Use of the Modified Emotional Stroop Task to Detect Suicidality in College Population

Lower- versus higher-order suicide-related attentional processing measures as predictors of adolescent suicide ideation and attempt

Cognitive theories suggest that biased suicide-related attentional processing confers risk for suicide ideation (SI) and attempts (SAs), but studies to date, which have been mixed, have not compared lower- and higher-order measures of attentional processes. The present study examined attention fixation, attention disengagement, and semantic interference as predictors of future SI and SA among adolescents, a high-risk age group for onset of SI and SAs. Adolescents (N = 135) (75 % female), ages 12-19 (M = 15.4, SD = 1.9), who presented to emergency or outpatient departments with SI (n = 84) or a SA (n = 51) completed an attention disengagement task (ADT), Suicide Stroop task, and the Attentional Fixation on Suicide Experiences Questionnaire (AFSEQ). A subsample of adolescents completed 3-month (n = 98) and 12-month follow-up assessments (n = 96) of SI severity and SA (n = 118) (based on adolescent or caregiver report). AFSEQ score predicted SI severity at 3- and 12-months, respectively, b = 0.47, p < .05; b = 0.44, p < .01, adjusting for ADT and relevant covariates, and also predicted SA at follow up, OR = 1.06, 95 % CI = 1.00-1.12, p < .05, adjusting for SA history, but not after adjusting for SI. Greater suicide-related attention disengagement difficulty predicted greater SI severity at 12 months, b = 0.03, p < .05, but not at 3 months. Self-reported, higher-order, attentional fixation may better predict future suicide-related risk among diverse adolescents than lower-order cognitive tasks assessing suicide-related attention disengagement or semantic interference.

Cognitive control impairment in suicide behaviors: what do we know? A systematic review and meta-analysis of Stroop in suicide behaviors

BACKGROUND

Suicidal behavior results from a complex interplay between stressful events and vulnerability factors, including cognitive deficits. Poorer performance on the Stroop task, a measure of cognitive control, has been associated with suicidal behavior in numerous studies. The objective was to conduct an updated systematic review of the literature on the Stroop task as a neuropsychological test of vulnerability to suicidal acts in patients with mood and other psychiatric disorders, while also looking at how the type (classic versus emotional) or the version (paper or computerized) of the Stroop task, as well as the characteristics of the patient (clinical population, age, sex) moderated the Stroop effect.

METHODS

A search on Medline, Embase, PsycInfo databases, and article references was performed. 53 studies (6781 participants) met the selection criteria. Interference time and errors of the Stroop Test were assessed in at least 3 studies to be analyzed. Moderators, such as the type (classic versus emotional) of the Stroop task and the characteristics of the patient (clinical population, age, sex) were also assessed.

RESULTS

Interference time on Stroop performance was lower in suicide attempters than in patient controls (g = 0.20; 95%CI [0.10-0.30]) and healthy controls (g = 0.79; 95 % CI [0.29-1.29]), with patient controls scoring lower than healthy controls (g = -0.63; 95%CI [-1.01-0.25]). This was moderated by age and having a mood disorder. In terms of interference errors, suicide attempters performed worse than healthy controls (g = 0.57; 95%CI [0.01-1.15]) but did not perform differently from patient controls (g = 0.20; 95 % CI [-0.06-0.45]). Patient controls also did not score differently than healthy controls (g = -0.18; 95 % CI [-0.54-0.18]). There was a significant moderation effect for the type (i.e., original Stroop task) and version (i.e., paper format) of the Stroop task, and for some characteristics of the patient (i.e., older patients and having a mood disorder).

CONCLUSIONS

Cognitive control impairment was associated with a history of suicidal behavior in patients, especially in older populations and those with mood disorders, however this result was moderated by outcome measure (interference time vs. errors), the type (i.e., original Stroop task) and the version (i.e., paper format) of the Stroop task. Cognitive control processes may be an important factor of suicidal vulnerability. Choosing the right neurocognitive test in the right population to detect suicide vulnerability is important direction for future research.

Suicide Ideation Severity and Oculomotor Avoidance of Suicide-Related Stimuli

INTRODUCTION

Identifying variables linked to distinct suicide outcomes has long been among suicidology's research priorities. Cognitive theories of suicide identify attentional processes that may vary for individuals at a greater suicide risk. However, an overreliance on self-report and objective measures that are poor estimates of attention has led to mixed findings.

