worse executive functioning performance was associated with lower FA in the superior corona radiata and superior longitudinal fasciculus. Memory performance was not associated with FA. These findings suggest that white matter integrity may be involved in cognitive dysfunction and increased risk for SI. Interventions that target cognitive dysfunction may ameliorate SI, and in turn, reduce risk for suicide among Veterans.

The colors of our brain: an integrated approach for dimensionality reduction and explainability in fMRI through color coding (i-ECO)

Several systematic reviews have highlighted the role of multiple sources in the investigation of psychiatric illness. For what concerns fMRI, the focus of recent literature preferentially lies on three lines of research, namely: functional connectivity, network analysis and spectral analysis. Data was gathered from the UCLA Consortium for Neuropsychiatric Phenomics. The sample was composed by 130 neurotypicals, 50 participants diagnosed with Schizophrenia, 49 with Bipolar disorder and 43 with ADHD. Single fMRI scans were reduced in their dimensionality by a novel method (i-ECO) averaging results per Region of Interest and through an additive color method (RGB): local connectivity values (Regional Homogeneity), network centrality measures (Eigenvector Centrality), spectral dimensions (fractional Amplitude of Low-Frequency Fluctuations). Average images per diagnostic group were plotted and described. The discriminative power of this novel method for visualizing and analyzing fMRI results in an integrative manner was explored through the usage of convolutional neural networks. The new methodology of i-ECO showed between-groups differences that could be easily appreciated by the human eye. The precision-recall Area Under the Curve (PR-AUC) of our models was > 84.5% for each diagnostic group as evaluated on the test-set – 80/20 split. In conclusion, this study provides evidence for an integrative and easy-to-understand approach in the analysis and visualization of fMRI results. A high discriminative power for psychiatric conditions was reached. This proof-of-work study may serve to investigate further developments over more extensive datasets covering a wider range of psychiatric diagnoses.

Abnormal within- and cross-networks functional connectivity in different outcomes of herpes zoster patients

Neuroimaging studies have displayed aberrant brain activities in individual sensory- and emotional-linked regions in postherpetic neuralgia (PHN) patients. However, multi-dimensional dysfunction in chronic pain may rely on the interplay between networks. Little is known about the changes in the functional architecture of resting state networks (RSNs) in PHN. In this cross-sectional study, we recruited 31 PHN patients, 33 RHZ patients and 34 HCs; all participants underwent resting-state functional magnetic resonance imaging scans. We investigated the differences of within- and cross-network connectivities between different outcomes of HZ patients [including PHN and recuperation from herpes zoster (RHZ)] and healthy controls (HCs) so as to extract a characteristic network pattern of PHN. The abnormal network connectivities were then correlated with clinical variables in respective groups. PHN and RHZ patients could be similarly characterized by abnormal within-default mode network (DMN), DMN-salience network (SN) and SN-basal ganglia network (BGN) connectivity relative to HCs. Of note, compared with RHZ patients, PHN patients could be characterized by abnormal DMN-BGN and within-BGN connectivity. Furthermore, the within-DMN connectivity was associated with pain-induced emotional scores among PHN patients. Our study presented that network-level imbalance could account for the pain-related dysfunctions in different outcomes of herpes zoster patients. These insights are potentially useful for understanding neuromechanism of PHN and providing central therapeutic targets for PHN.

Dissociating default mode network resting state markers of suicide from familial risk factors for depression

Neural signatures of suicide risk likely reflect a combination of specific and non-specific factors, and clarifying specific factors may facilitate development of novel treatments. Previously, we demonstrated an altered pattern of resting state connectivity between the dorsal and ventral posterior cingulate cortex (d/vPCC) and the dorsal anterior cingulate cortex (dACC), as well as altered low frequency oscillations in these regions, in individuals with a history of suicidal thoughts and behaviors (STBs) compared to healthy controls. It remains uncertain, however, whether these markers were directly related to STBs or, more generally, reflect a trait-level risk factor for depression. Here, we examined data from a 3-generational longitudinal study of depression where resting state fMRI data were analyzed from 2nd and 3rd generation offspring of probands with (FH+ = 44: STB+ = 32, STB- = 12) and without (FH- = 25: STB+ = 15, STB- = 10) a family history of major depressive disorder (MDD). Standard seed-based methods and a frequency-based analysis of intrinsic neural activity (ALFF/fALFF) were employed. FH of MDD, but not a personal history of STBs or MDD, was associated with relatively reduced dPCC-dACC, and enhanced vPCC-dACC functional connectivity. FH of MDD showed a pattern of reduced ALFF in the dPCC whereas an STB history was associated with an increase. All findings were invariant to confounding by lifetime MDD and current depression severity. Overall, contrary to predictions, resting state functional connectivity within the default mode network (DMN) was associated with FH of depression rather than STBs. These findings confirm the relevance of DMN functional connectivity for mood disorders and underscore the importance of disambiguating biological factors that differentially relate to mental disorders versus STBs.

