A Prospective Examination of the Interpersonal-Psychological Theory of Suicidal Behavior in Adolescents.

OBJECTIVE: Given the large and complex array of suicide risk factors, theoretical frameworks are critical to furthering our understanding of risk. This study prospectively examined several key constructs of the interpersonal-psychological theory of suicidal behavior (IPTS) in a large, geographically diverse sample of U.S. adolescents. METHOD: Conducted in collaboration with the Pediatric Emergency Care Applied Research Network, adolescents, ages 12 to 17, were recruited from emergency departments. Baseline and 6-month follow-up samples were comprised of 6,448 (59% female sex) and 2,009 (64% female sex) adolescents, with self-identified race/ethnicity as follows (baseline/follow-up): White (52%/54%), Black (22%/23%), Multiracial (6%/6%), American Indian (3%/3%), other/unknown race (15%/14%), and Latinx (25%/23%). Youth and parents completed adolescent suicide risk surveys at baseline and 6-month follow-up (retention, 69%). Latent class analysis was used to identify classes of painful and provocative events (PPE), considered a precursor to acquired capability. RESULTS: In keeping with IPTS tenets, thwarted belongingness (TB), perceived burdensomeness (PB), and the interaction between TB and PB were each significant predictors of suicidal ideation at baseline and follow-up. However, only PB and PPE were significant predictors of cross-sectional suicide attempts and only TB and PPE were significant predictors of prospective suicide attempts in models that adjusted for baseline suicidal ideation. The three-way interaction among PB, TB and PPE was nonsignificant. CONCLUSIONS: Results from this large-scale prospective study suggest the importance of TB, PB, and PPE to our understanding of suicidal thoughts and suicide attempts among adolescents, pointing to promising prevention and intervention targets.

Using machine learning with intensive longitudinal data to predict depression and suicidal ideation among medical interns over time.

BACKGROUND: Use of intensive longitudinal methods (e.g. ecological momentary assessment, passive sensing) and machine learning (ML) models to predict risk for depression and suicide has increased in recent years. However, these studies often vary considerably in length, ML methods used, and sources of data. The present study examined predictive accuracy for depression and suicidal ideation (SI) as a function of time, comparing different combinations of ML methods and data sources. METHODS: Participants were 2459 first-year training physicians (55.1% female; 52.5% White) who were provided with Fitbit wearable devices and assessed daily for mood. Linear [elastic net regression (ENR)] and non-linear (random forest) ML algorithms were used to predict depression and SI at the first-quarter follow-up assessment, using two sets of variables (daily mood features only, daily mood features + passive-sensing features). To assess accuracy over time, models were estimated iteratively for each of the first 92 days of internship, using data available up to that point in time. RESULTS: ENRs using only the daily mood features generally had the best accuracy for predicting mental health outcomes, and predictive accuracy within 1 standard error of the full 92 day models was attained by weeks 7-8. Depression at 92 days could be predicted accurately (area under the curve >0.70) after only 14 days of data collection. CONCLUSIONS: Simpler ML methods may outperform more complex methods until passive-sensing features become better specified. For intensive longitudinal studies, there may be limited predictive value in collecting data for more than 2 months.

Does coping reduce suicidal urges in everyday life? Evidence from a daily diary study of adolescent inpatients.

BACKGROUND: Youth suicide has been increasing at an alarming rate. Identifying how youth at risk for suicide cope with daily distress and suicidal thoughts could inform prevention and intervention efforts. We investigated the relationship between previous-day coping and next-day suicidal urge intensity in a high-risk adolescent sample for a 4-week period. We also investigated the influence of adolescents' average coping levels, over 4 weeks, on daily severity of suicidal urges. METHODS: A total of 78 adolescents completed daily diaries after psychiatric hospitalization (n = 1621 observations). Each day, adolescents reported their use of specific coping strategies, overall coping helpfulness, and intensity of suicidal urges. RESULTS: Greater professional support seeking from providers/crisis lines and perceptions of coping helpfulness on the previous day were associated with lower next-day suicidal urges. Adolescents who reported greater average use of cognitive strategies, personal support seeking from family/friends, and higher average perceptions of coping helpfulness, relative to others, had lower daily suicidal urges. Noncognitive strategy use was not related to daily suicidal urge intensity. CONCLUSION: Findings point to the benefit of intervention efforts focusing on strengthening personal and professional supportive relationships, assisting youth with developing a broader coping repertoire, and working with adolescents to identify strategies they perceive to be helpful.

