Genetic factors associated with suicidal behaviors and alcohol use disorders in an American Indian population.

American Indians (AI) demonstrate the highest rates of both suicidal behaviors (SB) and alcohol use disorders (AUD) among all ethnic groups in the US. Rates of suicide and AUD vary substantially between tribal groups and across different geographical regions, underscoring a need to delineate more specific risk and resilience factors. Using data from over 740 AI living within eight contiguous reservations, we assessed genetic risk factors for SB by investigating: (1) possible genetic overlap with AUD, and (2) impacts of rare and low-frequency genomic variants. Suicidal behaviors included lifetime history of suicidal thoughts and acts, including verified suicide deaths, scored using a ranking variable for the SB phenotype (range 0-4). We identified five loci significantly associated with SB and AUD, two of which are intergenic and three intronic on genes AACSP1, ANK1, and FBXO11. Nonsynonymous rare and low-frequency mutations in four genes including SERPINF1 (PEDF), ZNF30, CD34, and SLC5A9, and non-intronic rare and low-frequency mutations in genes OPRD1, HSD17B3 and one lincRNA were significantly associated with SB. One identified pathway related to hypoxia-inducible factor (HIF) regulation, whose 83 nonsynonymous rare and low-frequency variants on 10 genes were significantly linked to SB as well. Four additional genes, and two pathways related to vasopressin-regulated water metabolism and cellular hexose transport, also were strongly associated with SB. This study represents the first investigation of genetic factors for SB in an American Indian population that has high risk for suicide. Our study suggests that bivariate association analysis between comorbid disorders can increase statistical power; and rare and low-frequency variant analysis in a high-risk population enabled by whole-genome sequencing has the potential to identify novel genetic factors. Although such findings may be population specific, rare functional mutations relating to PEDF and HIF regulation align with past reports and suggest a biological mechanism for suicide risk and a potential therapeutic target for intervention.

Sleep disturbances as an evidence-based suicide risk factor.

Increasing research indicates that sleep disturbances may confer increased risk for suicidal behaviors, including suicidal ideation, suicide attempts, and death by suicide. Despite increased investigation, a number of methodological problems present important limitations to the validity and generalizability of findings in this area, which warrant additional focus. To evaluate and delineate sleep disturbances as an evidence-based suicide risk factor, a systematic review of the extant literature was conducted with methodological considerations as a central focus. The following methodologic criteria were required for inclusion: the report (1) evaluated an index of sleep disturbance; (2) examined an outcome measure for suicidal behavior; (3) adjusted for presence of a depression diagnosis or depression severity, as a covariate; and (4) represented an original investigation as opposed to a chart review. Reports meeting inclusion criteria were further classified and reviewed according to: study design and timeframe; sample type and size; sleep disturbance, suicide risk, and depression covariate assessment measure(s); and presence of positive versus negative findings. Based on keyword search, the following search engines were used: PubMed and PsycINFO. Search criteria generated N = 82 articles representing original investigations focused on sleep disturbances and suicide outcomes. Of these, N = 18 met inclusion criteria for review based on systematic analysis. Of the reports identified, N = 18 evaluated insomnia or poor sleep quality symptoms, whereas N = 8 assessed nightmares in association with suicide risk. Despite considerable differences in study designs, samples, and assessment techniques, the comparison of such reports indicates preliminary, converging evidence for sleep disturbances as an empirical risk factor for suicidal behaviors, while highlighting important, future directions for increased investigation.

The prediction of study-emergent suicidal ideation in bipolar disorder: a pilot study using ecological momentary assessment data.

