Psychiatric heterogeneity of recent suicide attempters: A latent class analysis

Empirical clustering to identify individuals for whom insomnia is more closely related to suicidal ideation

BACKGROUND

Although the effect sizes are modest, insomnia is consistently associated with suicidal thoughts and behaviors. Subgroup analyses can efficiently identify for whom insomnia is most relevant to suicidal ideation. To improve clinical case identification, the present study sought to identify subclusters of lifetime suicidal ideators for whom insomnia was most closely related to current suicidal ideation.

METHODS

Data on N = 4750 lifetime suicidal ideators were extracted from the Military Suicide Research Consortium's Common Data Elements. Data on sociodemographic characteristics, severity and history of suicidal thoughts and behaviors, and related clinical characteristics were clustered by unsupervised machine learning algorithms. Robust Poisson regression estimated cluster by insomnia associations with current suicidal ideation.

RESULTS

Three clusters were identified: a modest symptom severity cluster (N = 1757, 37.0 %), an elevated severity cluster (N = 1444 30.4 %), and a high severity cluster (N = 1549 32.6 %). In Cluster 1, insomnia was associated with current suicidal ideation (PRR 1.29 [1.13-1.46]) and remained significant after adjusting for sociodemographic and clinical covariates. In Cluster 2, insomnia was associated with current suicidal ideation (PRR 1.14 [1.01-1.30]), but not after adjusting for sociodemographic and clinical covariates. In Cluster 3, insomnia was associated with current suicidal ideation (PRR 1.12 [1.03-1.21]) and remained significant after adjusting for sociodemographic covariates, but not clinical covariates.

LIMITATIONS

Cross-sectional design, lack of diagnostic data, non-representative sample.

CONCLUSION

Insomnia appears more closely related to current suicidal ideation among modest severity individuals than other subgroups. Future work should use prospective designs and more comprehensive risk factor measures to confirm these findings.

Typologies of Psychiatric Diagnoses Among Inpatients with Recent Suicide Attempts

OBJECTIVE

Psychiatric multimorbidity is a well-documented risk factor for suicide. However, diagnostic heterogeneity and patterns of comorbidity likely exists within the population of those who attempt suicide. Person-centered statistical approaches, such as latent class analysis (LCA), extract distinguishable groups differentiated by prevalence and comorbidity of psychiatric disorders.

METHOD

The present study used LCA to identify typologies of psychiatric heterogeneity in a sample of 213 inpatients (M age = 33.04 [SD = 12.67]; 57.3% female; 62.4% White; 23.9% Hispanic/Latino) with a history of suicide attempt who were recruited for a suicide prevention clinical trial. Class differences in suicide history characteristics; demographic characteristics; and cognitive-affective and behavioral risk factors, obtained from an initial evaluation involving the administration of a semi-structured diagnostic interview, suicide risk assessment, and battery of self-report measures, were explored.

RESULTS

LCA identified three classes in the best-fitting solution: Depressive-High Comorbidity (n = 68), Depressive-Low Comorbidity (n = 86), and Bipolar (n = 59). The Depressive-Low Comorbidity class reported less severe suicidal ideation (p < .001), anxiety (p < .001), stress (p < .001), unlovability beliefs (p = .006), and impulsivity (p < .001). The Depressive-Low Comorbidity class also reported fewer actual attempts than the Bipolar class (p = .001) and fewer interrupted attempts than the Depressive-High Comorbidity class (p = .004).

CONCLUSIONS

The Depressive-High Comorbidity and Bipolar classes consistently endorsed higher levels of suicide risk factors. These findings may help to illuminate typologies of suicide attempters with unique clinical needs, which is an essential step toward personalized medicine.

Heterogeneity in suicide risk: Evidence from personalized dynamic models

Most theories of suicide propose within-person changes in psychological states cause suicidal thoughts/behaviors; however, most studies use between-person analyses. Thus, there are little empirical data exploring current theories in the way they are hypothesized to occur. We used a form of statistical modeling called group iterative multiple model estimation (GIMME) to explore one theory of suicide: The Interpersonal Theory of Suicide (IPTS). GIMME estimates personalized statistical models for each individual and associations shared across individuals. Data were from a real-time monitoring study of individuals with a history of suicidal thoughts/behavior (adult sample: participants = 111, observations = 25,242; adolescent sample: participants = 145, observations = 26,182). Across both samples, none of theorized IPTS effects (i.e., contemporaneous effect from hopeless to suicidal thinking) were shared at the group level. There was significant heterogeneity in the personalized models, suggesting there are different pathways through which different people come to experience suicidal thoughts/behaviors. These findings highlight the complexity of suicide risk and the need for more personalized approaches to assessment and prediction.

