Cognitive inhibition in depression and suicidal behavior: a neuroimaging study

TAAR1 in dentate gyrus is involved in chronic stress-induced impairments in hippocampal plasticity and cognitive function

Multiple lines of evidence suggest that the trace amine-associated receptor 1 (TAAR1) holds promise as a potential target for stress-related disorders, such as treating major depressive disorder (MDD). The role of TAAR1 in the regulation of adult neurogenesis is recently supported by transcriptomic data. However, it remains unknown whether TAAR1 in dentate gyrus (DG) mediate chronic stress-induced negative effects on hippocampal plasticity and related behavior in mice. The present study consisted of a series of experiments using RNAscope, genetic approaches, behavioral tests, immunohistochemical staining, Golgi-Cox technique to unravel the effects of TAAR1 on alterations of dentate neuronal plasticity and cognitive function in the chronic social defeat stress model. The mice subjected to chronic defeat stress exhibited a noteworthy decrease in the mRNA level of TAAR1 in DG. Additionally, they exhibited compromised social memory and spatial object recognition memory, as well as impaired proliferation and maturation of adult-born dentate granule cells. Moreover, the selective knockout TAAR1 in DG mostly mimicked the cognitive function deficits and neurogenesis impairment induced by chronic stress. Importantly, the administration of the selective TAAR1 partial agonist RO5263397 during stress exposure attenuated the adverse effects of chronic stress on cognitive function, adult neurogenesis, dendritic arborization, and the synapse number of dentate neurons in DG. In summary, our findings suggest that TAAR1 plays a crucial role in mediating the detrimental effects of chronic stress on hippocampal plasticity and cognition. TAAR1 agonists exhibit therapeutic potential for individuals suffering from cognitive impairments associated with MDD.

Risky decision-making in major depressive disorder: A three-level meta-analysis

Background

Individuals with major depressive disorder (MDD) are usually observed making inappropriate risky decisions. However, whether and to what extent MDD is associated with impairments in risky decision-making remains unclear. We performed a three-level meta-analysis to explore the relationship between risky decision-making and MDD.

Method

We searched the Web of Science, PubMed, Scopus, and PsycINFO databases up to February 7, 2023, and calculated Hedges' g to demonstrate the difference in risky decision-making between MDD patients and healthy controls (HCs). The moderating effect of sample and task characteristics were also revealed.

Results

Across 73 effect sizes in 39 cross-sectional studies, MDD patients exhibited greater risk-seeking than HCs (Hedges' g = 0.187, p = .030). Furthermore, age (p = .068), region (p = .005), and task type (p < .001) were found to have moderating effects. Specifically, patients preferred risk-seeking over HCs as age increased. European patients showed significantly increased risk-seeking compared to American and Asian patients. Patients in the Iowa Gambling Task (IGT) exhibited a notable rise in risk-seeking compared to other tasks, along with an increased risk aversion in the Balloon Analogue Risk Task (BART). The multiple-moderator analysis showed that only task type had significant effects, which may be explained by a tentative framework of "operationalization-mechanism-measure" specificity.

Conclusions

MDD patients generally exhibit higher risk-seeking than HCs. It implies that impaired risky decision-making might be a noteworthy symptom of depression, which should be placed more emphasis for clinical management and psycho-education.

Deficits in specific executive functions manifest by severity in major depressive disorder: a comparison of antidepressant naïve inpatient, outpatient, subclinical, and healthy control groups

Introduction

Previous research has highlighted the executive function (EF) deficits present in depressed patients; however, conflicting results exist regarding the impact of depression severity on the size of these deficits. This study aimed to compare deficits in EF between antidepressant naïve inpatient and outpatient depressed, a group with subclinical depression symptoms, and a healthy control group while controlling for education, sex, and age.

Methods

In cross-sectional research, 245 antidepressant naive participants (46 inpatient, 68 outpatient, 65 subclinical, and 67 healthy control individuals) were recruited by convenience sampling. The Structured Clinical Interview for DSM-5 Disorders (SCID-5) and Beck Depression Inventory-II (BDI-II) were used to assess depression. EF was measured using several neuropsychological tests, including the Stroop Color-Word Test, the Wisconsin Card Sorting Test, and the N-back Test, which assessed the components of Inhibition, Shifting, and Updating, respectively. Multivariate analysis of covariance revealed a significant difference between the groups in EF components (p < 0.001). Pairwise comparisons further showed that inpatient and outpatient patients had more depressive symptoms and worse EF performance than subclinical and healthy control groups (p < 0.05).

Results

In the analysis of EF measures, a significant difference was found among the four groups, with post-hoc tests revealing variations in specific EF components. Overall, patients with more severe depressive symptoms show more deficits in EF. Additionally, correlations between clinical characteristics and EF measures varied across patient groups, but many correlations became non-significant after adjusting for the false discovery rate (FDR).

Discussion

This study emphasizes the impact of depression severity on deficits in the EF of depressed patients and at-risk populations. Consequently, it is important to consider executive dysfunctions as an underlying vulnerability in the development and persistence of depressive disorder.

Toward objective characterizations of suicide risk: A narrative review of laboratory-based cognitive and behavioral tasks

Although suicide is a leading cause of preventable death worldwide, current prevention efforts have failed to substantively mitigate suicide risk. Suicide research has traditionally relied on subjective reports that may not accurately differentiate those at high versus minimal risk. This narrative review supports the inclusion of objective task-based measures in suicide research to complement existing subjective batteries. The article: 1) outlines risk factors proposed by contemporary theories of suicide and highlights recent empirical findings supporting these theories; 2) discusses ongoing challenges associated with current risk assessment tools and their ability to accurately evaluate risk factors; and 3) analyzes objective laboratory measures that can be implemented alongside traditional measures to enhance the precision of risk assessment. To illustrate the potential of these methods to improve our understanding of suicide risk, the article reviews how acute stress responses in a laboratory setting can be modeled, given that stress is a major precipitant for suicidal behavior. More precise risk assessment strategies can emerge if objective measures are implemented in conjunction with traditional subjective measures.

Emotional Modulation of Response Inhibition in Adolescents During Acute Suicidal Crisis: Event-Related Potentials in an Emotional Go/NoGo Task

Objectives. Suicide is the second leading cause of adolescent deaths and may be linked to difficulties with inhibitory and emotional processing. This study assessed the neural correlates of cognitive inhibition during emotional processing in adolescents hospitalized for a suicidal crisis. Methods. Event-related potentials were recorded during an emotional Go/NoGo task in 12 adolescents who attempted suicide and 12 age- and sex-matched healthy controls. Results. Compared to the control group, the suicidal group showed significantly reduced positivity at the time of the P3d (difference waveform reflecting NoGo minus Go trials) in response to happy and neutral, but not sad stimuli. For happy stimuli, this group difference was restricted to the right hemisphere. Further analyses indicated that the suicidal group had a reversed pattern of P3 amplitude in response to inhibition, with lower amplitudes in the NoGo compared to the Go conditions. Suicidal symptoms severity strongly correlated with lower amplitude of the P3d in response to neutral faces. Conclusions. These findings provide more insight into inhibition difficulties in adolescents with acute suicidal risk. Interactions between emotional and inhibition processing should be considered when treating acutely suicidal youths.

