Sleep Disturbance and Subsequent Suicidal Behaviors in Preadolescence.

Importance: Suicide is a leading cause of death among adolescents, who demonstrate high rates of sleep disturbance. Poor sleep appears to confer risk for suicide, but longitudinal investigation of suicidal behaviors remains rare, particularly in the transition from childhood to early adolescence. Objective: To evaluate sleep disturbances in preadolescent children (aged 9 and 10 years) in association with longitudinal risk for suicidal ideation and suicide attempts at the 2-year follow-up. Design, Setting, and Participants: This cohort study used data from the Adolescent Brain Cognitive Development Study between June 2016 and January 2021. This dataset included children aged 9 or 10 years at baseline and their parents or caregivers who were recruited at 21 sites across the US. Data were analyzed July 2023 to June 2024. Exposures: The Sleep Disturbance Scale for Children, a 26-item parent-reported inventory, was administered at baseline, generating a total score and 6 subscales. Central covariates included the Child Behavior Checklist Anxiety and Depression subscale and demographic variables. Main Outcomes and Measures: The computerized Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-COMP) assessed parent- and youth-reported suicidal behaviors and outcomes (none; passive, active nonspecific, and active specific suicidal ideation; and suicide attempt) at the 2-year follow-up. Sleep disturbance was further grouped by symptom severity (minimal, moderate, elevated, high, and severe). Results: Of the 10 136 youths who reported no baseline suicidal ideation or behavior, 8807 youths (mean [SD] age, 9.9 [0.6] years; 4507 males [51.2%]; 197 Asian individuals [2.2%], 1273 Black individuals [14.5%], and 5775 White individuals [65.6%]) completed the K-SADS-COMP assessment at the 2-year follow-up and were included in the analysis. At the follow-up, 8044 participants (91.3%) had no suicidal behavior, 317 (3.6%) had passive suicidal ideation, 258 (2.9%) had active nonspecific suicidal ideation, 130 (1.5%) had active specific suicidal ideation, and 58 (0.7%) had a first-time suicide attempt. Baseline sleep disturbance was associated with increased incidence risk for suicidal behavior at age 12 years (odds ratio, 2.68; 95% CI, 1.44-4.98; P = .002), adjusting for covariates. Individual subscales or items demonstrating associations with risk included disorders of excessive somnolence and frequency of nightmares. Conclusions and Relevance: Results of this longitudinal cohort study revealed that disturbed sleep at age 10 years was associated with risk for suicidal thoughts and behaviors in the next 2 years. The findings highlight the potential importance of sleep as a visible risk factor and intervention target in the prevention of youth suicide.

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.

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.

Comorbidity of anxiety/affective, conduct/antisocial, attention deficit, and alcohol use disorders with suicidal behaviors in an American Indian community sample of adults and adolescents.

AIMS: To study the associations of anxiety/affective disorders, conduct/antisocial disorders (ASPD/CD), attention deficit disorders (ADHD), and alcohol use disorders (AUD) with suicidal behaviors in an American Indian (AI) community sample of adolescents and adults. METHODS: Participants were AI (360 adolescents, 925 adults) recruited from reservations who were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). RESULTS: Among AI adults (mean age = 33 years), 17% percent reported lifetime experiences of suicidal thoughts (ideation and/or plans) and 14% reported suicidal acts (including either a suicide attempt history or verified death by suicide; n = 19 deaths). Among AI adolescents (mean age = 15 years), 20% experienced suicidal thoughts and 9% experienced suicidal acts (including 3 deaths). In logistic regression analyses, suicidal thoughts were significantly associated with lifetime diagnoses of affective disorder, CD and ADHD in adolescents, and with anxiety disorder, affective disorder, and ASPD/CD in adults. Suicidal acts were associated with affective disorder, ADHD, and alcohol drinking in adolescents and with anxiety disorder, ASPD/CD and AUD in adults. The number of comorbid disorders greatly increased the risk of both suicidal thoughts and acts among both adolescents and adults. CONCLUSIONS: In addition to affective disorders, both ADHD and CD in adolescents, and ASPD in adults, demonstrated an association with suicidal thoughts. Alcohol use by adolescents and AUD among adults also were associated with suicidal attempts in this AI sample. These findings suggest need for additional research and potential integration of alcohol in screening and intervention programs focused on the prevention of suicide among AI.