Evidence for Altered Electroencephalography Coherence in Depressed Adolescents with Suicidal Ideation and Behaviors

Introduction: Major depressive disorder (MDD) is a primary risk factor for suicide, which is one of the leading causes of death among adolescents worldwide. Understanding the heterogeneity of suicidality in adolescents with MDD is critical for suicide prevention and intervention discovery. Quantitative electroencephalography (EEG) is a promising tool to address the knowledge gaps related to the neurophysiological characteristics of depression and suicidality. This study sought to examine resting-state EEG coherence differences in adolescents with MDD and suicidal ideation (SI)/behaviors (SB) and healthy controls (HC) to assess the utility of coherence as a biomarker of suicide. Methods: Twenty-six adolescents with MDD who were hospitalized for suicidality and 30 HC were recruited. The clinical sample was divided into SI (n = 9) and SB (n = 19) subgroups. Eyes closed resting-state EEG were recorded, and coherence was calculated. Depression severity and suicidality were assessed with the Children's Depression Rating Scale Revised and the Columbia Suicide Severity Rating Scale, respectively. Results: There were intrahemispheric differences in the right hemisphere across multiple electrode pairs. Delta, alpha, and beta coherence were higher in the SB group over the right prefrontofrontal and left parietooccipital electrode pairs, while alpha coherence was higher in the HC group over the right centroparietal electrode pair. There were no significant differences between HC and SI groups in any electrode pair. Conclusions: Patients with recent SB showed increased coherence in right frontal regions compared with patients with SI, suggesting altered cognitive states between those with SB and SI. These findings may have implications for suicide prevention in adolescents and could serve as useful biomarkers in clinical settings, but larger studies are needed to confirm the results.

Suicidal thoughts and behaviours among military veterans: protocol for a prospective, observational, neuroimaging study

INTRODUCTION

This study's overarching goal is to examine the relationship between brain circuits and suicidal thoughts and behaviours (STBs) in a transdiagnostic sample of US military veterans. Because STBs have been linked with maladaptive decision-making and disorders linked to impulsivity, this investigation focuses on valence and inhibitory control circuits.

METHODS AND ANALYSIS

In this prospective, observational study, we will collect functional MRI (fMRI), cognitive and clinical data from 136 veterans (target sample size) recruited from the Providence VA Health System (PVAHS): 68 with STBs and 68 matched controls. Behavioural data will be collected using standardised measures of STBs, psychiatric symptoms, cognition, functioning and medical history. Neuroimaging data will include structural, task and resting fMRI. We will conduct follow-up interviews and assessments at 6, 12 and 24 months post-enrolment. Primary analyses will compare data from veterans with and without STBs and will also evaluate whether activation and connectivity within circuits of valence and inhibition covary with historical and prospective patterns of suicidal ideation and behaviour.

ETHICS AND DISSEMINATION

The PVAHS Institutional Review Board approved this study (2018-051). Written informed consent will be obtained from all participants. Findings from this study will be published in peer-reviewed journals and presented at local, regional, national and international conferences.Nauder Namaky, Ph.D.* nauder_namaky@brown.edu.

A latent class analysis using the integrated motivational-volitional model of suicidal behaviour: Understanding suicide risk over 36 months

BACKGROUND

The use of latent class analysis (LCA) to understand suicide risk is often not guided by theoretical frameworks. This study used the Integrated Motivational-Volitional (IMV) Model of Suicidal Behaviour to inform the classification of subtypes of young adults with a suicidal history.

METHODS

Data from young adults in Scotland (n = 3508) were used in this study including a subgroup of participants (n = 845) with a history of suicidality. LCA using risk factors from the IMV model was conducted on this subgroup, and the subgroups and non-suicidal control group were compared. Trajectories of suicidal behaviour over 36 months was compared between the classes.

