Seeing adolescents grow from many angles using a multilevel approach: A tribute to the contributions of Dante Cicchetti to the field of developmental psychopathology.

Dante Cicchetti propelled forward the field of developmental psychopathology by advancing this framework and championing new methods, including emphasizing the central role that multilevel analysis holds for explicating pathways of risk and resilience. His work continues to change the face of existing science. It has also paved the way for the formation of new projects, like the Research Domain Criteria initiative. This paper uses our laboratory's work on multilevel approaches to studying adolescent depression, non-suicidal self-injury, and suicidal thoughts and behaviors to shine a spotlight on Dr Cicchetti's contributions. In addition, we review recent developments, ongoing challenges, and promising future directions within developmental psychopathology as we endeavor to carry on the tradition of growth in the field.

Validity, Reliability, and Factor Structure of the Suicide Crisis Scale in Turkish.

Objective: In our study, we aimed to adapt the Suicide Crisis Inventory (SCI), which can be used specifically to assess the acute phase of suicide, to the Turkish population by examining its Turkish validity and reliability in a non-clinical sample. Methods: In this cross-sectional study, a total of 300 university students aged 18-24 years were evaluated online using the Socio-demographic and Clinical Data Form, the SCI, and the Suicide Behavior Questionnaire (SBQ). Criterion validity, discriminative validity, and factor analyses (exploratory and confirmatory) were conducted for the validity of the SCI, and internal consistency and item-total correlations were examined for reliability analyses. Additionally, a linear regression model was constructed to assess the predictive validity of the SCI. The predictive validity of past SCI scores was evaluated using a simple regression model. Results: When the linear regression model was tested with SCI scores as the independent variable and SBQ scores as the dependent variable [F(1-298) = 203.625; P = .000], it was found that the independent variable explained 41% of the variance in the dependent variable (r = 0.637; r 2 = 0.406). SCI scores significantly predicted SBQ scores (t = 14.270; B = 0.047; Bsth = 0.003; ß = 0.647; P = .000). In the validity analysis, the items removed from the scale could be evaluated for the total score, as they did not belong to any factor as originally specified. When items were removed, the total item reliability was Cronbach's alpha = 0.981. Conclusion: We believe that the SCI will be a useful tool in assessing short-term suicide risk in a Turkish sample and in conducting scientific research. The SCI was found to be sufficient for use in a Turkish sample for the evaluation of short-term suicide risk, considering some limitations.

Using Natural Language Processing to develop risk-tier specific suicide prediction models for Veterans Affairs patients.

Suicide is a leading cause of death. Suicide rates are particularly elevated among Department of Veterans Affairs (VA) patients. While VA has made impactful suicide prevention advances, efforts primarily target high-risk patients with documented suicide risk. This high-risk population accounts for less than 10% of VA patient suicide deaths. We previously evaluated epidemiological patterns among VA patients that had lower classified suicide risk and derived moderate- and low-risk groupings. Expanding upon VA's leading suicide prediction model, this study uses national VA data to refine high-, moderate-, and low-risk specific suicide prediction methods. We selected all VA patients who died by suicide in 2017 or 2018 (n = 4584), matching each case with five controls who remained alive during treatment year and shared suicide risk percentiles. We extracted all sample unstructured electronic health record notes, analyzed them using natural language processing, and applied machine-learning classification algorithms to develop risk-tier-specific predictive models. We calculated area under the curve (AUC) and suicide risk concentration to evaluate predictive accuracy and analyzed derived words. RESULTS: Our high-risk model (AUC = 0.621 (95% CI: 0.55-0.68)), moderate-risk (AUC = 0.669 (95% CI: 0.64-0.71)), and low-risk (AUC = 0.673 (95% CI: 0.63-0.72)) models offered significant predictive accuracy over VA's leading suicide prediction algorithm. Derived words varied considerably, the high-risk model including chronic condition service words, moderate-risk model including outpatient care, and low-risk model including acute condition care. Study suggests benefit of leveraging unstructured electronic health records and expands prediction resources for non-high-risk suicide decedents, an historically underserved population.

The Importance of Time: Nurses' Experiences of Working With Suicide Prevention and Suicide Risk Assessment in the Care of Older People.