Safety intervention for improving functioning in suicidal attempters (STRONG): A secondary prevention study. Study rationale and research protocol

BACKGROUND

Suicide is one of the most largely preventable causes of death worldwide. The aim of the STRONG study is to assess the effectiveness of a specific intervention (an extended Safety Planning Intervention) called iFightDepression-SURVIVE (iFD-S) in suicidal attempters by changes in psychosocial functioning. As secondary outcomes, quality of life, cognitive performance, clinical state and neuroimaging correlates will be considered.

OBJECTIVE

To describe the rationale and design of the STRONG study, an extension of the SURVIVE study, a national multicenter cohort about on prevention in suicidal attempters.

METHODS

The STRONG study is a two-year clinical trial. A total sample of 60 patients will be randomly allocated to two arms: a group will receive a iFD-S and treatment as usual (TAU) (n=30 treatment group), while another group will exclusively receive TAU (n=30 control group). There will be three study points: baseline; 3-month; and 6-month follow-up assessments, all of which will include rater-blinded evaluation of psychosocial functioning, quality of life, clinical state, cognitive performance and neuroimaging acquisition.

RESULTS

It is expected to obtain data on the efficacy of iFD-S in patients who have committed a suicide attempt.

CONCLUSION

Results will provide insight into the effectiveness of IFD-S in suicidal attempters with respect to improvements in psychosocial functioning, quality of life, cognition, and neuroimaging correlates.

CLINICAL TRIALS ID

NCT05655390.

The amygdala connectivity with depression and suicide ideation with suicide behavior: A meta-analysis of structural MRI, resting-state fMRI and task fMRI

In recent decades, the primary intention of neuroscientists and psychiatrics is to evaluate the connectivity between brain regions and psychiatric disorders. The amygdala has central immersion in memory alliance, stress response, emotional perception, and automatic responses to emotional stimuli. This paper uses a meta-analysis approach to establish the relationship between structural resting state and functional amygdala connectivity with depression and suicide ideation with suicide behavior. In addition, this study explores the moderating effect of patients' demographic characteristics (gender and age) based on 30 studies. The results show that structural amygdala connectivity is positively related to the instability of depression, while for resting and task functional connectivity amygdala shows a significant negative connection with depression. Furthermore, the amygdala showed a partial activation for non-suicide self-injuries and suicide ideation. From structural and functional magnetic imaging, the current findings also support the moderating effect of the age of the participants on the amygdala connectivity with psychiatric conditions. Generally, amygdala connectivity with psychiatric disorders was not significantly moderate with the role of gender, however, this study enhances the existing hypothetical review articles and confirms the connectivity of the psychological condition with the amygdala region. It concludes that the amygdala plays a vital role in regulating and responding to emotions.

Structural and functional brain correlates of suicidal ideation and behaviors in depression: A scoping review of MRI studies

Identifying and integrating the neural correlates of suicidal ideation and behaviors is crucial to expand the knowledge and develop targeted strategies to prevent suicide. This review aimed to describe the neural correlates of suicidal ideation, behavior and the transition between them, using different magnetic resonance imaging (MRI) modalities, providing an up-to-date overview of the literature. To be included, the observational, experimental, or quasi-experimental studies must include adult patients currently diagnosed with major depressive disorder and investigate the neural correlates of suicidal ideation, behavior and/or the transition using MRI. The searches were conducted on PubMed, ISI Web of Knowledge and Scopus. Fifty articles were included in this review: 22 on suicidal ideation, 26 on suicide behaviors and two on the transition between them. The qualitative analysis of the included studies suggested alterations in the frontal, limbic and temporal lobes in suicidal ideation associated with deficits in emotional processing and regulation, and in the frontal, limbic, parietal lobes, and basal ganglia in suicide behaviors associated with impairments in decision-making. Gaps in the literature and methodological concerns were identified and might be addressed in future studies.

Impulsivity in Depression: Its Relation to Suicidality

OBJECTIVE

Impulsivity is an important risk for suicidality, which is common in patients with major depressive disorder (MDD). The goal of this study was to examine multiple facets of impulsivity in depressed patients compared with healthy controls and to assess their relationship to suicidality.

METHOD

Outpatients diagnosed with MDD using the Structured Clinical Interview for DSM-IV were recruited. Two groups were constituted as "MDD in remission" (n=32) and "MDD" (n=71). The "healthy control" group (n=30) consisted of individuals who had never been diagnosed with any psychiatric disorder. Impulsivity was assessed with the Barratt Impulsivity Scale (BIS), a self-rating measure, and with the following behavioral tasks: Go/No-go Task, Iowa Gambling Task, and Balloon Analogue Risk Task. The scores of the 3 groups (n=133) were compared to evaluate the effect of MDD. The scores were also analyzed and compared in the patients in the 2 MDD groups (n=103) with respect to their current and lifetime suicidality.

RESULTS

There was no difference in the 3 groups in task scores, but nonplanning BIS was correlated with the severity of depressive symptoms. Patients with suicidal ideation (SI) had higher BIS total and attention impulsivity scores and more commission errors on the Go/No-go Task, reflecting failure in response inhibition, compared with the patients without SI.

CONCLUSIONS

Failure to show differences in impulsivity-related tasks suggests that there might be no relationship between the state of depression and impulsivity. However, these findings confirm that there is an association between SI and response inhibition and the attention facet of impulsivity in depression.

Probing the Association between Cognition, Suicidal Behavior and Tryptophan Metabolism in a Sample of Individuals Living with Bipolar Disorder: A Secondary Analysis

Background and Objectives: Alterations in hot cognition and in the tryptophan metabolism through serotonin (5-HT) and kynurenine (KYN) pathways have been associated with an increased risk of suicidal behavior. Here, we aim at probing the association between Stroop test performances and tryptophan pathway components in a sample of individuals with bipolar disorder (BD). Materials and Methods: We explored the association between the Emotion Inhibition Subtask (EIS) performances of the Brief Assessment of Cognition for Affective Disorders (BAC-A) and plasmatic levels of 5-hydroxytriptophan (5-HTP), 5-HT, KYN, 3-hydroxykynurenine (3-HK), quinolinic acid (QA), and kynurenic acid (KYNA) among subjects reporting lifetime suicide ideation (LSI) vs. non-LSI and subjects reporting lifetime suicide attempts (LSA) vs. non-LSA. Results: In a sample of 45 subjects with BD, we found a statistically significant different performance for LSA vs. non-LSA in the color naming (CN) and neutral words (NW) EIS subtasks. There was a significant association between CN performances and plasma 5-HTP levels among LSI and LSA subjects but not among non-LSI or non-LSA. Conclusions: In our sample, patients with LSA and LSI presented lower performances on some EIS subtasks compared to non-LSA and non-LSI. Moreover, we found an inverse correlation between plasma 5-HTP concentration and some EIS performances in LSA and LSI but not among non-LSA or non-LSI. This may represent an interesting avenue for future studies probing this complex association.

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.

Sex differences in the association of plasma cytokines and neurocognition in first-episode major depressive disorder

BACKGROUND

Peripheral cytokines were found to be involved in the pathophysiology of neurocognition in individuals with major depressive disorder (MDD). However, whether there are sex differences in this association between cytokines and cognition in MDD remains unknown. Our aim is to examine sex differences in the relationship between plasma cytokines and cognition in MDD.