RESULTS

Three classes were identified. Class 1 (62 %) had low scores on all risk factors, Class 2 (23 %) had moderate scores, and Class 3 (14 %) had high scores on all risk factors. Those in Class 1 had a stable low risk of suicidal behaviour, while those in Class 2 and 3 showed marked variation over time, although Class 3 had the highest risk across all timepoints.

LIMITATIONS

The rate of suicidal behaviour in the sample was low, and differential dropout may have impacted the findings.

CONCLUSIONS

These findings suggest that young adults can be classified into different profiles based on suicide risk variables derived from the IMV model, which still distinguishes them 36 months later. Such profiling may help determining who is most at risk for suicidal behaviour over time.

Risk of suicide attempt repetition after an index attempt: A systematic review and meta-analysis

OBJECTIVES

To estimate the risk of suicide attempt repetition among individuals with an index attempt. It also aims to study the role of risk factors and prevention programme in repetition.

METHODS

This systematic review and meta-analysis was conducted in keeping with the PRISMA 2020 guidelines. Studies on attempt repetition (both cohort studies and intervention studies) were searched from inception to 2022.

RESULTS

A total of 110 studies comprising 248,829 attempters was reviewed. The overall repetition rate was 0.20 (0.17, 0.22). Repetition risk linearly increased over time. A higher risk of attempt repetition was associated with female sex and index attempts in which self-cutting methods were used. Moreover, a mental disorder diagnosis was associated with an increasing repetition risk (OR = 2.02, p < .01). The delivery of a preventive programme reduced the repetition risk, OR = 0.76, p < .05; however, this effect was significant for psychotherapy interventions, OR = 0.38, p < .01.

CONCLUSION

One in five suicide attempters will engage in a new suicide attempt. An elevated repetition risk is associated with being female, more severe index methods and psychiatric disorder diagnosis. Preventive programmes, particularly psychotherapy, may contribute to reducing repetition risk and eventually save lives.

A Latent Class Analysis of Suicidal Behaviors in Adolescents

OBJECTIVE

The purpose of the present study was to identify adolescents' suicide subgroups using five indicators (depression, anxiety, suicide ideation, and planned and attempted suicide), and explore the distinctive features of each subgroup.

METHODS

This study included 2,258 teenagers from four schools. Both adolescents and their parents, who voluntarily agreed to participate in the study, completed a series of self-reported questionnaires on depression, anxiety, suicide, self-harm, self-esteem, impulsivity, childhood maltreatment, and deviant behaviors. The data were analyzed using latent class analysis, a person-centered method.

RESULTS

Four classes were detected: "high risk for suicide without distress," "high risk for suicide with distress," "low risk for suicide with distress," and "healthy." The "high risk for suicide with distress" class was the most severe on all evaluated psychosocial risk factors, namely, impulsivity, low self-esteem, self-harming behaviours, deviant behaviour problems, and childhood maltreatment, followed by "high risk for suicide without distress."

CONCLUSION

This study identified two high risk subgroups for adolescent' suicidality, "high risk for suicide with or without distress." Both high risk subgroups for suicide showed higher scores for all psychosocial risk factors than low risk subgroups for suicide. Our findings suggest that special attention needs to be paid to the latent class "high risk for suicide without distress," as this group's "cry for help" might be relatively difficult to detect. Specific interventions for each group (e.g., distress safety plans for "suicidal potential with or without emotional distress") need to be developed and implemented.

Leveraging latent profile analysis to synthesize childhood and adolescent risk factors for suicidal ideation

Person-centered typologies identified with latent profile analysis can clarify patterns of chronic and acute risk factors for suicidal ideation. We derived five profiles of individuals using cognitive, behavioral, and familial factors relating to suicidal ideation risk factors. Participants (n = 1,142) were assessed at age 8 using the Laboratory Temperament Assessment Battery and mother-reported parenting measures and at age 14 using interviews about clinical symptoms and suicidal ideation. The best-fitting model included five profiles: typical, elevated adolescent symptomology, mildly elevated typical, low childhood persistence, and very low childhood persistence/mixed symptoms. Participants in the elevated adolescent symptomology and very low childhood persistence/mixed symptoms profiles were 2.6 and 5.3 times more likely to report suicidal ideation compared with the typical profile. Overall, our results underscore how using a person-centered pattern recognition approach and incorporating facets of childhood behavior may enhance conceptualizations of adolescent suicidal ideation risk.

