Impulsive aggression, delay discounting, and adolescent suicide attempts: effects of current psychotropic medication use and family history of suicidal behavior

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.

Potential association between suicide risk, aggression, impulsivity, and the somatosensory system

Aggression and impulsivity are linked to suicidal behaviors, but their relationship to the suicidal crisis remains unclear. This magnetoencephalography (MEG) study investigated the link between aggression, impulsivity, and resting-state MEG power and connectivity. Four risk groups were enrolled: high-risk (HR; n = 14), who had a recent suicidal crisis; lower-risk (LR; n = 41), who had a history of suicide attempts but no suicide attempt or ideation in the past year; clinical control (CC; n = 38), who had anxiety/mood disorders but no suicidal history; and minimal risk (MR; n = 28), who had no psychiatric/suicidal history. No difference in resting-state MEG power was observed between the groups. Individuals in the HR group with high self-reported aggression and impulsivity scores had reduced MEG power in regions responsible for sensory/emotion regulation vs. those in the HR group with low scores. The HR group also showed downregulated bidirectional glutamatergic feedback between the precuneus (PRE) and insula (INS) compared to the LR, CC, and MR groups. High self-reported impulsivity was linked to reduced PRE to INS feedback, whereas high risk-taking impulsivity was linked to upregulated INS to postcentral gyrus (PCG) and PCG to INS feedback. These preliminary findings suggest that glutamatergic-mediated sensory and emotion-regulation processes may function as potential suicide risk markers.

Lateralization of self-control over the dorsolateral prefrontal cortex in decision-making: a systematic review and meta-analytic evidence from noninvasive brain stimulation

The dorsolateral prefrontal cortex (DLPFC) has been widely recognized as a crucial brain "control area." Recently, its causal role in promoting deliberate decision-making through self-control and the asymmetric performance of the left and right DLPFC in control functions have attracted the interest of many researchers. This study was designed to investigate the role of DLPFC in decision-making behaviors and lateralization of its control function by systematically examining the effects of noninvasive brain stimulation (NIBS) over the DLPFC on intertemporal choice, risk decision-making, and social fairness-related decision-making tasks. Literature searches were implemented at PubMed, Embase, Cochrane, Web of Science, Wanfang Data, China Science and Technology Journal Database, and China National Knowledge Infrastructure until May 10, 2022. Meta-analytic results for included studies were estimated by random-effect models. A total of 33 eligible studies were identified, yielding 130 effect sizes. Our results indicated that compared to sham group, excitatory NIBS over the left DLPFC reduced delay discounting rate (standardized mean differences, SMD = -0.51; 95% confidence interval, 95% CI: [-0.81, -0.21]) and risk-taking performance (SMD = -0.39, 95% CI [-0.68, -0.10]), and inhibitory NIBS over the right DLPFC increased self-interested choice of unfair offers (SMD = 0.50, 95% CI [0.04, 0.97]). Finding of current work indicated that neural excitement of the DLPFC activation improve individuals' self-control during decision-makings, whereas neural inhibition results in impaired control. In addition, our analyses furnish causal evidence for the presence of functional lateralization in the left and right DLPFC in monetary impulsive decision-making and social decision-making, respectively.

Mood Disorders and Aggressive Traits Mediate Effects of Reported Childhood Adversity on Suicide Attempt Risk

BACKGROUND

Childhood adversity (CA) is linked to suicidal behavior as well as to mood disorders and aggressive traits. This raises the possibility that depression and aggressive traits mediate the relationship of childhood adversity to suicide risk. Moreover, it is not known if they operate independently or interactively.

AIMS

To determine whether, and how, mood disorders and aggressive traits mediate the effects of reported physical and sexual abuse on future suicidal behavior.

METHODS

Five hundred and forty-eight subjects, offspring of parents with mood disorders, were interviewed at baseline and at yearly follow-ups with questionnaires assessing aggression, mood disorders, and suicidal behavior. The mediation analysis involved a three-step process, testing the relationships between (1) CA and attempt; (2) CA and putative mediators; and (3) putative mediators and suicide attempt, adjusting for CA.

RESULTS

Aggressive trait severity and mood disorder onset each mediated the relationship between CA and future suicide attempts. Greater aggression severity also raised the hazard of the development of a mood disorder. If aggressive trait severity was clearly elevated, then onset of mood disorder did not increase further the hazard of the suicide attempt. Including family as a random effect had a much bigger effect on attempt outcome for physical abuse compared with sexual abuse.

CONCLUSIONS

Amelioration of aggressive traits and treatment of mood disorders in CA-exposed offspring of a parent with a mood disorder may prevent future suicide attempts and may reduce the risk of mood disorder. Familial factors influence the impact of childhood physical abuse but not sexual abuse. HIGHLIGHTSChildhood Adversity (CA) predicted future mood disorder and aggression severity.Depression and aggression mediate the relationship between CA and suicide attempts.When one mediator is present, the presence of the other does not increase the hazard.Between family variation contributed much more to suicidal behavior outcomes relative to the effect of physical abuse, but sexual abuse contributed to suicidal outcomes more than family variation.

