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

Bisphenol AF exposure synergistically increases the risk for suicidality among early adolescents with child maltreatment: A prospective cohort study

BACKGROUND

Child maltreatment (CM) is correlated with suicidality risk among adolescents. Additionally, exposure to bisphenol AF (BPAF) may increase this risk. However, the combined effect of CM and BPAF exposure remains unknown and should be further investigated.

METHODS

In this study, 1,475 early adolescents (mean age = 12.48 years) from the Chinese Early Adolescents Cohort were enrolled. Data were collected at three time points with an interval of 12 months between 2019 and 2021. Participants' history of CM and suicidality (including suicidal ideation and suicidal attempts) were evaluated using a self-report questionnaire. Blood samples were obtained from participants to measure serum BPAF concentrations at baseline. Group-based trajectory modeling was employed to identify different developmental trajectories of suicidality across the three waves. After adjusting for potential confounders, the association between CM and BPAF exposure on suicidal ideation and suicidal attempts was assessed using logistic regression and Poisson regression analyses.

RESULTS

Participants with CM were associated with a risk of one- and two-year incident suicidality (all ps < 0.05), and BPAF levels were positively associated with two-year incident suicidal ideation (adjusted OR = 1.68, 95% CI: 1.13-2.50). Additionally, middle and high levels of BPAF exposure synergistically increase the risk for one- and two-year incident suicidal ideation among participants with CM (adjusted ORs = 2.00-3.83). Similarly, participants exposed to high-level BPAF as well as CM were at a greater risk of one- and two-year incident suicidal attempts than those with low-level BPAF exposure and no CM (adjusted incidence rate ratio [IRRs] = 2.82-4.34). Moreover, compared with participants with a low developmental trajectory of suicidality across the three waves, high BPAF exposure exhibited a significant synergistic effect on participants with CM in the persistently high suicidal ideation trajectory and the increasing suicidal attempts trajectory (all ps < 0.05). Sex subgroup analysis revealed that females were more susceptible to the synergistic effect of BPAF and CM exposure on suicidality than males.

CONCLUSIONS

Environmental factors and the psychological status of individuals may synergistically increase their susceptibility to suicidality. These results offer novel insights into enhancing our understanding of suicidality among adolescents.

Impulsive Decision-Making, Affective Experiences, and Parental History of Self-Injurious Thoughts and Behaviors within Parent-Adolescent Dyads

Impulsive decision-making, particularly during states of affective intensity, is associated with greater risk of engagement in self-injurious thoughts and behaviors (SITBs) during adolescence. The proximal (dyadic parent-adolescent affect and impulsivity) and distal (family history of SITBs) risk factors that occur within the family system could be relevant processes at stake in the intergenerational transmission of risk. The current study tests the interdependence of parent-adolescent factors associated with risk for SITBs and probes the extent to which parent-adolescent affective states influence their own (actor-effects) and each other's (partner-effects) impulsive decision-making, and further whether these relationships are moderated by a parent's history of SITBs. Participants included 212 (106 dyads) community parents and their adolescents who completed self-report and behavioral tasks related to positive and negative affective states, impulsive decision-making, and lifetime history of SITBs. Application of the Actor-Partner Interdependence Model (APIM) revealed a partner-effect where greater parent negative affect in the past week was associated with elevated adolescent impulsive decision-making among families with a history of SITBs (Estimate = 0.66, Standard Error = 0.13, p < 0.001). In addition, a significant actor-effect was observed where greater positive affect was associated with decreased impulsive decision-making among adolescents (Estimate = -0.21, Standard Error = 0.10, p = 0.03), however, moderating effects of parent history of SITBs were not detected. Findings from the present study shed light on the interdependence of affect and impulsivity within parent-adolescent dyads, and the extent to which these interactions may be particularly salient for families with known vulnerabilities for SITBs.