Nonmedical Social Determinants, Syndemic Conditions, and Suicidal Thoughts and Behaviors in a Treatment-seeking Community Sample: A Latent Class Analysis

OBJECTIVE

Knowledge gaps remain regarding whether syndemic conditions identify treatment-seeking individuals most at risk for suicidal thoughts and behaviors (STB). We employed latent class analysis to: (1) model treatment-seeking individuals' syndemic conditions, (2) examine latent classes across nonmedical social determinants, and (3) assess associations between class membership and STB.

METHOD

Participants were 982 individuals presenting at a community mental health clinic between October 2014 and February 2020. The three-step latent class analytic approach was used. Regression analyses were employed to examine nonmedical social determinants and STB outcomes associated with class membership.

RESULTS

Participants were aged 18 to >72 (75.8% White; 76.7% heterosexual; 53.7% cisgender woman; 73.8% earned ≥$20,000 annually). Latent class analysis resulted in a three-class solution. Participants in Class 1 were characterized by low probabilities across syndemic conditions. Class 2 was characterized by high probabilities of anxiety and depression. Class 3 was characterized by high probabilities of eating disorders, anxiety, and depression. Participants of color, sexual minority participants, cisgender women, and those experiencing financial distress were more likely to be in classes characterized by syndemic conditions. Classes characterized by syndemic conditions, relative to no syndemic conditions, were associated with greater risk of STB.

CONCLUSION

Findings confirm the concentrated clustering of co-occurring syndemic conditions among marginalized groups and highlight differing risks for those considering suicide or who have attempted suicide vs. those engaging in self-harm. Results underscore the need for resource allocation and multilevel interventions targeting syndemic conditions and suicidality for minority populations and those experiencing financial distress.

Suicide risk profiles and barriers to professional help-seeking among college students with elevated risk for suicide

Suicide is the second leading cause of death among college students, yet many students with elevated suicide risk do not seek professional help. This study identified suicide risk profiles among college students and examined these in relation to students' perceived barriers to professional help-seeking. Data were obtained from college students (n = 1689) identified to be at elevated risk for suicide based at four US universities. Latent class analysis was performed to determine risk profiles, followed by examinations of differences in help-seeking barriers by profile groupings. Results revealed three student groupings: (1) moderate internalizing and externalizing symptoms (with low alcohol misuse), (2) highest internalizing and externalizing symptoms (with highest social disconnection), and (3) lowest internalizing symptoms and low externalizing (with highest social connection and alcohol misuse). Group 1 included the youngest and most racially and sexually diverse students, Group 2 endorsed the most help-seeking barriers, and Group 3 endorsed the fewest barriers. Group 2 is especially concerning, considering the severe clinical characteristics, high number of barriers, and low connectedness to others for potential support. Understanding these differences across risk and barrier profiles is an important step towards developing tailored approaches to increase mental health care in college populations.

Comparing warning signs of suicide between suicide decedents with depression and those non-diagnosed psychiatric disorders

OBJECTIVE

Early recognition of a high-risk group impending suicide is important. We aimed to compare warning signs depending on the nature of the psychiatric disorder and whether it was a documented diagnosis.

METHODS

Data of suicide decedents were collected from police records from 2013 to 2017. We evaluate psychiatric symptoms and warning signs in three aspects (language, behavior, and affect) using the Korea-Psychological Autopsy Checklist for Police Records (K-PAC-PR).

RESULTS

A total of 13,265 suicide decedents were recruited for this study. Of them, 66.9% of females and 46.7% of males diagnosed psychiatric disorders, with depressive disorder being the most common one. Warning signs were observed in 93.0% of suicide decedents. They were observed more in those who were diagnosed with psychiatric disorders, especially in those with a depressive disorder. "Talking about dying or suicide" was the most common warning sign in all groups, and "apathetic behavior" was the most related warning sign for depressive disorder. Especially for "talking about dying or suicide," the proportion of observed "within a week" was high, making it valuable as a warning sign.

CONCLUSION

Warning signs were commonly found in suicide decedents regardless of gender. They were more common among the decedents diagnosed with psychiatric disorders, especially among those with a depressive disorder.