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 mutations in four genes including SERPINF1 (PEDF), ZNF30, CD34, and SLC5A9, and non-intronic rare 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 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 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.

Poor self-reported sleep quality associated with suicide risk in a community sample of American Indian adults.

Study Objectives: Although American Indian/Alaska Native (AI/AN) have high suicide rates few studies have systematically investigated sleep quality and its association with suicidal behaviors in AI/AN. This study is a cross-sectional investigation of self-reported sleep quality and suicidal behaviors in an adult AI population. Methods: A semi-structured interview was used to collect data on suicidal ideation, suicidal plans, and suicidal attempts and the Pittsburgh Sleep Quality Index (PSQI) was collected to assess sleep quality in American Indian adults. Results: In this sample (n = 477), 91 (19%) of the participants endorsed suicidal ideation (thoughts and plans), and 66 (14%) reported suicidal attempts, including four who subsequently died by suicide. More women reported suicidal thoughts or acts than men. Those endorsing suicidal thoughts slept fewer hours during the night, reported more nocturnal awakenings, and showed poorer subjective sleep quality according to PSQI total scores compared to those with no suicidal thoughts or acts. Participants with suicidal acts (n = 66) reported more bad dreams and higher PSQI total scores compared to those with no suicidal thoughts or acts. When those with any suicidal thoughts or acts (n = 157, 33%) were compared to those without, they were more likely to endorse nocturnal awakenings and bad dreams and demonstrated significantly higher PSQI total scores. Conclusions: Although additional research is needed to evaluate sleep disturbances as a proximal, causal risk factor for suicidal behaviors in AI, findings highlight need for further study of sleep as a warning sign and intervention tool for suicide prevention among American Indian adults.

Using a Safety Planning Mobile App to Address Suicidality in Young People Attending Community Mental Health Services in Ireland: Protocol for a Pilot Randomized Controlled Trial.

BACKGROUND: Over 700,000 people die by suicide annually, making it the fourth leading cause of death among those aged 15-29 years globally. Safety planning is recommended best practice when individuals at risk of suicide present to health services. A safety plan, developed in collaboration with a health care practitioner, details the steps to be taken in an emotional crisis. SafePlan, a safety planning mobile app, was designed to support young people experiencing suicidal thoughts and behaviors and to record their plan in a way that is accessible immediately and in situ. OBJECTIVE: The aim of this study is to assess the feasibility and acceptability of the SafePlan mobile app for patients experiencing suicidal thoughts and behaviors and their clinicians within Irish community mental health services, examine the feasibility of study procedures for both patients and clinicians, and determine if the SafePlan condition yields superior outcomes when compared with the control condition. METHODS: A total of 80 participants aged 16-35 years accessing Irish mental health services will be randomized (1:1) to receive the SafePlan app plus treatment as usual or treatment as usual plus a paper-based safety plan. The feasibility and acceptability of the SafePlan app and study procedures will be evaluated using both qualitative and quantitative methodologies. The primary outcomes are feasibility outcomes and include the acceptability of the app to participants and clinicians, the feasibility of delivery in this setting, recruitment, retention, and app use. The feasibility and acceptability of the following measures in a full randomized controlled trial will also be assessed: the Beck Scale for Suicide Ideation, Columbia Suicide Severity Rating Scale, Coping Self-Efficacy Scale, Interpersonal Needs Questionnaire, and Client Service Receipt Inventory. A repeated measures design with outcome data collected at baseline, post intervention (8 weeks), and at 6-month follow-up will be used to compare changes in suicidal ideation for the intervention condition relative to the waitlist control condition. A cost-outcome description will also be undertaken. Thematic analyses will be used to analyze the qualitative data gathered through semistructured interviews with patients and clinicians. RESULTS: As of January 2023, funding and ethics approval have been acquired, and clinician champions across mental health service sites have been established. Data collection is expected to commence by April 2023. The submission of completed manuscript is expected by April 2025. CONCLUSIONS: The framework for Decision-making after Pilot and feasibility Trials will inform the decision to progress to a full trial. The results will inform patients, researchers, clinicians, and health services of the feasibility and acceptability of the SafePlan app in community mental health services. The findings will have implications for further research and policy regarding the broader integration of safety planning apps. TRIAL REGISTRATION: OSF Registries osf.io/3y54m; https://osf.io/3y54m. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/44205.

Trauma, historical trauma, PTSD and suicide in an American Indian community sample.