METHOD

The current study utilizes eye tracking with a novel passive viewing task to explore differences in viewing patterns for suicide- and neutral-image pairings, as a function of suicide outcomes. Young adults (N = 124, 83.9% women) were oversampled for recent suicidal thoughts and behaviors, and completed a series of self-report questionnaires specific to suicide history, as well as relevant covariates prior to completing the eye-tracking task.

RESULTS

Multilevel modeling revealed that individuals with low-to-moderate ratings of past-year ideation displayed a significant decline in the amount of time spent viewing suicide images as compared to neutral images over the course of the task (oculomotor avoidance). However, the same pattern was not seen among individuals with high suicide ideation, specifically those with resolved plans and preparation. Furthermore, no differences were found between people with and without a suicide attempt history.

CONCLUSION

These results suggest a suicide-specific disengagement bias among individuals high in suicide ideation and more specifically, resolved plans and preparation.

Differences in suicide-specific attentional bias based on stimuli across the suicide Stroop and disengagement tasks

BACKGROUND

Evidence of suicide-specific attentional bias has been mixed, including the effect of specific suicide words (e.g., "suicide" versus "overdose"). The current study examined the psychometric properties and convergent validity of specific suicide words on the Stroop and disengagement tasks.

METHODS

Adults (79.8 % male, mean age = 42.19 ± 12.66) on a psychiatric inpatient unit completed both tasks, as well as clinical and demographic measures, following a recent suicide attempt (SA) (n = 55) or recent suicidal ideation (SI) with (n = 29) or without (n = 26) a SA history.

RESULTS

Mean reaction times (RTs) on both tasks demonstrated good internal consistency and were moderately correlated across tasks, while interference scores demonstrated poor reliability and were not correlated. Attentional bias to specific suicide words did not differentiate SA groups, except for a small, unexpected effect on the Stroop task showing greater interference to the word "funeral" among the recent SA group. Correlations with suicide risk factors differed for males and females.

LIMITATIONS

Participants all endorsed elevated SI, limiting generalizability beyond a recent suicidal crisis. Different suicide words were used on each task limiting direct comparisons. Groups based on SA history and gender were uneven, and correlations need to be replicated. Effects involving interference scores should be interpreted with caution given poor internal consistency.

CONCLUSION

The suicide Stroop and disengagement tasks partially capture distinct aspects of suicide-relevant attentional bias. Greater attention is needed regarding the particular stimuli and scoring methods as well as the role gender plays in suicide-relevant attentional bias.

A suicide attentional bias as implicit cognitive marker of suicide vulnerability in a high-risk sample

Introduction

Suicide risk assessment based on self-report questionnaires is considered as problematic because risk states are dynamic and at-risk individuals may conceal suicidal intentions for several reasons. Therefore, recent research efforts increasingly focus on implicit risk markers such as the suicide attentional bias (SAB) measured with the Suicide Stroop Task (SST). However, most SST studies failed to demonstrate a SAB in individuals with suicide risk and repeatedly demonstrated insufficient psychometrics of the SST. This study aimed to investigate a SAB using a modified SST (M-SST) and to test its psychometric properties.

Method

We compared n = 61 healthy controls and a high-risk inpatient sample of n = 40 suicide ideators and n = 40 suicide attempters regarding interference scores of positive, negative and suicide-related words. Interference scores were calculated by subtracting the mean reaction time (mean RT) of the neutral words from the mean RT of the suicide-related words (mean RT Suicide -mean RT Neutral), resulting in a suicide-specific interference score. Similarly, interference scores were calculated for the positive and negative words by subtracting the mean RT of neutral words from the mean RT of positive and negative words.

Results

A Group × Interference ANOVA showed a significant interaction effect (p <.001, ηp2 = .09), indicating that group effects significantly vary across interference type. Post hoc comparisons revealed that both ideators and attempters demonstrated greater interferences only for suicide-related words compared to healthy controls, indicating a SAB in patients, while a difference between ideators and attempters was lacking. The suicide interference score classified with an AUC = 0.73, 95% CI [0.65 - 0.82], p <.001, between controls and patients with STBs. The M-SST demonstrated good internal consistency and convergent validity.