Perception of social inclusion/exclusion and response inhibition in adolescents with past suicide attempt: a multidomain task-based fMRI study

The occurrence of suicidal behaviors increases during adolescence. Hypersensitivity to negative social signals and deficits in cognitive control are putative mechanisms of suicidal behaviors, which necessitate confirmation in youths. Multidomain functional neuroimaging could enhance the identification of patients at suicidal risk beyond standard clinical measures. Three groups of adolescents (N = 96; 78% females, age = 11.6-18.1) were included: patients with depressive disorders and previous suicide attempts (SA, n = 29); patient controls with depressive disorders but without any suicide attempt history (PC, n = 35); and healthy controls (HC, n = 32). We scanned participants with 3T-MRI during social inclusion/exclusion (Cyberball Game) and response inhibition (Go-NoGo) tasks. Neural activation was indexed by the blood-oxygenation-level dependent (BOLD) of the hemodynamic response during three conditions in the Cyberball Game ("Control condition", "Social Inclusion", and "Social Exclusion"), and two conditions in Go-NoGo task ("Go" and "NoGo" blocks). ANCOVA-style analysis identified group effects across three whole-brain contrasts: 1) NoGo vs. Go, 2) Social inclusion vs. control condition, 3) Social exclusion vs. control condition. We found that SA had lower activation in the left insula during social inclusion vs. control condition compared to PC and HC. Moreover, SA compared to PC had higher activity in the right middle prefrontal gyrus during social exclusion vs. control condition, and in bilateral precentral gyri during NoGo vs. Go conditions. Task-related behavioral and self-report measures (Self-reported emotional reactivity in the Cyberball Game, response times and number of errors in the Go-NoGo Task) did not discriminate groups. In conclusion, adolescent suicidal behaviors are likely associated with neural alterations related to the processing of social perception and response inhibition. Further research, involving prospective designs and diverse cohorts of patients, is necessary to explore the potential of neuroimaging as a tool in understanding the emergence and progression of suicidal behaviors.

Impulsivity in adolescent girls diagnosed with trichotillomania: an evaluation of clinical and neuropsychological characteristics

The aim of this study is to compare the clinical and neuropsychological features of impulsivity in adolescent girls with trichotillomania (TTM) and healthy controls, and to assess the relationships between the severity of TTM and the impulsivity/concomitant symptoms of anxiety and depression. The study sample consisted of 43 adolescent girls who were 12 to 18 years old. The Kiddie-Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version DSM-5 (K-SADS-PL) was administered to the adolescents and their parents. All of the participants completed a sociodemographic data form, the Revised Children's Anxiety and Depression Scale-Child Version (RCADS-CV), the Barratt Impulsiveness Scale-Brief (BIS-Brief), and the Massachusetts General Hospital Hairpulling Scale (MGH-HPS). The Eriksen Flanker task, the Stop Signal Reaction Time (SSRT) task, the Go/No-Go task, and the Balloon Analog Risk Task (BART) were used to assess behavioral impulsivity. The adolescents with TTM reported higher levels of impulsivity and anxiety/depression symptoms than the healthy controls, and they also performed worse on the behavioral tasks. While there were no relationships between clinical and behavioral impulsivity and TTM severity, social anxiety symptoms were the most important predictor of the severity of TTM. It seems important to better understand the role of impulsivity in the onset and persistence of TTM symptoms in adolescents.

Social-ecological perspective on the suicidal behaviour factors of early adolescents in China: a network analysis

Background

In early adolescence, youth are highly prone to suicidal behaviours. Identifying modifiable risk factors during this critical phase is a priority to inform effective suicide prevention strategies.

Aims

To explore the risk and protective factors of suicidal behaviours (ie, suicidal ideation, plans and attempts) in early adolescence in China using a social-ecological perspective.

Methods

Using data from the cross-sectional project 'Healthy and Risky Behaviours Among Middle School Students in Anhui Province, China', stratified random cluster sampling was used to select 5724 middle school students who had completed self-report questionnaires in November 2020. Network analysis was employed to examine the correlates of suicidal ideation, plans and attempts at four levels, namely individual (sex, academic performance, serious physical illness/disability, history of self-harm, depression, impulsivity, sleep problems, resilience), family (family economic status, relationship with mother, relationship with father, family violence, childhood abuse, parental mental illness), school (relationship with teachers, relationship with classmates, school-bullying victimisation and perpetration) and social (social support, satisfaction with society).