Alterations in resting-state global brain connectivity in bipolar I disorder patients with prior suicide attempt

BACKGROUND

Bipolar I disorder (BD-I) is associated with a high risk of suicide attempt; however, the neural circuit dysfunction that confers suicidal vulnerability in individuals with this disorder remains largely unknown. Resting-state functional magnetic resonance imaging (rs-fMRI) allows non-invasive mapping of brain functional connectivity. The current study used an unbiased voxel-based graph theory analysis of rs-fMRI to investigate the intrinsic brain networks of BD-I patients with and without suicide attempt.

METHODS

A total of 30 BD-I patients with suicide attempt (attempter group), 82 patients without suicide attempt (non-attempter group), and 67 healthy controls underwent rs-fMRI scan, and then global brain connectivity (GBC) was computed as the sum of connections of each voxel with all other gray matter voxels in the brain.

RESULTS

Compared with the non-attempter group, we found regional differences in GBC values in emotion-encoding circuits, including the left superior temporal gyrus, bilateral insula/rolandic operculum, and right precuneus (PCu)/cuneus in the bipolar disorder (BD) attempter group, and these disrupted hub-like regions displayed fair to good power in distinguishing attempters from non-attempters among BD-I patients. GBC values of the right PCu/cuneus were positively correlated with illness duration and education in the attempter group.

CONCLUSIONS

Our results indicate that abnormal connectivity patterns in emotion-encoding circuits are associated with the increasing risk of vulnerability to suicide attempt in BD patients, and global dysconnectivity across these emotion-encoding circuits might serve as potential biomarkers for classification of suicide attempt in BD patients.

Disrupted rich-club network organization and individualized identification of patients with major depressive disorder

BACKGROUND

Altered structural and functional brain networks have been extensively studied in major depressive disorder (MDD) patients. However, whether the differential connectivity patterns in the rich-club organization, assessed from structural brain network analyses, and the associated connections of these regions are particularly susceptible to depression remain unclear.

METHODS

We acquired resting-state functional magnetic resonance imaging (R-fMRI) and diffusion tensor imaging (DTI) from 31 unmedicated MDD patients and 32 cognitively normal (CN) subjects and completed a series of neuropsychological tests. Rich-club organization, network properties, and coupling between structural and functional connectivity (SC-FC) were explored. Furthermore, whether these indices could potentially deliver effective clinical predictive value for MDD patients were examined.

RESULTS

The MDD patients showed disrupted structural rich-club organization and modularity, as well as a distinct correlation pattern between global efficiency and rich-club organization. Importantly, reduced SC-FC coupling, reflecting a decreased agreement in the integrity of the networks, was significantly associated with the strength of structural rich-club connections in the MDD patients. Furthermore, the disrupted structural rich-club organization, which was primarily located in the default mode network (DMN) and executive control network (ECN), emerged as a valuable indicator to distinguish between MDD and CN.

CONCLUSIONS

Findings of this study identified that the disrupted rich-club structural organization significantly influenced brain structural network modularity and integrity and could serve as a promising biological marker for the identification of MDD patients.

Higher Negative Self-Reference Level in Patients With Personality Disorders and Suicide Attempt(s) History During Biological Treatment for Major Depressive Disorder: Clinical Implications

Objective: The aim of the study was to identify clinical variables associated with changes in specific domains of self-reported depression during treatment by antidepressant and/or repetitive Transcranial Magnetic Stimulation (rTMS) in patients with Major Depressive Disorder (MDD).