Electronic bridge to mental health for college students: A randomized controlled intervention trial

OBJECTIVE

Suicide is the second leading cause of death among college students in the United States, and the percentage of students reporting suicidal thoughts is increasing. Nevertheless, many students at risk do not seek mental health (MH) services. This randomized controlled trial (RCT) examined the efficacy of Electronic Bridge to Mental Health for College Students (eBridge) for increasing at-risk students' linkage to MH services.

METHOD

Students from four universities were recruited via email; 40,347 (22.6%) completed the online suicide risk screen; and 3,363 (8.3%) met criteria for randomization based on suicide risk factors and lack of current treatment (62.2% female, 35.0% male, 2.8% transgender/nonbinary; 73.2% White, 7.0% Black, 19.9% Asian, 11.7% other; 12.4% Hispanic, 76.2% undergraduate). These students were randomized to eBridge [personalized feedback (PF) with option of online counseling] or Control (PF). The primary outcome was linkage to MH services within 6 months.

RESULTS

Among students assigned to eBridge, 355 students (21.0%) posted ≥1 message, and 168 (10.0%) posted ≥2 messages to the counselor. In intent-to-treat analyses, there was no eBridge effect on obtaining MH services. However, within the eBridge group, students who posted ≥1 message were significantly more likely to link to MH services.

CONCLUSIONS

eBridge shows promise for reaching a relatively small subset of college students at risk for suicide; however, engagement in eBridge was low. This study underscores the urgent need for more effective strategies to engage young adults in online mental health interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Alcohol dependence and heavy episodic drinking are associated with different levels of risk of death or repeat emergency service attendance after a suicide attempt

BACKGROUND

Alcohol use is a multidimensional risk factor for suicidal behaviour. However, suicide prevention strategies often take 'one-size-fits-all' approaches to alcohol use, reflecting an evidence base built on unidimensional measures. Latent Class Analysis can use a range of measures to differentiate distinct patterns of alcohol using behaviour and their associated risks.

METHODS

We analysed Electronic Health Record data from 650 suicidal adults detained for up to 36 h using police powers (Section 136 of the Mental Health Act 1983, amended 2007) to facilitate psychiatric assessment at a Health-Based Place of Safety, a dedicated emergency psychiatric care centre in London, UK. We conducted a Latent Class Analysis of alcohol using behaviours at first detention, and used multivariable logistic regression to estimate the association of each identified latent class with subsequent death or recontact with emergency psychiatric care over a median follow-up of 490 days, adjusting for sex, age and past-year psychiatric diagnosis.

RESULTS

Three classes of alcohol use were identified: low risk drinkers, heavy episodic drinkers and dependent drinkers. The dependent drinking class had twice the odds of death or recontact with emergency psychiatric care as the low risk drinking class (OR 2.32, 95 %CI 1.62-3.32, p < 0.001). Conversely, the heavy episodic drinking class was associated with lower odds of death or recontact than the low risk drinking class (OR 0.66, 95 %CI 0.53-0.81, p < 0.001).

CONCLUSIONS

The risk of adverse outcomes after a suicide attempt are not uniform for different alcohol use classes. Clinical assessment and suicide prevention efforts should be tailored accordingly.

Serum Fatty Acid Latent Classes Are Associated With Suicide in a Large Military Personnel Sample

OBJECTIVE

Fatty acids (FAs) are involved in the functioning of biological systems previously associated with suicidal behavior (eg, monoamine signaling and the immune system). We sought to determine (1) whether observed FA levels in a sample of military suicide decedents and living matched controls were consistent with latent classes having distinctive FA profiles and (2) whether those latent classes were associated with suicide and mental health diagnoses.

METHODS

Serum samples from 800 US military suicide decedents who died between 2002 and 2008 and 800 demographically matched living controls were selected at random from a large military serum repository and assayed for 22 different FAs. A latent class cluster analysis was performed using values of 6 FAs previously individually associated with suicide. Once the latent classes were identified, they were compared in terms of suicide decedent proportion, demographic variables, estimated FA enzyme activity, diagnoses, and mental health care usage.

RESULTS

A 6-latent class solution best characterized the dataset. Suicide decedents were less likely to belong to 2 of the classes and more likely to belong to 3 of the classes. The low-decedent classes differed from the high-decedent classes on 9 FAs and on estimated indices of activity for 3 FA enzymes: 14:0, 24:0, 18:1 n-9, 24:1 n-9, 22:5 n-3, 22:6 n-3, 20:2 n-6, 20:4 n-6, 22:5 n-6, elongation of very long chain fatty acids protein 1 (ELOVL1), ELOVL6, and Δ9 desaturase. The FA profiles of the latent classes were consistent with biological abnormalities previously associated with suicidal behavior.