Results

In total, 37.9%, 19.0% and 5.5% of the students reported suicidal ideation, plans and attempts in the past 6 months, respectively. The estimated network revealed that suicidal ideation, plans and attempts were collectively associated with a history of self-harm, sleep problems, childhood abuse, school bullying and victimisation. Centrality analysis indicated that the most influential nodes in the network were history of self-harm and childhood abuse. Notably, the network also showed unique correlates of suicidal ideation (sex, weight=0.60; impulsivity, weight=0.24; family violence, weight=0.17; relationship with teachers, weight=-0.03; school-bullying perpetration, weight=0.22), suicidal plans (social support, weight=-0.15) and suicidal attempts (relationship with mother, weight=-0.10; parental mental illness, weight=0.61).

Conclusions

This study identified the correlates of suicidal ideation, plans and attempts, and provided practical implications for suicide prevention for young adolescents in China. Firstly, this study highlighted the importance of joint interventions across multiple departments. Secondly, the common risk factors of suicidal ideation, plans and attempts were elucidated. Thirdly, this study proposed target interventions to address the unique influencing factors of suicidal ideation, plans and attempts.

Gender differences in prevalence and associations between cognitive symptoms and suicidal ideation in patients with recurrent major depressive disorder: findings from the Chinese NSSD study

BACKGROUND

This study aimed to explore gender differences in associations between cognitive symptoms and suicidal ideation (SI) among patients with recurrent major depressive disorder (MDD).

METHODS

We recruited 1222 patients with recurrent MDD from the National Survey on Symptomatology of Depression (NSSD), a survey designed to investigate the symptoms experienced during current major depressive episodes in China. A four-point Likert questionnaire was used to assess the frequency of cognitive symptoms and SI in the past two weeks.

RESULTS

Gender differences in clinical features and cognitive symptoms of participants with recurrent MDD were found. Specifically, male patients had a higher prevalence of memory loss, decreased verbal output, indecisiveness, and impaired interpersonal relationships, while female patients exhibited a higher prevalence of impaired social and occupational functioning (all P < 0.05). No significant difference in SI prevalence was found between male and female patients. The logistic regression analysis revealed that in male patients, SI was associated with indecisiveness and impaired interpersonal relationships. In female patients, reduced verbal output and impaired social and professional functions were also associated with SI in addition to the above-mentioned variables.

CONCLUSION

The findings of gender differences in associations between cognitive symptoms and SI highlight the need to carefully assess gender-specific cognitive predictors of SI in patients with recurrent MDD. This has further implications for more targeted prevention and treatment strategies for SI based on gender.

Integrative Analyses of scRNA-seq, Bulk mRNA-seq, and DNA Methylation Profiling in Depressed Suicide Brain Tissues

BACKGROUND

Suicidal behaviors have become a serious public health concern globally due to the economic and human cost of suicidal behavior to individuals, families, communities, and society. However, the underlying etiology and biological mechanism of suicidal behavior remains poorly understood.

METHODS

We collected different single omic data, including single-cell RNA sequencing (scRNA-seq), bulk mRNA-seq, DNA methylation microarrays from the cortex of Major Depressive Disorder (MDD) in suicide subjects' studies, as well as fluoxetine-treated rats brains. We matched subject IDs that overlapped between the transcriptome dataset and the methylation dataset. The differential expression genes and differentially methylated regions were calculated with a 2-group comparison analysis. Cross-omics analysis was performed to calculate the correlation between the methylated and transcript levels of differentially methylated CpG sites and mapped transcripts. Additionally, we performed a deconvolution analysis for bulk mRNA-seq and DNA methylation profiling with scRNA-seq as the reference profiles.

RESULTS

Difference in cell type proportions among 7 cell types. Meanwhile, our analysis of single-cell sequence from the antidepressant-treated rats found that drug-specific differential expression genes were enriched into biological pathways, including ion channels and glutamatergic receptors.

CONCLUSIONS

This study identified some important dysregulated genes influenced by DNA methylation in 2 brain regions of depression and suicide patients. Interestingly, we found that oligodendrocyte precursor cells (OPCs) have the most contributors for cell-type proportions related to differential expression genes and methylated sites in suicidal behavior.