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.

Neurobiological metric of cortical delay discounting differentiates risk for self- and other-directed violence among trauma-exposed individuals

Self- and other-directed violence (SDV/ODV) contribute to elevated rates of mortality. Early trauma exposure shows robust positive associations with these forms of violence but alone does not distinguish those at heightened risk for later engagement in SDV/ODV. Novel assessment metrics could aid early identification efforts for individuals with vulnerabilities to violence perpetration. This study examined a novel neurobiological measure of impulsive choice for reward as a potential moderator of associations between childhood trauma exposure and lifetime SDV/ODV. A high-risk community sample of 177 adults (89 men; 50.3%) were assessed for childhood trauma exposure, engagement in SDV (e.g., suicide attempts), and ODV (e.g., assault). A cortical delay discounting (C-DD) measure was created using a multivariate additive model of gray matter thickness across both hemispheres, previously found to be positively associated with susceptibility to impulsivity and externalizing disorders. Childhood trauma exposure was positively associated with ODV and SDV; however, these relationships differed as a function of C-DD. Engagement in ODV increased as scores on C-DD increased, and SDV increased as scores on C-DD decreased. Furthermore, moderation revealed biological sex differences, as the association between childhood trauma and SDV depended on C-DD for women but not for men. Findings from the present work demonstrate that risk conferred by childhood trauma exposure to violence varied as a function of a C-DD. Together, these findings point to the utility of neurobiological markers of impulsive decision-making for differentiating risk for violence among individuals with a history of trauma exposure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Personality and emotion dysregulation profiles predict differential engagement in a wide range of health-risk behaviors

OBJECTIVE

Health-risk behaviors have an unclear etiology and college students have elevated risk for engagement. Emotion dysregulation and several personality dimensions have been implicated in health-risk behaviors, but these constructs have rarely been studied together. Further, it is unknown if different types of health-risk behaviors have distinct etiologies.

PARTICIPANTS

2077 college students completed a cross-sectional survey.

METHODS

Latent profile analysis discerned classes of participants from emotion dysregulation and personality dimensions. Differential engagement in self-injury, suicidality, disordered eating, substance misuse, and unprotected sex was evaluated across classes.

RESULTS

Three classes were identified, which were primarily distinguished by emotion dysregulation, urgency, and neuroticism. Health-risk behaviors generally increased across classes with increasing emotion-related constructs. Self-injury and suicidality demonstrated different patterns than other health-risk behaviors.

CONCLUSIONS

Results elucidate heterogeneity in health-risk behavior engagement. Focusing on emotional difficulties may be more important for reducing self-injury and suicidality than disordered eating, substance misuse, and risky sex.

Cross-phenotype relationship between opioid use disorder and suicide attempts: new evidence from polygenic association and Mendelian randomization analyses

Clinical epidemiological studies have found high co-occurrence between suicide attempts (SA) and opioid use disorder (OUD). However, the patterns of correlation and causation between them are still not clear due to psychiatric confounding. To investigate their cross-phenotype relationship, we utilized raw phenotypes and genotypes from >150,000 UK Biobank samples, and genome-wide association summary statistics from >600,000 individuals with European ancestry. Pairwise association and a potential bidirectional relationship between OUD and SA were evaluated with and without controlling for major psychiatric disease status (e.g., schizophrenia, major depressive disorder, and alcohol use disorder). Multiple statistical and genetics tools were used to perform epidemiological association, genetic correlation, polygenic risk score prediction, and Mendelian randomizations (MR) analyses. Strong associations between OUD and SA were observed at both the phenotypic level (overall samples [OR = 2.94, P = 1.59 ×10-14]; non-psychiatric subgroup [OR = 2.15, P = 1.07 ×10-3]) and the genetic level (genetic correlation rg = 0.38 and 0.5 with or without conditioning on psychiatric traits, respectively). Consistently, increasing polygenic susceptibility to SA is associated with increasing risk of OUD (OR = 1.08, false discovery rate [FDR] =1.71 ×10-3), and similarly, increasing polygenic susceptibility to OUD is associated with increasing risk of SA (OR = 1.09, FDR = 1.73 ×10-6). However, these polygenic associations were much attenuated after controlling for comorbid psychiatric diseases. A combination of MR analyses suggested a possible causal association from genetic liability for SA to OUD risk (2-sample univariable MR: OR = 1.14, P = 0.001; multivariable MR: OR = 1.08, P = 0.001). This study provided new genetic evidence to explain the observed OUD-SA comorbidity. Future prevention strategies for each phenotype needs to take into consideration of screening for the other one.