Discussion

The study adds evidence to the assumptions of the Cognitive Model of Suicide, viewing a SAB as a cognitive marker of suicide vulnerability independently of the engagement in suicidal behavior. The results' clinical implications are discussed in the context of recommended intervention strategies during an acute suicidal state. Future studies with the M-SST should include non-suicidal patient controls to investigate whether a SAB is uniquely related to suicidality.

Psychometric properties of the modified Suicide Stroop Task (M-SST) in patients with suicide risk and healthy controls

The Cognitive Model of Suicide proposes a suicide attentional bias in individuals with suicidal thoughts and behavior (STBs). The Suicide Stroop Task (SST) was developed as a behavioral measure to assess this attentional bias. However, prior studies demonstrated poor psychometric properties of the SST.

Methods

We developed a modified Suicide Stroop Task (M-SST) and tested its psychometric properties in a sample of healthy controls (n = 30) and inpatients with STBs (n = 24). Participants (50% female, aged 18 to 61 years) completed the M-SST with neutral, positive, negative, suicide-related positive and suicide-related negative words. Interference scores were calculated by subtracting the mean reaction time (mean RT) of the neutral words from the mean RT of the suicide-related positive words (mean RTSuicide-Positive-mean RTNeutral) and suicide-related negative words (mean RTSuicide-Negative-mean RTNeutral), resulting in two suicide-specific interference scores. Similarly, interference scores were calculated for the positive and negative words by subtracting the mean RT of neutral words from the mean RT of positive and negative words.

Results

When analyzed separately, patients with STBs showed greater interferences for suicide-related positive words (p = 0.039), and for suicide-related negative words (p = 0.016), however, we found no group differences in interference scores for positive and negative words, suggesting a suicide attentional bias in patients with STBs. Controlling for the repeated measure design, a repeated measure ANOVA failed to detect a significant group × interference interaction effect (p = 0.176), which limits the generalizability of the findings. However, the interference score of suicide-related negative words showed an adequate classification accuracy (AUC = 0.72, 95% CI [0.58-0.86], p = 0.006) for differentiating between healthy controls and patients with STBs. Moreover, the interference scores showed acceptable internal reliability for the total sample and only suicide-related interference scores were correlated with clinical characteristics, thus demonstrating convergent validity.

Conclusion

The results provide preliminary evidence for a suicide attentional bias in individuals with STBs compared to healthy controls. The M-SST represents a promising tool for assessing a suicide attentional bias by revealing adequate psychometric properties. Future studies with larger samples are needed to confirm these preliminary findings.

The Suicide Dot Probe Task: Psychometric properties and validity in relation to suicide-related outcomes

BACKGROUND

Attentional biases to suicide-related stimuli have been linked to suicide-related outcomes. However, behavioral tasks that have been previously modified to capture suicide-specific attentional biases have demonstrated inconsistent reliability and validity. Adaptation of the Dot Probe Task, a computerized assessment that has been adapted to study a wide variety of biases, may be a promising candidate for assessing suicide-specific biases.

METHODS

In 280 recently discharged inpatients (51% male; Mage  = 40.22 years), we evaluated the psychometric properties of a modified Suicide Dot Probe Task. Participants completed this task and assessments of suicidal thoughts and behaviors at baseline and 6-month follow-up.

RESULTS

The Suicide Dot Probe Task demonstrated poor-to-moderate internal consistency and poor test-retest reliability, and participant response times were slower to suicide-specific and dysphoric stimuli than positive stimuli. However, there were no differences based on the presence or characteristics of recent or lifetime suicidal ideation or attempts. Participants' suicide-specific biases were not predictive of suicidal ideation or attempts at follow-up.

CONCLUSIONS

The Suicide Dot Probe Task exhibited questionable reliability, and differences in attentional biases were not associated with suicidal ideation or attempts. This study contributes to a body of research demonstrating the questionable utility of several behavioral tasks to study suicide-specific attentional biases.

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.

