Intact alternation performance in high lethality suicide attempters

Plasma Phospholipid Polyunsaturated Fatty Acid Associations with Neurocognition

Neurocognitive deficits are implicated in major depressive disorder (MDD) and suicidal behavior, and cognitive function may be affected by blood levels of polyunsaturated fatty acids (PUFAs). Neuroprotective functions have been described for omega-3 (n-3) PUFAs, while omega-6 (n-6) PUFAs exhibit broadly opposing activities. Both classes of PUFAs are linked to MDD and suicidal behavior. However, few studies have investigated the relationships between PUFAs and neurocognitive function with respect to MDD or suicidal behavior. Among participants with MDD (n = 45) and healthy volunteers (HV, n = 30) we assessed performance on tasks of attentional capacity and executive function and its relationship to plasma phospholipid PUFA levels, expressed as a percentage of total plasma phospholipids, for eicosapentaenoic acid (EPA%), docosahexaenoic acid (DHA%), and arachidonic acid (AA%). Regression models tested the correlations between PUFA levels and task performance in three groups: MDD with a history of suicide attempt (SA, n = 20), MDD with no attempts (NA, n = 25), and HV. Interaction testing indicated a significant positive correlation of EPA% with continuous performance test scores in the NA group (F = 4.883, df = 2,72, p = 0.01), a measure of sustained attention. The AA% correlated negatively with performance on two executive function tasks, object alternation (beta = -3.97, z-score = -2.67, p = 0.008) and the Wisconsin card sort (beta = 0.80, t-score = -2.16, df = 69, p = 0.035), after adjustment for group and age, with no group effects. Our findings suggest a role for PUFA imbalance in attentional functioning and executive performance; however, no MDD-specific effect was observed.

Hill L, Kline A, Stanley BH, Interian A. Improving the prospective prediction of a near-term suicide attempt in veterans at risk for suicide, using a go/no-go task

BACKGROUND

Neurocognitive testing may advance the goal of predicting near-term suicide risk. The current study examined whether performance on a Go/No-go (GNG) task, and computational modeling to extract latent cognitive variables, could enhance prediction of suicide attempts within next 90 days, among individuals at high-risk for suicide.

METHOD

136 Veterans at high-risk for suicide previously completed a computer-based GNG task requiring rapid responding (Go) to target stimuli, while withholding responses (No-go) to infrequent foil stimuli; behavioral variables included false alarms to foils (failure to inhibit) and missed responses to targets. We conducted a secondary analysis of these data, with outcomes defined as actual suicide attempt (ASA), other suicide-related event (OtherSE) such as interrupted/aborted attempt or preparatory behavior, or neither (noSE), within 90-days after GNG testing, to examine whether GNG variables could improve ASA prediction over standard clinical variables. A computational model (linear ballistic accumulator, LBA) was also applied, to elucidate cognitive mechanisms underlying group differences.

RESULTS

On GNG, increased miss rate selectively predicted ASA, while increased false alarm rate predicted OtherSE (without ASA) within the 90-day follow-up window. In LBA modeling, ASA (but not OtherSE) was associated with decreases in decisional efficiency to targets, suggesting differences in the evidence accumulation process were specifically associated with upcoming ASA.

CONCLUSIONS

These findings suggest that GNG may improve prediction of near-term suicide risk, with distinct behavioral patterns in those who will attempt suicide within the next 90 days. Computational modeling suggests qualitative differences in cognition in individuals at near-term risk of suicide attempt.

Cognitive flexibility in inpatient children and adolescents with a history of suicide attempts

An increase in suicide rates during adolescence has made it the second leading cause of death for this age group. While potential deficits in cognitive flexibility have been thought to contribute to suicidality, this factor has been evaluated in only a few studies among this age group. The current study sought to evaluate cognitive flexibility in 100 psychiatric inpatient children and adolescents (age X=14.39, SD=2.53), with (n=26) and without (n=74) a history of suicide attempts, using the Wisconsin Card Sorting Test (WCST). Results showed no differences between the groups in WCST scores. However, in a small sub-sample with mood disorders only, those with a history of a suicide attempt performed better than those without such history. These findings are contrary to our hypothesis that those who attempted suicide have worse cognitive flexibility, though consistent with earlier data in adults. Further research is needed to shed light on these findings.

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.

Inflammation biomarkers in suicide attempts and their relation to abuse, global functioning and cognition

OBJECTIVES

To explore the link between cytokines and suicide attempts and their relationship with the psychological aspects of this complex multifactorial phenomenon.

