Alexander J. Millner

Single-Item Measurement of Suicidal Behaviors: Validity and Consequences of Misclassification

Suicide is a leading cause of death worldwide. Although research has made strides in better defining suicidal behaviors, there has been less focus on accurate measurement. Currently, the widespread use of self-report, single-item questions to assess suicide ideation, plans and attempts may contribute to measurement problems and misclassification. We examined the validity of single-item measurement and the potential for statistical errors. Over 1,500 participants completed an online survey containing single-item questions regarding a history of suicidal behaviors, followed by questions with more precise language, multiple response options and narrative responses to examine the validity of single-item questions. We also conducted simulations to test whether common statistical tests are robust against the degree of misclassification produced by the use of single-items. We found that 11.3% of participants that endorsed a single-item suicide attempt measure engaged in behavior that would not meet the standard definition of a suicide attempt. Similarly, 8.8% of those who endorsed a single-item measure of suicide ideation endorsed thoughts that would not meet standard definitions of suicide ideation. Statistical simulations revealed that this level of misclassification substantially decreases statistical power and increases the likelihood of false conclusions from statistical tests. Providing a wider range of response options for each item reduced the misclassification rate by approximately half. Overall, the use of single-item, self-report questions to assess the presence of suicidal behaviors leads to misclassification, increasing the likelihood of statistical decision errors. Improving the measurement of suicidal behaviors is critical to increase understanding and prevention of suicide.

Identifying differences between depressed adolescent suicide ideators and attempters

BACKGROUND Adolescent depression and suicide are pressing public health concerns, and identifying key differences among suicide ideators and attempters is critical. The goal of the current study is to test whether depressed adolescent suicide attempters report greater anhedonia severity and exhibit aberrant effort-cost computations in the face of uncertainty. METHODS Depressed adolescents (n=101) ages 13-19 years were administered structured clinical interviews to assess current mental health disorders and a history of suicidality (suicide ideators=55, suicide attempters=46). Then, participants completed self-report instruments assessing symptoms of suicidal ideation, depression, anhedonia, and anxiety as well as a computerized effort-cost computation task. RESULTS Compared with depressed adolescent suicide ideators, attempters report greater anhedonia severity, even after concurrently controlling for symptoms of suicidal ideation, depression, and anxiety. Additionally, when completing the effort-cost computation task, suicide attempters are less likely to pursue the difficult, high value option when outcomes are uncertain. Follow-up, trial-level analyses of effort-cost computations suggest that receipt of reward does not influence future decision-making among suicide attempters, however, suicide ideators exhibit a win-stay approach when receiving rewards on previous trials. LIMITATIONS Findings should be considered in light of limitations including a modest sample size, which limits generalizability, and the cross-sectional design. CONCLUSIONS Depressed adolescent suicide attempters are characterized by greater anhedonia severity, which may impair the ability to integrate previous rewarding experiences to inform future decisions. Taken together, this may generate a feeling of powerlessness that contributes to increased suicidality and a needless loss of life.

Identifying highly influential nodes in the complicated grief network.

The network approach to psychopathology conceptualizes mental disorders as networks of mutually reinforcing nodes (i.e., symptoms). Researchers adopting this approach have suggested that network topology can be used to identify influential nodes, with nodes central to the network having the greatest influence on the development and maintenance of the disorder. However, because commonly used centrality indices do not distinguish between positive and negative edges, they may not adequately assess the nature and strength of a nodes influence within the network. To address this limitation, we developed 2 indices of a nodes expected influence (EI) that account for the presence of negative edges. To evaluate centrality and EI indices, we simulated single-node interventions on randomly generated networks. In networks with exclusively positive edges, centrality and EI were both strongly associated with observed node influence. In networks with negative edges, EI was more strongly associated with observed influence than was centrality. We then used data from a longitudinal study of bereavement to examine the association between (a) a nodes centrality and EI in the complicated grief (CG) network and (b) the strength of association between change in that node and change in the remainder of the CG network from 6- to 18-months postloss. Centrality and EI were both correlated with the strength of the association between node change and network change. Together, these findings suggest high-EI nodes, such as emotional pain and feelings of emptiness, may be especially important to the etiology and treatment of CG. (PsycINFO Database Record

Behavioral and electrophysiological correlates of training-induced cognitive control improvements☆ , ☆☆

Cognitive control--the ability to exert control over thoughts, attention and behavior in order to achieve a goal--is essential to adaptive functioning and its disruption characterizes various neuropsychiatric and neurodegenerative disorders. In recent years, increased attention has been devoted to investigating the effects of training on performance and brain function, but little is known about whether cognitive control can be improved through training. To fill this gap, we designed a brief training targeting various components of cognitive control, including conflict monitoring and interference resolution. Twenty participants performed a 3-day training protocol, preceded and followed by identical pre- and post-training sessions, respectively, which included event-related potential (ERP) recordings. To detect transfer effects, the training and pre-/post-training sessions employed different tasks hypothesized to rely on similar interference resolution mechanisms. We hypothesized that training would selectively improve performance for high-interference (i.e., incongruent) trials and be associated with reduced amplitudes in the N2 component, a waveform known to index interference. Trial-to-trial behavioral adjustments were also analyzed to assess potential mechanisms of training-induced improvements. Relative to pre-training, participants showed reduced reaction time (RT) and N2 amplitude for incongruent, but not congruent, trials, suggesting improved interference resolution. Critically, participants showing the greatest reductions in interference effects during the course of the training displayed the largest pre- to post-training reductions in N2 amplitudes in a separate task, highlighting transfer effects. Overall, results suggest that a brief training can improve cognitive control, specifically the ability to inhibit task-irrelevant information.