Abnormal attentional bias in individuals with suicidal ideation during an emotional Stroop task: an event-related potential study

Introduction

There is increasing evidence that suicidal individuals exhibit an attentional bias toward negative or suicide-related stimuli, but the underlying neural mechanism remains unclear. This study aimed to investigate the neural mechanism of attentional bias toward emotional stimuli using a modified emotional Stroop task (EST) and to further explore the influencing factor of abnormal attention processing by identifying whether mental disorders or suicidal ideation contributes to attention processing disruptions.

Methods

Fourteen students with suicidal ideation and mental disorders (SIMDs), sixteen students with suicidal ideation but no mental disorders (SINMDs), and fourteen sex- and age-matched healthy controls (HCs) were recruited. Moreover, 64-channel electroencephalography (EEG) data and behavioral responses were recorded simultaneously during the EST. Participants were instructed to respond to the ink color for various types of words (positive, neutral, negative, and suicide) while ignoring their meanings. Event-related potentials (ERPs) were analyzed to evaluate attention to the stimuli. Spearman correlations between clinical psychological assessment scales and ERP signatures were analyzed to determine the risk factors for suicide.

Results

The results showed that the SIMD group exhibited longer early posterior negativity (EPN) latency compared to the SINMD and HC groups, indicating that early attention processing was affected during the EST, and the automatic and rapid processing of emotional information decreased. Furthermore, P300 latency for positive words was positively correlated with current suicidal ideation in the SINMD group, suggesting that delayed responses or additional processing to positive information may lead individuals with suicidal ideation to an incorrect interpretation of external events.

Conclusions

Generally, our findings suggest that the neural characteristics of the SIMD group differed from those of the SINMD and HC groups. EPN latency and P300 latency during the EST may be suicide-related neurophysiological indicators. These results provide neurophysiological signatures of suicidal behavior.

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

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

Implicit Cognition Tests for the Assessment of Suicide Risk: a Systematic Review

PURPOSE OF REVIEW

Suicide risk assessment is a challenge in clinical practice. Implicit measures may present with advantages with respect to explicit methods, and therefore may be useful for the assessment of suicide risk. We conducted a systematic review of 2 databases (PubMed and EMBASE) about implicit tests that measure suicide risk to explore their validity and reliability.

RECENT FINDINGS

Initial research revealed 321 articles. After the selection process, 31 articles were included in the review. The most death-related implicit cognition test used was the Death/Suicide Implicit association test (D/S IAT), followed by the Suicide Stroop Task. The Suicide Affect Misattribution Procedure (S-AMP) and the Death version of the Implicit Relational Assessment Procedure (D-IRAP) were also used. We found that the measures reviewed were generally valid for the assessment of past and future suicidal thoughts and behaviors, with statistically significant results regarding retrospective and prospective associations.

The relationship between suicide-specific rumination and suicidal intent above and beyond suicidal ideation and other suicide risk factors: A multilevel modeling approach

Suicide-specific rumination, characterized by perseveration on and difficulties disengaging from suicidal thoughts and ideas, has been linked to increased suicide risk; however, previous studies were limited by the use of a cross-sectional design and relatively lower risk samples. This study aimed to replicate and extend previous findings by examining the short-term longitudinal association between suicide-specific rumination and suicidal intent, controlling for numerous robust covariates, in a sample of community-based adults at high risk for suicide, who were recruited from suicide-related forums online. Ninety-one adults with significant suicidal ideation (M_age = 27.03, SD = 8.64; 53.8% female, 44.0% male, 1.1% non-binary, 1.1% transgender female) completed brief online self-report measures at six time-points, each three days apart. Multilevel modeling analyses indicated that suicide-specific rumination was associated with suicidal intent, above and beyond suicidal ideation, perceived burdensomeness, thwarted belongingness, agitation, insomnia, nightmares, and sociodemographic characteristics. Further, a lagged model demonstrated that suicide-specific rumination predicted subsequent time-point suicidal intent, controlling for current suicidal intent and all other covariates. Overall, these findings suggest that perseverating on one's suicidal thoughts may serve as a proximal factor that increases suicide risk. Future investigations should explore potential mechanisms of this association, as well as interventions that may reduce suicide-specific rumination.

Psychometric Properties of the Suicide Stroop Task in a Chinese College Population

Objective

This study aimed to test the psychometric properties of the suicide stroop task in a Chinese college population.

