Differential effects of executive functioning on suicide attempts

Sociodemography, pattern, and response inhibition in suicide survivors: A case-control study

Introduction

Suicide is a global phenomenon. Psychiatric disorders are estimated to contribute to a large proportion of suicides; however, impulsive suicide is also common. Among the ages of 15-29 years, suicide was the second leading cause of death worldwide and has been hypothesized to have reduced response inhibition and decision-making abilities as contributing factors, which directly relate to impaired executive functioning and suicidal behavior.

Aim

This study aimed to study sociodemography, method, and pattern of suicide, and response inhibition in suicide survivors.

Material and Methods

A case-control study was designed in a tertiary medical center in Madhya Pradesh using convenient sampling of suicide survivors and controls from the general population over 3 months. Data collection was semi-structured pro forma, and response inhibition was assessed using the Stroop test. Statistical analysis was performed using IBM Statistical Package for the Social Sciences (SPSS) Windows version 25.0. Independent-samples Student's t-test, Chi-square test, and Mann-Whitney U-test were used for analyzing means of continuous data, nominal data, and ordinal data, respectively. The level of significance was at P < 0.05.

Result

A total of 126 suicide survivors and 99 controls were assessed after the end of the study period. Age (mean age for cases 25.4 ± 9.16; controls 23 ± 7.9), gender (F ~ M), and socioeconomic status were used to match cases and controls. 85.7% of suicide survivors had no history of suicide, but the majority had precipitating factors. Anomic suicide was the most common type, and poisoning was the most common method of suicide. Response inhibition between cases and control was significantly different.

Conclusion

The majority of suicide attempts were impulsive in youth, with no gender discrimination. Response inhibition seemed to play a role in a suicide attempt.

Associations between Suicidal Thoughts and Behaviors and Genetic Liability for Cognitive Performance, Depression, and Risk-Taking in a High-Risk Sample

Background

Suicidal thoughts and behaviors (STBs) and nonsuicidal self-injury (NSSI) behaviors are moderately heritable and may reflect an underlying predisposition to depression, impulsivity, and cognitive vulnerabilities to varying degrees.

Objectives

We aimed to estimate the degrees of association between genetic liability to depression, impulsivity, and cognitive performance and STBs and NSSI in a high-risk sample.

Methods

We used data on 7,482 individuals of European ancestry and 3,359 individuals of African ancestry from the Collaborative Study on the Genetics of Alcoholism to examine the links between polygenic scores (PGSs) for depression, impulsivity/risk-taking, and cognitive performance with 3 self-reported indices of STBs (suicidal ideation, persistent suicidal ideation defined as ideation occurring on at least 7 consecutive days, and suicide attempt) and with NSSI.

Results

The PGS for depression was significantly associated with all 4 primary self-harm measures, explaining 0.6-2.5% of the variance. The PGS for risk-taking behaviors was also associated with all 4 self-harm behaviors in baseline models, but was no longer associated after controlling for a lifetime measure of DSM-IV alcohol dependence and abuse symptom counts. Polygenic predisposition for cognitive performance was negatively associated with suicide attempts (q = 3.8e-4) but was not significantly associated with suicidal ideation nor NSSI. We did not find any significant associations in the African ancestry subset, likely due to smaller sample sizes.

Conclusions

Our results encourage the study of STB as transdiagnostic outcomes that show genetic overlap with a range of risk factors.

Etiopathogenesis of Suicide: A Conceptual Analysis of Risk and Prevention Within a Comprehensive, Deterministic Model

Suicide is a rising global health concern receiving disproportionate attention in comparison to other health conditions. In spite of substantial technological and scientific advancements, suicide research has continued to move slowly in terms of clinical translation due to the complexity of neural mechanisms, and subjective experiences that seem to underpin this complex human behavior. This paper analyzes the concepts of risk and prevention in the context of suicide in an attempt to bridge the large methodological and theoretical gaps between the biological, psychological, and sociological dimensions. This paper aims to accomplish the following objectives: (1) operationalize the concepts of suicide risk and prevention as they relate to current knowledge and capabilities; (2) synthesize and integrate suicide research across biological, psychological, and sociological dimensions; (3) discuss limitations of each dimension in isolation; (4) suggest a model of etiopathogenesis that incorporates extant literature and bridges unnecessary gaps between dimensions; and (5) suggest future directions for multidimensional research through the inclusion of principles from the physical sciences. Ultimately, this paper provides a basis for a comprehensive model of suicide within a deterministic, chaotic system.

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.