OBJECTIVES: Bipolar disorder is associated with idiosyncratic precursors of clinically important states such as suicidal ideation. Ecological momentary assessment (EMA) - high frequency data collection in a subject's usual environment - provides the potential for development of temporal, individualized prediction of risk states. The present study tested the ability of EMA data to predict individual symptom change in clinician-rated suicidal ideation. METHODS: Thirty-five adults diagnosed with inter-episode bipolar disorder completed daily measures of affect in their home environments using diaries administered over an eight-week assessment timeline. Suicidal ideation was assessed monthly at in-person visits using the Inventory of Depressive Symptomatology-Clinician Rated. We used a novel application of functional linear models (FLMs) to generate prospective predictions of suicidal ideation at in-person clinician assessments based on intensively sampled trajectories of daily affect. RESULTS: Eight instances of suicidal ideation scores > 0 were recorded during the study period on six participants. Utilizing trajectories of negative and positive affect, cross-validated predictions attained 88% sensitivity with 95% specificity for elevated suicidal ideation one week prior to in-person clinician assessment. This model strongly outperformed prediction models using cross-sectional data obtained at study visits alone. CONCLUSIONS: Utilizing EMA data with FLM prediction models substantially increases the accuracy of prediction of study-emergent suicidal ideation. Prediction algorithms employing intensively sampled longitudinal EMA data could sensitively detect the warning signs of suicidal ideation to facilitate improved suicide risk assessment and the timely delivery of preventative interventions.

A review of multidisciplinary clinical practice guidelines in suicide prevention: toward an emerging standard in suicide risk assessment and management, training and practice.

OBJECTIVE: The current paper aims to: (1) examine clinical practice guidelines in suicide prevention across fields, organizations, and clinical specialties and (2) inform emerging standards in clinical practice, research, and training. METHODS: The authors conducted a systematic literature review to identify clinical practice guidelines and resource documents in suicide prevention and risk management. The authors used PubMed, Google Scholar, and Google Search, and keywords included: clinical practice guideline, practice guideline, practice parameters, suicide, suicidality, suicidal behaviors, assessment, and management. To assess for commonalities, the authors reviewed guidelines and resource documents across 13 key content categories and assessed whether each document suggested validated assessment measures. RESULTS: The search generated 101 source documents, which included N = 10 clinical practice guidelines and N = 12 additional resource documents (e.g., non-formalized guidelines, tool-kits). All guidelines (100 %) provided detailed recommendations for the use of evidence-based risk factors and protective factors, 80 % provided brief (but not detailed) recommendations for the assessment of suicidal intent, and 70 % recommended risk management strategies. By comparison, only 30 % discussed standardization of risk-level categorizations and other content areas considered central to best practices in suicide prevention (e.g., restricting access to means, ethical considerations, confidentiality/legal issues, training, and postvention practices). Resource documents were largely consistent with these findings. CONCLUSIONS: Current guidelines address similar aspects of suicide risk assessment and management, but significant discrepancies exist. A lack of consensus was evident in recommendations across core competencies, which may be improved by increased standardization in practice and training. Additional resources appear useful for supplemental use.

Social zeitgeber and sleep loss as risk factors for suicide in American Indian adolescents.

American Indians / Alaska Natives (AI/AN) bear a high burden of suicide, the reasons for which are not completely understood, and rates can vary by tribal group and location. This article aims to identify circumstances reported by a community group of American Indian adolescent participants to be associated with their depression and/or suicide. American Indian adolescents (n = 360) were recruited from contiguous reservations and were assessed with a semi-structured diagnostic interview. Twenty percent of the adolescents reported suicidal thoughts (ideation, plans), an additional 8% reported a history of suicide attempts, and three deaths due to suicide were reported. Suicidal behaviors and major depressive disorder (MDD) co-occurred and were more common among female adolescents. The distressing events that adolescents most often reported were: death in the family, family disruption, peer relationship problems, and school problems. All of these events were significantly associated with suicidal behaviors, however those with suicidal acts were more likely to report death in the family. Those with MDD but no suicidal behaviors were more likely to report disruptions in the family. Disruptions in falling asleep were also associated with suicidal behaviors and having experienced a death in the family. Disruptions in important relationships, particularly through death or divorce, may be interpreted as a loss or disruption in "social zeitgebers" that may in turn disturb biological rhythms, such as sleep, thus potentially increase the risk for MDD and/or suicide. Prevention programs aimed at ameliorating the impact of disruptions in important relationships may potentially reduce suicidal behaviors in AI/AN adolescents.