Methods

College students (n = 121) who were in the 1st–4th grade, fluent in Chinese, and without color blindness were recruited from a university in Guangzhou, China from September to December 2019. Participants were administered the suicide stroop task at baseline and 1-month follow-up.

Results

The suicide stroop task showed excellent internal reliability (Cronbach’s α ranged from 0.940 to 0.953). However, the suicide stroop task did not reveal suicide-related attentional biases among current suicide ideators and was not significantly associated with the severity of suicidal ideation, depression, hopelessness, nor anhedonia (all p values > 0.05), indicating a lack of concurrent validity for the task. Additionally, the two-time data of interference scores could not generate intraclass correlation coefficients (ICCs) due to a negative average covariance among data, which indicated poor test–retest consistency for the task.

Conclusion

The results of this study did not support the use of the suicide stroop task on the identification of suicidal risk among Chinese college students. It is crucial to assess the psychometric properties of behavioral measures rigorously as self-report measures before large applications in clinical and community settings.

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

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

Influence of the GABA Receptor Subunit Gene Polymorphism and Childhood Sexual Abuse on Processing Speed in Major Depression and Suicide Attempt

Background: Suicide is moderately heritable and also more common in those who report childhood abuse. Previously, it was found that allele A of GABRG2 (GABA A receptor subunit gamma2) polymorphism rs211034 was protective in a suicide attempt (SA). Hence, it was proposed that rs211034 may interact with childhood trauma to influence cognitive deficits related to SA or depression risk. Genetic variants may predict the benefits of certain cognitive treatments. Methods: A total of 52 individuals who had attempted suicide, 59 individuals with major depressive disorder (MDD) or bipolar depression who had not previously attempted suicide, and 90 healthy volunteers were subjected to the modified Suicide Stroop task and were clinically assessed using the Childhood Trauma Questionnaire (CTQ) and Hamilton Depression Scale-24 items (HAMD-24). rs211034 was genotyped using Sanger sequencing. Results: After correcting for covariates, depressed participants displayed longer reaction times for all emotional conditions, including suicide-related words, compared with healthy controls. Depressed suicide attempters displayed longer reaction times for negative words than depressed non-attempters. Depressed non-attempters displayed higher interference scores for negative words compared with healthy controls. There was an interaction between rs211034 risk allele and the effects of reported childhood sexual abuse (CSA) on reaction time for all emotional words and suicide-related words. Carriers of the rs211034 risk allele A exhibited shorter reaction times, but the protective effects of this allele were eliminated in those exposed to reported CSA. Conclusion: Only limited results were found regarding effects of a past suicide attempt on response times to emotional and suicide-related words, but there was an overall effect of major depression on slower response time. Protective genetic effects of the rs211034 A allele on this slowing were eliminated in those with a history of sexual abuse during childhood. Further research is needed to better characterize the mechanisms underlying the effects of childhood trauma on these genetic effects.

Towards the objective assessment of suicidal states: Some neurocognitive deficits may be temporally related to suicide attempt

Neurocognitive detection of suicidal states has the potential to significantly advance objective risk assessment. This goal requires establishing that neurocognitive deficits fluctuate around the time of a suicide attempt. The current study therefore evaluated whether neurocognitive performance is temporally related to suicide attempt, in a sample at highrisk for suicide (n = 141). Evaluations consisted of a clinician-administered interview, self-report questionnaires, and neurocognitive tasks assessing response inhibition, attentional control, and memory recognition. Analyses examined whether neurocognitive scores significantly differed according to the following temporal suicide attempt categories: (a) past-week attempt; (b) past-year attempt (not in past week); and (c) no past-year attempt. Univariate results showed that response inhibition and memory recognition were significantly related to suicide attempt recency. Post-hoc pairwise tests showed that participants with a past-week suicide attempt showed greater impairments than those without a past-year attempt. Multivariate tests showed the same pattern of results, adjusting for age, suicide attempts prior to past year, mood disturbance, and suicidal ideation. These results show that neurocognitive assessment of response inhibition and memory recognition shows sensitivity to the recency of a suicide attempt. While future prospective studies are needed, results suggest that phasic neurocognitive deficits may serve as objective markers of short-term suicide risk.