METHODS

96 participants, including 20 patients with a recent suicide attempt and diagnosis of Major Depression Disorder (MDD), 33 MDD patients with a lifetime history of suicide attempt, 23 non-attempter MDD patients, and 20 healthy controls underwent an assessment on depressive symptoms, global functioning, aggressive behaviour, presence of abuse and attention performance. Additionally, all participants had a blood extraction for IL-2, IL2-R, IL-4, IL-6, and TNF-α plasma levels analysis.

RESULTS

IL-6 levels were significantly different across groups (F(3,89)=3.690; p = 0.015), with higher concentrations in both recent (p = 0.04) and distant (p = 0.015) attempt in comparison to MDD non-attempters. IL-6 was associated with adult physical abuse (B = 2.591; p = 0.021), lower global functioning score (B = -0.512; p = 0.011), and poorer performance on attention (B = -0.897; p = 0.011).

CONCLUSIONS

Recent and distant suicidal behaviour is associated with elevated IL-6 levels, which may be influenced by stressful and traumatic experiences. Elevated concentrations of IL-6 could have a negative impact on attention, increasing suicide risk. More research is needed to clarify the role of cytokines in suicide-related features to explore novel treatments and more effective preventive interventions.

Cognition in Recent Suicide Attempts: Altered Executive Function

Background: Neuropsychological alterations can lead to inaccurate perception, interpretation, and response to environmental information, which could be a risk factor for suicide. Methods: Ninety-six subjects were recruited from the Psychiatry Department of the Araba University Hospital-Santiago, including 20 patients with a recent attempt and diagnosis of major depressive disorder (MDD) according to DSM-V, 33 MDD patients with history of attempted suicide, 23 non-attempter MDD patients, and 20 healthy controls. All participants underwent a clinical interview and neuropsychological assessment on the following cognitive domains: working memory, processing speed, decision-making, executive function, and attention. Backward multiple regressions were performed adjusting for significant confounding variables. For group comparisons, ANOVA and Bonferroni post-hoc tests were performed with a p < 0.05 significance level. Results: The patient groups did not differ regarding severity of depression and stressful events in the last 6 months. In comparison to healthy controls, depressed patients with lifetime suicide attempts had more general trauma (p = 0.003), emotional abuse (p = 0.003), emotional negligence (p = 0.006), and physical negligence (p = 0.009), and depressed patients with recent suicide attempts had experienced more child sexual abuse (p = 0.038). Regarding neuropsychological assessment, all patient groups performed significantly worse than did healthy controls in processing speed, decision-making, and attention. Comparisons between patient groups indicated that recent suicide attempters had poorer performance on executive function in comparison to both depressed lifetime attempters and depressed non-attempters (B = 0.296, p = 0.019, and B = 0.301, p = 0.028, respectively). Besides, women with recent attempts had slightly better scores on executive function than males. Regarding the rest of the cognitive domains, there were no significant differences between groups. Conclusion: Executive function performance is altered in recent suicide attempts. As impaired executive function can be risk factor for suicide, preventive interventions on suicide should focus on its assessment and rehabilitation.

Poor Sleep and Decision-Making Disturbance Are Associated With Suicidal Ideation in Pre-natal Depression

Although many risk factors for suicidal ideation have been identified, few studies have focused on suicidal ideation and pre-natal depression. The purpose was to investigate the relationship between decision-making (DM) dysfunction and sleep disturbance on suicidal ideation in pre-natal depression. Participants included 100 women in the third trimester of pregnancy, including pregnant women with pre-natal depression who had recent suicidal ideation (n = 30), pre-natal depression without SI (n = 35) and healthy controls (n = 35). The Iowa Gambling Task (IGT) was used to evaluate the DM function and the Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep index. The Edinburgh Post-natal Depression Scale (EPDS) was used to assess suicidal ideation and the seriousness of depression. Overall, the two groups with pre-natal depression showed worse sleep quality and decreased DM function compared with healthy controls. The pre-natal depression with suicidal ideation group showed a significantly higher score in subjective sleep quality and a lower score in block 5 of IGT than the pre-natal depression without suicidal ideation group. Further correlation analysis showed that suicidal ideation positively correlated with subjective sleep quality, sleep duration, and daytime function, and negatively correlated with IGT scores. Sleep disturbance and impaired DM function may be risk factors for suicidal ideation in pre-natal depression.

Suicidal behaviour and cognition: A systematic review with special focus on prefrontal deficits

BACKGROUND

Suicide is a major health concern worldwide, thus, identifying risk factors would enable a more comprehensive understanding and prevention of this behaviour. Neuropsychological alterations could lead to difficulties in interpreting and managing life events resulting in a higher risk of suicide.