METHOD

One hundred and twenty-seven first episode drug naïve patients with MDD and sixty healthy controls (HCs) were recruited for present study. The MATRICS Consensus Cognitive Battery was administered to measure the cognition. Plasma concentrations of nineteen cytokines were measured using high sensitivity multiplex bead-based assays.

RESULTS

Both female and male patients with MDD had significant cognitive impairment in verbal learning and visual learning and had higher levels of a range of cytokines than HCs (all p < 0.05). Female patients performed worse in trail making (F = 4.442, p = 0.018) and had higher concentration of interleukin (IL)-4 (F = 7.775, p = 0.006) than males. In female MDD, a significant positive association between category frequency and level of IL-4 was observed (B = 8.040, p = 0.031). However, this association was not present in male MDD or HCs (p > 0.05).

LIMITATION

Present study used a cross-sectional design.

CONCLUSION

Female MDD patients had worse trail making performance and higher level of IL-4 than males. The elevated IL-4 in female MDD was positively associated with category fluency, suggesting that IL-4 may be involved in the pathophysiology related to specific cognitive domain in female MDD patients.

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.

A Systematic Review of Behavior-Outcome Psychological Assessments as Correlates of Suicidality

AIM

Identifying correlates of suicidality is an important goal for suicide researchers because these correlates may predict suicidal behaviors. Psychological tasks that assess sensitivity to the outcomes of actions (i.e., consequence-based learning) have been commonly used by researchers seeking to identify correlates of suicidality. This is likely due to the straightforward integration of the tasks within most theoretical frameworks for understanding suicidality. Contextual factors have been shown to have a substantial effect on responding in behavior-outcome tasks. However, the direct relevance of these factors as determinants of behavior in suicide research is not clear. Thus, the purpose of this review was to assess the role of context in tasks involving behavior-outcome relations in suicide research.

METHODS

Four databases were searched using terms from general learning theory. Articles that featured evaluation of tasks with hypothetical or real outcomes to differentiate suicidality were included.

RESULTS

Eighty-two studies met inclusion criteria. Across studies there were 27 different tasks. Most instances of tasks across studies involved rewards (76.9%), while others emphasized punishment (15.7%), social (5.6%), or virtual suicide (1.8%) outcomes. Differentiation of suicidality was detected by 43.4%, 64.7%, 83.3%, and 50% of tasks featuring reward, punishment, social contexts, and virtual suicide respectively. All but five studies were retrospective.

CONCLUSION

Tasks that more closely mimic contexts and outcomes related to suicide appear to produce more pronounced differentiation of people with suicidality from people without suicidality. The lack of prospective designs is an important limitation of the literature.HIGHLIGHTSTasks that involve punishment or social outcomes better discriminate suicidality.Reward-based tasks are overused in suicide research.The conditioning hypothesis of suicidality is closely aligned with the literature.Only 5 of 82 studies incorporated prospective measures.

The association between overweight/obesity and poor cognitive function is mediated by inflammation in patients with major depressive disorder

BACKGROUND

Cognitive dysfunction is a common and core feature of major depressive disorder (MDD). Evidences exerted a potentially harmful role of obesity and higher peripheral levels of inflammation in cognitive function, but few studies have explored whether markers of peripheral inflammation might mediate the association between overweight/obesity and deficits in cognitive function. Our study aimed to examine the cognitive function in MDD patients and clarify the effects of overweight/obesity and inflammatory cytokines on cognitive dysfunction in this population.

METHOD

We used a cross-sectional design in this study. A total of 265 patients with MDD were enrolled and divided into underweight, normal weight and overweight/obese groups. The MATRICS Consensus Cognitive Battery (MCCB) was administered to measure the cognition. Plasma levels of nineteen cytokines were measured using high sensitivity multiplex bead-based assays.

RESULTS

We found overweight/obese MDD patients associated with higher plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-8, and macrophage inflammatory protein (MIP)-1β and worse performance in speed of processing and working memory. The mediation analysis found higher levels of IL-8 (direct: β = -0.591 (95 % Confidence Interval (CI): -1.0 to -0.2), P = 0.002; indirect: β = 0.060 (95 % CI.: 0.0-0.2), P = 0.032) and TNF-α (direct: β = -0.589 (95 % CI.: -1.0 to -0.2), P = 0.002; indirect: β = 0.059 (95 % CI.: 0.1-0.2), P = 0.037) were associated with more deficits in speed of processing, and partially mediated the relationship between body mass index and speed of processing.

CONCLUSION

Our results suggest that elevated inflammation might be one biological mechanism underlying the link between higher body mass and deficits in processing speed in patients with MDD.

Adaptation of an Emotional Stroop Test for Screening of Suicidal Ideation in Portugal

Cognitive instruments, especially those with emotional components, may be useful to address the limitations of self-report scales commonly used to assess suicidal ideation. The aim of this study was to develop an emotional Stroop test for screening suicidal ideation in Portugal. The project was developed in five phases using different samples for each phase. The first two phases were focused on the formulation of the potential words that would compose the slides. For this purpose, five biology teachers (neutral slide) and five mental health professionals (positive and negative slides) were invited to help choose the words that were most representative for each slide. The third phase validated the words defined in the previous phase. In this phase, 300 university students participated (M_age = 21.66; SD = 3.67; 68% female). They rated the words on a Likert scale in terms of their frequency of use, familiarity, level of understanding, and degree of image evocation. In the fourth phase, the researchers developed the complete version of the test, which consists of three slides with neutral, positive, and negative emotional stimuli, consecutively. Finally, in the fifth phase, we validated the final version of the test through a comparative study between a clinical group and a non-clinical group, each one composed by 50 participants (M_age = 32; SD = 9.70; 55% female). Results indicated that the clinical group demonstrated significantly higher scores for depression and suicidal ideation and lower scores for the three Stroop tasks. Words related to negative emotions were strongly correlated with suicidal ideation. Finally, the three Stroop slides explained 74.1% of the variance in suicidal ideation. These findings suggest that this test can be a viable complementary measure in the psychological assessment of suicide ideation, and intervention in the field of suicide prevention in Portugal.

Repetitive transcranial magnetic stimulation promotes response inhibition in patients with major depression during the stop-signal task

BACKGROUND

Response inhibition (RI) deficit is an aspect of cognitive impairment in depressed individuals, but currently no effective treatment has been established. This study aimed to explore the effect of individualized repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (lDLPFC)-nucleus accumbens (NAcc) network on RI in patients with major depressive disorder (MDD).

METHODS

Fourty-four patients diagnosed with MDD were randomized to receive 15 once-daily sessions of active (10 Hz, 100% of resting motor threshold) or sham rTMS within a double-blind, sham-controlled trial. We measured the efficacy of rTMS by the improvements in behavioral and neurological manifestations during the stop-signal task. The Hamilton Depression Rating Scale-17 items (HAMD-17) was used to assess depressive symptoms. We analyzed the differences in RI performance between MDD patients and 30 healthy controls (HCs) at baseline and assessed whether MDD patients who completed rTMS treatment had comparable RI ability to HCs.