The effect of social exclusion on intertemporal choice in suicide attempters: A preliminary experimental study

BACKGROUND

Suicide-related theories and a growing body of evidence suggest that suicidal patients may have a tendency toward "short-sightedness"-the preference for immediate gratification when making intertemporal choice-and that social exclusion may exacerbate this tendency in suicidal patients. The present study examined the intertemporal choice performance of suicide attempters under conditions of social exclusion in a sample of affective disorder patients.

METHODS

A total of 64 affective disorder patients (22 non-suicidal patients, 24 single-suicide attempters and 18 multiple-suicide attempters) completed an intertemporal choice task in an exclusion or a non-exclusion condition. Social exclusion was manipulated using the Cyberball paradigm.

RESULTS

Non-suicidal patients and single-suicide attempters both exhibited an exaggerated preference for immediate rewards in the exclusion condition compared with the non-exclusion condition; in contrast, the multiple-suicide attempters appeared relatively indifferent to the social exclusion, exhibiting virtually identical preferences for immediate rewards in both the exclusion and non-exclusion conditions. In addition, the multiple-suicide attempters exhibited an exaggerated preference for immediate rewards compared with non-suicidal patients and single-suicide attempters in the non-exclusion condition, while the three groups did not differ in the exclusion condition.

CONCLUSIONS

Affective disorder patients with a single or no suicide attempts are more short-sighted after being excluded, while those with multiple suicide attempts appeared consistent short-sightedness in both exclusion and non-exclusion conditions. The study provides preliminary evidence of the role of disadvantageous intertemporal choice in the suicidal process. Future research replicate and extend these findings could have implications for suicide prevention and intervention.

Self-injurious thoughts and behaviors and alterations in positive valence systems: A systematic review of the literature

Self-injurious thoughts and behaviors (SITBs), which include suicidal ideation (SI), suicide attempts (SA), and nonsuicidal self-injury (NSSI), are prevalent and associated with impairments in functioning and elevated risk of suicide deaths. Preventing suicide is a complex problem, with numerous systems likely contributing to the onset and maintenance of SITBs, and there is a critical need to identify more precise predictors of risk. Positive valence systems (PVS) are an understudied domain with promise for improving understanding of risk processes underlying SITBs. In this systematic review, we evaluate the evidence for the potential role of altered PVS function in SI, SA, and/or NSSI, including alterations in reward responsiveness, learning, and valuation assessed through behavioral, physiological and circuit measures. Results provide preliminary support for associations between distinct aspects of PVS function and alterations in SITBs. Specifically, SI appears to be characterized by low reward responsiveness, whereas little research has examined reward responsiveness in SA, and NSSI has been characterized by hyper-responsiveness to rewards. Alterations in reward learning and valuation are commonly examined in SA, with some evidence that they may be more strongly associated with attempts than SI or NSSI. At the same time, the literature is limited in that some constructs are commonly examined in one form of SITBs but not others. Further, research is predominantly cross-sectional and focused on adults, raising questions about the role of PVS function in developmental pathways to SITBs. We conclude by integrating the research to date and highlighting promising directions for future research.

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.

Neural Correlates of Reactive Aggression in Adult Attention-Deficit/Hyperactivity Disorder

Despite not being part of the core diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD), emotion dysregulation is a highly prevalent and clinically important component of (adult) ADHD. Emotionally dysregulated behaviors such as reactive aggression have a significant impact on the functional outcome in ADHD. However, little is known about the mechanisms underlying reactive aggression in ADHD. In this study, we aimed to identify the neural correlates of reactive aggression as a measure of emotionally dysregulated behavior in adults with persistent ADHD during implicit emotion regulation processes. We analyzed associations of magnetic resonance imaging-based whole-brain activity during a dynamic facial expression task with levels of reactive aggression in 78 adults with and 78 adults without ADHD, and also investigated relationships of reactive aggression with symptoms and impairments. While participants with ADHD had higher reactive aggression scores than controls, the neural activation patterns of both groups to processing of emotional faces were similar. However, investigating the brain activities associated with reactive aggression in individuals with and without ADHD showed an interaction of diagnosis and reactive aggression scores. We found high levels of activity in the right insula, the hippocampus, and middle and superior frontal areas to be particularly associated with high reactive aggression scores within the ADHD group. Furthermore, the limbic activity was associated with more hyperactivity/impulsivity symptoms. These results suggest a partly differential mechanism associated with reactive aggression in ADHD as compared to controls. Emotional hyper-reactivity in the salience network as well as more effortful top-down regulation from the self-regulation network might contribute to emotionally dysregulated behavior as measured by reactive aggression.

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

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

Delay discounting in suicidal behavior: Myopic preference or inconsistent valuation?