AIM: To describe nurses' experiences of working with suicide prevention and suicide risk assessment in the care of older people. BACKGROUND: Suicide is a problem among older people, worldwide. Risk factors for suicide are, among others, depression, illness and pain and a feeling of isolation. Nurses have valuable experience in suicide prevention and risk assessments. This study can shed light on what is needed to promote the mental health of older people, which has been partly overlooked in previous research. METHODS/DESIGN: A descriptive qualitative study was conducted. Ten nurses working in care of older people across four different municipalities were interviewed. Conventional content analysis was used to analyse the data. RESULTS: Despite shortcomings in guidelines, nurses describe performing suicide risk assessments and suicide prevention in a similar manner. The importance of giving the patients time is emphasised, although time is exactly what appears to be lacking. CONCLUSION: By engaging with the experiences of nurses, important aspects that require further attention are highlighted. Nurses should inquire about suicidal ideation, even if older persons do not explicitly express such thoughts. Normal ageing needs to be comprehended and considered in assessments. In this work, time is important. PATIENT OR PUBLIC CONTRIBUTION: The results were coproduced by means of interviews with nurses working in care of older people. REPORTING METHOD: The study was conducted in accordance with the Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines. IMPLICATIONS FOR PRACTICE: Encountering older people who may have experienced the loss of loved ones and addressing one's personal capabilities in the context of the ageing body imposes substantial challenges on nursing care, necessitating a capacity to adeptly navigate and address these complex issues.

Measuring psychache as a suicide risk variable: A Mokken analysis of the Holden's Psychache Scale.

BACKGROUND: The Psychache Scale (PAS) is a questionnaire measuring trait-level psychological pain with satisfactory internal consistency and a strong correlation with suicidal ideation severity. However, inconsistent results have been reported for the PAS dimensionality. In the present study we used a non-parametric item response theory model, called Mokken Scale Analysis (MSA), to refine an unidimensional version of the PAS. METHODS: The sample was composed of 400 Italian adults (312 females and 88 males) nonrandomly recruited from the general population. RESULTS: A final set of 10 items satisfied the unidimensionality, local independence, and monotonicity assumptions, although it did not satisfy the double monotonicity assumption. The internal consistency of the PAS-10 was satisfactory (ordinal alpha = 0.98, ω = 0.97, and AVE = 0.82), and ROC curves analysis indicated good discriminant validity when differentiating participants with higher suicide risk from those with lower suicide risk. LIMITATIONS: Structural invariance between nonclinical and clinical samples was not investigated, and the presence of suicide ideation and behaviors was assessed with self-report measures with potential under-reporting of the phenomenon. CONCLUSION: The PAS-10 resulted to be a potentially valid and unidimensional measure of psychological pain (i.e., psychache) that could be used to screen adults at higher risk for suicide. Future studies are needed to investigate psychometric properties of the PAS-10 in clinical samples and to replicate results in independent samples.

Transitions in Suicide Risk from Early Adolescence to Early Adulthood.

OBJECTIVE: Understanding patterns of suicide risk over the course of development can aid our ability to prevent suicide. Our community-based study examined changes in suicide risk status and predictors of changes in risk status in a sample of 521 adolescents over six assessments between the start of middle school and young adulthood (ages 12-22). METHODS: Suicidal thoughts and behaviors (STB) were measured with the Diagnostic Interview Schedule for Children and the Moods and Feelings Questionnaire. Latent transition analysis (LTA) was utilized to evaluate transitions in suicide risk status over the course of development. Nine risk factors' initial values and change over time were modeled as predictors in the LTA. RESULTS: Latent class analysis identified a four-class model of developmental suicide risk patterns: Class 1: Infrequent STB (73-87% of participants), Class 2: Diminishing STB (1-17% of participants), Class 3: Escalating STB (6-16% of participants), and Class 4: Consistently High STB (1-5% of participants). LTA demonstrated that infrequent STB members and escalating STB members were likely to maintain their risk class across time points. CONCLUSIONS: Classification of STB trajectories demonstrated self-worth and family involvement were salient variables affecting transitions in risk over time and suggest prevention targets early in adolescence that could have impact on suicide risk in adulthood.

A systematic review of suicide risk management strategies in primary care settings.