Suicidal Desire in Adolescents: An Examination of the Interpersonal Psychological Theory Using Daily Diaries.

OBJECTIVE: Despite decades of research, relatively little is known about short-term predictors of suicidal thoughts and behavior. Intensive longitudinal methods are increasingly applied to investigate near-term risk factors of suicidal thoughts in daily life. The aim of this study was to examine short-term predictors of daily-level suicidal thoughts in a high-risk adolescent sample using the interpersonal-psychological theory of suicidal behavior (IPTS) as a guiding framework; the theory proposes that interpersonal experiences of thwarted belongingness in combination with perceived burdensomeness lead to suicidal desire. METHODS: Seventy-eight adolescents hospitalized due to suicide risk responded to one survey/day for 28 days after discharge (n = 1621 unique observations). Multilevel models examined IPTS-informed predictors of same- and next-day suicidal urge intensity. RESULTS: Partial and time-dependent support for the theory was found. The hypothesized two-way interaction between burdensomeness and thwarted belongingness (either family or peer) was significantly associated with increasing same-day, but not next-day, suicidal ideation; specifically, greater belongingness attenuated adverse impact of burdensomeness. The only significant predictor of next-day ideation was higher previous-day burdensomeness. Baseline burdensomeness also emerged as a predictor of day-to-day suicidal ideation. CONCLUSION: Using a theoretically informed model, this study offers an in-depth examination of short-term predictors of suicidal ideation among high-risk adolescents. Findings underscore the importance of fostering peer and family relationships in reducing suicidal thoughts in the post-discharge period. Results additionally suggest that both state- and trait-level burdensomeness have lasting influence on suicidal thoughts during this high-risk period. These findings could inform intervention efforts for high-risk youth.

Predictors of Parent Behavioral Engagement in Youth Suicide Discharge Recommendations: Implications for Family-Centered Crisis Interventions.

The number of youth presenting to Emergency Departments (EDs) with psychiatric chief complaints has almost doubled in the last decade. With pediatric patients, ED brief interventions and discharge recommendations necessitate meaningful parental engagement to optimize youth safety and support. This study examined parent-level factors (stigmatizing attitudes, self-efficacy beliefs, distress symptoms, and illness-related stressors) in relation to parents' behavioral engagement (i.e., participation in and follow-through with best practice discharge recommendations). In this short-term prospective study, participants were 118 parent-youth (aged 11-18) dyads (57% female) recruited from a psychiatric ED. Parents' behavioral engagement was measured with parent- and youth-self report at 2-week follow-up. Parents' self-reported anxious and depressive symptoms, insomnia, stress, and stigmatizing attitudes were not related to engagement 2 weeks later. Higher parental self-efficacy beliefs were significantly associated with greater engagement in standard discharge recommendations. Implications for maximizing parent implementation of clinical recommendations during a youth suicide crisis are discussed.

Adaptive intervention for prevention of adolescent suicidal behavior after hospitalization: a pilot sequential multiple assignment randomized trial.