Biological bases of suicidal behaviours: A narrative review

Suicidal behaviour is a multifaceted phenomenon that concerns all human populations. It has been suggested that a complex interaction between the individual genetic profile and environmental factors throughout life underlies the pathophysiology of suicidal behaviour. Although epidemiological and genetic studies suggest the existence of a genetic component, exposure to biological and psychosocial adversities, especially during critical developmental periods, also contributes to altering the biological responses to threat and pleasure. This results in amplified maladaptive cognitive and behavioural traits and states associated with suicidal behaviours. Alterations in the cognitive inhibition and decision-making capacity have been implicated in suicidal behaviours. Structural and functional changes in key brain regions and networks, such as prefrontal cortex, insula and default mode network, may underlie this relationship. Furthermore, the shift from health to suicidal behaviour incorporates complex and dynamic changes in the immune and stress responses, monoaminergic system, gonadal system and neuroplasticity. In this review, we describe the major findings of epidemiological, genetic, neuroanatomical, neuropsychological, immunological and neuroendocrinological studies on suicide behaviours to provide a solid background for future research in this field. This broad overview of the biological bases of suicide should promote neuroscience research on suicidal behaviours. This might lead to improved biological models and to the identification of evidence-based biomarkers, treatment options and preventive strategies.

Investigating the psychometric properties of the Suicide Stroop Task

Behavioral measures are increasingly used to assess suicidal thoughts and behaviors. Some measures, such as the Suicide Stroop Task, have yielded mixed findings in the literature. An understudied feature of these behavioral measures has been their psychometric properties, which may affect the probability of detecting significant effects and reproducibility. In the largest investigation of its kind, we tested the internal consistency and concurrent validity of the Suicide Stroop Task in its current form, drawing from seven separate studies (N = 875 participants, 64% female, aged 12 to 81 years). Results indicated that the most common Suicide Stroop scoring approach, interference scores, yielded unacceptably low internal consistency (rs = -.09-.13) and failed to demonstrate concurrent validity. Internal consistency coefficients for mean reaction times (RTs) to each stimulus type ranged from rs = .93-.94. All scoring approaches for suicide-related interference demonstrated poor classification accuracy (AUCs = .52-.56) indicating that scores performed near chance in their ability to classify suicide attempters from nonattempters. In the case of mean RTs, we did not find evidence for concurrent validity despite our excellent reliability findings, highlighting that reliability does not guarantee a measure is clinically useful. These results are discussed in the context of the wider implications for testing and reporting psychometric properties of behavioral measures in mental health research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Cognitive-Affective Correlates of Suicide Ideation and Attempt: Mindfulness is Negatively Associated with Suicide Attempt History but not State Suicidality

The objective of this study was to test whether 3 cognitive-affective correlates,--mindfulness, emotion reactivity, and depressive symptom severity-have different associations with current suicidal ideation (SI), a history of suicide attempt (SA) and SA + SI among emerging adults. Whether impulsive-aggression (IA) moderated associations between cognitive-affective correlates of suicidal behavior and suicidality was also tested. Survey data on current SI, SA history, mindfulness, emotion reactivity, depressive symptom severity, and IA were collected from 780 emerging adults. Results from multinomial logistic regression analysis showed greater depressive symptom severity among emerging adults with current SI, regardless of SA history. Those with a history of SA reported greater depressive symptom severity and less mindfulness than controls. IA did not moderate relationships of SI and/or SA and mindfulness, emotion reactivity, or depressive symptom severity. Mindfulness is a marker of SA, and depressive symptom severity is associated with current SI and SA history in emerging adults. IA does not moderate these associations. To the extent that a history of SA is indicative of elevated trait-like suicide risk and SI indicates state suicidality, our findings suggest that mindfulness protects against longer-term vulnerability to suicide while depressive symptom severity is associated with suicide state-trait risk.