Morningness-eveningness and depression: preliminary evidence for the role of the behavioral activation system and positive affect.

There is considerable evidence of circadian rhythm abnormalities in mood disorders. Morningness-eveningness, the degree to which people prefer organizing their activity and sleep patterns toward the morning or evening, is related to circadian phase and is associated with mood, with relatively greater psychological distress among evening types. Given that circadian rhythms may also relate to the Behavioral Activation System (BAS) and positive affect (PA), but not to the Behavioral Inhibition System (BIS) or negative affect (NA), it was hypothesized that individual differences in BAS sensitivity and levels of PA, but not BIS and NA, would explain the association between morningness-eveningness and depression in a sample of 208 individuals with a range of depressive symptomatology. As predicted, increasing eveningness was associated with greater depression, lower BAS, and lower PA, but not directly associated with NA. Path analyses supported a model wherein morningness-eveningness is associated with depression via multi-step indirect paths including BAS-Reward Responsiveness, PA, and NA. A path between BIS and depression was distinct from the one involving morningness-eveningness. A variety of alternative path models all provided a weaker fit to the data. Thus, results were consistent with the BAS and PA mediating the effects of morningness-eveningness on depression.

Artificial Intelligence and Suicide Prevention: A Systematic Review of Machine Learning Investigations.

Suicide is a leading cause of death that defies prediction and challenges prevention efforts worldwide. Artificial intelligence (AI) and machine learning (ML) have emerged as a means of investigating large datasets to enhance risk detection. A systematic review of ML investigations evaluating suicidal behaviors was conducted using PubMed/MEDLINE, PsychInfo, Web-of-Science, and EMBASE, employing search strings and MeSH terms relevant to suicide and AI. Databases were supplemented by hand-search techniques and Google Scholar. Inclusion criteria: (1) journal article, available in English, (2) original investigation, (3) employment of AI/ML, (4) evaluation of a suicide risk outcome. N = 594 records were identified based on abstract search, and 25 hand-searched reports. N = 461 reports remained after duplicates were removed, n = 316 were excluded after abstract screening. Of n = 149 full-text articles assessed for eligibility, n = 87 were included for quantitative synthesis, grouped according to suicide behavior outcome. Reports varied widely in methodology and outcomes. Results suggest high levels of risk classification accuracy (>90%) and Area Under the Curve (AUC) in the prediction of suicidal behaviors. We report key findings and central limitations in the use of AI/ML frameworks to guide additional research, which hold the potential to impact suicide on broad scale.

Delta Event-Related Oscillations Are Related to a History of Extreme Binge Drinking in Adolescence and Lifetime Suicide Risk.

Alcohol exposure typically begins in adolescence, and heavy binge drinking is associated with health risk behaviors. Event-related oscillations (EROs) may represent sensitive biomarkers or endophenotypes for early alcohol exposure as well as other risk behaviors such as suicidal thoughts and actions. In this study, young adults (age 18-30 years) of American Indian (AI) (n = 479) and Mexican American (MA) (n = 705) ancestry were clinically assessed, and EROs were generated to happy, sad and neutral faces. Extreme adolescent binge drinking (10+ drinks) was common (20%) in this population of AI/MA and associated with a significantly increased risk of a lifetime history of suicidal acts (SA, suicide attempts, deaths) but not suicidal thoughts (ST, ideation, plans). ST were reported among MA participants, whereas SA were more common among AI young adults. Extreme adolescent binge drinking was also associated with errors in detection of sad and neutral faces, increases in delta ERO energy, and decreases in phase locking (PL), particularly in parietal areas. A lifetime history of ST was associated with increases in delta ERO energy and PL, whereas SA were associated with decreases in both. These studies suggest that ERO measures may represent important potential biomarkers of adolescent extreme binge drinking and risk for suicidal behaviors.