Introduction and Objective: Suicide is a major public health concern. Recently, suicide rates have increased among traditionally low-risk groups (e.g., white, middle-aged males). Suicide risk assessments and prevention strategies should be tailored to specific at-risk populations. This systematic review examines suicide risk detection and management in primary care, focusing on treatments to reduce suicide rates and improve prevention efforts. Methodology: A systematic review was conducted following PRISMA guidelines. Literature was collected and analyzed using Boolean operators with relevant keywords in databases (e.g., PubMed, Google Scholar, PsycINFO) to identify randomized and non-randomized studies focusing on suicide risk factors and management strategies in primary care, published in the past 10 years. The risk of bias 2.0 and Newcastle Ottawa scale was used to assess risk of bias, and data from moderate-quality studies were synthesized. Results: Thirteen moderate-quality studies were reviewed. Key findings include the need for assessing modifiable risk factors like substance use and mental health. General practitioner (GP) engagement post-suicide attempt (SA) improves outcomes and reduces repeat SAs. Effective strategies include comprehensive risk assessments, collaborative treatment, and enhanced GP support. Barriers to effective suicide prevention include insufficient information, judgmental communication, lack of positive therapeutic relationships, and inadequate holistic assessments. These findings highlight the need for tailored suicide prevention strategies in primary care. However, the evidence sample size is small with reduced statistical power that limits generalizability. The included studies were also regional examinations, which restrict their broader relevance. Discussion: Significant risk factors, barriers, and effective strategies for suicide prevention were identified. For children aged 12 or younger, preexisting psychiatric, developmental, or behavioral disorders, impulsive behaviors, aggressiveness, and significant stressful life events within the family were critical. For adults, loneliness, gaps in depression treatment, and social factors are significant. Barriers to suicide prevention included insufficient information, judgmental communication, lack of positive therapeutic relationships, inadequate holistic risk assessments, lack of individualized care, insufficient tangible support and resources, inconsistent follow-up procedures, variability in risk assessment, poor communication, stigma, and negative attitudes. Effective methods include the Postvention Assisting Bereaved by Suicide training program, continued education, comprehensive clinical assessments, individualized care, and community-based interventions like the SUPRANET program. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024550904.

The correlation of inflammation, tryptophan-kynurenine pathway, and suicide risk in adolescent depression.

Accumulating evidence suggests a role for the tryptophan-kynurenine pathway (TKP) in the psychopathology of major depressive disorder (MDD). Abnormal inflammatory profile and production of TKP neurotoxic metabolites appear more pronounced in MDD with suicidality. Progress in understanding the neurobiology of MDD in adolescents lags significantly behind that in adults due to limited empirical evidence. Aims of this study was to investigate the association between inflammation, TKP, and suicidality in adolescent depression. Seventy-three adolescents with MDD were assessed for serum levels of interleukin (IL)-1ß, IL-6, IL-18, IL-10, tumor necrosis factor-α (TNF-α), tryptophan (TRP), kynurenine (KYN), 3-hydroxykynurenine (3-HK), and kynurenine acid (KA). Correlations between cytokines and TKP measures were examined. Patients were divided into high- (n = 42) and non-high-suicide-risk groups (n = 31), and serum levels of cytokines and TKP metabolites were compared. Significant negative correlations were found between TRP and IL-8 (r = - 0.27, P < 0.05) and IL-10 (r = - 0.23, P < 0.05), while a significant positive correlation was observed between 3-HK and IL-8 (r = 0.39, P < 0.01) in depressed adolescents. The KYN/TPR (index of indoleamine 2,3-dioxygenase, IDO) was positively correlated with IL-1ß (r = 0.34), IL-6 (r = 0.32), IL-10 (r = 0.38) and TNF-α (r = 0.35) levels (P < 0.01); and 3-HK/KYN (index of kynurenine3-monooxidase, KMO) was positively correlated with IL-8 level (r = 0.31, P < 0.01). Depressed adolescents at high suicide risk exhibited significantly higher levels of IL-1ß (Z = 2.726, P < 0.05), IL-10 (Z = 2.444, P < 0.05), and TNF-α (Z = 2.167, P < 0.05) and lower levels of 3-HK (Z = 2.126, P < 0.05) compared to their non-high suicide risk counterparts. Our findings indicated that serum inflammatory cytokines were robustly associated with IDO and KMO activity, along with significantly decreased serum level of TRP, increased level of 3-HK, and higher suicide risk in adolescent depression.