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

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

Systematic Review and Meta-analysis: International Prevalence of Suicidal Ideation and Attempt in Youth

OBJECTIVE

Globally, rates of youth suicide vary considerably. Suicidal thoughts and behaviors (STB) are consistently associated with risk of death by suicide. However, international trends in STB have not yet been compared. To address this gap, an international meta-analysis of epidemiological and school-based studies that report on STB in youth was conducted.

METHOD

Systematic searches were conducted in PubMed and PsycINFO through April 2022. Eligible studies included prevalence of active suicidal ideation (SI) or suicide attempts (SA) in community youth younger than age 22. All studies were coded by 2 authors. Mixed models accounting for shared methods and including hypothesized moderators were conducted using the metafor package in R.

RESULTS

There were 371 effect sizes for SI, 94 for SI with a plan, and 316 for SA, representing 149 regions. Year of data collection ranged from 1981 to 2021. Participants were 6 to 21 years old. The prevalence of SI ranged across regions from 14.3% to 22.6%; the prevalence of SA ranged from 4.6% to 15.8%. Year was not associated with increasing STB prevalence except for studies from the United States, which showed increasing rates of SI and SA since 2007.

CONCLUSION

This is the most comprehensive meta-analysis of STB in youth, providing valuable data about how risk factors most commonly associated with suicide vary internationally and over time. International rates of STB among youth are not improving and may be getting worse in the United States, despite efforts to reduce suicide risk. Most studies did not report rates of SI or SA separately for LGBTQIA+ (lesbian, gay, bisexual, transgender, queer, intersex, asexual, and others) youth and youth of color. A better understanding of proximal risk at the individual level will be important to informing future prevention efforts, especially for high-risk groups.

Impaired decision-making in borderline personality disorder

Introduction

Borderline personality disorder (BPD) is a complex mental disorder with core symptoms like interpersonal instability, emotion dysregulation, self-harm, and impulsive decision-making. Previous neuropsychological studies have found impairment in the decision-making of patients with BPD related to impulsivity. In our study, we focus on a better, more nuanced understanding of impulsive decision-making in BPD with the help of Rogers' decision-making test that simulates a gambling situation.

Methods

A novelty of our study is that we excluded from further analysis non-compliant participants based on their performance. Outlier participants on the measures proportion of good choices and average of wager choice number were filtered out to represent the population that understood the basic premise of the task and showed minimal motivation to gain rewards. Thus participants often choosing the less likely color or frequently choosing the first bet amount available (to probably speed up the test) were omitted from further analysis. Another novelty is that we assessed and reported six variables that examine Deliberation Time, Quality of Decision, Risk-taking, Overall proportion bet, Delay aversion, and Risk adjustment. Forty-three women with BPD participated in the study, and 16 non-compliant were excluded. As for the healthy control group, 42 women participated in the study, and four non-compliant were excluded. Thus, we compared the data of 27 patients with BPD with 38 healthy controls.

Results

Our results show that there are significant differences amongst the groups regarding the Quality of Decision Making (F (1,63) = 5.801, p = 0.019) and Risk Adjustment (F (1,63) = 6.522, p = 0.013). We also found significant interactions between group and winning probability regarding Risk Taking (F (4,252) = 4.765 p = 0.001) and Overall proportion of bets, i.e., the average proportion of bets relative to the total score of the subject (F (4,252) = 4.505, p = 0.002).

Discussion

Our results show that the two groups use different decision-making strategies that can have various associations with everyday life situations.

Ketamine and esketamine in suicidal thoughts and behaviors: a systematic review

BACKGROUND

More than 2% of the general population experience suicidal ideas each year and a large number of them will attempt suicide. Evidence-based therapeutic options to manage suicidal crisis are currently limited.

OBJECTIVES

The aim of this study was to overview the findings on the use of ketamine and esketamine for the treatment of suicidal ideas and acts.

DESIGN

Systematic review.

DATA SOURCES AND METHODS

PubMed, article references, and Clinicaltrials.gov up to June 30, 2022. Meta-analyses published within the last 2 years were also reviewed.