Suicide Risk Assessment and Management Training Practices in Pediatric Residency Programs: A Nationwide Needs Assessment Survey.

PURPOSE: Youth suicide is a public health emergency, and its prevention is a national imperative. Pediatric providers are critical to risk assessment, triage, and intervention, yet little is known about the content, quality, and perceived adequacy of suicide prevention pediatric residency training. We thus sought to (1) characterize suicide risk assessment and management training practices in pediatric residency programs nationwide and (2) assess areas of training need to guide curricular development. METHODS: An online nationwide needs assessment was distributed to all 204 pediatric residency program directors (PDs) and 494 pediatric chief residents (CRs) through the Association of Pediatric Program Directors listservs (May to June 2017). Descriptive statistics and comparisons between PDs and CRs are reported. RESULTS: Ninety-five PDs and 210 CRs (47% and 43% response rate, respectively) completed the survey. Although 82% of respondents rated suicide prevention training in residency as "very" or "extremely" important, a minority (18% PDs and 10% CRs) reported adequate preparation relative to need. Formal training was not universal (66% PDs and 45% CRs) and practices varied across programs (PD median = 3 hours [interquartile range: 1-4.5 hours], CR median = 1.5 hours [interquartile range: 0-3 hours]). Top-ranked educational priorities included interviewing adolescents about risk, risk factor identification, and locating community resources. Training barriers included limited time, lack of training resources, and need for additional expert faculty to guide training. CONCLUSIONS: PDs and CRs reported constraints to suicide prevention training for pediatric residents despite high perceived importance and need. Programs may benefit from explicit guidelines and standardized curricula that emphasize educational priorities, building on these findings.

The Validity of Google Trends Search Volumes for Behavioral Forecasting of National Suicide Rates in Ireland.

Annual suicide figures are critical in identifying trends and guiding research, yet challenges arising from significant lags in reporting can delay and complicate real-time interventions. In this paper, we utilized Google Trends search volumes for behavioral forecasting of national suicide rates in Ireland between 2004 and 2015. Official suicide rates are recorded by the Central Statistics Office in Ireland. While similar investigations using Google trends data have been carried out in other jurisdictions (e.g., United Kingdom, United Stated of America), such research had not yet been completed in Ireland. We compiled a collection of suicide- and depression-related search terms suggested by Google Trends and manually sourced from the literature. Monthly search rate terms at different lags were compared with suicide occurrences to determine the degree of correlation. Following two approaches based on vector autoregression and neural network autoregression, we achieved mean absolute error values between 4.14 and 9.61 when incorporating search query data, with the highest performance for the neural network approach. The application of this process to United Kingdom suicide and search query data showed similar results, supporting the benefit of Google Trends, neural network approach, and the applied search terms to forecast suicide risk increase. Overall, the combination of societal data and online behavior provide a good indication of societal risks; building on past research, our improvements led to robust models integrating search query and unemployment data for suicide risk forecasting in Ireland.

"Impulsive" youth suicide attempters are not necessarily all that impulsive.

BACKGROUND: The relationship between impulsivity and suicide has been conceptualized in the literature as a direct one. In contrast, Joiner's [Joiner, T.E., 2005. Why people die by suicide. Harvard University Press, Cambridge, MA.] theory posits that this relationship is indirect in that impulsive individuals are more likely to engage in suicidal behavior because impulsivity makes one more likely to be exposed to painful and provocative stimuli. METHOD: Adolescents were selected from the Youth Risk Behavior Survey (YRBS) sample between the years of 1993-2003 who had planned for a suicide attempt but did not actually attempt (n=5685), who did not plan but did attempt ("impulsive attempters;" n=1172), and who both planned and attempted (n=4807). Items were selected from the YRBS to assess demographic variables, suicidal behaviors, and impulsive behaviors. RESULTS: Participants who had planned suicide without attempting were significantly less impulsive than those who had attempted without planning and than those who had both planned and attempted. Crucially, participants who had made a suicide attempt without prior planning were less impulsive than those who had planned and attempted. LIMITATIONS: We were unable to conduct a multi-method assessment (i.e., measures were self-report); the measure of impulsivity consisted of items pulled from the YRBS rather than a previously validated impulsivity measure. CONCLUSIONS: The notion that the most impulsive individuals are more likely to plan for suicide attempts is an important one for many reasons both theoretical and clinical, including that it may refine risk assessment and attendant clinical decision-making.