Suicide-Specific Rumination Relates to lifetime suicide attempts above and beyond a variety of other suicide risk factors

Suicide-specific rumination, defined as a mental fixation on one's suicidal thoughts, intentions, and plans, may be an important predictor of suicidal behavior. To date, suicide-specific rumination has demonstrated convergence with, yet distinction from, a variety of suicide risk factors, and differentiated suicide attempters from ideators. However, no research has examined whether suicide-specific rumination is associated with lifetime suicide attempts above and beyond the presence of a host of other relevant suicide risk factors. The present study tested this hypothesis in samples of students (N = 300) and community members recruited via Amazon's MTurk (N = 209) who reported a lifetime history of suicidal ideation. Results indicated that suicide-specific rumination was associated with the presence of a lifetime suicide attempt, above and beyond a variety of other commonly-cited risk factors for suicidal thoughts and behaviors in both samples, including suicidal ideation, general rumination, interpersonal theory variables, emotion-relevant factors (dysregulation, experiential avoidance, distress tolerance, negative affect), symptoms of depression and anxiety, and overarousal. Overall, though limited by the use of non-clinical samples and a cross-sectional study design, that suicide-specific rumination outperformed all other suicide risk factors in predicting the presence of a lifetime suicide attempt suggests the potential potency of this relatively understudied risk factor in understanding transitions to suicidal behavior.

Positive and Negative Suicide Ideation (PANSI) Inventory: Initial Psychometric Properties as a Suicide Risk Screening Tool Among Nigerian University Students

Objective:

The objective of this study is to examine the factor structure, validity, reliability, and the screening properties as a suicide risk assessment tool of the 14-item Positive and Negative Suicide Ideation (PANSI) in a nonclinical sample of Nigerian university students.

Methods:

A total of 514 students completed the PANSI, in addition to the Beck Depression Inventory-II (BDI-II) and the General Health Questionnaire-12 (GHQ-12).

Results:

Prior to the factor analysis, the sample was randomly divided into two. In one half of the sample (sample 1), exploratory factor analysis of the inventory yielded a 2-factor model (Negative Suicide Ideation [PANSI-NSI] and Positive Ideation [PANSI-PI]), whereas confirmatory factor analysis in the other half (sample 2) produced a 2-factor model with indices of fitness that indicated a satisfactory model fit ( c2 = 93.8; df = 67; χ2/degree of freedom = 1.400; P = .017; goodness of fit index = 0.951; Tucker-Lewis index = 0.964; comparative fit index = 0.974; root mean square error of approximation = 0.040). The internal consistencies of the items of the PANSI-PI and PANSI-NSI subscales were 0.75 and 0.79, respectively. The construct validity of the 2 subscales was modestly satisfactory: PANSI-PI had negative correlations with the GHQ-12 ( r = −.239, P < .001) and the BDI-II ( r = −.190, P < .001), whereas the PANSI-NSI had positive correlations with the GHQ-12 ( r = .248, P < .001) and the BDI-II ( r = .376, P < .001). In addition, a cutoff total score of 17 on the PANSI-NSI was associated with the best sensitivity (80.0%) and specificity (92.5%) in the identification of those students who endorsed experiencing suicidal ideation (area under the curve = 0.82, 95% confidence interval = 0.58-1.00).

Conclusions:

The PANSI has exhibited satisfactory psychometric properties as a self-rated suicidal behavior assessment instrument in the evaluation of the positive and negative thoughts associated with suicidal ideation among Nigerian university students.

The Association Between Suicidal Behavior, Attentional Control, and Frontal Asymmetry

It can be difficult to identify those at risk of suicide because suicidal thoughts are often internalized and not shared with others. Yet to prevent suicide attempts it is crucial to identify suicidal thoughts and actions at an early stage. Past studies have suggested that deficits in attentional control are associated with suicide, with the argument that individuals are unable to inhibit negative thoughts and direct resources away from negative information. The current study aimed to investigate the association of suicidal behavior with neurological and behavioral markers, measuring attentional bias and inhibition in two Stroop tasks. Fifty-four participants responded to the color of color words in a standard Stroop task and the color of positive, negative, and neutral words in an emotional Stroop task. Electroencephalographic (EEG) activity was recorded from frontal areas during each task and at resting. Participants were separated into a low-risk and high-risk group according to their self-reported suicidal behavior. Participants in the high-risk group showed slower response times in the color Stroop and reduced accuracy to incongruent trials, but faster response times in the emotional Stroop task. Response times to the word "suicide" were significantly slower for the high-risk group. This indicates an attentional bias toward specific negative stimuli and difficulties inhibiting information for those with high levels of suicidal behavior. In the emotional Stroop task the high-risk group showed reduced activity in leftward frontal areas, suggesting limitations in the ability to regulate emotional processing via the left frontal regions. The findings support the argument that deficits in attentional control are related to suicidal behavior. The research also suggests that under certain conditions frontal asymmetry may be associated with suicidal behavior.