Prior studies sought to explain the predisposition to suicidal behavior in terms of myopic preference for immediate versus delayed reward, generating mixed evidence. Data from gambling and bandit tasks, however, suggest that suboptimal decisions in suicidal individuals are explained by inconsistent valuation rather than myopic preferences. We tested these two alternative hypotheses using a delay discounting task in 622 adults (suicide attempters with depression, suicide ideators with depression, nonsuicidal participants with depression, and healthy controls) recruited across three sites through inpatient psychiatric units, mood disorders clinics, primary care, and advertisements. Multilevel models revealed group differences in valuation consistencies in all three samples, with high-lethality suicide attempters exhibiting less consistent valuation than all other groups in Samples 1 and 3 and less consistent valuation than the healthy controls or participants with depression in Sample 2. In contrast, group differences in preference for immediate versus delayed reward were observed only in Sample 1 and were due to the high-lethality suicide attempters displaying a weaker preference for immediate reward than low-lethality suicide attempters. The findings were robust to confounds such as cognitive functioning and comorbidities. Seemingly impulsive choices in suicidal behavior are explained by inconsistent reward valuation rather than a true preference for immediate reward. In a suicidal crisis, this inconsistency may result in a misestimation of the value of suicide relative to constructive alternatives and deterrents. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

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.

Prevalence and risk factors of suicidal ideation in adult inpatients with five different types of mental disorders

BACKGROUND

Suicide is a major but preventable public health problem in the world. Mental disorders are related to suicide, and can predict suicidal ideation (SI). This study aims to compare the differences in the prevalence and risk factors of SI among patients with five types of mental disorders.

METHODS

This study involved adult inpatients with five types of mental disorders in Beijing Anding Hospital. Text mining was used to extract information from the electronic medical records. We performed the Pearson's Chi-square analysis and multivariable unconditional logistic regression to filter factors to assess odds of SI for each type of mental disorders.

RESULTS

Of the 21,287 participants included, 2,619 had experienced SI. For both sexes, the highest risk of SI was found for patients with recurrent depressive disorder (OR = 7.096; P <.001), followed by patients with depressive episode and bipolar affective disorder when comparing with those with substance use disorder. Gender, age, occupation, drinking, single child, personal relationship, family history of mental disorder, family history of suicide and psychological trauma were associated with SI after adjusting for confounding factors, but the risk factors and their effects in each type were different.

LIMITATIONS

The clear causal associations between mental disorders and SI cannot be elucidated. In addition, the ability to study the predictors of SI is constrained by the fact that the sample excluded people who completed suicide.

CONCLUSIONS

SI is common and distinct strategies should be taken in suicide prevention for patients with different types of mental disorders.

Neural networks during delay discounting as trans-disease marker: A meta-analytical review

Delay discounting reflects a devaluation of delayed long-term benefits but pursuing immediate rewards. Higher discounting rates (h-DR) are found ubiquitous in many diseases and unhealthy conditions, particularly in addiction disorder (AD), attention-deficit/hyperactivity disorder (ADHD), and obesity. Thus, h-DR was considered to be a common benchmark across many diseases facilitating to understand one disease to relevant others, which was called trans-disease process. However, the common and specific neural biomarkers associated with this process has not yet been studied well. We performed a voxel-wise task-related neuroimaging meta-analysis to clarify the neural pattern of trans-disease process across AD, ADHD and obesity. We recruited 19 eligible papers, including 9 AD papers (154 patients), 6 ADHD papers (106 patients) and 4 obesity studies (94 patients). Neuroimaging meta-analysis demonstrated the presence of neural biomarkers of trans-disease process: these patients showed inadequate brain response in caudate, ventromedial and dorsolateral prefrontal cortex (dlPFC) than do of healthy controls (HCs). Disease-specific neural patterns were also found, with prominent hypoactivation in parahippocampal-striatum network for AD, hyperactivation in dopamine-projection striatum network for ADHD and decreased activity in dorsal anterior cingulate cortex and dlPFC for obesity. This study provided robust evidence to reveal the neural substrates of trans-disease process, as well further promoted the triple brain network model in favor of the theoretical developments of these neuropsychiatric disorders.

Search for solutions, learning, simulation, and choice processes in suicidal behavior

Suicide may be viewed as an unfortunate outcome of failures in decision processes. Such failures occur when the demands of a crisis exceed a person's capacity to (i) search for options, (ii) learn and simulate possible futures, and (iii) make advantageous value‐based choices. Can individual‐level decision deficits and biases drive the progression of the suicidal crisis? Our overview of the evidence on this question is informed by clinical theory and grounded in reinforcement learning and behavioral economics. Cohort and case–control studies provide strong evidence that limited cognitive capacity and particularly impaired cognitive control are associated with suicidal behavior, imposing cognitive constraints on decision‐making. We conceptualize suicidal ideation as an element of impoverished consideration sets resulting from a search for solutions under cognitive constraints and mood‐congruent Pavlovian influences, a view supported by mostly indirect evidence. More compelling is the evidence of impaired learning in people with a history of suicidal behavior. We speculate that an inability to simulate alternative futures using one's model of the world may undermine alternative solutions in a suicidal crisis. The hypothesis supported by the strongest evidence is that the selection of suicide over alternatives is facilitated by a choice process undermined by randomness. Case–control studies using gambling tasks, armed bandits, and delay discounting support this claim. Future experimental studies will need to uncover real‐time dynamics of choice processes in suicidal people. In summary, the decision process framework sheds light on neurocognitive mechanisms that facilitate the progression of the suicidal crisis.