The Suicide Status Form-4 (SSF-IV) as a potentially therapeutic suicide risk assessment tool.

BACKGROUND: Empirically supported suicide risk assessment and conceptualization is a central aim of the Zero Suicide model. The Suicide Status Form (SSF) is the essential document and scaffolding of the Collaborative Assessment and Management of Suicidality-Brief Intervention (CAMS-BI) and is hypothesized as an example of a psychological assessment as therapeutic intervention (PATI). However, this hypothesis has never been directly tested. METHODS: N = 57 patients deemed at risk for outpatient suicidal behavior and treated as part of an inpatient psychiatric consultation and liaison service were recruited to participate in CAMS-BI at a Level 1 trauma center in the southeastern United States. During the CAMS-BI process, patients were asked to rate their subjective units of distress (SUDS) at five time points throughout the intervention (k = 285). RESULTS: The omnibus random intercept multilevel model revealed a significant difference in pre- to post-session ratings of SUDS across patients. Post hoc pairwise comparisons revealed no significant differences between SSF sections (e.g., Section A, Section B, and Section C) and relative reductions in SUDS; however, there was an observable trend toward a favorable effect of Section A of the SSF. CONCLUSIONS: The SSF may represent an example of PATI pending replication and extension of the current results.

Comparing suicide risk screening strategies in Spanish-speaking pediatric patients.

BACKGROUND: Suicide and suicidal behaviors pose significant global public health challenges, especially among young individuals. Effective screening strategies are crucial for addressing this crisis, with depression screening and suicide-specific tools being common approaches. This study compares their effectiveness by evaluating the Ask Suicide-Screening Questions (ASQ) against item 9 of the Patient Health Questionnaire-A (PHQ-A). METHODS: This study is a secondary analysis of the Argentinean-Spanish version of the ASQ validation study, an observational, cross-sectional, and multicenter study conducted in medical settings in Buenos Aires, Argentina. A convenience sample of pediatric outpatients/inpatients aged 10 to 18 years completed the ASQ, PHQ-A, and Suicide Ideation Questionnaire (SIQ) along with clinical and sociodemographic questions. RESULTS: A sample of 267 children and adolescents were included in this secondary analysis. Results show that the ASQ exhibited higher sensitivity (95.1%; 95% CI: 83% - 99%) compared to PHQ-A item 9 (73.1%; 95% CI: 57% - 85%), and superior performance in identifying suicide risk in youth. LIMITATIONS: The study included a convenience sampling and was geographically restricted to Buenos Aires, Argentina. The study also lacked longitudinal follow-up to assess the predictive validity of these screening tools for suicide risk. CONCLUSION: The study highlights the ASQ's effectiveness in identifying suicide risk among youth, emphasizing the importance of specialized screening tools over depression screening tools alone for accurate risk assessment in this population.

Suicide Risk among Chinese Left-Behind Adolescents: Developmental Trajectories and Multi-Contextual Predictors.

Suicide is prevalent among left-behind youth, a group that has yet to be thoroughly explored in terms of the developmental dynamics of their suicide risk and associated factors. This study adopted a person-centered approach to investigate the developmental trajectories of suicide risk among Chinese left-behind adolescents, along with multi-dimensional predictors. A total of 774 left-behind adolescents (Mage = 13.60, 50.1% female) completed three surveys over a year, with six-month intervals. Result of Latent Class Growth Modeling identified three subgroups with distinct developmental trajectories: High Risk-Escalating (7.6% of participants started at the highest levels with a worsening trend), Risk-Holding (21.6% maintained a stable but risk level starting above the critical threshold), and Low Risk-Diminishing (70.8% started low and continued to decrease). Gender (being a female), increased levels of childhood maltreatment, psychological pain, and depression were risk factors for High Risk-Escalating and/or Risk-Holding trajectories, while increased sense of control and regulatory emotional self-efficacy played protective roles. The findings underscore the malignant developmental patterns of suicide risk among left-behind adolescents. The predictive factors play a crucial role in distinguishing and improving these developmental trajectories.