RESULTS

We identified 12 randomized controlled trials with reduction of suicidal ideation as the primary objective and 14 trials as secondary objectives. Intravenous racemic ketamine was superior to control drugs (placebo or midazolam) within the first 72 h, in spite of large placebo effects. Adverse events were minor and transient. In contrast, intranasal esketamine did not differ from placebo in large-scale studies. Limitations, clinical considerations, and opportunities for future research include the following points: large placebo effects when studying suicidal ideation reduction; small concerns about blinding quality due to dissociative effects; no studies on the risk/prevention of suicidal acts and mortality; lack of studies beyond affective disorders; no studies in adolescents and older people; lack of knowledge of long-term side effects, notably liability for abuse; no robust predictive markers; limited understanding of the mechanisms of ketamine on suicidal ideas; need for improved assessment of suicidal ideation in clinical trials; need for studies in outpatient settings, emergency room, and liaison consultation; need for research on ketamine administration; limited knowledge on the positive and negative effects of concomitant treatments.

CONCLUSION

Overall, there is compelling evidence for a favorable short-term benefit-risk balance with intravenous racemic ketamine but not intranasal esketamine. The place of ketamine will have to be defined within a multimodal care strategy for suicidal patients. Caution remains necessary for clinical use, and pharmacovigilance will be essential.

Cognitive Flexibility and Impulsivity Deficits in Suicidal Adolescents

Although neurocognitive deficits have been documented in adolescents with suicidal ideation (SI) and suicide attempts (SA), it is unclear whether certain impairments differentiate these groups, potentially suggesting heightened risk for SA. Focus on specific facets of impulsivity and cognitive control may indicate distinctions between adolescents with SA vs. SI. The current study examined dimensions of impulsivity and cognitive control in 141 adolescents with SA (n = 41) vs. SI without SA (n = 49) vs. typically-developing controls (TDCs; n = 51). Adolescents completed cross-sectional neurocognitive tasks via the Cambridge Neuropsychological Testing Automated Battery, in addition to demographic and clinical measures. Analyses involved ANOVAs and ANCOVAs. Results indicated that adolescents with SA demonstrated less set shifting/cognitive flexibility (reduced ability to adapt to/disengage from stimuli) and greater impulsive decision making (reduced ability to collect/evaluate information before making decisions) compared to TDCs. In addition, both TDCs and adolescents with SA had greater response inhibition (increased ability to stop motor responses that have begun/become prepotent) than those with SI. Similar results were found when analyzing female adolescents separately. There were no significant differences for male adolescents, potentially due to the small subsample (n = 40). There were no significant findings for spatial planning/problem solving or visuospatial working memory. Findings suggest: 1) less set shifting/cognitive flexibility and greater impulsive decision making for adolescents with SA vs. TDCs; and 2) greater response inhibition for TDCs and adolescents with SA vs. SI. Such information may be useful for improving risk assessments (adding neurocognitive tasks) and targeted treatments (incorporating cognitive remediation) for this impaired population.

Decision-making biases in suicide attempters with major depressive disorder: A computational modeling study using the balloon analog risk task (BART)

BACKGROUND

In the last decade, suicidality has been increasingly theorized as a distinct phenomenon from major depressive disorder (MDD), with unique psychological and neural mechanisms, rather than being mostly a severe symptom of MDD. Although decision-making biases have been widely reported in suicide attempters with MDD, little is known regarding what components of these biases can be distinguished from depressiveness itself.

METHODS

Ninety-three patients with current MDD (40 with suicide attempts [SA group] and 53 without suicide attempts [NS group]) and 65 healthy controls (HCs) completed psychometric assessments and the balloon analog risk task (BART). To analyze and compare decision-making components among the three groups, we applied a five-parameter Bayesian computational modeling.

RESULTS

Psychological assessments showed that the SA group had greater suicidal ideation and psychological pain avoidance than the NS group. Computational modeling showed that both MDD groups had higher risk preference and lower ability to learn and adapt from within-task observations than HCs, without differences between the SA and NS patient groups. The SA group also had higher loss aversion than the NS and HC groups, which had similar loss aversion.

CONCLUSIONS

Our BART and computational modeling findings suggest that psychological pain avoidance and loss aversion may be important suicide risk factor that are distinguishable from depression illness itself.