METHOD

A systematic literature search from 2000 to 2020 was performed in Medline (Pubmed), Web of Science, SciELO Citation Index, PsycInfo, PsycArticles and Cochrane Library databases regarding studies comparing cognition of attempters versus non-attempters that share same psychiatric diagnosis.

RESULTS

1.885 patients diagnosed with an Affective Disorder (n = 1512) and Schizophrenia/ Schizoaffective Disorder (n = 373) were included. In general comparison, attention was found to be clearly dysfunctional. Regarding diagnosis, patients with Schizophrenia and previous history of suicidal behaviour showed a poorer performance in executive function. Patients with current symptoms of an Affective Disorder and a previous history of suicidal attempt had poorer performance in attention and executive function. Similarly, euthymic affective patients with history of suicidal behaviour had worse decision-making, attention and executive function performance compared to euthymic non-attempters.

LIMITATIONS

The number of papers included in this review is limited to the few studies using non-attempter clinically-matched control group and therefore results regarding diagnosis, symptomatology and time of the attempt are modest and contradictory.

CONCLUSIONS

Patients who have attempted suicide have a poorer neuropsychological functioning than non-attempters with a similar psychiatric disorder in attention and executive function. These alterations increase vulnerability for suicide.

Using resting-state intrinsic network connectivity to identify suicide risk in mood disorders

BACKGROUND

Little is known about the neural substrates of suicide risk in mood disorders. Improving the identification of biomarkers of suicide risk, as indicated by a history of suicide-related behavior (SB), could lead to more targeted treatments to reduce risk.

METHODS

Participants were 18 young adults with a mood disorder with a history of SB (as indicated by endorsing a past suicide attempt), 60 with a mood disorder with a history of suicidal ideation (SI) but not SB, 52 with a mood disorder with no history of SI or SB (MD), and 82 healthy comparison participants (HC). Resting-state functional connectivity within and between intrinsic neural networks, including cognitive control network (CCN), salience and emotion network (SEN), and default mode network (DMN), was compared between groups.

RESULTS

Several fronto-parietal regions (k > 57, p < 0.005) were identified in which individuals with SB demonstrated distinct patterns of connectivity within (in the CCN) and across networks (CCN-SEN and CCN-DMN). Connectivity with some of these same regions also distinguished the SB group when participants were re-scanned after 1-4 months. Extracted data defined SB group membership with good accuracy, sensitivity, and specificity (79-88%).

CONCLUSIONS

These results suggest that individuals with a history of SB in the context of mood disorders may show reliably distinct patterns of intrinsic network connectivity, even when compared to those with mood disorders without SB. Resting-state fMRI is a promising tool for identifying subtypes of patients with mood disorders who may be at risk for suicidal behavior.

Cognitive modelling to assess decision-making impairments in patients with current depression and with/without suicide history

It has been reported that decision making is impaired in suicide attempters. Decision making is a complex process and little is known about its different components. Yet, this information would help to understand the functioning of suicidal minds. In this study, the Prospect Valence-Learning (PVL) computational model was applied to the Iowa Gambling Task (IGT) to investigate and compare decision-making components in patients with affective disorder and with/without history of suicide attempts and in healthy controls. To this aim, 116 inpatients with current major depressive episode (among whom 62 suicide attempters) and 38 healthy controls were recruited. Decision-making performance was measured using the IGT. The Bayesian computational PVL model was applied to compare the feedback sensitivity, loss aversion, learning/memory, and choice consistency components of decision making in the different groups. Depressive symptomatology was assessed using the Beck Depression Inventory short form (BDI-SF). The total IGT net score and the loss aversion and learning/memory scores were lower in suicide attempters than in healthy controls. The choice consistency score was low in all patients (with/without suicide history) compared with healthy controls. Moreover, patients with high BDI score showed a positive relationship between the choice consistency score and suicide attempt. These findings suggest that decision-making impairment in depressed patients with and without suicidal history might be the result of underlying problems in feedback processing and task learning, which influence the building of long-term strategies. All these impairments should be targeted in therapeutic strategies for suicidal patients.