Tree hole rescue: an AI approach for suicide risk detection and online suicide intervention.

Adolescent suicide has become an important social issue of general concern. Many young people express their suicidal feelings and intentions through online social media, e.g., Twitter, Microblog. The "tree hole" is the Chinese name for places on the Web where people post secrets. It provides the possibility of using Artificial Intelligence and big data technology to detect the posts where someone express the suicidal signal from those "tree hole" social media. We have developed the Web-based intelligent agents (i.e., AI-based programs) which can monitor the "tree hole" websites in Microblog every day by using knowledge graph technology. We have organized Tree-hole Rescue Team, which consists of more than 1000 volunteers, to carry out suicide rescue intervention according to the daily monitoring notifications. From 2018 to 2023, Tree-hole Rescue Team has prevented more than 6600 suicides. A few thousands of people have been saved within those 6 years. In this paper, we present the basic technology of Web-based Tree Hole intelligent agents and elaborate how the intelligent agents can discover suicide attempts and issue corresponding monitoring notifications and how the volunteers of Tree Hole Rescue Team can conduct online suicide intervention. This research also shows that the knowledge graph approach can be used for the semantic analysis on social media.

Childhood trauma and suicide risk: Investigating the role of adult attachment.

BACKGROUND: Suicide is a leading cause of death globally and a serious public health concern. Childhood trauma has been found to be associated with adult suicide vulnerability. Recent research has turned attention to investigating the role of attachment in the context of the childhood trauma-adult suicide relationship. The current study investigated for the first time whether attachment influences and moderates the childhood trauma-suicidality relationship, using a daily diary design, in the general population. METHODS: 481 participants completed questionnaires assessing experiences of childhood trauma, attachment patterns, and history of suicidality. 243 participants continued to a daily diary phase where measures of daily stress, defeat and entrapment were completed for 7 consecutive days. RESULTS: Higher levels of childhood trauma were associated with a history of suicide ideation and attempt and also higher levels of daily defeat, entrapment and stress during the 7 day study. Similarly, higher levels of attachment anxiety and avoidance were associated with a history of suicide ideation and attempt together with higher levels of daily defeat, entrapment and stress. However, the effects of childhood trauma on suicide history and on daily suicide vulnerability factors were not moderated by attachment anxiety or avoidance. LIMITATIONS: The measure of childhood trauma was a retrospective self-report tool that may be influenced by memory biases. CONCLUSIONS: Childhood trauma and insecure attachment are implicated in adult suicide risk. Interventions aimed at mitigating the negative effects of childhood trauma and insecure attachment should also incorporate components that target modifiable risk factors such as defeat, entrapment and stress.

Suicide Risk Factors in High School Students.

In Mexico, suicide has become an important public health problem, representing the third leading cause of death in the adolescent population. Suicidal behavior in adolescents is associated with the interaction of complex relationships between personal, interpersonal, and sociocultural factors. Through a quantitative, descriptive, and correlational cross-sectional study, the present study aimed to analyze the prevalence and risk factors associated with suicidal ideation among adolescents from different high schools of the high school system (SEMS) of the University of Guadalajara, in response to the psychosocial impact of the COVID-19 pandemic. A descriptive statistical analysis was carried out on the data obtained from the 3583 students surveyed, followed by a principal component analysis (PCA) to identify closely related social, emotional, and behavioral variables. The PCA yielded eight principal components, which together represent 75.42% of the variance across psychometric tests. A multiple linear regression analysis was used, with a regression value (R2) of 0.4811, indicating that the explanatory model can predict 48.1% of the variability in suicidal ideation, with a statistical significance level of 0.05. According to the studies conducted, 19% (688 students) showed indicators of high suicide risk and 26.8% (960 students) showed moderate risk. Depression, mental health, health-related quality of life, physical and psychological well-being, and mood and emotions are the most influential factors in suicidal ideation.

Clinical characteristics and 6-month follow-up of adults with and without alcohol use disorder who self-harm.