BACKGROUND: The need for effective interventions for psychiatrically hospitalized adolescents who have varying levels of postdischarge suicide risk calls for personalized approaches, such as adaptive interventions (AIs). We conducted a nonrestricted pilot Sequential, Multiple Assignment, Randomized Trial (SMART) to guide the development of an AI targeting suicide risk after hospitalization. METHODS: Adolescent inpatients (N = 80; ages 13-17; 67.5% female) were randomized in Phase 1 to a Motivational Interview-Enhanced Safety Plan (MI-SP), delivered during hospitalization, alone or in combination with postdischarge text-based support (Texts). Two weeks after discharge, participants were re-randomized in Phase 2 to added telephone booster calls or to no calls. Mechanisms of change were assessed with daily diaries for four weeks and over a 1- and 3-month follow-up. This trial is registered with clinicaltrials.gov (identifier: NCT03838198). RESULTS: Procedures were feasible and acceptable. Mixed effects models indicate that adolescents randomized to MI-SP + Texts (Phase 1) and those randomized to booster calls (Phase 2) experienced significant improvement in daily-level mechanisms, including safety plan use, self-efficacy to refrain from suicidal action, and coping by support seeking. Those randomized to MI-SP + Texts also reported significantly higher coping self-efficacy at 1 and 3 months. Although exploratory, results were in the expected direction for MI-SP + Texts, versus MI-SP alone, in terms of lower risk of suicide attempts (Hazard ratio = 0.30; 95% CI = 0.06, 1.48) and suicidal behavior (Hazard ratio = 0.36; 95% CI = 0.10, 1.37) three months after discharge. Moreover, augmentation with booster calls did not have an overall meaningful impact on suicide attempts (Hazard ratio = 0.65; 95% CI = 0.17, 3.05) or suicidal behavior (Hazard ratio = 0.78; 95% CI = 0.23, 2.67); however, boosters benefited most those initially assigned to MI-SP + Texts. CONCLUSIONS: The current SMART was feasible and acceptable for the purpose of informing an AI for suicidal adolescents, warranting additional study. Findings also indicate that postdischarge text-based support offers a promising augmentation to safety planning delivered during hospitalization.

Short-term change and prediction of suicidal ideation among adolescents: a daily diary study following psychiatric hospitalization.

BACKGROUND: Our understanding of suicidal ideation (SI) and its risk precursors is largely informed by studies spanning over wide time intervals (weeks, months, years). Little is known about SI as it occurs in daily lives of individuals at risk for suicide, the extent to which suicidal thoughts are dynamic over short periods of time, and the degree to which theoretically informed risk factors predict near-term SI. METHODS: Thirty-four adolescents hospitalized due to last-month suicide attempt and/or last-week SI (76% female; ages 13-17) responded to daily surveys sent to their cell phones for four consecutive weeks after discharge (n = 652 observations). RESULTS: There was notable variability in day-to-day SI, with half of ideation ratings changing at least one within-person standard deviation from one day to the next. Results of mixed effects models revealed concurrent (same-day), but not short-term prospective (next-day), associations between SI (frequency, duration, urge) and well-established predictors (connectedness, burdensomeness, hopelessness). However, synergistic effects of low connectedness with either high burdensomeness or high hopelessness were reliably associated with more severe same- and next-day suicidal ideation. CONCLUSIONS: This study adds to emerging literature indicating that suicidal thoughts fluctuate considerably among individuals at risk for suicide, further extending it by focusing on adolescents in the critical posthospitalization period. Fostering high-risk adolescents' sense of connectedness to others may be an especially promising intervention target. Frequent assessment of SI and its predictors, independently and in combination, could help identify promising predictors of short-term risk and meaningful intervention targets in high-risk teens.

Parental Self-Efficacy to Support Teens During a Suicidal Crisis and Future Adolescent Emergency Department Visits and Suicide Attempts.