Event-Related Potential Measures of Attention Capture in Adolescent Inpatients With Acute Suicidal Behavior

Impaired executive functions, modulated by the frontal lobes, have been suggested to be associated with suicidal behavior. The present study examines one of these executive functions, attentional control, maintaining attention to the task-at-hand. A group of inpatient adolescents with acute suicidal behavior and healthy controls were studied using a passively presented auditory optimal paradigm. This "optimal" paradigm consisted of a series of frequently presented homogenous pure tone "standards" and different "deviants," constructed by changing one or more features of the standard. The optimal paradigm has been shown to be a more time-efficient replacement to the traditional oddball paradigm, which makes it suitable for use in clinical populations. The extent of processing of these "to-be-ignored" auditory stimuli was measured by recording event-related potentials (ERPs). The P3a ERP component is thought to reflect processes associated with the capturing of attention. Rare and novel stimuli may result in an executive decision to switch attention away from the current cognitive task and toward a probe of the potentially more relevant "interrupting" auditory input. On the other hand, stimuli that are quite similar to the standard should not elicit P3a. The P3a has been shown to be larger in immature brains in early compared to later adolescence. An overall enhanced P3a was observed in the suicidal group. The P3a was larger in this group for both the environmental sound and white noise deviants, although only the environmental sound P3a attained significance. Other deviants representing only a small change from the standard did not elicit a P3a in healthy controls. They did elicit a small P3a in the suicidal group. These findings suggest a lowered threshold for the triggering of the involuntary switch of attention in these patients, which may play a role in their reported distractibility. The enhanced P3a is also suggestive of an immature frontal central executive and may provide a promising marker for early identification of some of the risk factors for some of the cognitive difficulties linked to suicidality.

The Relationship of Self-reported Executive Functioning to Suicide Ideation and Attempts: Findings from a Large U.S.-based Online Sample

An increasing number of studies demonstrate that individuals with a history of suicidality exhibit impaired executive functioning abilities. The current study examines whether these differences are linked to suicidal thoughts or suicidal acts-a crucial distinction given that most people who think about suicide will not act on their thoughts. A large online sample of U.S. participants with a history of suicide ideation (n = 197), suicide attempts (n = 166), and no suicidality (n = 180) completed self-report measures assessing executive functioning, suicide ideation and attempts; in addition, depression, self-efficacy, and history of drug abuse and brain injury were assessed as potential covariates. Individuals with recent suicide attempts reported significantly worse executive functioning than ideators. This difference was not accounted for by depression, self-efficacy, history of drug abuse or brain injury. Self-reported executive functioning may represent an important short-term risk factor for suicide attempts.

Measurement of latent cognitive abilities involved in concept identification learning

INTRODUCTION

We used cognitive and psychometric modeling techniques to evaluate the construct validity and measurement precision of latent cognitive abilities measured by a test of concept identification learning: the Penn Conditional Exclusion Test (PCET).

METHOD

Item response theory parameters were embedded within classic associative- and hypothesis-based Markov learning models and were fitted to 35,553 Army soldiers' PCET data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

RESULTS

Data were consistent with a hypothesis-testing model with multiple latent abilities-abstraction and set shifting. Latent abstraction ability was positively correlated with number of concepts learned, and latent set-shifting ability was negatively correlated with number of perseverative errors, supporting the construct validity of the two parameters. Abstraction was most precisely assessed for participants with abilities ranging from 1.5 standard deviations below the mean to the mean itself. Measurement of set shifting was acceptably precise only for participants making a high number of perseverative errors.

CONCLUSIONS

The PCET precisely measures latent abstraction ability in the Army STARRS sample, especially within the range of mildly impaired to average ability. This precision pattern is ideal for a test developed to measure cognitive impairment as opposed to cognitive strength. The PCET also measures latent set-shifting ability, but reliable assessment is limited to the impaired range of ability, reflecting that perseverative errors are rare among cognitively healthy adults. Integrating cognitive and psychometric models can provide information about construct validity and measurement precision within a single analytical framework.

[Suicide in the elderly: age-related specificities?]

Suicide in the elderly raises the question of our relationship with aging and death. Suicide rate is relatively high in this group and is significantly related to depression widely under-diagnosed in the elderly. Suicidal behaviour in the elderly has clinical specificities including high intentionality and lethality, usually little personal history of suicidal behaviour and low levels of impulsivity-aggression. Suicidal vulnerability could rely on etiopathogenic mechanisms both common and different according to age; for example, a preponderance of early developmental factors and impulsivity-aggression in adolescents and young adults vs. pathological aging in older adults, but partly similar neurocognitive deficits leading individuals not to respond adequately to their environment (itself different with age). Direct comparisons between elderly and younger subjects would be required. The article concludes with a summary of the principles of recognition and management of suicide risk.

Neurocognitive alterations in first degree relatives of suicide completers

BACKGROUND

Suicide aggregates within families and the relatives of suicide completers are at an increased risk for suicide. Though neurocognitive changes are gaining increasing attention as part of the vulnerability for suicide, the literature on neurocognitive alterations among suicide relatives as possible endophenotypes of suicide is sparse.

METHOD

Normothymic first-degree relatives (n=14) of suicide completers without personal histories of suicide attempts were compared to individuals without family histories of suicide (n=14) matched for age-, sex- and education. Participants completed the Wisconsin card sorting test, a well validated test of cognitive control in a changing environment.

RESULTS

First-degree relatives of suicide completers made significantly more perseverative errors and have a lower level of conceptual responses than comparison subjects.

CONCLUSION

Alterations found in first-degree relatives of suicide completers suggest a decreased responsiveness to changing, yet unambiguous, conditions. These neurocognitive impairments are similar to deficits observed among individuals engaging in suicide attempts. Neurocognitive impairments revealed by the Wisconsin card sorting test may represent a neurocognitive endophenotype of suicide.