CONCLUSIONS

This study suggests the utility of methods that simultaneously examine multiple FAs when trying to understand their relationship with suicide and psychiatric illness.

Identifying Distinguishable Clinical Profiles Between Single Suicide Attempters and Re-Attempters

More than 800,000 individuals die from suicide each year in the world, which has a devastating impact on families and society. Ten to twenty times more attempt suicide. Previous studies showed that suicide attempters represent a heterogeneous group regarding demographic characteristics, individual characteristics of a suicidal attempt, and the assumed clinical factors, e.g., hopelessness or impulsivity, thus differently contributing to the likelihood of suicidal behavior. Therefore, in the present study, we aim to give a comprehensive clinical description of patients with repeated suicide attempts compared to single attempters. We explored putative differences between groups in clinical variables and personality traits, sociodemographic information, and specific suicide attempt-related information. A sample of patients with a recent suicide attempt (n = 252), defined according to DSM-5 criteria for a suicidal behavior disorder (SBD), was recruited in four psychiatric hospitals in Thuringia, Germany. We used a structured clinical interview to assess the psychiatric diagnosis, sociodemographic data, and to collect information regarding the characteristics of the suicide attempt. Several clinical questionnaires were used to measure the suicide intent and suicidal ideations, depression severity, hopelessness, impulsivity, aggression, anger expression, and the presence of childhood trauma. Univariate and multivariate statistical methods were applied to evaluate the postulated risk factors and, to distinguish groups based on these measures. The performed statistical analyses indicated that suicide attempters represent a relatively heterogeneous group, nevertheless associated with specific clinical profiles. We demonstrated that the re-attempters had more severe psychopathology with significantly higher levels of self-reported depression, suicidal ideation as well as hopelessness. Furthermore, re-attempters had more often first-degree relatives with suicidal behavior and emotional abuse during childhood. They also exhibited a higher degree of specific personality traits, i.e., more "urgency" as a reaction to negative emotions, higher excitability, higher self-aggressiveness, and trait anger. The multivariate discriminant analysis significantly discriminated the re-attempters from single attempters by higher levels of self-aggressiveness and suicidal ideation. The findings might contribute to a better understanding of the complex mechanisms leading to suicidal behavior, which might improve the early identification and specific treatment of subjects at risk for repeated suicidal behavior.

Psychotherapy and youth suicide prevention: An interpretative phenomenological analysis of specialist clinicians' experiences

The study explored psychologists' experiences in delivering short-term psychotherapy for suicidal adolescents and sought to clarify how these experiences fit with empirically supported interventions and the interpersonal psychological theory of suicide. Semistructured interviews were conducted with 12 psychologists' who provided short-term psychotherapy in a suicide prevention programme for youth (12- to 25-year-olds). Interview transcripts were analysed using interpretative phenomenological analysis. Three superordinate themes were identified: (i) understand the experience and context of the suicidality and the importance of a formulation-based approach to engagement and individualized treatment planning; (ii) involve broad support systems, and in particular families, to help the young person reduce feelings of burdensomeness and increase safety, connectedness and belonging; and (iii) improve affect regulation and reflective functioning, important not only for the young person but also for the support system to maximize the positive impact of supports via emotional coregulation and effective problem-solving. Interventions and approaches as well as the potential underlying processes of change being targeted are discussed in light of these findings. As an example, the development of a suicide safety plan was an intervention that traversed these themes. When used as a process tool, it helped foster a collaborative, formulation, dimensional and biopsychosocial approach to treat psychopathology and suicidality and extended beyond the therapist-client dyad. Moreover, treatment needs to be extended beyond the therapist-client dyad to allow therapists to facilitate a systemic treatment response, as this was seen as a major component of interventions for suicidal youth.