This article is categorized under:

Economics > Individual Decision‐Making

Psychology > Emotion and Motivation

Psychology > Learning

Neuroscience > Behavior

Adolescents' Bipolar Experiences and Suicide Risk: Well-being and Mental Health Difficulties as Mediators

Bipolar disorder is usually accompanied by a high suicide risk. The main aim was to identify the risk and protective factors involved in suicide risk in adolescents with bipolar experiences. Of a total of 1506 adolescents, 467 (31%) were included in the group reporting bipolar experiences or symptoms, 214 males (45.8%) and 253 (54.2%) females. The mean age was 16.22 (SD = 1.36), with the age range between 14 and 19. Suicide risk, behavioral and emotional difficulties, prosocial capacities, well-being, and bipolar experiences were assessed through self-report. Mediation analyses, taking gender as a moderator and controlling age as a covariate, were applied to estimate suicide risk. The results indicated that the effect of bipolar experiences on suicide risk is mediated by behavioral and emotional difficulties rather than by prosocial behavior and subjective well-being. Specifically, emotional problems, problems with peers, behavior problems, and difficulties associated with hyperactivity were the most important variables. This relationship was not modulated by gender. However, the indirect effects of some mediators varied according to gender. These results support the development of suicide risk prevention strategies focused on reducing emotional difficulties, behavioral problems, and difficulties in relationships with others.

Contemporary methods in delayed discounting: Applications for suicidology with simulation

OBJECTIVE

To present an approach for integrating recently developed methods in behavioral economics into suicidology research. At present, existing applications of delay discounting in suicidology have focused predominantly on hypothetical choices related to monetary value as a proxy to "risky" choices linked to unsafe or suicidal behavior. In this report, we outline a more targeted approach that directly indexes choices related to treatment in suicide prevention initiatives and incorporates the strengths afforded by multi-level modeling. This more targeted approach precludes the need for multi-step comparisons (improving power), avoids compressing choice variability across delays into individual values (improving precision), and better accommodates decision-making at the upper and lower extremes (improving reliability).

METHOD

We present this analytical approach within the context of a Hypothetical Firearm Decision-making Task with simulated participants. A simulated study is provided to illustrate how this approach can be used to evaluate how individuals make temporally delayed decisions related to treatment for suicidal behavior (i.e., temporarily limiting their access to firearms while undergoing treatment).

RESULTS AND CONCLUSIONS

The results of this simulated study are provided to illustrate how more advanced behavioral decision-making models can be used to supplement existing research methods in suicidology.

Association between family history of suicide attempt and neurocognitive functioning in community youth

BACKGROUND

Suicidal behavior is highly familial. Neurocognitive deficits have been proposed as an endophenotype for suicide risk that may contribute to the familial transmission of suicide. Yet, there is a lack of research on the neurocognitive functioning of first-degree biological relatives of suicide attempters. The aim of the present study is to conduct the largest investigation to date of neurocognitive functioning in community youth with a family history of a fatal or nonfatal suicide attempt (FH).

METHODS

Participants aged 8-21 years from the Philadelphia Neurodevelopmental Cohort completed detailed clinical and neurocognitive evaluations. A subsample of 501 participants with a FH was matched to a comparison group of 3,006 participants without a family history of suicide attempt (no-FH) on age, sex, race, and lifetime depression.

RESULTS

After adjusting for multiple comparisons and including relevant clinical and demographic covariates, youth with a FH had significantly lower executive function factor scores (F[1,3432] = 6.63, p = .010) and performed worse on individual tests of attention (F[1,3382] = 7.08, p = .008) and language reasoning (F[1,3387] = 5.12, p = .024) than no-FH youth.

CONCLUSIONS

Youth with a FH show small differences in executive function, attention, and language reasoning compared to youth without a FH. Further research is warranted to investigate neurocognitive functioning as an endophenotype for suicide risk. Implications for the prevention and treatment of suicidal behaviors are discussed.

Steep Discounting of Future Rewards as an Impulsivity Phenotype: A Concise Review

This chapter provides an overview over the behavioral economic index of impulsivity known as delay discounting. Specifically, delay discounting refers to an individual's preference for smaller immediate rewards over a larger delayed rewards. The more precipitously an individual discounts future rewards, the more impulsive they are considered to be. First, the chapter reviews the nature of delay discounting as a psychological process and juxtaposes it with nominally similar processes, including other facets of impulsivity. Second, the chapter reviews the links between delay discounting and numerous health behaviors, including addiction, attention deficit/hyperactivity disorder, and obesity. Third, the determinants of individual variation in delay discounting are discussed, including both genetic and environmental contributions. Finally, the chapter evaluates delay discounting as a potentially modifiable risk factor and the status of clinical interventions designed to reduce delay discounting to address deficits in self-control in a variety of maladaptive behaviors.