AIMS: To study the associations between perceived historical trauma, current traumatic events, diagnoses of post-traumatic stress disorder (PTSD), and suicidal behaviors in an American Indian community sample. METHODS: Participants were American Indians recruited from reservations who were assessed with the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), as well as the Historical Loss Scale, Historical Loss Associated Symptoms Scale, and Stressful Life Events Scale. RESULTS: In data from 447 American Indian adults (mean age = 33 years), twenty percent reported lifetime experiences of suicidal thoughts (ideation and/or plans) and 14% reported suicidal acts, (including either a suicide attempt history or verified death by suicide (n = 4)). Diagnosis of PTSD and experience of assaultive trauma were each significantly associated with suicidal thoughts and acts, although assaultive trauma did not remain significant in models adjusting for gender and PTSD. High endorsement of symptoms associated with historical trauma was significantly associated with suicidal acts, and this remained significant when adjusting for gender and PTSD. CONCLUSIONS: PTSD and historical trauma have an association with suicide and suicidal attempts in this American Indian community. Although further research is needed to evaluate the causal nature of these relations, these findings suggest treatment and prevention programs for American Indian suicide may benefit from addressing issues related to feelings of historical losses, PTSD, and their associated symptomatology.

Examining subjective sleep quality in adults with hoarding disorder.

Hoarding disorder (HD), characterized by difficulty parting with possessions and functionally impairing clutter, affects 2-6% of the population. Originally considered part of Obsessive-Compulsive Disorder (OCD), HD became a distinct diagnostic entity in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. While sleep impacts OCD, little is known about sleep in HD. As HD patients often report poor sleep in clinical settings, understanding global subjective sleep quality and disturbances may lead to novel therapeutic targets. To address this gap, the authors used a sample of convenience: an existing data set designed to screen research study eligibility and explore the psychopathology and phenomenology of OCD and HD. The data set included information collected from individuals with HD (n = 38), OCD (n = 26), and healthy participants (n = 22) about insomnia, sleep quality, and mood using interviews and structured instruments including the Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Depression Anxiety Stress Scales (DASS). In this data set, HD and OCD groups reported significantly greater insomnia symptoms and poorer sleep quality compared with healthy controls while controlling for depression, age, and gender. A sizable minority of HD and OCD individuals met criteria for comorbid sleep disorders. OCD and HD groups differed in delayed sleep phase prevalence. To our knowledge, this is the first study examining subjective sleep quality and insomnia in HD as compared to healthy individuals and those with OCD, while controlling for relevant clinical characteristics. Given that there are evidence-based treatments for insomnia and other sleep disorders, our study raises the possibility that treatment interventions targeting sleep may improve HD outcomes.

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.

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.

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.

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.

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.

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.

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.

Nocturnal Wakefulness Is Associated With Next-Day Suicidal Ideation in Major Depressive Disorder and Bipolar Disorder.

OBJECTIVE: Self-reported sleep disturbances may confer elevated risk for suicidal ideation, suicide attempts, and death. However, limited research has evaluated polysomnographically determined sleep disturbance as an acute physiologic risk factor for suicidal thoughts. This study sought to investigate the relationship between nocturnal wakefulness in association with next-day suicidal ideation using overnight polysomnography assessment from data collected between 2006 and 2013. METHODS: Sixty-five participants with DSM-IV-diagnosed major depressive disorder or bipolar depression underwent overnight polysomnography monitoring in a sleep laboratory. The Hamilton Depression Rating Scale (HDRS) was administered the morning after polysomnography recording to assess next-day suicidal ideation, severity of depressive symptoms, and subjective sleep disturbances. RESULTS: Using a generalized linear mixed model, a significant time-by-ideation interaction was found indicating greater nocturnal wakefulness at 4:00 am among participants with suicidal ideation (F4,136 = 3.65, P = .007). Increased time awake during the 4:00 am hour (4:00 to 4:59) was significantly associated with elevated suicidal thoughts the next day (standardized ß = 0.31, P = .008). This relationship persisted after controlling for age, gender, diagnosis, and severity of depressive symptoms. CONCLUSIONS: Greater nocturnal wakefulness, particularly in the early morning hours, was significantly associated with next-day suicidal thoughts. Polysomnographically documented sleep disruption at specific times of night may represent an acute risk factor of suicidal ideation that warrants additional research. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00024635.

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