ERP investigation of attentional disengagement from suicide-relevant information in patients with major depressive disorder

BACKGROUND

Previous studies suggest the presence of attentional bias towards suicide-relevant information in suicidal individuals. However, the findings are limited by their reliance on behavioral measures. This study investigates the role of difficulty in disengaging attention from suicide-relevant stimuli using the P300 component of event-related potentials (ERPs).

METHODS

Forty-four adults with Major Depressive Disorder (MDD) were administered the spatial cueing task using suicide-relevant and negatively-valenced words as cue stimuli. Disengagement difficulty was measured using reaction time and P300 during invalid trials.

RESULTS

P300 amplitudes at Pz were higher in suicide-relevant compared to negatively-valenced word condition on invalid trials for participants with low rates of suicidal behavior. However, no such difference was found among participants with high rates of suicidal behavior. P300 amplitudes for suicide-relevant word condition were negatively correlated with "lifetime suicide ideation and attempt" at Pz. No significant results were found for the reaction time data, indicating that the ERP may be more sensitive in capturing the attentional disengagement effect.

LIMITATIONS

The groups were divided according to Suicidal Behaviors Questionnaire-Revised (SBQ-R) total score. Neutral stimulus was not included as cue stimuli. Most participants were under medication during the experiment.

CONCLUSIONS

Our results indicate that patients with MDD and low rates of suicidal behavior show difficulty in disengaging attention from suicide-relevant stimuli. We suggest that suicide-specific disengagement difficulties may be related to recentness of suicide attempt and that acquired capability for suicide may contribute to reduced disengagement difficulties.

Detecting Suicide Risk Among College Students: A Test of the Predictive Validity of the Modified Emotional Stroop Task

Detecting suicide risk among nonclinical populations is challenging due to low base rates and the help-negation tendency of at-risk individuals. The current longitudinal study investigated the predictive validity of the modified emotional Stroop task (EST) by conducting a follow-up study of 197 students who participated in a study by Chung and Jeglic (2016). The EST latencies for suicide-related cues and past suicidal behaviors were the only significant predictors of suicide risk. The findings of this study provide preliminary support for the use of the EST as part of a suicide risk screening battery that could add to the detection of suicide risk.

Attentional bias toward suicide-relevant information in suicide attempters: A cross-sectional study and a meta-analysis

OBJECTIVE

Previous studies using a modified Stroop test suggested that suicide attempters, in contrast to depressed patients with no suicidal history, display a particular attentional bias toward suicide-related cues. However, negative results have also been reported. In the present study, we collected new data and pooled them as part of a meta-analysis intended to shed further light on this question.

METHOD

We conducted 1) a cross-sectional study comparing performance on the modified Stroop task for suicide-related, positively-valenced and negatively-valenced words in 33 suicide attempters and 46 patient controls with a history of mood disorders; 2) a systematic review and a meta-analysis of studies comparing performance on the modified Stroop task among patients with vs. without a history of suicidal acts in mood disorders.

RESULTS

The cross-sectional study showed no significant difference in interference scores for any type of words between suicide attempters and patient controls. A meta-analysis of four studies, including 233 suicide attempters and 768 patient controls, showed a significant but small attentional bias toward suicide-related words (Hedges'g=0.22, 95%CI [0.06-0.38], Z=2.73, p=0.006), but not negatively-valenced words (Hedges'g=0.06, 95%CI [-0.09-0.22], Z=0.77, p=0.4) in suicide attempters compared to patient controls.

LIMITATIONS

Positively-valenced words and healthy controls could not be assessed in the meta-analysis.

CONCLUSION

Our data support a selective information-processing bias among suicide attempters. Indirect evidence suggests that this effect would be state-related and may be a cognitive component of the suicidal crisis. However, we could not conclude about the clinical utility of this Stroop version at this stage.