Structural brain alterations associated with suicidal thoughts and behaviors in young people: results from 21 international studies from the ENIGMA Suicidal Thoughts and Behaviours consortium

Identifying brain alterations associated with suicidal thoughts and behaviors (STBs) in young people is critical to understanding their development and improving early intervention and prevention. The ENIGMA Suicidal Thoughts and Behaviours (ENIGMA-STB) consortium analyzed neuroimaging data harmonized across sites to examine brain morphology associated with STBs in youth. We performed analyses in three separate stages, in samples ranging from most to least homogeneous in terms of suicide assessment instrument and mental disorder. First, in a sample of 577 young people with mood disorders, in which STBs were assessed with the Columbia Suicide Severity Rating Scale (C-SSRS). Second, in a sample of young people with mood disorders, in which STB were assessed using different instruments, MRI metrics were compared among healthy controls without STBs (HC; N = 519), clinical controls with a mood disorder but without STBs (CC; N = 246) and young people with current suicidal ideation (N = 223). In separate analyses, MRI metrics were compared among HCs (N = 253), CCs (N = 217), and suicide attempters (N = 64). Third, in a larger transdiagnostic sample with various assessment instruments (HC = 606; CC = 419; Ideation = 289; HC = 253; CC = 432; Attempt=91). In the homogeneous C-SSRS sample, surface area of the frontal pole was lower in young people with mood disorders and a history of actual suicide attempts (N = 163) than those without a lifetime suicide attempt (N = 323; FDR-p = 0.035, Cohen's d = 0.34). No associations with suicidal ideation were found. When examining more heterogeneous samples, we did not observe significant associations. Lower frontal pole surface area may represent a vulnerability for a (non-interrupted and non-aborted) suicide attempt; however, more research is needed to understand the nature of its relationship to suicide risk.

Gambling-related suicides and suicidality: A systematic review of qualitative evidence

The relationship between gambling and suicides or suicidality has received much research attention in recent years. Review studies have already mapped the quantitative occurrence of suicide attempts, suicides, and self-harm among gamblers, and found a positive association. Related comorbidities and conditions have also been charted in previous reviews. However, there is still a gap in knowledge regarding the actual processes that connect gambling and suicidal behavior. To understand these processes, the current paper conducts a systematic review of qualitative evidence on gambling-related suicides and suicidality. The aim was to identify the role of gambling as well as of confounding factors in suicidality, and what kind of support suicidal individuals have received or would need. We searched for relevant literature in seven scientific databases. We included all studies that presented empirical qualitative evidence on gambling-related suicide, suicidality and/or self-harm (N = 20). The results show two main processes that connect gambling and suicidal behavior: indebtedness and shame. At the same time, suicide is a multifactorial phenomenon, and related to other confounding factors. These include psychiatric conditions, personality traits, and life conditions. In many cases, these appear to emerge as a consequence of gambling. Treatment for suicidality has been effective in some cases, but indebtedness and shame may also function as barriers to help-seeking. We conclude that effective prevention is needed by adapting a more comprehensive public health approach and population-level interventions.

Alpha-beta decoupling relevant to inhibition deficits leads to suicide attempt in major depressive disorder

BACKGROUND

One devastating outcome of major depressive disorder (MDD) is high suicidality, especially for patients with suicide attempt (SA). Evidence indicated that SA may be strongly associated with inhibitory control deficits. We hypothesized that the inhibition function deficits of patient with SA might be underpinned by abnormal neuronal oscillations.

METHODS

Our study recruited 111 subjects including 74 patients and 37 controls, who performed a GO/NOGO task during magnetoencephalography recording. Time-frequency-representations and phase-amplitude-coupling were measured for the brain circuits involved in the inhibitory function. Phase-slope-indexes were calculated between regions to determine the direction of power flow.

RESULTS

Significant increased reaction time and decreased judgment accuracy were observed in SA group. During the perception stage of GO task (approximately 125 ms), SA group manifested elevated alpha power in ventral prefrontal cortex (VPFC) and attenuated beta power in dorsal anterior cingulate (dACC) compared with other groups (p < 0.01). In the processing stage of NOGO task (approximately 300 ms), they showed decreased beta power in VPFC and increased alpha power in dACC (p < 0.01). Alpha-beta decoupling during both tasks was observed in SA group. Furthermore, the decoupling from VPFC to dACC under NOGO tasks was significantly correlated with suicide risk level.

LIMITATIONS

The number of participants was relatively small, and psychological elements were not involved in current study.