RESULTS

At baseline, the depressed patients showed longer stop-signal response time (SSRT), smaller P3 amplitudes, and weaker theta-band power in successful stop trials (SSTs) than HCs. The active group exhibited RI ability comparable to that of HCs after rTMS treatment, but the improvements were not significant in the sham group. The active group showed significant remission in depression symptoms post-treatment compared to the sham group, and the changes in P3 amplitudes and theta-band power during SSTs were negatively correlated with the decrease of HAMD-17 scores.

CONCLUSION

The depressed patients have impaired RI and treatment with the individualized rTMS protocol may be an effective approach.

Sustained attention alterations in major depressive disorder: A review of fMRI studies employing Go/No-Go and CPT tasks

BACKGROUND

Major depressive disorder (MDD) is a severe psychiatric condition characterized by selective cognitive dysfunctions. In this regard, functional Magnetic Resonance Imaging (fMRI) studies showed, both at resting state and during tasks, alterations in the brain functional networks involved in cognitive processes in MDD patients compared to controls. Among those, it seems that the attention network may have a role in the disease pathophysiology. Therefore, in this review we aim at summarizing the current fMRI evidence investigating sustained attention in MDD patients.

METHODS

We conducted a search on PubMed on case-control studies on MDD employing fMRI acquisitions during Go/No-Go and continuous performance tasks. A total of 12 studies have been included in the review.

RESULTS

Overall, the majority of fMRI studies reported quantitative alterations in the response to attentive tasks in selective brain regions, including the prefrontal cortex, the cingulate cortex, the temporal and parietal lobes, the insula and the precuneus, which are key nodes of the attention, the executive, and the default mode networks.

LIMITATIONS

The heterogeneity in the study designs, fMRI acquisition techniques and processing methods have limited the generalizability of the results.

CONCLUSIONS

The results from the included studies showed the presence of alterations in the activation patterns of regions involved in sustained attention in MDD, which are in line with current evidence and seemed to explain some of the key symptoms of depression. However, given the paucity and heterogeneity of studies available, it may be worthwhile to continue investigating the attentional domain in MDD with ad-hoc study designs to retrieve more robust evidence.

Trait Anxiety Mediates Impulsivity and Suicidal Ideation in Depression During COVID-19 Pandemic

Suicidality in patients with major depressive disorder (MDD) has been an urgent affair during the COVID-19 pandemic. It is well-established that impulsivity and trait anxiety are two risk factors for suicidal ideation. However, literature is still insufficient on the relationships among impulsivity, (state/trait) anxiety and suicidal ideation in individuals with MDD. The present study aims to explore the relationships of these three variables in MDD patients during the COVID-19 pandemic through three scales, including Barrett Impulsivity Scale (BIS), State-Trait Anxiety Scale (STAI) and Self-rating Idea of Suicide Scale (SIOSS). Sixty-three MDD patients (low SIOSS group and high SIOSS group, which were split by the mean score of SIOSS) and twenty-seven well-matched healthy controls were analyzed. Our results showed that the high SIOSS group had higher trait anxiety (p < 0.001, 95% CI = [-19.29, -5.02]) but there was no difference in state anxiety (p = 0.171, 95% CI = [-10.60, 1.25]), compared with the low SIOSS group. And the correlation between impulsivity and suicidal ideation was significant in MDD patients (r = 0.389, p = 0.002), yet it was not significant in healthy controls (r = 0.285, p = 0.167). Further, mediation analysis showed that trait anxiety significantly mediate impulsivity and suicidal ideation in patients with depression (total effect: β = 0.304, p = 0.002, 95% CI = [0.120, 0.489]; direct effect: β = 0.154, p = 0.076, 95% CI = [-0.169, 0.325]), indicating impulsivity influenced suicidal ideation through trait anxiety in MDD patients. In conclusion, our results suggested that trait anxiety might mediate the association of impulsivity and suicidal ideation in MDD patients. Clinicians may use symptoms of trait anxiety and impulsivity for screening when actively evaluating suicidal ideation in MDD patients, especially in the setting of COVID-19 pandemic.

Electrophysiological Changes Between Patients With Suicidal Ideation and Suicide Attempts: An Event-Related Potential Study

INTRODUCTION

Inhibitory control is regarded as an important ability related to the transition from suicidal ideation to suicide attempts. In event-related potential, patients with dysfunction of inhibitory control demonstrate a reduction in the no-go amplitude. This study aimed to determine the association between the no-go event-related potential component and suicidal behaviors among suicide attempters and ideators who never attempted suicide.

METHODS

Overall, 150 patients who visited the emergency room by suicide attempts or patients who visited the psychiatric department with suicidal ideation were recruited and instructed to perform a go/no-go task during electroencephalography recording. The Beck Depression Inventory, Beck Anxiety Inventory, Barratt Impulsivity Scale, Difficulties in Emotional Regulation Scale, and Acquired Capability for Suicide Scale were used. Individuals were divided into two groups: those with suicide attempt group) and with suicidal ideation (SI group) without SA. The psychological characteristics and event-related potentials of the two groups were compared. Correlation analyses were conducted to test the association between the clinical characteristics and event-related potentials.

RESULTS

The SA group had significantly decreased no-go P3 amplitudes at all electrodes compared to the SI group. In the correlation analysis between the clinical measurements and event-related potentials in all the participants, no-go P3 amplitudes in whole electrode sites were negatively correlated with the scores of the acquired capability for the suicide scale.

CONCLUSIONS

This study revealed that suicide attempters have dysfunction in controlling inhibition compared to suicide ideators reflected in the no-go P3. Our findings suggested that no-go P3 can be a biomarker associated suicide attempts in suicide ideators.

Decision-making and cognitive control in adolescent suicidal behaviors: a qualitative systematic review of the literature

Suicide and suicidal behaviors represent a leading cause of morbidity and mortality during adolescence. While several lines of evidence suggest that suicidal behaviors are associated with risky decisions and deficient cognitive control in laboratory tasks in adults, comparatively less is known about adolescents. Here, we systematically reviewed the literature on the association between these neurocognitive variables and adolescent suicidal behaviors. The online search strategy identified 17 neurocognitive studies examining either cognitive control or decision-making processes in adolescents with past suicidal behaviors. Several studies have reported that adolescents with a history of suicidal behaviors present neuropsychological differences in the cognitive control (using Go/NoGo, suicide Stroop Test, continuous performance test, suicide/death Implicit Association Test), and decision-making (Iowa Gambling Task, Cambridge Gambling Task, cost computation, delay discounting, loss aversion tasks) domains. Due to a lack of replication or conflicting findings, our systematic review suggests that no firm conclusion can be drawn as to whether altered decision-making or poor cognitive control contribute to adolescent suicidal behaviors. However, these results collectively suggest that further research is warranted. Limitations included scarcity of longitudinal studies and a lack of homogeneity in study designs, which precluded quantitative analysis. We propose remediating ways to continue neuropsychological investigations of suicide risk in adolescence, which could lead to the identification of novel therapeutic targets and predictive markers, enabling early intervention in suicidal youth.

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.

Applying ideation-to-action theories to predict suicidal behavior among adolescents

BACKGROUND

Although many risk factors for adolescent suicidal behavior have been identified, less is known about distinct risk factors associated with the progression from suicide ideation to attempts. Based on theories grounded in the ideation-to-action framework, we used structural equation modeling to examine risk and protective factors associated with the escalation from suicide ideation to attempts in adolescents.