Methods: Data from a trial involving 170 patients with MDD receiving either venlafaxine, rTMS or both were re-analyzed. Depressive symptoms were assessed each week during the 2 to 6 weeks of treatment with the 13-item Beck Depression Inventory (BDI₁₃). Associations between depression changes on BDI₁₃ domains (Negative Self-Reference, Sad Mood, and Performance Impairment), treatment arm, time, and clinical variables were tested in a mixed linear model.

Results: A significant decrease of self-reported depressive symptoms was observed over time. The main characteristics associated with persistent higher depressive symptomatology on Negative Self-Reference domain of the BDI₁₃ were personality disorders (+2.1 points), a past history of suicide attempt(s) (+1.7 points), age under 65 years old (+1.5 points), and female sex (+1.1 points).

Conclusions: Early cognitive intervention targeting specifically negative self-referencing process could be considered during pharmacological or rTMS treatment for patients with personality disorders and past history of suicide attempt(s).

Comparisons between suicide in persons with serious mental illness, other mental disorders, or no known mental illness: Results from 37 U.S. states, 2003-2017

BACKGROUND

Suicide is a leading cause of death in persons with schizophrenia and other serious mental illnesses (SMI), however, little is known about the characteristics and circumstances of suicide decedents with SMI in the US compared to those with other or no known mental illness.

METHODS

This study was a retrospective analysis of suicide deaths in individuals aged ≥18 years from the National Violent Death Reporting System, 2003-2017. Odds ratios compared sociodemographic and clinical characteristics, cause of death, precipitating circumstances, and post-mortem toxicology results. All analyses were stratified by gender.

RESULTS

Of the 174,001 suicide decedents, 8.7% had a known SMI, 33.0% had other mental disorders, and 58.2% had no known mental illness. Relative to persons with other mental disorders, SMI decedents were younger and more likely to have previous suicide attempts and co-occurring drug use. Problems with intimate partners, poor physical health, and recent institutional release were the most common precipitating circumstances for SMI decedents. Firearms were the most common suicide method for males with SMI. Although 67.0% male and 76.0% of female SMI decedents were currently in treatment, toxicology results suggest many were not taking antipsychotic or antidepressant medications at the time of death.

CONCLUSIONS

Persons with SMI are over-represented in suicide deaths. Efforts to improve treatment of co-occurring substance use disorders, continuity of care following hospitalization, medication adherence, and to reduce access to firearms are important suicide prevention strategies.

New Methods for Assessing Rapid Changes in Suicide Risk

Rapid-acting interventions for the suicide crisis have the potential to transform treatment. In addition, recent innovations in suicide research methods may similarly expand our understanding of the psychological and neurobiological correlates of suicidal thoughts and behaviors. This review discusses the limitations and challenges associated with current methods of suicide risk assessment and presents new techniques currently being developed to measure rapid changes in suicidal thoughts and behavior. These novel assessment strategies include ecological momentary assessment, digital phenotyping, cognitive and implicit bias metrics, and neuroimaging paradigms and analysis methodologies to identify neural circuits associated with suicide risk. This review is intended to both describe the current state of our ability to assess rapid changes in suicide risk as well as to explore future directions for clinical, neurobiological, and computational markers research in suicide-focused clinical trials.

Clinical Response of Major Depressive Disorder Patients With Suicidal Ideation to Individual Target-Transcranial Magnetic Stimulation

Suicidal ideation increases precipitously in patients with depression, contributing to the risk of suicidal attempts. Despite the recent advancement in transcranial magnetic stimulation, its effectiveness in depression disorder and its wide acceptance, the network mechanisms of the clinical response to suicidal ideation in major depressive disorder remain unclear. Independent component analysis for neuroimaging data allows the identification of functional network connectivity which may help to explore the neural basis of suicidal ideation in major depressive disorder. Resting-state functional magnetic resonance imaging data and clinical scales were collected from 30 participants (15 major depressive patients with suicidal ideation and 15 healthy subjects). Individual target-transcranial magnetic stimulation (IT-TMS) was then used to decrease the subgenual anterior cingulate cortex activity through the left dorsolateral prefrontal cortex. Thirty days post IT-TMS therapy, seven of 15 patients (46.67%) met suicidal remission criteria, and 12 patients (80.00%) met depression remission criteria. We found that IT-TMS could restore the abnormal functional network connectivity between default mode network and precuneus network, left executive control network and sensory-motor network. Furthermore, the changes in functional network connectivity between the default mode network and precuneus network were associated with suicidal ideation, and depressive symptoms were related to connectivity between left executive control network and sensory-motor network. These findings illustrate that IT-TMS is an effective protocol for the accurate restoration of impaired brain networks, which is consistent with clinical symptoms.