This study of adolescents seeking emergency department (ED) services and their parents examined parents' self-efficacy beliefs to engage in suicide prevention activities, whether these beliefs varied based on teens' characteristics, and the extent to which they were associated with adolescents' suicide-related outcomes. Participants included 162 adolescents (57% female, 81.5% Caucasian), ages 13-17, and their parents. At index visit, parents rated their self-efficacy to engage in suicide prevention activities and their expectations regarding their teen's future suicide risk. Adolescents' ED visits for suicide-related concerns and suicide attempts were assessed 4 months later. Parents endorsed high self-efficacy to engage in most suicide prevention activities. At the same time, they endorsed considerable doubt in being able to keep their child safe if the teen has thoughts of suicide and in their child not attempting suicide in the future. Parents whose teens experienced follow-up suicide-related outcomes endorsed, at clinically meaningful effect sizes, lower self-efficacy for recognizing suicide warning signs, for obtaining the teen's commitment to refrain from suicide, and for encouraging their teen to cope, as well as lower confidence that their teen will not attempt suicide; self-efficacy to recognize warning signs was at trend level. Despite endorsing high self-efficacy for the majority of suicide prevention activities, parents of high-risk teens expressed less confidence in their capacity to influence their teen's suicidal behavior, which could undermine parents' effort to implement these strategies. The relationship between parental self-efficacy and youth suicide-related outcomes points to its potential value in guiding clinical decision making and interventions.

Suicide Risk Screening in Healthcare Settings: Identifying Males and Females at Risk.

Suicide is the tenth leading cause of death in the United States, accounting for more than 42,000 deaths in 2014. Although this tragedy cuts across groups defined by age, gender, race/ethnicity, and geographic location, it is striking that nearly four times as many males as females die by suicide in the U.S. We describe the current regulations and recommendations for suicide risk screening in healthcare systems and also describe the aspirational goal of "Zero Suicide," put forth by the National Action Alliance for Suicide Prevention. We then provide information about suicide risk screening tools and steps to take when a patient screens positive for suicide risk. Given the substantially higher suicide rate among males than females, we argue that it is important to consider how we could optimize suicide risk screening strategies to identify males at risk and females at risk. Further research is needed to accomplish this goal. It is recommended that we consider multi-factorial suicide risk screens that incorporate risk factors known to be particularly important for males as well as computerized, adaptive screens that are tailored for the specific risk considerations of the individual patient, male or female. These strategies are not mutually exclusive. Finally, universal suicide risk screening in healthcare settings, especially primary care, specialty medical care, and emergency department settings, is recommended.

SELF-RATED EXPECTATIONS OF SUICIDAL BEHAVIOR PREDICT FUTURE SUICIDE ATTEMPTS AMONG ADOLESCENT AND YOUNG ADULT PSYCHIATRIC EMERGENCY PATIENTS.

BACKGROUND: This study's purpose was to examine the predictive validity and clinical utility of a brief measure assessing youths' own expectations of their future risk of suicidal behavior, administered in a psychiatric emergency (PE) department; and determine if youths' ratings improve upon a clinician-administered assessment of suicidal ideation severity. The outcome was suicide attempts up to 18 months later. METHODS: In this medical record review study, 340 consecutively presenting youths (ages 13-24) seeking PE services over a 7-month period were included. Subsequent PE visits and suicide attempts were retrospectively tracked for up to 18 months. The 3-item scale assessing patients' perception of their own suicidal behavior risk and the clinician-administered ideation severity scale were used routinely at the study site. RESULTS: Cox regression results showed that youths' expectations of suicidal behavior were independently associated with increased risk of suicide attempts, even after adjusting for key covariates. Results were not moderated by sex, suicide attempt history, or age. Receiver-operating characteristic (ROC) analyses indicated that self-assessed expectations of risk improved the predictive accuracy of the clinician-administered suicidal ideation measure. CONCLUSIONS: Youths' ratings indicative of lower confidence in maintaining safety uniquely predicted follow-up attempts and provided incremental validity over and above the clinician-administered assessment and improved its accuracy, suggesting their potential for augmenting suicide risk formulation. Assessing youths' own perceptions of suicide risk appears to be clinically useful, feasible to implement in PE settings, and, if replicated, promising for improving identification of youth at risk for suicidal behavior.

Longitudinal trajectories of suicidal ideation and subsequent suicide attempts among adolescent inpatients.