METHODS

In this cross-sectional study, data from the 2013 and 2015 Hawaii High School Youth Risk Behavior Surveys (N = 8,113) were analyzed. The sample was 54.0% female and racially/ethnically diverse. Risk factors included depression, victimization, self-harm, violent behavior, disinhibition, and hard substance use, and protective factors included adult support, sports participation, academic achievement and school safety.

RESULTS

One in 6 adolescents (16.4%) reported suicide ideation, and nearly 1 in 10 (9.8%) adolescents had made a suicide attempt. Overall, disinhibition predicted the escalation to attempts among adolescents with suicide ideation, and higher academic performance was associated with lower suicide attempt risk. Depression and victimization were associated with suicide ideation.

LIMITATIONS

This study examined data from the Youth Risk Behavior Survey, and other known risk factors such as anxiety and family history of suicide were not available in these data.

CONCLUSIONS

Findings provide guidance for targets for clinical interventions focused on suicide prevention. Programs that incorporate behavioral disinhibition may have the greatest potential for reducing suicide attempt risk in adolescents with suicidal thoughts.

Repetitive negative thinking and depressive symptoms are differentially related to response inhibition: The influence of non-emotional, socio-emotional, and self-referential stimuli

Identifying transdiagnostic correlates of response inhibition deficits is important for understanding risk for internalizing disorders. Little work has compared the relationships between internalizing symptoms and repetitive negative thinking (RNT) with response inhibition across non-emotional and emotional domains, and no work has compared these relationships for inhibition of socio-emotional relative to self-referential stimuli. Undergraduate students (N = 71, 18.44 ± 0.71 years) selected on extremes of internalizing symptoms completed the Perseverative Thinking Questionnaire (PTQ) and a Go/No-Go paradigm using non-emotional stimuli, other individuals' sad facial expressions, and participants' own sad facial expressions. Participants exhibited more commission errors for sad facial expressions than non-emotional trials, though commission errors for others' and participants' own sad facial expressions did not differ. Depressive symptoms were associated with poorer inhibition of non-emotional stimuli; however, PTQ scores were associated with more successful inhibition of non-emotional stimuli. Our results provide evidence that transdiagnostic RNT as assessed by the PTQ may be related to better inhibition in non-emotional domains, but negative emotional stimuli may interfere with successful inhibition for those with high RNT, while depressive symptoms were linked to poorer inhibition of non-emotional stimuli. These findings have implications for internalizing disorders, which often are accompanied by RNT.

Functional alterations of the suicidal brain: a coordinate-based meta-analysis of functional imaging studies

Altered brain activities in suicidal subjects have been reported in a number of neuroimaging studies. However, the activity aberrances were inconsistent in previous investigations. Thus, we aimed to address activity abnormalities in suicidal individuals. Databases were searched to perform a meta-analysis of whole-brain functional MRI studies of suicidal individuals through January 14, 2020. Meta-analyses were conducted using Seed-based d Mapping software. Based on a meta-analysis of 17 studies comprising 381 suicidal individuals and 642 controls, we mainly found that increased activity in the bilateral superior temporal gyrus, left middle temporal gyrus, and bilateral middle occipital gyrus, along with decreased activity in the right putamen and left insula, were detected in suicidal individuals compared with nonsuicidal subjects. To reduce methodological heterogeneity between the included studies, subanalyses of behavioral domains were conducted, and the right superior temporal gyrus was found to increase in all subanalyses of domains. In subanalyses of suicidal attempters and ideators, suicide attempters displayed hyperactivation in the bilateral superior temporal gyrus and left middle temporal gyrus and blunted responses in the left insula relative to controls. Suicidal ideators demonstrated elevated activation in the right middle occipital gyrus and reduced activity in the right putamen relative to controls. The bilateral superior temporal gyrus was the most robust finding, replicable in all data sets in the jackknife sensitive analysis. Moreover, increased activity in the right superior temporal gyrus, left middle temporal gyrus, and right middle occipital gyrus was found to be involved with higher suicide ideation scores. This study revealed several brain regions associated with suicidality. These findings may contribute to our understanding of the pathophysiology of suicide and have important implications for suicide prevention and interventions.

Functional connectivity evidence for state-independent executive function deficits in patients with major depressive disorder

BACKGROUND

Persistent neurocognitive deficits are often associated with poor outcomes of major depressive disorder (MDD). Executive dysfunction is the most common cognitive deficit in MDD. However, it remains unclear which subcomponent of executive dysfunction is state-independent with distinct neural substrates.

METHODS

A comprehensive neurocognitive test battery was used to assess four subcomponents of executive function (working memory, inhibition, shifting, and verbal fluency) in 95 MDD patients and 111 matched healthy controls (HCs). After 6 months of paroxetine treatment, 56 patients achieved clinical remission (rMDD) and completed the second-time neurocognitive test. Network-based statistics analysis was utilized to explore the changes in functional connectivity (FC).

RESULTS

Compared with the HCs, all the four subcomponents of MDD patients were significantly impaired. After treatment, there was a significant improvement in working memory, inhibition, and verbal fluency in the rMDD group. And shifting and verbal fluency of the rMDD group remained impaired compared with the HCs. Fifteen functional connections were interrupted in the MDD group, and 11 connections remained in a disrupted state after treatment. Importantly, verbal fluency was negatively correlated with the disrupted FC between the right dorsal prefrontal cortex and the left inferior parietal lobule in patients with MDD and remitted MDD.

LIMITATIONS

The correlation analysis of the association between cognitive impairment and connectivity alterations precluded us from making causal inferences.

CONCLUSIONS

Verbal fluency is the potential state-independent cognitive deficit with distinct neural basis in patients with MDD.

Neurocognitive Functioning in Adolescents at Risk for Suicidal Behaviors

Today, little is still known about the neurocognitive functioning of the individual at risk for suicide in a relevant developmental stage like adolescence. Thus, the main goal of the present work was to analyze the neurocognitive performance of adolescents at high risk for suicide. A total of 1509 adolescents from a stratified random cluster sampling were selected. Adolescents at risk for suicidal behaviors included 83 participants. A comparison group of 83 participants matched by age and gender was also randomly selected from the sample. The Paykel Suicide Scale (PSS) and the University of Pennsylvania Computerized Neurocognitive Battery for children (included 14 tasks assessing five neurobehavioral domains: executive functions, episodic memory, complex cognition, social cognition, and sensorimotor speed) were used. Adolescents at risk for suicide revealed statistically significant impairments across different neurocognitive domains including complex cognition, episodic memory and social cognition. No significant differences were found for Sensorimotor and Executive Function domains. Results found in the present study contribute relevant information about the nature of the neurocognitive impairments associated with suicide and add information in order to deeper comprehend the tentative etiology of suicide thoughts and attempts in adolescents with the aim to establish preventive treatments.

Hope and Distress Are Not Associated With the Brain Tumor Stage

Objective

Hopelessness and depression are strongly associated with suicidality. Given that physical and psychological outcomes can be altered with hope, hope is a therapeutic goal of increasing importance in the treatment of brain tumor patients. Moreover, it is not yet understood which factors affect the perception of hope in brain tumor patients. In addition, it remains uncertain whether lower-grade brain tumor patients suffer less from psycho-oncological distress than higher-grade brain tumor patients.