Altered Functional Connectivity Differences in Salience Network as a Neuromarker of Suicide Risk in Euthymic Bipolar Disorder Patients

Objective

The occurrence of death by suicide in patients diagnosed with bipolar disorder is as much as 60 times greater than in the general population. Even during the state of euthymia patients are characterized by suicide risk. The aim of the study is to investigate the baseline brain activity in euthymic bipolar disorder patients in regard to suicide risk. We hypothesized that patients compared to healthy control group will demonstrate altered functional connectivity among resting state networks which will be directly related to current suicide risk.

Method

41 subjects were enrolled in the study consisting control group (n = 21) and euthymic bipolar disorder patients group (n = 20). Functional magnetic resonance imaging was used to evaluate resting state brain activity and ROI-ROI functional connectivity analysis was performed. Suicidal risk was estimated using The Suicide Behaviors Questionnaire-Revised.

Results

A two sample t-test revealed decreased functional connectivity between regions involved in the salience network in patients compared to the control group. This decrease was negatively correlated with current suicide risk.

Conclusion

Obtained results suggest the association between risk of suicide and activity of regions responsible for functions such as learning from mistakes, prospective thinking, and sensory integration.

Common and distinct patterns of intrinsic brain activity alterations in major depression and bipolar disorder: voxel-based meta-analysis

Identification of intrinsic brain activity differences and similarities between major depression (MDD) and bipolar disorder (BD) is necessary. However, results have not yet yielded consistent conclusions. A meta-analysis of whole-brain resting-state functional MRI (rs-fMRI) studies that explored differences in the amplitude of low-frequency fluctuation (ALFF) between patients (including MDD and BD) and healthy controls (HCs) was conducted using seed-based d mapping software. Systematic literature search identified 50 studies comparing 1399 MDD patients and 1332 HCs, and 15 studies comparing 494 BD patients and 593 HCs. MDD patients displayed increased ALFF in the right superior frontal gyrus (SFG) (including the medial orbitofrontal cortex, medial prefrontal cortex [mPFC], anterior cingulate cortex [ACC]), bilateral insula extending into the striatum and left supramarginal gyrus and decreased ALFF in the bilateral cerebellum, bilateral precuneus, and left occipital cortex compared with HCs. BD showed increased ALFF in the bilateral inferior frontal gyrus, bilateral insula extending into the striatum, right SFG, and right superior temporal gyrus (STG) and decreased ALFF in the bilateral precuneus, left cerebellum (extending to the occipital cortex), left ACC, and left STG. In addition, MDD displayed increased ALFF in the left lingual gyrus, left ACC, bilateral precuneus/posterior cingulate gyrus, and left STG and decreased ALFF in the right insula, right mPFC, right fusiform gyrus, and bilateral striatum relative to BD patients. Conjunction analysis showed increased ALFF in the bilateral insula, mPFC, and decreased ALFF in the left cerebellum in both disorders. Our comprehensive meta-analysis suggests that MDD and BD show a common pattern of aberrant regional intrinsic brain activity which predominantly includes the insula, mPFC, and cerebellum, while the limbic system and occipital cortex may be associated with spatially distinct patterns of brain function, which provide useful insights for understanding the underlying pathophysiology of brain dysfunction in affective disorders, and developing more targeted and efficacious treatment and intervention strategies.

Disrupted default mode network dynamics in recuperative patients of herpes zoster pain

Introduction

Previous studies of herpes zoster (HZ) have focused on acute patient manifestations and the most common sequela, postherpetic neuralgia (PHN), both serving to disrupt brain dynamics. Although the majority of such patients gradually recover, without lingering severe pain, little is known about life situations of those who recuperate or the brain dynamics. Our goal was to determine whether default mode network (DMN) dynamics of the recuperative population normalize to the level of healthy individuals.