Are suicide attempters more impulsive than suicide ideators?

OBJECTIVE

For over 100 years impulsiveness has been cited as a key factor in why some people that think about killing themselves go on to attempt suicide. Yet prior studies are limited by not using experimental groups that can test this hypothesis and by treating impulsiveness as a unidimensional construct. To overcome these limitations, we compared suicide ideators and suicide attempters on several dimensions of impulsiveness.

METHOD

In Study 1 we compared inpatient suicide attempters who made an attempt within the prior two weeks (n = 30), current inpatient suicide ideators (n = 31), and community controls (n = 34) on several dimensions of impulsiveness using self-report and behavioral measures. In Study 2 (n = 346), we compared three similar groups based on lifetime and past year suicidal behaviors on several of the measures in Study 1.

RESULTS

In Study 1, we found only that negative urgency was clearly elevated among attempters compared with ideators. In Study 2, there were no significant differences on any impulsiveness constructs, including negative urgency.

CONCLUSIONS

Results from the two studies suggest that attempters may not have significantly elevated trait impulsiveness, compared to ideators; however, attempters may have higher impulsiveness when in a negative state.

Impulsivity in the self-harm and suicidal behavior of young people: A systematic review and meta-analysis

BACKGROUND

Impulsivity is considered a possible phenotype underlying the expression of self-harm and suicidal behaviors. Yet impulsivity is a not a unitary construct and there is evidence that different facets of impulsivity follow different neurodevelopmental trajectories and that some facets may be more strongly associated with such behaviors than others. Moreover, it is unclear whether impulsivity is a useful predictor of self-harm or suicidal behavior in young people, a population already considered to display heightened impulsive behavior.

METHODS

A systematic review and meta-analysis of studies published in Medline, PubMed, PsychInfo or Embase between 1970 and 2017 that used a neurocognitive measure to assess the independent variable of impulsivity and the dependent variable of self-harm and/or suicidal behavior among young people (mean age < 30 years old).

RESULTS

6183 titles were identified, 141 full texts were reviewed, and 18 studies were included, with 902 young people with a self-harm or suicidal behavior and 1591 controls without a history of these behaviors. Deficits in inhibitory control (13 studies, SMD 0.21, p-value = 0.002, 95% confidence interval (CI) (0.08-0.34), prediction interval (PI) = 0.06-0.35) and impulsive decision-making (14 studies, SMD 0.17, p-value = 0.008, 95% CI (0.045-0.3), PI = 0.03-0.31) were associated with self-harm or suicidal behavior. There were no significant differences between measures of different facets of impulsivity (ie. delay discounting, risky decision-making, cognitive or response inhibition) and self-harm or suicidal behavior.

CONCLUSION

Multiple facets of impulsivity are associated with suicidal behavior in young people. Future suicide research should be designed to capture impulsive states and investigate the impact on different subtypes of impulsivity.

Adolescent suicide attempts and ideation are linked to brain function during peer interactions

Understanding the neural correlates of social interaction among depressed adolescents with suicidal tendencies might help personalize treatment. We tested whether brain function during social interaction is disrupted for depressed adolescents with (1) high suicide ideation and (2) recent attempts. Depressed adolescents with high suicide ideation, including attempters (n = 45;HS) or low suicide ideation (n = 42;LS), and healthy adolescents (n = 39;HC), completed a version of the Cyberball peer interaction task during an fMRI scan. Groups were compared on brain activity during peer exclusion and inclusion versus a non-social condition. During peer exclusion and inclusion, HS youth showed significantly lower activity in precentral and postcentral gyrus, superior temporal gyrus, medial frontal gyrus, insula, and putamen compared to LS youth; and significantly reduced activity in caudate and anterior cingulate cortex compared to HC youth. In a second analysis, suicide attempters (n = 26;SA) were compared to other groups. SA adolescents showed significantly higher activity in ACC and superior and middle frontal gyrus than all other groups. Brain activity was significantly correlated with negative emotionality, social functioning, and cognitive control. Conclusions: Adolescent suicide ideation and attempts were linked to altered neural function during positive and negative peer interactions. We discuss the implications of these findings for suicide prevention efforts.