Methods

Neuro-oncological patients were examined perioperatively with the Distress Thermometer (DT) and the Herth Hope Index (HHI). In addition, psychological comorbidities (anxiety GAD-2, depression PHQ-2) and an assessment of general psycho-oncological distress were recorded.

Results

Sixty-six brain tumor patients were included (median age 53 years, 35% higher-grade brain tumors, i.e., WHO grade III/IV). No differences between higher- and lower-grade brain tumor patients were observed for general psycho-oncological distress and hope. However, higher-grade brain tumor patients showed a significantly higher level of depression (p ≤ 0.001) and more negative expectations regarding therapeutic success (H = 4.873, p ≤ 0.050). The extent of depression correlated negatively with hope.

Conclusion

Unexpectedly, higher-grade brain tumor patients remained as hopeful as lower-grade brain tumor patients despite the devastating diagnosis, higher levels of depression, and a worse expectation of therapeutic success. Conversely, lower-grade brain tumor patients experience as much psycho-oncological distress as patients with a higher-grade brain tumor, underpinning the imperative need for comprehensive psycho-oncological screening. For all brain tumor patients, considering hope is important to avoid suicides resulting from hopelessness and depression.

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.

Neural activity during response inhibition associated with improvement of dysphoric symptoms of PTSD after trauma-focused psychotherapy-an EEG-fMRI study

Although trauma-focused cognitive behavioural therapy (TF-CBT) is the frontline treatment for posttraumatic stress disorder (PTSD), up to one half of patients do not respond optimally to this treatment. Inhibitory functions are important for successful management of PTSD, yet there is a dearth of knowledge regarding the extent to which neural mechanisms unpinning response inhibition are associated with TF-CBT response. Treatment-seeking PTSD patients (n = 40) were assessed during a response inhibition task (the Go/No-Go task) while undergoing functional magnetic imaging (fMRI) and event-related potentials (ERP) in separate sessions. PTSD symptom severity was assessed with the Clinician-Administered PTSD Scale, before undergoing nine sessions of TF-CBT. They were then reassessed post-treatment to estimate reduction in fear and dysphoric symptoms of PTSD. Although neural responses during the inhibitory task did not predict overall symptom change, reduced activation in the left precuneus and the right superior parietal cortex predicted greater improvement in dysphoric symptoms. ERP responses during response inhibition indicated that lower P3 peak latency predicted greater reduction of dysphoric symptoms. There were no significant predictors of changes of fear symptoms. These findings indicate that neural activity associated with response inhibition can act as a predictive biomarker of TF-CBT response for PTSD symptoms. This pattern of findings underscores the importance of delineating the role of biomarkers to predict remission of subtypes of PTSD.

Multimodal Neuroimaging of Suicidal Thoughts and Behaviors in a U.S. Population-Based Sample of School-Age Children

OBJECTIVE

Suicide deaths and suicidal thoughts and behaviors are considered a public health emergency, yet their underpinnings in the brain remain elusive. The authors examined the classification accuracy of individual, environmental, and clinical characteristics, as well as multimodal brain imaging correlates, of suicidal thoughts and behaviors in a U.S. population-based sample of school-age children.

METHODS

Children ages 9-10 years (N=7,994) from a population-based sample from the Adolescent Brain Cognitive Development study were assessed for lifetime suicidal thoughts and behaviors. After quality control procedures, structural MRI (N=6,238), resting-state functional MRI (N=4,134), and task-based functional MRI (range, N=4,075-4,608) were examined. Differences with Welch's t test and equivalence tests, with observed effect sizes (Cohen's d) and their 90% confidence intervals <|0.15|, were examined. Classification accuracy was examined with area under precision-recall curves (AUPRCs).

RESULTS

Among the 7,994 unrelated children (females, N=3,757, 47.0%), those with lifetime suicidal thoughts and behaviors based on child (N=684, 8.6%), caregiver (N=654, 8.2%), and concordant (N=198, 2.5%) reports had higher levels of social adversity and psychopathology, among themselves and their caregivers, compared with never-suicidal children (N=6,854, 85.7%). Only one imaging test survived statistical correction: caregiver-reported suicidal thoughts and behaviors were associated with a thinner left bank of the superior temporal sulcus. On the basis of the prespecified bounds of |0.15|, approximately 48% of the group mean differences for child-reported suicidal thoughts and behaviors comparisons and approximately 22% for caregiver-reported suicidal thoughts and behaviors comparisons were considered equivalent. All observed effect sizes were relatively small (d≤|0.30|), and both non-imaging and imaging correlates had low classification accuracy (AUPRC ≤0.10).

CONCLUSIONS

Commonly applied neuroimaging measures did not reveal a discrete brain signature related to suicidal thoughts and behaviors in youths. Improved approaches to the neurobiology of suicide are critically needed.

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.

Risky decision-making in suicide attempters, and the choice of a violent suicidal means: an updated meta-analysis

BACKGROUND

Studies showed disadvantageous decision-making in suicide attempters. The present meta-analysis aims to examine the stability of these findings and related questions.

METHODS

EMBASE and Pubmed databases were searched for studies published between 01/01/2000 and 01/01/2020 with an additional search through bibliographical references. English or French articles published in peer-reviewed journals, reporting quantitative task-based measures of decision-making in suicide attempters were included: 3,582 records were identified, 33 full-text articles screened, and 21 articles finally included.

RESULTS

All studies were conducted in mood disorders; 18 used the Iowa Gambling Task (IGT) and 3 the Cambridge Gamble Task (CGT). With the IGT, suicide attempters showed riskier choices than patient controls (Hedges' g=-0.28 95%CI (-0.44 - -0.12)) and healthy controls (g=-0.54 (-0.83 - -0.25)) with no significant difference between control groups. The difference between suicide attempters and patient controls was not related to age group, mood disorder type, author, or research center while an effect of time of publication was found (p=0.006). Poorer performance was also found in suicide attempters compared to patient controls when using the CGT (g=-0.57 95%CI (-0.82 - -0.31)). Suicide attempters who used a violent means showed poorer IGT performance than those who used a non-violent means (3 studies).

LIMITATION

Limited number of studies outside mood disorders. No data to calculate a gender effect.

CONCLUSION

The present meta-analysis confirmed riskier decision-making in suicide attempters. Although group differences appear to be of modest effect size in general, they were particularly marked in the subgroup of those who used a violent suicidal means.

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.

Attentional Bias Deficits in Adolescent Suicide Attempters During an Emotional Stroop Task: An ERP Study

There is increasing evidence that, in adolescence, attentional bias plays a critical role in the vulnerability for suicidal behaviour. No studies to date have investigated the neurophysiological correlates of attentional bias in adolescent suicidality. The present study uses event-related potentials (ERPs) to investigate such processing in inpatient adolescents admitted for an acute suicide crisis using an Emotional Stroop Task (EST). In this task, participants are asked to name the colour of words varying in emotional valence (positive, negative, neutral, suicide-related). Suicidal individuals are hypothesised to be more preoccupied by the context of the suicide-related stimuli, which may interfere with their ability to perform the colour naming task. Seventeen adolescents with acute suicidal behaviour and 17 age- and gender-matched healthy controls performed an EST while ERPs were recorded. Suicide attempters showed increased reaction times to suicide-related words compared to other emotion categories, while the controls did not. The amplitude of the early posterior negativity (EPN) was not significantly different across groups or emotional valence. A double peak P3 (early-P3 and late-P3) was observed in both groups. Both the early- and late-P3 were significantly reduced in amplitude in the suicide attempter group compared to the control group, regardless of emotional valence. The late-P3 latency was also significantly delayed in the suicide attempters compared to controls. The behavioural findings support the attentional bias theories of suicide attempters and extend these findings to adolescents. Furthermore, large early- and late-P3 provide evidence that cognitive strategies employed by two groups did markedly differ.