Methods

For this purpose, we conducted resting‐state functional magnetic resonance imaging (fMRI) studies in 30 patients recuperating from HZ (RHZ group) and 30 healthy controls (HC group). Independent component analysis (ICA) was initially undertaken in both groups to extract DMN components. DMN spatial maps and within‐DMN functional connectivity were then compared by group and then correlated with clinical variables.

Results

Relative to controls, DMN spatial maps of recuperating patients showed higher connectivity in middle frontal gyrus (MFG), right/left medial temporal regions of cortex (RMTC/LMTC), right parietal lobe, and parahippocampal gyrus. The RHZ (vs HC) group also demonstrated significant augmentation of within‐DMN connectivity, including that of LMTC‐MFG and LMTC‐posterior cingulate cortex (PCC). Furthermore, the intensity of LMTC‐MFG connectivity correlated significantly with scoring of pain‐induced emotions and life quality.

Conclusion

Findings of this preliminary study indicate that a disrupted dissociative pattern of DMN persists in patients recuperating from HZ, relative to healthy controls. We have thus provisionally established the brain mechanisms accounting for major outcomes of HZ, offering heuristic cues for future research on HZ transition states.

Decreased Relative Cerebral Blood Flow in Unmedicated Heroin-Dependent Individuals

Understanding the brain mechanisms of heroin dependence is invaluable for developing effective treatment. Measurement of regional cerebral blood flow (CBF) provides a method to visualize brain circuits that are functionally impaired by heroin dependence. This study examined regional CBF alterations and their clinical associations in unmedicated heroin-dependent individuals (HDIs) using a relatively large sample. Sixty-eight (42 males, 26 females; age: 40.9 ± 7.3 years) HDIs and forty-seven (34 males, 13 females; age: 39.3 ± 9.2 years) matched healthy controls (HCs) underwent high-resolution T1 and whole-brain arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) scans. Additionally, clinical characteristics were collected for neurocognitive assessments. HDIs showed worse neuropsychological performance than HCs and had decreased relative CBF (rCBF) in the bilateral middle frontal gyrus (MFG), inferior temporal gyrus, precuneus, posterior cerebellar lobe, cerebellar vermis, and the midbrain adjacent to the ventral tegmental area; right posterior cingulate gyrus, thalamus, and calcarine. rCBF in the bilateral MFG was negatively correlated with Trail Making Test time in HDIs. HDIs had limbic, frontal, and parietal hypoperfusion areas. Low CBF in the MFG indicated cognitive impairment in HDIs. Together, these findings suggest the MFG as a critical region in HDIs and suggest ASL-derived CBF as a potential marker for use in heroin addiction studies.

Symptom trajectories in the months before and after a suicide attempt in individuals with bipolar disorder: A STEP-BD study

OBJECTIVES

The suicide crisis is a relatively short-lived psychiatric emergency, with transient symptoms that ebb and flow around the suicide attempt. Understanding the dynamic processes of symptoms before and after suicide attempt may aid future prevention efforts.

METHODS

Data were drawn from the NIMH STEP-BD study, which followed 4,360 patients with bipolar disorder; a subset attempted suicide during the trial (245/4100 or 5.97% of the sample eligible for analysis). This analysis focused on change in suicidal ideation (SI) in the 120 days before and 120 days after suicide attempt; similar analyses were conducted for other depressive symptoms. Generalized linear mixed models with a two-piece linear function of time corresponding to pre- and post-suicide attempt trends were used.

RESULTS

SI ratings from 216 individuals were analyzed (n = 1,231 total; n = 395 pre-attempt, n = 126 circa-attempt, n = 710 post-attempt) and compared to data from a matched sample of 648 non-attempters. SI worsened in the 120 days pre-attempt but improved afterwards, reaching non-attempter levels by 90 days post-attempt. A similar pattern was found for other depressive symptoms, including depressed mood, loss of interest, guilt, and self-esteem. Pre/post differences in tension/activating symptoms of depression-anxiety, agitation, and irritability-were less pronounced and more time-limited.

CONCLUSIONS

The suicide crisis is dynamic, and the days before and after suicide attempt may be particularly critical. The findings extend previous research on proximal symptoms of suicide and underscore that some SI and affective/cognitive symptoms of depression can remain elevated up to 90 days post-attempt in individuals with bipolar disorder.