Gray matter volumetric study of major depression and suicidal behavior

Structural brain deficits are linked to risk for suicidal behavior. However, there is disagreement about the nature of these deficits, probably due to the heterogeneity of suicidal behavior in terms of the suicidal act's lethality. We hypothesized that individuals with major depressive disorder (MDD) and history of more lethal suicide attempts would have lower gray matter volume (GMV) of the prefrontal regions and insula compared with MDD lower-lethality attempters and MDD non-attempters. We collected structural MRI scans on 91 individuals with MDD; 11 with history of higher-lethality suicide attempts, 14 with lower-lethality attempts, and 66 were non-attempters. Differences in GMV between these three groups were examined using both regions-of-interest (ROI) and brain-wide voxel-based morphometry (VBM) analyses. Both ROI and VBM analyses showed that higher-lethality suicide attempters have greater GMV of the prefrontal cortical regions and insula, compared with the other two groups. Although this contrasts with our hypothesis, the observed larger prefrontal cortex GMV in higher-lethality suicide attempters may underlie the set of attributes observed previously in this suicidal subgroup, including enhanced suicide attempt planning, greater response inhibition, and delayed reward capabilities. Future studies should further examine the role of these brain regions in relation to suicidal intent and planning.

The lack of meaningful association between depression severity measures and neurocognitive performance

BACKGROUND

Neurocognitive deficits are common in depression, but most prior studies have not found strong associations between standard measures of symptom severity and the extent of these neurocognitive deficits. Diagnostic heterogeneity, or the lack of specific questions about neurocognition in these measures, may be undermining these associations.

METHOD

Neuropsychological performance was assessed via 10 tasks in a sample of 262 unmedicated patients with Major Depressive Disorder (MDD) and compared to that in healthy volunteers (n = 140), then correlated with (1) standard measures of depression severity including the Hamilton Depression Rating Scale and Beck Depression Inventory, (2) previously established, factor-analytically derived symptom factors that characterize the heterogeneity of these scales, and (3) a separate measure of cognitive complaint (Cognitive Failures Questionnaire) that was included to address the absence of specific questions about cognition in standard rating scales.

RESULTS

Neurocognitive performance in these unmedicated MDD patients was not significantly associated with either total scores on the depression severity measures, any of their derived symptom factors, or the degree of subjective cognitive complaint - which itself was most strongly associated with mood disturbance.

LIMITATIONS

Depressed patients with the most prominent neurovegetative symptoms may be underrepresented in this sample.

CONCLUSIONS

Neurocognitive deficits were only weakly associated with standard depression symptom ratings, and not captured by self-report ratings of cognitive complaint. Neurocognitive deficits appear to be a separate symptom dimension that cannot be inferred from overall depression severity and require their own assessment, given that they have prognostic value for functional outcomes, suicide risk, and differential therapeutics.

The concept of violent suicide, its underlying trait and neurobiology: A critical perspective

Suicide is one of the leading causes of death and represents a significant public health problem world-wide. Individuals who attempt or die by suicide represent a highly heterogeneous population. Recently, efforts have been made to identify sub-populations and variables to categorize them. A popular dichotomy in suicide research of the past years is violent versus non-violent suicide - based on the method. This dichotomy is important given that there is an association between method of attempted suicide and risk of subsequent death by suicide. The differentiation concerning suicide methods is also critical regarding preventive efforts. In this review, we have tried to approach the concept of violent suicide from different perspectives, including a discussion about its definition and overlapping categories. In addition, we have critically discussed aggression as underlying trait, the question of intent to die, and sociodemographic, environmental, neuropsychological, and neurobiological factors potentially associated with violent suicide.

Decision making under risk and under ambiguity in depressed suicide attempters, depressed non-attempters and healthy controls

BACKGROUND

A number of neuropsychological alterations have been found in patients who have attempted suicide. Most studies investigating decision making (DM) abilities in suicide attempters so far have used one single DM task and included patients with a lifetime history of suicide attempts. These studies have yielded conflicting results.

METHOD

In this study, currently depressed in-patients who had a recent suicide attempt (within the last six months) (n = 21), depressed in-patients without a lifetime history of suicide attempts (n = 31) and a healthy control group (n = 26) were assessed with two tasks for the assessment of DM. The Game of Dice Task (GDT) measures DM under risk and the Iowa Gambling Task (IGT) DM under ambiguity. Further, depression severity, impulsiveness and suicidal intent of the current suicide attempt were assessed.

RESULTS

Both depressed groups differed from controls with respect to marital and partnership status, smoking, impulsiveness and psychiatric family history. In terms of DM, IGT scores did not differ significantly between groups. However, suicide attempters made significantly more risky decisions as assessed with the GDT than both control groups (p < 0.05 for pairwise comparisons, p = 0.065 for overall comparison of the 3 groups).

LIMITATIONS

The available tasks assess DM under laboratory conditions which may not reflect the emotional status of suicidal individuals. No general cognitive assessment was included.