Suicidal behaviors and irritability in children and adolescents: a systematic review of the nature and mechanisms of the association

While many psychiatric disorders are associated with an increased risk for suicidal behaviors (SB) in children and adolescents, a few studies have explored the role of clinical symptoms based on a dimensional approach. Irritability is seen as a marker, a general psychopathology, and a symptom of both externalizing and internalizing disorders. In this review, we are interested in determining whether and how irritability can predict SB in youth. First, we reviewed consistencies and variation in the literature linking irritability to suicidal ideation (SI) and suicide attempt (SA). Second, based on the available models, we proposed specific mechanistic pathways, whereby irritability may modulate the risk for SB. Irritability has been found associated with SB both in cross-sectional and in longitudinal studies. The relation is consistent in different settings (i.e., general population and clinical settings) and across psychiatric disorders. The association is reduced but persists after adjusting for psychiatric disorder, including depression. On one hand, irritability constitutes a risk factor for SI via the onset of internalized disorder. On the other hand, irritable youth may be more prone to attempt suicide when experiencing SI. The measures for irritability were heterogeneous. A limited number of studies were designed to explore the role of mediators and/or moderators. Recognizing irritability in children and adolescents is a key issue with regards to suicide prevention.

Reduced dorsal striatal gray matter volume predicts implicit suicidal ideation in adolescents

Suicidal ideation (SI), a potent risk factor for suicide attempts, increases in adolescence. While alterations in dopaminergic functioning have been implicated in suicidal acts—particularly in adults—we do not know whether morphological alterations in dopamine-rich regions of the brain, such as the striatum, are vulnerability factors for the emergence of SI in adolescents. At baseline, a community sample of 152 adolescents (89 female; mean age: 11.41 ± 1.01 years) completed a magnetic resonance imaging (MRI) scan that was used to estimate gray matter volumes (GMVs) of three striatal structures: caudate, nucleus accumbens and putamen. At a 24 month follow-up session, participants completed a self-report measure of SI frequency [Suicidal Ideation Questionnaire (SIQ)] and the death version of the Implicit Association Test (IAT). Robust linear regression models were conducted to predict SIQ and IAT scores from striatal GMV. Bilateral putamen and left caudate GMV significantly predicted IAT scores (all Ps < 0.03). No other associations were significant (all Ps > 0.05). Our finding of reduced dorsal striatal GMV predicting implicit SI may indicate that downstream dopaminergic dysfunction is implicated in the development of overt suicidal behaviors. Self-reported SI was not associated with striatal GMV, suggesting that biological correlates of suicide risk may correlate specifically with objective measurements of SI in adolescents.

Features for medically serious suicide attempters who do not have a strong intent to die: a cross-sectional study in rural China

OBJECTIVE

Previous studies have implied that there were many Chinese suicide attempters who did not want to die by suicide. In the current study, we explored the factors which were associated with low levels of suicide intent. We also examined features for medically serious suicide attempters who do not have a strong intent to die in rural china.

DESIGN

Cross-sectional study.

SETTING

The interviews occurred between May 2012 and July 2013 in 13 rural counties in Shandong and Hunan provinces, China.

PARTICIPANTS

Subjects were 791 medically serious suicide attempters whose injury and wounds were so serious they required hospitalisation or immediate medical care.

RESULTS

The results supported that less years of education (β=-0.11, p=0.037), religious beliefs (β=1.20, p=0.005), living alone (β=1.92, p=0.017), negative life events (β=0.29, p=0.003), low levels of impulsivity (β=-0.10, p=0.013) and mental disorders (β=2.82, p<0.001) were associated with higher levels of suicide intent.

CONCLUSION

Results imply that there are some medically serious suicide attempters with a higher education and/or exhibit impulsivity who do not want to die by suicide. These findings can inform practice to prevent suicide in rural China.

Comparison of familial and non-familial suicidal behaviors among people with major depressive disorder: Testing the discriminative predicting role of high-yield clinical variables

BACKGROUND

Suicidal behavior in first-degree relatives of people diagnosed with major depressive disorder (MDD) increases the risk of suicidal behavior. Such an effect may be the result of genetic risk factors or environmental ones, including imitation, or both. Surprisingly few studies have examined this question and thus, there still is little known about the effect of first-degree family history of suicidal behavior on the type of suicidal behavior and profile of risk factors related to the diathesis for suicidal behavior. Even less is known about intra-familial risk transmission.

METHODS

Patients with MDD (n = 252) experiencing a current major depressive episode and who had a previous suicide attempt were studied. Those with and without a family history of first-degree relatives who had made a suicide attempt or died by suicide were compared across clinical and suicide-related characteristics.

RESULTS

Suicide attempters with (FDR⁺, n = 59) and without a first-degree relative with suicide attempt or suicide (FDR^-, n = 193) were similar in terms of type or frequency of suicide attempts, level of lifetime aggression and impulsivity, age of onset of depression and age at first suicide attempt.

LIMITATIONS

Cross-Sectional study. Lack of additional external validators.

CONCLUSIONS

Contrary to our hypothesis and the concept of "genetic anticipation", a first-degree family history of suicide attempt or suicide in currently depressed attempters with MDD was not associated with a range of clinical and suicide-related characteristics. Longitudinal studies incorporating external validators and potential biological markers may advance this area of research.