Background: Alcohol use disorder (AUD) is associated with suicidal behavior, but prospective clinical studies are lacking. Aim: To compare clinical characteristics and 6-month outcomes in persons with and without AUD who self-harm. Methods: 804 adults (mean age 33, age range 18-95, 541 women and 263 men, 666 with suicide attempts and 138 with non-suicidal self-injuries at index) at three Swedish university hospitals took part in a research interview that included the Mini International Neuropsychiatric Interview (MINI). Subsequent non-fatal suicidal behavior within six months was identified by record review; suicides were identified by national register. Results: At index, 39% of the men and 29% of the women had AUD. Over two thirds of these cases (69%) were identified by the MINI, but not by clinical AUD diagnosis. While trait impulsivity was more common among persons with AUD than those without (56% vs 36%, P adj = <.001), impulsivity in connection with the index attempt was noted in half of the participants in each group (48% vs 52%, P adj = 1). Subsequent suicidal behavior (fatal/non-fatal) occurred in 67 persons with AUD (26%) and in 98 without AUD (18%), a 60% higher risk among persons with AUD (OR = 1.60, 95% [CI 1.13-2.28], P = .009). Four persons with AUD (2%) and six without (1%) died by suicide within 6 months. Conclusion: Almost a third of patients presenting at psychiatric emergency settings after self-harm fulfilled criteria for AUD, but clinicians often missed this diagnosis. Risk for subsequent suicidal behavior was elevated in patients with AUD. Educational interventions to improve recognition of alcohol use disorder may aid clinicians in the assessment and management of patients who present with self-harm.

Successful treatment for serious depression with suicidal risk in a heart transplant patient.

INTRODUCTION: Major depressive disorder is related to unfavourable outcomes in patients with severe comorbidities. In transplant patients, major depression is associated with worse clinical outcomes. CASE REPORT: We present the case of a 55-year-old man with a heart transplant due to heart failure of ischaemic origin. Six months after the transplant he developed depressed mood, anhedonia and suicidal ideation with a score of 20/27 on the PHQ-9 depression screening scale. After receiving mirtazapine 30 mg/night for a week and persisting with a high suicide risk, it was decided to administer ketamine infusion for 24 h, with which a significant improvement in mood was observed, and the disappearance of suicidal ideation 24 h after the infusion. DISCUSSION: Depression in transplant patients is a factor associated with graft loss and post-transplant mortality, in addition to favouring other negative outcomes such as deep vein thrombosis. CONCLUSIONS: Ketamine infusion was shown to be an effective and safe option to treat major depression with suicidal risk in a heart transplant patient.

The impact of neural emotion reactivity and regulation on the association between depression and suicide ideation in high-risk adults.

BACKGROUND: Depression is closely related to suicidal ideation (SI); however, it is unclear who is most vulnerable to SI within the context of depression. Research suggests that individual differences in emotion reactivity and regulation may be potential moderators of the link between depression and SI. Therefore, the current study tested this hypothesis using objective markers of emotion reactivity and volitional cognitive regulation capacity during functional magnetic resonance imaging (fMRI). METHODS: Adults (n = 91) with active SI completed validated self-report measures of current depressive symptoms and SI severity. Participants completed an fMRI task designed to probe neural response to aversive stimuli and during cognitive reappraisal - a form of volitional emotion regulation. Activation of the amygdala during aversive emotion reactivity was measured. Activation of ventrolateral, dorsolateral, and dorsomedial prefrontal cortex (vlPFC, dlPFC, and dmPFC) during cognitive reappraisal were also measured. A series of hierarchical linear regressions testing the unique and interactive effects of depression symptoms and neural activation on severity of SI were conducted. RESULTS: Analyses revealed a depression x amygdala activation interaction. The positive association between depression and SI severity was more robust in the context of high amygdala reactivity than low amygdala reactivity. Analyses also indicated there was no PFC activity (neural cognitive reappraisal) by depression interaction. LIMITATIONS: Psychoactive medications were allowed and all participants endorsed suicidal intent. CONCLUSION: Strategies aimed at targeting exaggerated emotion reactivity within the context of depression may be beneficial.

Identifying Reddit Users at a High Risk of Suicide and Their Linguistic Features During the COVID-19 Pandemic: Growth-Based Trajectory Model.