A period of particularly high risk for suicide attempts among adolescent inpatients is within 12 months after discharge. However, little is known about longitudinal trajectories of suicidal ideation in this high-risk group and how these relate to posthospitalization suicide attempts and rehospitalizations. Our objectives were to identify these trajectories and examine their relationships with posthospitalization psychiatric crises. We also examined predictors of trajectory group membership. Participants (N = 376; ages 13-17; 72% female) were assessed at hospitalization and 3, 6, and 12 months later. Trajectory groups, and their predictors, were identified with latent class growth modeling. We used logistic regression to examine associations between trajectory groups and likelihood of suicide attempts and rehospitalization, controlling for attempt history. Three trajectory groups were identified: (a) subclinical ideators (31.6%), (b) elevated ideators with rapidly declining ideation (57.4%), and (c) chronically elevated ideators (10.9%). Adolescents in the chronically elevated ideation group had 2.29, confidence interval (CI) [1.08, 4.85], p = .03, and 4.15, CI [1.65, 10.44], p < .01, greater odds of attempting suicide and 3.23, CI [1.37, 7.69], p = .01, and 11.20, CI [4.33, 29.01], p < .001, greater odds of rehospitalization relative to rapidly declining and subclinical groups, respectively. Higher baseline hopelessness was associated with persisting suicidal ideation. Results suggest that suicidal ideation severity at hospitalization may not be an adequate marker for subsequent suicidal crises. It is important to identify adolescents vulnerable to persisting suicidal ideation, as they are at highest risk of psychiatric crises. Addressing hopelessness may facilitate faster declines in ideation after hospitalization. Results also highlight a need for consistent monitoring of these adolescents' suicidal ideation after discharge.

Predicting Future Suicide Attempts Among Adolescent and Emerging Adult Psychiatric Emergency Patients.

The purpose of this study was to longitudinally examine specific characteristics of suicidal ideation in combination with histories of suicide attempts and non-suicidal self-injury (NSSI) to best evaluate risk for a future attempt among high-risk adolescents and emerging adults. Participants in this retrospective medical record review study were 473 (53% female; 69% Caucasian) consecutive patients, ages 15 to 24 years (M=19.4 years) who presented for psychiatric emergency services during a 9-month period. These patients' medical records, including a clinician-administered Columbia-Suicide Severity Rating Scale, were coded at the index visit and at future visits occurring within the next 18 months. Logistic regression models were used to predict suicide attempts during this period. Socioeconomic status, suicidal ideation severity (i.e., intent, method), suicidal ideation intensity (i.e., frequency, controllability), a lifetime history of suicide attempt, and a lifetime history of NSSI were significant independent predictors of a future suicide attempt. Suicidal ideation added incremental validity to the prediction of future suicide attempts above and beyond the influence of a past suicide attempt, whereas a lifetime history of NSSI did not. Sex moderated the relationship between the duration of suicidal thoughts and future attempts (predictive for male patients but not female). Results suggest value in incorporating both past behaviors and current thoughts into suicide risk formulation. Furthermore, suicidal ideation duration warrants additional examination as a potential critical factor for screening assessments evaluating suicide risk among high-risk samples, particularly for male patients.

Assessment of microRNAs in patients with unstable angina pectoris.

AIMS: While cardiac troponin measurements have significantly improved the early diagnosis of myocardial infarction, the timely biomarker-based diagnosis of unstable angina pectoris (UAP) remains a major unmet clinical challenge. The aim of this study was to assess levels of circulating microRNAs (miRNAs) as possible novel biomarkers in patients with UAP. METHODS AND RESULTS: A three-phase approach was conducted, comprising (i) profiling of miRNAs in patients with UAP and controls groups; (ii) replication of significant miRNAs in an independent patient cohort, (iii) validation of a multi-miRNAs panel in a third cohort. Out of 25 miRNAs selected for replication, 8 miRNAs remained significantly associated with UAP. In a validation phase, a miRNA panel including miR-132, miR-150, and miR-186 showed the highest discriminatory power [area under the receiver-operating-characteristic curve (AUC): 0.91; CI: 0.84-0.98]. CONCLUSION: Using a profiling-replication-validation model, we identified eight miRNAs, which may facilitate the diagnosis of UAP.