Systematic Literature Review of Attempted Suicide and Offspring

Background: Exposure to parental suicide attempt is associated with higher risks of adverse outcomes like lower educational performance, drug abuse and delinquent behavior. When a patient is hospitalized after a suicide attempt, this presents a unique opportunity to identify whether the patient has children, and thereby provide adequate follow-up for both the parent/patient and their children. The objective of this paper was to review the existing literature on follow-up measures for children subjected to parental suicide attempt. Methods: In line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we conducted a systematic literature search. Results: The search resulted in a total of 1275 article titles, of which all abstracts were screened. Out of these, 72 full text papers were read, and a final four articles were included. Three of the included papers described parts of the same study from an emergency department in The Hague, where a protocol was implemented for monitoring and referring children of parents attempting suicide. The fourth article described the association between maternal attempted suicide and risk of abuse or neglect of their children. Conclusions: The lack of research in this particular area is striking. The circumstances surrounding a parent’s suicide attempt call for appropriate familial care.

A behavioral and cognitive neuroscience perspective on impulsivity, suicide, and non-suicidal self-injury: Meta-analysis and recommendations for future research

We conducted a meta-analysis of neurobehavioral and neurocognitive indices of impulsivity in relation to suicidal thoughts and behaviors, as well as non-suicidal self-injury (NSSI). In our systematic review, 34 studies were identified and submitted to a random-effects meta-analysis. A small pooled effect size was observed for the association between behavioral impulsivity and NSSI (OR=1.34, p<0.05). A small-to-medium pooled effect size (OR=2.23, p<0.001) was found for the association between behavioral impulsivity and suicide attempts, and a medium-to-large pooled effect size was observed for this outcome in relation to cognitive impulsivity (OR=3.14, p<0.01). Length of time between suicide attempt and impulsivity assessment moderated the strength of the relation between impulsivity and attempts, with a large pooled effect size (OR=5.54, p<0.001) evident when the suicide attempt occurred within a month of behavioral impulsivity assessment. Studies of clinically significant NSSI temporally proximal to impulsivity assessment are needed. Longitudinal research is required to clarify the prognostic value of behavioral and cognitive impulsivity for short-term risk for self-harm.

Risk-factor differences for nonsuicidal self-injury and suicide attempts in Mexican psychiatric patients

BACKGROUND

The present study compared sociodemographic characteristics, comorbidities with substance use, and impulsivity features in three groups of psychiatric patients - suicide attempters, nonsuicidal self-injury, and nonsuicidal without self-injury - to determine the predictive factors for nonsuicidal self-injury or suicide behavior.

PATIENTS AND METHODS

Demographic features and self-reported substance use were assessed in 384 Mexican psychiatric patients. Impulsivity features were evaluated using the Plutchik Impulsivity Scale. Comparison analyses between groups were performed and a logistic regression model used to determine the factors associated with nonsuicidal with self-injury behavior and suicidal behavior.

RESULTS

Different predictive factors were observed for nonsuicidal self-injury and suicidal behavior. Females were more likely to present nonsuicidal self-injury behaviors (odds ratio [OR] 0.42, 95% confidence interval [CI] 0.18-0.93; P=0.03). For suicide attempters, the factors associated were younger age (OR 0.89, 95% CI 0.85-0.93; P<0.001), less than 6 years of schooling (OR 0.2, 95% CI 0.06-0.6; P=0.004), and higher impulsivity traits, such as self-control (OR 1.19, 95% CI 1.03-1.36; P=0.01), planning of future actions (OR 0.79, 95% CI 0.66-0.95; P=0.01), and physiological behavior (OR 1.34, 95% CI 1.01-1.78; P=0.03).

CONCLUSION

Our results show that in a Mexican population, impulsivity features are predictors for suicide attempts, but not for self-injury. Other factors related to sociocultural background and individual features (such as personality) may be involved in this behavioral distinction, and should be studied in future research aimed at better understanding of both self-harmful behaviors.

Delay discounting and self-reported impulsivity in adolescent smokers and nonsmokers living in rural Appalachia

Background and Objectives This study evaluated whether impulsivity (delay discounting and BIS-11-A) is associated with adolescent smoking status in a region with strong environmental risk factors for smoking. Methods Forty-two adolescent smokers and nonsmokers from rural Appalachia completed discounting and self-reported impulsivity assessments. Results The BIS-11-A, but not the measure of discounting, was associated with smoking status; however, neither assessment predicted smoking status once parent/best-friend smoking variables were statistically accounted for. Discussion and Conclusions In regions with strong environmental risk factors for smoking, delay discounting may play a more limited role in risk of initiation. Scientific Significance Helps to better define impulsivity as risk factors for smoking in relation to familial and broader cultural variables.