Abnormal Large-Scale Network Activation Present in Bipolar Mania and Bipolar Depression Under Resting State

Introduction: Previous studies have primarily focused on the neuropathological mechanisms of the emotional circuit present in bipolar mania and bipolar depression. Recent studies applying resting-state functional magnetic resonance imaging (fMRI) have raise the possibility of examining brain-wide networks abnormality between the two oppositional emotion states, thus this study aimed to characterize the different functional architecture represented in mania and depression by employing group-independent component analysis (gICA). Materials and Methods: Forty-one bipolar depressive patients, 20 bipolar manic patients, and 40 healthy controls (HCs) were recruited and received resting-state fMRI scans. Group-independent component analysis was applied to the brain network functional connectivity analysis. Then, we calculated the correlation between the value of between-group differences and clinical variables. Results: Group-independent component analysis identified 15 components in all subjects, and ANOVA showed that functional connectivity (FC) differed significantly in the default mode network, central executive network, and frontoparietal network across the three groups. Further post-hoc t-tests showed a gradient descent of activity-depression > HC > mania-in all three networks, with the differences between depression and HCs, as well as between depression and mania, surviving after family wise error (FWE) correction. Moreover, central executive network and frontoparietal network activities were positively correlated with Hamilton depression rating scale (HAMD) scores and negatively correlated with Young manic rating scale (YMRS) scores. Conclusions: Three brain networks heighten activity in depression, but not mania; and the discrepancy regions mainly located in prefrontal, which may imply that the differences in cognition and emotion between the two states is associated with top-down regulation in task-independent networks.

Sexual Dimorphism in the Brain Correlates of Adult-Onset Depression: A Pilot Structural and Functional 3T MRI Study

Major Depressive Disorder (MDD) is a disabling illness affecting more than 5% of the elderly population. Higher female prevalence and sex-specific symptomatology have been observed, suggesting that biologically-determined dimensions might affect the disease onset and outcome. Rumination and executive dysfunction characterize adult-onset MDD, but sex differences in these domains and in the related brain mechanisms are still largely unexplored. The present pilot study aimed to explore any interactions between adult-onset MDD and sex on brain morphology and brain function during a Go/No-Go paradigm. We hypothesized to detect diagnosis by sex effects on brain regions involved in self-referential processes and cognitive control. Twenty-four subjects, 12 healthy (HC) (mean age 68.7 y, 7 females and 5 males) and 12 affected by adult-onset MDD (mean age 66.5 y, 5 females and 7 males), underwent clinical evaluations and a 3T magnetic resonance imaging (MRI) session. Diagnosis and diagnosis by sex effects were assessed on regional gray matter (GM) volumes and task-related functional MRI (fMRI) activations. The GM volume analyses showed diagnosis effects in left mid frontal cortex (p < 0.01), and diagnosis by sex effects in orbitofrontal, olfactory, and calcarine regions (p < 0.05). The Go/No-Go fMRI analyses showed MDD effects on fMRI activations in left precuneus and right lingual gyrus, and diagnosis by sex effects on fMRI activations in right parahippocampal gyrus and right calcarine cortex (p < 0.001, ≥ 40 voxels). Our exploratory results suggest the presence of sex-specific brain correlates of adult-onset MDD-especially in regions involved in attention processing and in the brain default mode-potentially supporting cognitive and symptom differences between sexes.

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.

A study on BOLD fMRI of the brain basic activities of MDD and the first-degree relatives

Introduction: The present study aims to explore the characteristics and differences of the ReHo, ALFF and fALFF of brain in the resting state of depression and first-degree relatives, in order to identify candidate central prodromal biomarkers of depression.Method: Three groups of medication-free patients (39-59 years old) was involved in this study, including the patients with major depression disorder (MDD group, n = 15), healthy volunteers with first-degree relatives with MDD (first-degree relatives group, n = 15), healthy volunteers with no personal or family history of MDD (the control group [HC], n = 15). Participants underwent functional MRI while staying in a resting state after a conventional MRI scanning on a clinical 3 T system(Siemens Skyra, Germany).Results: The ReHo, ALFF and fALFF values are different in brain of MDD, first-degree relatives, and HC (p<.05). MDD patients exhibited abnormal spontaneous activity in multiple brain regions which are closely related to emotion regulation and perception. The present findings provide further insight into the pathological mechanisms underlying MDD.Conclusion: With the widespread abnormal values of brain in MDD and first-degree relatives measured, we can get a hypothesis that these abnormalities may be associated with cognitive network disorders and emotional distress in MDD.Key pointsThe fMRI could increase the early validity of MDD as a new diagnostic and disease-monitoring tool.Monitoring ReHo, ALFF, fALFF values using fMRI can provide insight into the presence and evolution of MDD disease and permit objective evaluation of brain abnormalities.It appears that ReHo, ALFF, fALFF could be used as markers for monitoring disease progression and treatment effects in MDD patients in the future.

Impulsivity and Cognitive Flexibility as Neuropsychological Markers for Suicidality: A Multi-Modal Investigation Among Military Veterans with Alcohol Use Disorder and PTSD

To examine relations between self-report and behavioral measures of impulsivity and cognitive flexibility with suicidal ideation and self-harm and suicide attempt history. Methods: Eighty-seven military veterans who met DSM-5 diagnostic criteria for alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD) were evaluated for current suicidal ideation and self-harm, suicide attempt history, impulsivity, and cognitive flexibility. Results: Higher levels of self-reported impulsivity were associated with greater suicidal ideation and self-harm and lower behavioral inhibition was associated with greater likelihood of endorsing a suicide attempt. Conclusion: Use of multi-modal assessment of impulsivity and cognitive flexibility may aid in suicide screening and intervention among vulnerable and high-risk populations.

Neurocognitive markers of suicidal ideation in patients with anxiety and mood disorders

Objective: This study aims at identifying associations between cognitive function and suicidal ideation in the sample of patients with anxiety and mood disorders (AMD).Methods: In sum, 186 (age = 39 ± 12.3 years; 142 [76.3%] females) patients with AMD were enrolled in the study. Assessment included evaluation of socio-demographic information, medication use, anxiety and depression symptoms. Cognitive tests included measures of psychomotor performance and incidental learning using the Digit Symbol Test. Trail Making Tests respectively measured perceptual speed, task-switching and executive control. Additionally, 21 patients completed tests from the Cambridge Automated Neuropsychological Test Battery measuring set shifting (Interdimensional/extradimensional set-shift), executive planning (Stockings of Cambridge), and decision making (Cambridge Gamble Task [CGT]).Results: Almost half (45.0%, n = 86) of the study sample patients had experienced suicidal ideations. In multivariable regression analysis, suicidal ideation was associated with a greater overall proportion of bet and risk taking on the CGT task (β = 0.726, p = .010 and β = 0.634, p = .019), when controlling for socio-demographic characteristics, medication use, anxiety and depression symptoms.Conclusions: Outpatients with AMD and suicidal ideation could be distinguished by the presence of cognitive deficits in the executive function domain, particularly in impulse-control and risk taking.