Identifying subgroups within a sample of adults with a suicide attempt history using the Interpersonal Psychological Theory of Suicide

This study used a novel theory-informed latent class approach, based on the Interpersonal Psychological Theory of Suicide (IPTS), to identify subgroups of individuals with a suicide attempt history. The identification of subgroups can inform treatments that target these specific subgroups. Using data from a randomised controlled trial, latent class analysis was conducted on 227 adults with a suicide attempt history. Latent classes were identified based on suicide attempt history, perceived burdensomeness, thwarted belongingness, and capability for suicide at the trial baseline. Three classes were found. Classes 1 and 2 (80% of participants) at baseline had higher interpersonal risks and clinical symptoms, and lower protective psychological factors (e.g., positive reframing), compared to Class 3 (20% of participants). Class 1 had elevated suicidal ideation for the duration of the trial. Classes 1 and 2 also had elevated interpersonal risks relative to a population-based sample. These results suggest that some individuals with a suicide attempt history exhibit relatively low interpersonal risks, and given concurrent protective psychological factors, may be suited to low-intensity interventions. At the other extreme, some individuals with a suicide attempt history require high-intensity interventions addressing interpersonal risks, clinical symptoms, and protective psychological factors.

Heterogeneous association patterns of depressive subfactors in suicidality: The 2014 and 2016 Korea National Health and Nutrition Examination Surveys

BACKGROUND

The heterogeneity of depressive symptoms in suicidality is poorly understood. This study examines the heterogeneous association between subfactors of depressive symptoms in suicidality.

METHODS

The data of 5742 participants aged 19 and older were taken from the 2014 and 2016 Korean National Health and Nutrition Examination Surveys and analyzed. Subfactors of depressive symptoms were identified utilizing factor analyses that yielded two groups (typical- and other-depressive factors). Multivariable logistic regression models were used to estimate the association between each factor and suicidality after adjusting for covariates.

RESULTS

Typical depressive factors included cardinal and somatic symptoms, whereas other depressive factors contained cognitive and other symptoms. The typical factors were associated with each suicidality in succession, however, others depressive factors were not. The heterogeneity of subfactors made the greatest impact on suicide attempts, controlling for all covariates, followed by suicide plans, with a robust coefficient of typical depressive factors. These differential patterns of subfactors existed especially in females and younger people, suggesting the importance of concerning typical depressive factors for those groups.

LIMITATIONS

Although a confirmatory factor analysis was performed, depressive subfactors need validation and reliability tests.

CONCLUSIONS

Our study findings may help to explain why an improved understanding of the typical depressive factors including cardinal and somatic symptoms is important to prevent suicidality, especially in females and younger people.

Profiles of Risk for Suicidal Behavior in Past and Current United States Military Personnel: Latent Profile Analysis of Current Risk Factors

Person-centered approaches are underutilized to identify people with shared risk profiles. In this study, an at-risk sample of 773 past/current military personnel (Mage = 31.3 years, SD = 6.8) with current ideation (90.6%) and/or a prior suicide attempt (43.9%) were assessed using latent profile analysis. Variables included prior suicide attempts, suicidal ideation, alcohol/drug use, insomnia, depression, belongingness, burdensomeness, and post-traumatic stress disorder symptoms. Three classes emerged: Low Symptoms (N = 502), Elevated Suicidality (N = 176), and Elevated Substance Use (N = 95). At 1-month follow-up, the Elevated Suicidality and Elevated Substance Use classes had the highest odds of suicidal behavior. The finding concerning the Elevated Substance Use class suggests it may represent a distinct short-term risk group in military personnel.

A preliminary examination of the association between drinking as a typical coping strategy and level of acute alcohol consumption prior to a suicide attempt

Drinking to cope is associated with suicide ideation and attempts. Event-based research shows drinking, particularly when alcohol is consumed in large quantities, increases the intensity of suicidal thoughts and immediate risk for attempt. Such findings suggest those who typically drink to cope may be especially likely to drink heavily in the hours preceding a suicide attempt. In the first examination of the association between regular use of alcohol as a coping strategy and acute alcohol consumption prior to a suicide attempt, participants included 130 patients hospitalized for a recent attempt. The number of drinks consumed in the acute period preceding the attempt, as well as past-year heavy drinking frequency, typical drinking motives, and depressive symptoms were assessed. The unique impacts of coping motives on odds of consuming any alcohol, and of using specific amounts of alcohol in the acute period, were determined through binary and multinomial logistic regressions. Results demonstrated that commonly drinking for coping motives increased the odds of heavy drinking - but not of using alcohol at low levels - during the acute period. Results held after adjusting for relevant covariates. Clinicians should assess drinking motives and prioritize prevention of drinking to cope to reduce risk of alcohol-related suicide attempts.