Risk factors for the transition from suicide ideation to suicide attempt: Results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

Prior research has shown that most known risk factors for suicide attempts in the general population actually predict suicide ideation rather than attempts among ideators. Yet clinical interest in predicting suicide attempts often involves the evaluation of risk among patients with ideation. We examined a number of characteristics of suicidal thoughts hypothesized to predict incident attempts in a retrospective analysis of lifetime ideators (N = 3,916) drawn from a large (N = 29,982), representative sample of United States Army soldiers. The most powerful predictors of first nonfatal lifetime suicide attempt in a multivariate model controlling for previously known predictors (e.g., demographics, mental disorders) were: recent onset of ideation, presence and recent onset of a suicide plan, low controllability of suicidal thoughts, extreme risk-taking or “tempting fate,” and failure to answer questions about the characteristics of one’s suicidal thoughts. A predictive model using these risk factors had strong accuracy (area under the curve [AUC] = .93), with 66.2% of all incident suicide attempts occurring among the 5% of soldiers with highest composite predicted risk. This high concentration of risk in this retrospective study suggests that a useful clinical decision support model could be constructed from prospective data to identify those with highest risk of subsequent suicide attempt.

Classifying nonsuicidal overdoses: Nonsuicidal self-injury, suicide attempts, or neither?

Self-injurious behaviors (SIBs) are leading causes of death and injury. Unfortunately, disagreement regarding whether and how to classify suicidal and nonsuicidal SIBs has contributed to their misclassification, likely hindering clinical care and impeding scientific progress. The present study utilized a data-driven approach to facilitate classification and measurement of three forms of SIBs, with a particular focus on one with scant clinical and scientific attention: nonsuicidal overdoses (i.e. intentional overdoses where the person states that they had no intention of dying from the overdose). Results from this study demonstrated that nonsuicidal overdoses were similar to suicide attempts in terms of age of onset, and similar to nonsuicidal self-injury (NSSI) in terms of suicidal thoughts and desire to die when engaging in these behaviors. Nonsuicidal overdoses were unique from NSSI and suicide attempts in terms of the reported likelihood of dying from the behavior. The present study highlighted that current definitions for nonsuicidal behaviors (including requirements that the person has zero intent to die) may not accurately represent peoples intent when engaging in these behaviors. Additionally, the present study highlighted that empirical analysis of SIBs can provide important insights for classification of SIBs.

Are there sensitive periods when child maltreatment substantially elevates suicide risk? Results from a nationally representative sample of adolescents

Although child maltreatment is a well documented risk factor for suicidal behavior, little is known about whether the timing of child maltreatment differentially associates with risk of suicidal ideation, suicide plans, or suicide attempts. The goal of this study was to examine whether a first exposure to physical or sexual abuse during specific developmental periods significantly elevated risk for suicidal behavior in adolescents.

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.

Examining the role of sex in self-injurious thoughts and behaviors

Self-injurious thoughts and behaviors (SITBs), including nonsuicidal self-injury, suicidal thoughts, suicide attempts, and suicide death exhibit substantial sex differences. Across most countries, men die by suicide more frequently than women; yet, women think about and attempt suicide more frequently than men. Research on sex differences in nonsuicidal self-injury is less developed; however, nonsuicidal self-injury is historically understood as a primarily female phenomenon. This review describes current research on sex differences across SITBs with a focus on factors that moderate these effects, such as age, race, geographic region, and time. Additionally, this review describes factors that may help to explain why sex differences across SITBs exist, including differences in culture, access to lethal suicide methods, rates of mental illness, and utilization of health care. The role of gender, and particularly non-binary gender, is also discussed. Current understanding of these sex differences is described with an eye toward future research on this topic.

The Brief Death Implicit Association Test: Scoring recommendations, reliability, validity, and comparisons with the Death Implicit Association Test.

Assessing suicidal thoughts and behaviors is difficult because at-risk individuals often fail to provide honest or accurate accounts of their suicidal thoughts or intentions. Research has shown that the Death Implicit Association Test (D-IAT), a behavioral test that measures implicit (i.e., outside of conscious control) associations between oneself and death concepts, can differentiate among people with different suicidal histories, such as those with different severity or recency of suicidal behaviors. We report here on the development and evaluation of a shorter and simpler version of the D-IAT called the Death Brief Implicit Association Test (D-BIAT). We recruited large (ns > 1,500) samples of participants to complete the original D-IAT and shorter D-BIAT via a public web-based platform and evaluated different scoring approaches, assessed the reliability and validity of the D-BIAT and compared it with the D-IAT. We found that the D-BIAT was reliable, provided significant group differences with effect sizes on par with the D-IAT, as well as similarly sized classification metrics (i.e., receiver operator characteristics). Although the D-IAT was nonsignificantly better on most outcomes, the D-BIAT is 1–1[1/2] minutes shorter and provided larger effect sizes for distinguishing between past year and lifetime attempters. Thus, there is a trade-off between administration time and improved outcomes associated with increased data. The D-BIAT should be considered for use where time or participant burden needs to be minimized, such as in clinical settings.