Worsening Symptoms of Anxiety, Depression, and Sleep Problems in Caregivers Following Youth's Suicide-Related Emergency Department Visit.

OBJECTIVE: Although families assume considerable responsibility in caring for their child after a suicidal crisis, little is known about caregiver well-being following a suicide-related pediatric Emergency Department (ED) visit. This study aimed to (1) describe the course of caregiver distress symptoms (e.g., anxiety, depression, and negative affect) and sleep problems following their child's suicide-related ED visit and to (2) identify factors (e.g., parents' mental health history, youth suicide risk chronicity, and perception of feeling supported by the mental health system) hypothesized to be related to caregiver distress symptoms and sleep problems at follow-up using a diathesis-stress model framework. METHOD: Participants included 118 caregiver/youth (ages 11-17) dyads presenting to a psychiatric ED due to youths' suicide-related concerns. Caregivers and youth were assessed during index ED visit and 2-weeks following discharge. RESULTS: Caregivers' anxiety and depressive symptoms and sleep problems increased significantly from the time of the ED visit to 2-week follow-up. There was no significant change in caregiver negative affect. Caregivers with their own history of mental illness and those whose children had a previous ED visit due to a psychiatric concern, suggestive of chronic suicide risk, reported higher anxiety and depressive symptoms at follow-up. CONCLUSION: In the 2 weeks following an ED visit for their child's suicidal crisis, caregivers reported significant increases in anxiety and depressive symptoms and sleep problems. Findings highlight the need to consider the mental health of caregivers whose children are at elevated risk for suicide.HighlightsCaregivers report increases in distress symptoms following youth's suicidal crisis.Caregiver mental health history and youth suicide chronicity impacted distress.Caregiver mental health should be considered when planning youth interventions.

Rationale and design of the EMBRACE STEMI study: a phase 2a, randomized, double-blind, placebo-controlled trial to evaluate the safety, tolerability and efficacy of intravenous Bendavia on reperfusion injury in patients treated with standard therapy including primary percutaneous coronary intervention and stenting for ST-segment elevation myocardial infarction.

BACKGROUND: Although significant efforts have been made to improve ST-segment elevation myocardial infarction (STEMI) outcomes by reducing symptom-onset-to-reperfusion times, strategies to decrease the clinical impact of ischemic reperfusion injury have demonstrated limited success. Bendavia, an intravenously administered mitochondrial targeting peptide, has been shown to reduce myocardial infarct size and attenuate coronary no-reflow in experimental modelswhen given before reperfusion. DESIGN: The EMBRACE STEMI study is a phase 2a, randomized, double-blind, placebo-controlled trial enrolling 300 patients with a first-time anterior STEMI and an occluded proximal or mid-left anterior descending artery undergoing primary percutaneous coronary intervention (PCI) within 4 hours of symptom onset. Patients will be randomized to receive either Bendavia at 0.05 mg/kg per hour or an identically appearing placebo administered as an intravenous infusion at 60 mL/h. The primary end point is infarct size measured by the area under the creatine kinase-MB enzyme curve calculated from measurements from the central clinical chemistry laboratory obtained over the initial 72 hours after the primary PCI procedure, and the major secondary end point is infarct size calculated by the volume of infarcted myocardium (late contrast gadolinium enhancement) on the day 4±1 cardiac magnetic resonance imaging. SUMMARY: EMBRACE-STEMI is testing the hypothesis that Bendavia, in conjunction with standard-of-care therapy, is superior to placebo for the reduction of myocardial infarction size among patients with first time, acute, anterior wall STEMI who undergo successful reperfusion with primary PCI and stenting.

Safety plan use in the daily lives of adolescents after psychiatric hospitalization.