Family life stress and insomnia symptoms in a prospective evaluation of young adults.

The present study prospectively investigated the association between family life stress and insomnia symptoms among 115 undergraduates, ages 17-22 years. Participants completed the following questionnaires at 2 study time points, spaced 3 weeks apart: the Insomnia Severity Index, the Negative Life Events Questionnaire (NLEQ), and the Beck Depression Inventory. First, family life stress at baseline was hypothesized to predict elevated insomnia symptoms 3 weeks later, above and beyond depressive symptoms. Second, compared with academic stressors, negative family and social life events were expected to best predict increased insomnia. Regression analyses were conducted to test study predictions. Hypotheses were partially supported. Family life stress was significantly associated with increased insomnia symptomatology, even after controlling for depression. Results also revealed that negative family life events, together with academic stress, predicted the highest levels of insomnia.

Objectively Assessed Sleep Variability as an Acute Warning Sign of Suicidal Ideation in a Longitudinal Evaluation of Young Adults at High Suicide Risk.

OBJECTIVE: Young adults attempt suicide at disproportionately high rates relative to other groups and demonstrate high rates of sleep disturbance. No study has yet prospectively evaluated disturbed sleep as an acute indicator of risk using an objective index of sleep. We investigated objective and subjective parameters of disturbed sleep as a warning sign of suicidal ideation among young adults over an acute period. METHODS: A longitudinal study across a 21-day observation period and 3 time points. Fifty of 4,847 participants (aged 18-23 years) were prescreened from a university undergraduate research pool (February 2007-June 2008) on the basis of suicide attempt history and recent suicidal ideation. Actigraphic and subjective sleep parameters were evaluated as acute predictors of suicidal ideation (Beck Scale for Suicide Ideation), with adjustment for baseline symptoms. Hierarchical regression analyses were employed to predict residual change scores. RESULTS: Ninety-six percent of participants (n = 48) endorsed a suicide attempt history. Mean actigraphy values revealed objectively disturbed sleep parameters; 78% (n = 39) and 36% (n = 18) endorsed clinically significant insomnia and nightmares, respectively. When results were controlled for baseline suicidal and depressive symptoms, actigraphic and subjective sleep parameters predicted suicidal ideation residual change scores at 7- and 21-day follow-ups (P < .001). Specifically, actigraphy-defined variability in sleep timing, insomnia, and nightmares predicted increases in suicidal ideation (P < .05). In a test of competing risk factors, sleep variability outperformed depressive symptoms in the longitudinal prediction of suicidal ideation across time points (P < .05). CONCLUSIONS: Objectively and subjectively measured sleep disturbances predicted acute suicidal ideation increases in this population, independent of depressed mood. Self-reported insomnia and nightmares and actigraphically assessed sleep variability emerged as acute warning signs of suicidal ideation. These findings highlight the potential utility of sleep as a proposed biomarker of suicide risk and a therapeutic target.

Sleep architecture parameters as a putative biomarker of suicidal ideation in treatment-resistant depression.