Brain Differences Associated with Self-Injurious Thoughts and Behaviors: A Meta-Analysis of Neuroimaging Studies

This meta-analysis aims to evaluate whether the extant literature justifies any definitive conclusions about whether and how SITBs may be associated with brain differences. A total of 77 papers (N = 4,903) published through January 1, 2019 that compared individuals with and without SITBs were included, resulting in 882 coordinates. A pooled meta-analysis assessing for general risk for SITBs indicated a lack of convergence on structural differences. When all types of control groups were considered, functional differences in the left posterior cingulate cortex (PCC), right amygdala, left hippocampus, and right thalamus were significant using multi-level kernel density analysis (p_corrected < 0.05) but nonsignificant using activation-likelihood estimation. These results suggest that a propensity for internally-oriented, emotional processing coupled with under-active pain processing could potentially underlie SITBs, but additional research is needed to test this possibility. Separate analyses for types of SITBs suggested that the brain differences associated with deliberate self-harm were consistent with the overall findings. Checkered moderator effects were detected. Overall, the meta-analytic evidence was not robust. More studies are needed to reach definitive conclusions about whether SITBs are associated with brain differences.

Psychological Resilience, Mental Health, and Inhibitory Control Among Youth and Young Adults Under Stress

Psychological resilience allows one to cope successfully with adversities occurring during stressful periods, which may otherwise trigger mental illness. Recent models suggest that inhibitory control (IC), the executive control function which supports our goal-directed behavior and regulates our emotional response, may underlie resilience. However, the ways in which this is manifested during stressful situations in real life is still unclear. Here, we examined the relationship between IC, psychological resilience, psychological distress, and anxiety among 138 female and male participants in a stressful situation: during their initial combat training in the military. Using a mobile app, we assessed IC using emotional and non-emotional variations of the Go/No-Go task. Psychological resilience, psychological distress, and anxiety were assessed using mobile versions of self-report questionnaires. We found that psychological resilience is significantly correlated with non-emotional IC (r = 0.24, p < 0.005), but not with emotional IC; whereas, psychological distress and anxiety are correlated with emotional IC (r = -0.253, p < 0.005 and r = -0.224, p < 0.01, for psychological distress and anxiety, respectively), but not with non-emotional IC. A regression model predicting emotional IC confirmed non-emotional IC and distress as unique contributors to the variance, but not psychological distress. In addition, associations between psychological distress and emotional IC were found only for female participants. Collectively, the results clarify the link between IC, resilience, and mental health in real-life stressful situations, showing separate mechanisms of IC involved in resilience on the one hand, and mental health on the other hand. These results have implications for building mobile resilience interventions for youth and young adults facing stressful situations.

A qualitative systematic review of suicide behavior using the cognitive systems domain of the research domain criteria (RDoC) framework

Neurocognitive deficits are associated with both suicide behavior (SB) and psychiatric disorders. Application of a transdiagnostic framework to identify neurocognitive commonalities of SB may clarify important risk factors of SB across psychiatric disorders. The aim of this study was to conduct a qualitative systematic literature review of SB using the Research Domain Criteria (RDoC) Cognitive Systems framework to determine if cognitive deficits exist independently of psychiatric disorders in SB. The following six constructs that encompass the Cognitive Systems domain were assessed: 1) Attention, 2) Cognitive Control, 3) Declarative Memory, 4) Language, 5) Perception, and 6) Working Memory. A total of 1386 abstracts were identified and 74 studies met the inclusion criteria for this review. The majority of studies reviewed (65%) had significant differences in cognition between individuals with and without SB. Seventy-nine percent of studies with a patient control group showed significant cognitive deficits in SB groups. Deficits in cognitive control were associated with SB and had the greatest percentage of studies with significant main findings. Use of the RDoC cognitive systems framework to evaluate SB revealed that cognitive deficits may be a transdiagnostic risk factor for SB, especially alterations in cognitive control.

Cognitive inhibition and attentional biases in the affective go/no-go performance of depressed, suicidal populations

BACKGROUND

Although cognitive inhibition deficits and attentional biases have been associated with suicidality, these findings have not been consistently reported across samples. The aim of the current study was to further investigate these variables among participants with differing suicidal risk.

METHODS

We compared affective go/no-go performance in 100 depressed individuals with both current suicidal ideation and a prior history of attempted suicide, 100 depressed individuals with current suicidal ideation, but no history of attempted suicide, 100 suicide attempters without current depression or suicidal ideation, and 100 healthy controls.

RESULTS

Suicide ideators with a history of attempted suicide committed more commission errors during negative word trials than any other group. Additionally, suicide ideators with no attempt history made more commission errors than did controls and previous attempters. An interaction for group status and emotional word valence revealed that suicide ideators with a history of attempted suicide responded fastest to negative words and slowest to positive words. Suicide ideators without an attempt history displayed a similar, but less pronounced pattern. Whereas, controls and previous attempters responded more quickly to positively valenced words.

LIMITATIONS

The use of cross-sectional self-report data and inclusion of only female participants limits generalizability.

CONCLUSIONS

Cognitive dysfunctions were apparent in all suicide vulnerable subjects, but significantly greater in suicide ideators with a history of attempted suicide. Suicidal ideation may be associated with a processing bias and inhibitory deficit for negative, mood-congruent information. These findings increase our knowledge of cognitive impairment in suicidality and may potentially help improve intervention strategies.

Suicidal risk and executive functions in major depressive disorder: a study protocol

BACKGROUND

Suicide is a serious public health concern. Depression is the main gateway to suicidal behavior. The already established relationship between depression and suicidal risk should now focus on the investigation of more specific factors: recent studies have suggested an association between vulnerability to suicidal behavior and neurocognitive alterations, a nuclear symptom of depression. This project aims to identify alterations in the Executive Functions (EF) of patients suffering a first depressive episode that might constitute a risk factor for suicidal ideation, suicidal attempts and suicide, to allow for more adequate suicide prevention.

METHODS

Prospective longitudinal design involving two groups (first depressive episodes with and without alterations in their EF) and four repeated measures (0, 6, 12 and 24 months). The estimated minimum sample size is 216 subjects. The variables and measurement instruments will include socio-demographic variables, clinical variables (age of illness onset, family and personal antecedents, psychopathological and medical comorbidity, suicidal ideation, suicide attempts and completed suicides, severity of depression, including melancholic or atypical, remission of the depressive episode), and neuropsychological variables (EF and decision-making processes evaluated through the Cambridge Neuropsychological Test Automated Battery (CANTAB)).

DISCUSSION

First and foremost, the identification of clinical and neuropsychological risk factors associated with suicidal behavior will open the possibility to prevent such behavior in patients with a first depressive episode in the context of clinical practice. Secondly, interventions aimed at cognitive impairment (in particular: EF) derived from the study may be incorporated into strategies for the prevention of suicidal behavior. Finally, impaired neurocognitive function (even in early stages) could become an identifiable endophenotype or "marker" in clinical and neurobiological studies about suicidal behavior in depressive patients.