CONCLUSIONS

Depressed suicide attempters differed with regard to DM under risk but not DM under ambiguity. When studying DM it appears crucial to take varying aspects of DM into account.

Neuropsychological Markers of Suicidal Risk in the Context of Medical Rehabilitation

While great strides have been made to advance the understanding of the neurobiology of suicidal behavior (SB), the neural and neuropsychological mechanisms associated with SB are not well understood. The purpose of the current study is to identify neurocognitive markers of SB in the context of medical rehabilitation. The performances of 39 patients at a medical rehabilitation center, aged 21-78, were examined on a series of neurocognitive executive tasks-decision-making (Iowa Gambling Task - IGT), mental flexibility (WCST), response inhibition (SST) and working memory (digit span). Self-report questionnaires were administered, for Suicidal behaviors, depression, Anxiety, and PTSD as well as perceived social support. Suicidal participants performed more poorly on the IGT. A mediation analysis presented a significant direct effect of decision making on suicidal risk (p < 0.14) as well as significant indirect effect of decision making on suicidal risk that was mediated by the depressive symptoms (95% BCa CI [-0.15, -0.018]) with a medium effect size (κ² = 0.20, 95% BCa CI [0.067, 0.381]). Despite the complexity of relationship between decision-making and suicidal risk, these results suggest that clinicians should routinely assess decision-making abilities in adults at risk for suicide due to the fact that impaired decision-making may increase suicidal risk above and beyond that conferred by depression.

Decision-making in unipolar or bipolar suicide attempters

OBJECTIVE

Disadvantageous decision-making (mainly measured by the Iowa Gambling Task) has been demonstrated in patients with suicidal behavior compared to controls. We, therefore, aimed at clarifying the qualitative and quantitative relationship between decision-making and the risk of suicidal behavior in unipolar and bipolar disorders respectively, as well as establishing the strength of this relationship.

METHODS

(1) We conducted a cross-sectional study comparing IGT performances between 141 unipolar suicide attempters and 57 bipolar suicide attempters. (2) We conducted a systematic review and a meta-analysis of studies comparing IGT performances in patients with vs. without a history of suicidal acts in bipolar and unipolar disorder, together and separately.

RESULTS

(1) Among suicide attempters, bipolar and unipolar groups performed similarly (t(195)=-0.7; p=0.48). Unipolar non-attempters performed better IGT than unipolar suicide attempters (t(221)=3.1; p=0.002), only in female gender, whereas performances were similar in bipolar patients whatever the history of suicide attempt (t(77)=-0.3; p=0.7). (2) A meta-analysis of 10 studies confirmed significantly impaired decision-making with a moderate effect-size (-0.38 (95% CI[-0.61--0.16]; z=-3.3; p=0.001) in unipolar disorder and (g=-0.4 (95% CI[-0.75 to -0.05]; z=-2.2; p<0.026) in bipolar disorder suicide attempters compared to unipolar and bipolar non-attempters, respectively.

LIMITATIONS

It was not possible to analyse according to the level of lethality attempt.

CONCLUSION

Overall, a strong significant association was found between decision-making and the risk of suicidal behavior in unipolar disorder and bipolar disorder. However, further neuropsychological studies need to analyse separately unipolar and bipolar disorder and to study gender differences.

Suicide and sleep: Is it a bad thing to be awake when reason sleeps?

Suicide is the second leading cause of death, worldwide, for those between the ages of 24 and 44 y old. In 2013, more than 41,000 suicides occurred in the United States. These statistics underscore the need to 1) understand why people die by suicide and 2) identify risk factors that are potentially modifiable. While it has been posited that sleep disturbance may represent one such factor, systematic research in this arena did not begin until the 2000s. Since that time, sleep disturbance has been reliably identified as a risk factor for suicidal ideation, suicide attempts, and suicide. While insomnia, nightmares, and other sleep disorders have each been found to contribute to the risk for suicidal ideation and behavior, it is also possible that these factors share some common variance. One possibility is that sleep disturbance results in being awake at night, and being awake at night also confers risk. The hypothesis proffered here is that being awake when one is not biologically prepared to be so results in "hypofrontality" and diminished executive function, and that this represents a common pathway to suicidal ideation and behavior. Such a proposition is highly testable under a variety of possible protocols. The current review summarizes the extant literature on suicide rates by time-of-day, and discusses circadian, psychosocial, and neurocognitive explanations of risk. Such a focus promises to enhance our understanding of how sleep disturbance may confer risk, allows for the identification of future lines of research, and further justifies the need for interventions that promote good sleep continuity among at-risk individuals.