INTRODUCTION: Safety planning type interventions (SPTI's) are brief suicide-specific interventions. Little is known about safety plan use during high-risk periods, and whether safety plan use is influenced by baseline characteristics. This study examined how adolescents recently hospitalized for suicide risk use their safety plans post-discharge, tested moderators of safety plan utilization, and explored the relationship between changes in utilization and changes in suicidal ideation (SI) over time. METHODS: Seventy-eight adolescents hospitalized for suicide risk who participated in a pilot trial of safety planning responded to one survey/day for 4 weeks post-discharge and completed a 1-month assessment. RESULTS: Over 90% of adolescents reported having access to their safety plan during the month post-discharge. Safety plan use and SI declined over time. No baseline characteristics predicted safety plan use in the 4 weeks after discharge, or changes in safety plan use over time. However, the relationship between changes in safety plan use and changes in SI was moderated. For girls, SI and safety plan use rose and fell together; for boys, safety plan use declined regardless of changes in SI. CONCLUSIONS: High-risk adolescents retain and use their safety plans. Results underscore the importance of looking at sex effects on SPTI utilization.

A latent profile analysis of at-risk first-year undergraduate students.

Objective: We examined whether meaningful subgroups of self-injurious behaviors (SIBs) would emerge within a pool of first-year college students already deemed at elevated risk. Participants: First-year undergraduates (N = 1,068) recruited in 2015-2018 Fall terms. Methods: Past-year nonsuicidal self-injury (NSSI) frequency, past-year number of NSSI methods used, lifetime suicide attempt (SA) history, and recency of SA were included in a latent profile analysis. Results: Four subgroups emerged: low SIB (n = 558, 52%), high NSSI only (n = 182, 17%), high SIB (n = 141, 13%), and high SA only (n = 187, 18%). Students in the high SIB group reported higher levels of suicidal ideation at baseline and follow-up in comparison to all groups. Those in the high NSSI only or high SIB groups had relatively higher levels of NSSI at baseline and follow-up. Conclusions: Findings highlight the amount of heterogeneity within a high-risk group, along with the importance of considering distal and proximal SIBs in university screening efforts.

Evaluating potential of leaf reflectance spectra to monitor plant genetic variation.

Remote sensing of vegetation by spectroscopy is increasingly used to characterize trait distributions in plant communities. How leaves interact with electromagnetic radiation is determined by their structure and contents of pigments, water, and abundant dry matter constituents like lignins, phenolics, and proteins. High-resolution ("hyperspectral") spectroscopy can characterize trait variation at finer scales, and may help to reveal underlying genetic variation-information important for assessing the potential of populations to adapt to global change. Here, we use a set of 360 inbred genotypes of the wild coyote tobacco Nicotiana attenuata: wild accessions, recombinant inbred lines (RILs), and transgenic lines (TLs) with targeted changes to gene expression, to dissect genetic versus non-genetic influences on variation in leaf spectra across three experiments. We calculated leaf reflectance from hand-held field spectroradiometer measurements covering visible to short-wave infrared wavelengths of electromagnetic radiation (400-2500 nm) using a standard radiation source and backgrounds, resulting in a small and quantifiable measurement uncertainty. Plants were grown in more controlled (glasshouse) or more natural (field) environments, and leaves were measured both on- and off-plant with the measurement set-up thus also in more to less controlled environmental conditions. Entire spectra varied across genotypes and environments. We found that the greatest variance in leaf reflectance was explained by between-experiment and non-genetic between-sample differences, with subtler and more specific variation distinguishing groups of genotypes. The visible spectral region was most variable, distinguishing experimental settings as well as groups of genotypes within experiments, whereas parts of the short-wave infrared may vary more specifically with genotype. Overall, more genetically variable plant populations also showed more varied leaf spectra. We highlight key considerations for the application of field spectroscopy to assess genetic variation in plant populations.

Ecological Momentary Assessments and Passive Sensing in the Prediction of Short-Term Suicidal Ideation in Young Adults.