BACKGROUND: Suicide has emerged as a critical public health concern during the COVID-19 pandemic. With social distancing measures in place, social media has become a significant platform for individuals expressing suicidal thoughts and behaviors. However, existing studies on suicide using social media data often overlook the diversity among users and the temporal dynamics of suicide risk. OBJECTIVE: By examining the variations in post volume trajectories among users on the r/SuicideWatch subreddit during the COVID-19 pandemic, this study aims to investigate the heterogeneous patterns of change in suicide risk to help identify social media users at high risk of suicide. We also characterized their linguistic features before and during the pandemic. METHODS: We collected and analyzed post data every 6 months from March 2019 to August 2022 for users on the r/SuicideWatch subreddit (N=6163). A growth-based trajectory model was then used to investigate the trajectories of post volume to identify patterns of change in suicide risk during the pandemic. Trends in linguistic features within posts were also charted and compared, and linguistic markers were identified across the trajectory groups using regression analysis. RESULTS: We identified 2 distinct trajectories of post volume among r/SuicideWatch subreddit users. A small proportion of users (744/6163, 12.07%) was labeled as having a high risk of suicide, showing a sharp and lasting increase in post volume during the pandemic. By contrast, most users (5419/6163, 87.93%) were categorized as being at low risk of suicide, with a consistently low and mild increase in post volume during the pandemic. In terms of the frequency of most linguistic features, both groups showed increases at the initial stage of the pandemic. Subsequently, the rising trend continued in the high-risk group before declining, while the low-risk group showed an immediate decrease. One year after the pandemic outbreak, the 2 groups exhibited differences in their use of words related to the categories of personal pronouns; affective, social, cognitive, and biological processes; drives; relativity; time orientations; and personal concerns. In particular, the high-risk group was discriminant in using words related to anger (odds ratio [OR] 3.23, P<.001), sadness (OR 3.23, P<.001), health (OR 2.56, P=.005), achievement (OR 1.67, P=.049), motion (OR 4.17, P<.001), future focus (OR 2.86, P<.001), and death (OR 4.35, P<.001) during this stage. CONCLUSIONS: Based on the 2 identified trajectories of post volume during the pandemic, this study divided users on the r/SuicideWatch subreddit into suicide high- and low-risk groups. Our findings indicated heterogeneous patterns of change in suicide risk in response to the pandemic. The high-risk group also demonstrated distinct linguistic features. We recommend conducting real-time surveillance of suicide risk using social media data during future public health crises to provide timely support to individuals at potentially high risk of suicide.

Alpha oscillation mediates the interaction between suicide risk and symptom severity in Major Depressive Disorder.

Objective: The aim of our study was to explore the relationship between changes in neural oscillatory power in the EEG, the severity of depressive-anxiety symptoms, and the risk of suicide in MDD. Methods: 350 MDD patients' demographic and clinical data were collected, and their depressive and anxious symptoms were evaluated using HDRS-17 and HAMA-14, along with a suicide risk assessment using the Nurses' Global Assessment of Suicide Risk (NGASR). EEG data were captured, processed, and analyzed to study brain activity patterns related to MDD. The participants were divided based on suicide risk levels, and statistical analyses, including chi-square, t-tests, Pearson's correlations were used to explore the associations between brain activity, symptom severity, and suicide risk. Closely related variables were identified and ultimately the optimal model was screened using stepwise regression analysis with a forward strategy, and mediation effects were further used to determine the possible interactions between the variables in the regression model. Results: The regression model showed a significant effect of HDRS-17 and alpha power of Medial Occipital Cortex (MOC) on suicide risk, with elevated HDRS-17 increasing suicide risk and elevated alpha power decreasing suicide risk. Mediation effect analyses showed that MOC alpha power partially mediated the effect of depression level on suicide risk, and that an increase in depression severity may lead to a decrease in MOC alpha power, while a decrease in MOC alpha power may lead to an increase in suicide risk. Conclusion: The severity of depression directly increases suicide risk, whereas higher alpha power in the MOC serves as a protective factor, reducing this risk. Notably, MOC alpha power not only directly impacts suicide risk but also mediates the effects of both depression severity and anxiety levels on this risk. Limitations: The relatively small sample size of this study may limit the representativeness of the overall MDD patient population and the detailed analysis of different subgroups. This study did not delve into the relationship between the severity of cognitive symptoms in MDD patients and suicide risk.