CONCLUSION

Dysregulated oscillatory activities of dACC and VPFC suggested deficits in execution and inhibition functions triggering high suicide risks. The alpha-beta decoupling from VPFC to dACC could be served as a neuro-electrophysiological biomarker for identifying potential suicide risk.

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.

Correlates and predictors of the severity of suicidal ideation in adolescence: an examination of brain connectomics and psychosocial characteristics

BACKGROUND

Suicidal ideation (SI) typically emerges during adolescence but is challenging to predict. Given the potentially lethal consequences of SI, it is important to identify neurobiological and psychosocial variables explaining the severity of SI in adolescents.

METHODS

In 106 participants (59 female) recruited from the community, we assessed psychosocial characteristics and obtained resting-state fMRI data in early adolescence (baseline: aged 9-13 years). Across 250 brain regions, we assessed local graph theory-based properties of interconnectedness: local efficiency, eigenvector centrality, nodal degree, within-module z-score, and participation coefficient. Four years later (follow-up: ages 13-19 years), participants self-reported their SI severity. We used least absolute shrinkage and selection operator (LASSO) regressions to identify a linear combination of psychosocial and brain-based variables that best explain the severity of SI symptoms at follow-up. Nested-cross-validation yielded model performance statistics for all LASSO models.

RESULTS

A combination of psychosocial and brain-based variables explained subsequent severity of SI (R² = .55); the strongest was internalizing and externalizing symptom severity at follow-up. Follow-up LASSO regressions of psychosocial-only and brain-based-only variables indicated that psychosocial-only variables explained 55% of the variance in SI severity; in contrast, brain-based-only variables performed worse than the null model.

CONCLUSIONS

A linear combination of baseline and follow-up psychosocial variables best explained the severity of SI. Follow-up analyses indicated that graph theory resting-state metrics did not increase the prediction of the severity of SI in adolescents. Attending to internalizing and externalizing symptoms is important in early adolescence; resting-state connectivity properties other than local graph theory metrics might yield a stronger prediction of the severity of SI.

A mutant allele of glycoprotein M6-B (Gpm6b) facilitates behavioral flexibility but increases delay discounting

The neuronal membrane glycoprotein M6B (Gpm6b) gene encodes a membrane glycoprotein that belongs to the proteolipid protein family, and is enriched in neurons, oligodendrocytes, and subset of astrocytes in the central nervous system. GPM6B is thought to play a role in neuronal differentiation, myelination, and inactivation of the serotonin transporter via internalization. Recent human genome-wide association studies (GWAS) have implicated membrane glycoproteins (both GPM6B and GPM6A) in the regulation of traits relevant to psychiatric disorders, including neuroticism, depressed affect, and delay discounting. Mouse studies have implicated Gpm6b in sensorimotor gating and regulation of serotonergic signaling. We used CRISPR to create a mutant Glycoprotein M6B (Gpm6b) allele on a C57BL/6J mouse background. Because Gpm6b is located on the X chromosome, we focused on male Gpm6b mutant mice and their wild-type littermates (WT) in two behavioral tests that measured aspects of impulsive or flexible decision-making. We found that Gpm6b deletion caused deficits in a delay discounting task. In contrast, reward sensitivity was enhanced thereby facilitating behavioral flexibility and improving performance in the probabilistic reversal learning task. Taken together these data further delineate the role of Gpm6b in decision making behaviors that are relevant to multiple psychiatric disorders.

Psychobiological risk factors for suicidal thoughts and behaviors in adolescence: a consideration of the role of puberty

Suicide is the second leading cause of death among adolescents. While clinicians and researchers have begun to recognize the importance of considering multidimensional factors in understanding risk for suicidal thoughts and behaviors (STBs) during this developmental period, the role of puberty has been largely ignored. In this review, we contend that the hormonal events that occur during puberty have significant effects on the organization and development of brain systems implicated in the regulation of social stressors, including amygdala, hippocampus, striatum, medial prefrontal cortex, orbitofrontal cortex, and anterior cingulate cortex. Guided by previous experimental work in adults, we also propose that the influence of pubertal hormones and social stressors on neural systems related to risk for STBs is especially critical to consider in adolescents with a neurobiological sensitivity to hormonal changes. Furthermore, facets of the pubertal transition, such as pubertal timing, warrant deeper investigation and may help us gain a more comprehensive understanding of sex differences in the neurobiological and psychosocial mechanisms underlying adolescent STBs. Ultimately, advancing our understanding of the pubertal processes that contribute to suicide risk will improve early detection and facilitate the development of more effective, sex-specific, psychiatric interventions for adolescents.