Importance: Advancements in technology, including mobile-based ecological momentary assessments (EMAs) and passive sensing, have immense potential to identify short-term suicide risk. However, the extent to which EMA and passive data, particularly in combination, have utility in detecting short-term risk in everyday life remains poorly understood. Objective: To examine whether and what combinations of self-reported EMA and sensor-based assessments identify next-day suicidal ideation. Design, Setting, and Participants: In this intensive longitudinal prognostic study, participants completed EMAs 4 times daily and wore a sensor wristband (Fitbit Charge 3) for 8 weeks. Multilevel machine learning methods, including penalized generalized estimating equations and classification and regression trees (CARTs) with repeated 5-fold cross-validation, were used to optimize prediction of next-day suicidal ideation based on time-varying features from EMAs (affective, cognitive, behavioral risk factors) and sensor data (sleep, activity, heart rate). Young adult patients who visited an emergency department with recent suicidal ideation and/or suicide attempt were recruited. Identified via electronic health record screening, eligible individuals were contacted remotely to complete enrollment procedures. Participants (aged 18 to 25 years) completed 14 708 EMA observations (64.4% adherence) and wore a sensor wristband approximately half the time (55.6% adherence). Data were collected between June 2020 and July 2021. Statistical analysis was performed from January to March 2023. Main Outcomes and Measures: The outcome was presence of next-day suicidal ideation. Results: Among 102 enrolled participants, 83 (81.4%) were female; 6 (5.9%) were Asian, 5 (4.9%) were Black or African American, 9 (8.8%) were more than 1 race, and 76 (74.5%) were White; mean (SD) age was 20.9 (2.1) years. The best-performing model incorporated features from EMAs and showed good predictive accuracy (mean [SE] cross-validated area under the receiver operating characteristic curve [AUC], 0.84 [0.02]), whereas the model that incorporated features from sensor data alone showed poor prediction (mean [SE] cross-validated AUC, 0.56 [0.02]). Sensor-based features did not improve prediction when combined with EMAs. Suicidal ideation-related features were the strongest predictors of next-day ideation. When suicidal ideation features were excluded, an alternative EMA model had acceptable predictive accuracy (mean [SE] cross-validated AUC, 0.76 [0.02]). Both EMA models included features at different timescales reflecting within-day, end-of-day, and time-varying cumulative effects. Conclusions and Relevance: In this prognostic study, self-reported risk factors showed utility in identifying near-term suicidal thoughts. Best-performing models required self-reported information, derived from EMAs, whereas sensor-based data had negligible predictive accuracy. These results may have implications for developing decision algorithms identifying near-term suicidal thoughts to guide risk monitoring and intervention delivery in everyday life.

Acceptability and feasibility of ecological momentary assessment with augmentation of passive sensor data in young adults at high risk for suicide.

Ecological Momentary Assessment (EMA) and wearable sensor data have the potential to enhance prediction of suicide risk in real-world conditions. However, the feasibility of this methodology with high-risk populations, including over extended periods, warrants closer attention. This study examined the feasibility and acceptability of concurrent EMA and wearable sensor monitoring in young adults after emergency department (ED) care for suicide risk-related concerns. For 2 months after ED discharge, 106 participants (ages 18-25; 81.1% female) took part in EMA surveys (4x per day) and passive sensor (Fitbit) monitoring and completed an end-of-study phone interview. Overall adherence to EMA (62.1%) and wearable sensor (53.6%) was moderate and comparable to briefer protocols. Relative to EMAs (81%), fewer participants completed the full 8 weeks of Fitbit (63%). While lower initial hopelessness was linked to reduced EMA adherence, previous-day suicidal ideation predicted lower Fitbit adherence on the next day. Self-endorsed barriers to EMA and wearable sensor adherence were also examined. Participants tended to report positive experience with the protocol, with majority indicating EMAs were minimally burdensome, reporting that the Fitbit was generally comfortable, and expressing interest in participating in a similar study again. Findings provide support for the feasibility and acceptability of concurrent intensive self-report and wearable sensor data during a high-risk period. Implications and future directions are discussed.