BACKGROUND: Disturbed sleep may confer risk for suicidal behaviors. Polysomnographic (PSG) sleep parameters have not been systematically evaluated in association with suicidal ideation (SI) among individuals with treatment-resistant depression (TRD). METHODS: This secondary data analysis included 54 TRD individuals (N=30 with major depressive disorder (MDD) and N=24 with bipolar depression (BD)). PSG sleep parameters included Sleep Efficiency (SE), Total Sleep Time (TST), Wakefulness After Sleep Onset (WASO), REM percent/latency, and non-REM (NREM) Sleep Stages 1-4. The Hamilton Depression Rating Scale (HAM-D) was used to group participants according to presence or absence of SI. Sleep abnormalities were hypothesized among those with current SI. ANOVA analyses were conducted before (Model 1) and after adjusting for depression (Model 2) and diagnostic variables (Model 3). RESULTS: Significant differences in PSG parameters were observed in Model 1; those with SI had less NREM Stage 4 sleep (p<.05). After adjusting for central covariates, Models 2 and 3 revealed significantly less NREM Stage 4 sleep, lower SE (P<.05), and higher WASO (P<.05) among those with SI. BD participants with SI also had less NREM Stage 4 and more NREM Stage 1 sleep. LIMITATIONS: 1) a predominantly white sample; 2) exclusion of imminent suicide risk; 3) concomitant mood stabilizer use among BD patients; and 4) single-item SI assessment. CONCLUSIONS: Independent of depression severity, SI was associated with less NREM Stage 4 sleep, and higher nocturnal wakefulness across diagnostic groups. Sleep may warrant further investigation in the pathogenesis of suicide risk, particularly in TRD, where risk may be heightened.

Cross-cultural relevance of the Interpersonal Theory of suicide across Korean and U.S. undergraduate students.

This study investigated the cross-cultural relevance and validity of the Interpersonal Theory of Suicide (ITS) utilizing young adult samples from South Korea (n =554) and the United States (U.S.; n =390). To examine the ITS, all participants completed self-report questionnaires measuring Thwarted Belongingness, Perceived Burdensomeness, and Capability for Suicide. We examined whether each construct significantly predicted the severity of suicidal risk in both samples. We also determined whether the strength of the effects of Thwarted Belongingness and Perceived Burdensomeness on suicidal ideation differed between the two samples due to the greater degree of importance placed on interpersonal relationships in collectivistic cultures such as South Korea. Structural equation modeling was used to examine these hypotheses. Thwarted Belongingness, Perceived Burdensomeness, and Capability for Suicide significantly predicted elevated suicidal risk. However, there were no significant differences in the paths from Thwarted Belongingness or Perceived Burdensomeness to suicide risk between the South Korean and U.S. SAMPLES: These findings support the cross-cultural relevance and applicability of the ITS, whereby Thwarted Belongingness and Perceived Burdensomeness serve as indicators of suicide risk in both Western (U.S.) and East Asian (Korean) samples.

Antisuicidal Response Following Ketamine Infusion Is Associated With Decreased Nighttime Wakefulness in Major Depressive Disorder and Bipolar Disorder.

OBJECTIVE: Insomnia and disrupted sleep are associated with increased risk of suicide. The N-methyl-d-aspartate antagonist ketamine has been associated with reduced suicidal thoughts, but the mechanism of action is unknown. This study sought to evaluate differences in nocturnal wakefulness in depressed individuals who did and did not have an antisuicidal response to ketamine. METHODS: Thirty-four participants with baseline suicidal ideation diagnosed with either DSM-IV major depressive disorder (n = 23) or bipolar depression (n = 11) between 2006 and 2013 completed nighttime electroencephalography (EEG) the night before and the night after a single ketamine infusion (0.5 mg/kg over 40 minutes). Suicidal ideation was assessed at baseline and the morning after ketamine infusion via several measures, including the Hamilton Depression Rating Scale suicide item, the suicide item of the Montgomery-Asberg Depression Rating Scale, and the first 5 items of the Scale for Suicide Ideation. A generalized linear mixed model evaluated differences in nocturnal wakefulness, as verified by EEG, between those who had an antisuicidal response to ketamine and those who did not, controlling for baseline nocturnal wakefulness. Results were also compared to the sleep of healthy controls (n = 22). RESULTS: After analyses adjusted for baseline sleep, participants with an antisuicidal response to ketamine showed significantly reduced nocturnal wakefulness the night after ketamine infusion compared to those without an antisuicidal response (F1,22 = 5.04, P = .04). Level of nocturnal wakefulness after antisuicidal response to ketamine did not differ significantly from nocturnal wakefulness in the control sample but did differ at a trend level (F1,40 = 3.15, P = .08). CONCLUSIONS: Reductions in wakefulness following ketamine may point to a biological mechanism underlying the effect of ketamine on suicidal ideation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00088699.