Brain cortical and subcortical morphology in adolescents with depression and a history of suicide attempt

BACKGROUND

Suicidal behaviours are a major source of mortality and morbidity among adolescents. Given the maturational changes that occur in cortical and subcortical structures during adolescence, we tested whether atypical brain structural measurements were associated with a history of suicide attempt.

METHODS

We assessed 3 groups of adolescents (n = 92; 79% female, mean age 15.9 years, range 11.6-18.1 years): patients with a depressive disorder and a history of suicide attempt (n = 28); patient controls, who had a depressive disorder but no history of suicide attempt (n = 34); and healthy controls (n = 30). We derived regional cortical thickness and surface area, and subcortical volumes, from T1-weighted anatomic MRI scans acquired at 3 T.

RESULTS

We found significant group differences in surface area in the prefrontal, temporal and parietal regions, as well as in the volume of several subcortical nuclei (pFDR ≤ 0.05), but not in cortical thickness. Post hoc analyses indicated that morphological alterations primarily differentiated patients with a history of suicide attempt from healthy controls, but not from patient controls. However, patients with a history of suicide attempt exhibited positive correlations between age and cortical thickness in the temporal cortices and right insula, and between age and right putamen volume (i.e., thicker regional cortex and larger subcortical volumes with age). These correlations were negative in both patient controls and healthy controls (i.e., thinner regional cortex and smaller subcortical volumes).

LIMITATIONS

Sample sizes, cross-sectional findings and psychiatric heterogeneity were limitations of this study.

CONCLUSION

Macroscopic structural differences in several brain regions differentiated adolescents with a history of suicide attempt from healthy controls, but not from patient controls. However, adolescents with a history of suicide attempt may present with atypical maturation of specific cortical and subcortical regions that might contribute to the risk of suicidal behaviour.

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.

Toxoplasma gondii, Suicidal Behavior, and Intermediate Phenotypes for Suicidal Behavior

Within the general literature on infections and suicidal behavior, studies on Toxoplasma gondii (T. gondii) occupy a central position. This is related to the parasite's neurotropism, high prevalence of chronic infection, as well as specific and non-specific behavioral alterations in rodents that lead to increased risk taking, which are recapitulated in humans by T. gondii's associations with suicidal behavior, as well as trait impulsivity and aggression, mental illness and traffic accidents. This paper is a detailed review of the associations between T. gondii serology and suicidal behavior, a field of study that started 15 years ago with our publication of associations between T. gondii IgG serology and suicidal behavior in persons with mood disorders. This "legacy" article presents, chronologically, our primary studies in individuals with mood disorders and schizophrenia in Germany, recent attempters in Sweden, and in a large cohort of mothers in Denmark. Then, it reviews findings from all three meta-analyses published to date, confirming our reported associations and overall consistent in effect size [ranging between 39 and 57% elevation of odds of suicide attempt in T. gondii immunoglobulin (IgG) positives]. Finally, the article introduces certain links between T. gondii and biomarkers previously associated with suicidal behavior (kynurenines, phenylalanine/tyrosine), intermediate phenotypes of suicidal behavior (impulsivity, aggression) and state-dependent suicide risk factors (hopelessness/dysphoria, sleep impairment). In sum, an abundance of evidence supports a positive link between suicide attempts (but not suicidal ideation) and T. gondii IgG (but not IgM) seropositivity and serointensity. Trait impulsivity and aggression, endophenotypes of suicidal behavior have also been positively associated with T. gondii seropositivity in both the psychiatrically healthy as well as in patients with Intermittent Explosive Disorder. Yet, causality has not been demonstrated. Thus, randomized interventional studies are necessary to advance causal inferences and, if causality is confirmed, to provide hope that an etiological treatment for a distinct subgroup of individuals at an increased risk for suicide could emerge.