Birth month and depressive and suicidal symptoms in an elderly Australian sample born in the Southern or Northern Hemisphere.

We examined the relationship between season of birth and depressive and suicidal symptoms among 859 elderly outpatients. Date and country of birth were recorded for each participant. Those in utero during the Northern or Southern Hemisphere flu peak were expected to show the highest depressive and suicidal symptoms. Hypotheses were partially supported.

Limitations of a single-item assessment of suicide attempt history: Implications for standardized suicide risk assessment.

Although a suicide attempt history is among the single best predictors of risk for eventual death by suicide, little is known about the extent to which reporting of suicide attempts may vary by assessment type. The current study aimed to investigate the correspondence between suicide attempt history information obtained via a single-item self-report survey, multi-item self-report survey, and face-to-face clinical interview. Data were collected among a high-risk sample of undergraduates (N = 100) who endorsed a past attempt on a single-item prescreening survey. Participants subsequently completed a multi-item self-report survey, which was followed by a face-to-face clinical interview, both of which included additional questions regarding the timing and nature of previous attempts. Even though 100% of participants (n = 100) endorsed a suicide attempt history on the single-item prescreening survey, only 67% (n = 67) reported having made a suicide attempt on the multi-item follow-up survey. After incorporating ancillary information from the in-person interview, 60% of participants qualified for a Centers for Disease Control and Prevention (CDC)-defined suicide attempt. Of the 40% who did not qualify for a CDC-defined suicide attempt, 30% instead qualified for no attempt, 7% an aborted attempt, and 3% an interrupted attempt. These findings suggest that single-item assessments of suicide attempt history may result in the misclassification of prior suicidal behaviors. Given that such assessments are commonly used in research and clinical practice, these results emphasize the importance of utilizing follow-up questions and assessments to improve precision in the characterization and assessment of suicide risk. (PsycINFO Database Record

The Association between Sleep Disturbances and Depression among Firefighters: Emotion Dysregulation as an Explanatory Factor.

STUDY OBJECTIVES: To investigate emotion regulation difficulties in association with self-reported insomnia symptoms, nightmares, and depression symptoms in a sample of current and retired firefighters. METHODS: A total of 880 current and retired United States firefighters completed a web-based survey of firefighter behavioral health. Self-report measures included the Center for Epidemiologic Studies Depression Scale, Insomnia Severity Index, PTSD Checklist, and Difficulties in Emotion Regulation Scale. RESULTS: A notable portion of participants reported clinically significant depression symptoms (39.6%) and insomnia symptoms (52.7%), as well as nightmare problems (19.2%), each of which demonstrated a strong association with emotion regulation difficulties (rs = 0.56-0.80). Bootstrapped mediation analyses revealed that the indirect effects of overall emotion regulation difficulties were significant both for the relationship between insomnia and depression (95% CI: 0.385-0.566) and nightmares and depression (95% CI: 1.445-2.365). Limited access to emotion regulation strategies emerged as the strongest, significant indirect effect for both relationships (insomnia 95% CI: 0.136-0.335; nightmares 95% CI: 0.887-1.931). CONCLUSIONS: Findings extend previous affective neuroscience research by providing evidence that insomnia and nightmares may influence depression symptoms specifically through the pathway of explicit emotion regulation difficulties. Sleep disturbances may impair the ability to access and leverage emotion regulation strategies effectively, thus conferring risk for negative affect and depression.

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.