Intolerance of Uncertainty Moderates the Association Between Potentially Morally Injurious Events and Suicide Ideation and Behavior Among Combat Veterans

Exposure to potentially morally injurious events (PMIEs) among combat veterans has been acknowledged as significant stressful combat events that may lead to mental health problems, including self-injurious thoughts and behavior (SITB). However, few studies have examined the risk and protective factors that can explain the conditions in which PMIEs may contribute to the development and maintenance of SITB. In the current study, we aimed to examine the association between PMIEs and SITB among combat veterans and explore the moderating roles of intolerance of uncertainty (IU) in this association. A volunteer sample of 191 Israeli combat veterans was recruited during 2017. Participants completed validated self-report questionnaires in a cross-sectional study. Results indicated that two separate measures of PMIEs, the Perceived Perpetration by Oneself and Others subscale of the Moral Injury Events Scale (MIES) and the Causes subscale of the Moral Injury Questionnaire (MIQ-Causes), were positively associated with higher levels of SITB. Moreover, beyond the contributions of reserve duty, posttraumatic stress symptoms, and depressive symptoms, MIQ-Causes scores significantly predicted current SITB. Importantly, under low and average levels of inhibitory IU, significant positive effects were revealed for the MIQ-Causes on current SITB, R² = .34. Although veterans exposed to PMIEs are more prone to SITB, even years after their release from military service, their IU may temper the link between experiences of PMIEs and SITB.

Externalizing depression symptoms among Canadian males with recent suicidal ideation: A focus on young men

AIM

The primary aim was to quantify, relative to older men, young men's externalizing of depression symptoms and past-month suicidal ideation.

METHODS

A non-probability national sample of 1000 Canadian men self-reported internalizing and externalizing symptoms of depression and past-month suicidal ideation. Stratification quotas reflected Canadian census data to age and region.

RESULTS

Young men (18-25 years) were at markedly higher risk of past-month suicidal ideation than were older men. When controlling for internalizing depression, a multivariate age × recent suicidal ideation interaction indicated higher externalizing of depression symptoms in young men relative to older men, especially for those reporting recent suicidal ideation (P < .001). Interactions were observed for drug use, anger and aggression, and risk-taking domains. A sizable proportion of younger men were uniquely identified by the MDRS-22.

CONCLUSIONS

Screening tools that include assessment of externalizing symptoms may assist in improving detection of distress and suicide risk in young men.

The Underlying Structure of Comorbid Mental Health and Substance Use Disorders in Prison Populations

BACKGROUND

High rates of mental disorders have been reported for prison populations. Understanding patterns of comorbidity may be essential for the development of adequate treatment interventions. The present study aimed to assess the underlying structure of comorbidity between mental health and substance use disorders in prison populations.

METHODS

Current mental disorders were assessed using the Mini-International Neuropsychiatric Interview in a cross-sectional observational study of 427 individuals consecutively committed to prison facilities in Santiago, Chile. Five alternative structural models were tested using confirmatory factor analysis (CFA). Latent class analysis of comorbid mental health and substance use disorders was carried out.

RESULTS

CFA indicated the best fit for a bifactor model with a general psychopathology P factor and specific internalizing and externalizing factors. Borderline personality disorder loaded highest on the P factor (0.85). The latent comorbidity structure showed a four-class solution representing one class without relevant comorbidities (48% prevalence) and three classes representing the following comorbidities: (1) externalizing disorders including substance use and antisocial personality disorder (31%), (2) internalizing disorders including anxiety disorders (10%), and (3) all types of disorders co-occurring (11%). Major depression and borderline personality disorder were present across all three latent classes of comorbidity.

CONCLUSIONS

Prison mental health services need to serve a highly comorbid population. Specific approaches may be useful for an externalizing and an internalizing spectrum of disorders. An important group of individuals with all types of mental disorders co-occurring may need new approaches in treatment development.

Age at onset of first suicide attempt: Exploring the utility of a potential candidate variable to subgroup attempters

PURPOSE

Our objective was to explore the utility of age at first suicide attempt in identifying subgroups of suicide attempters.

METHODS

In a retrospective study design, we collected information from the clinical charts of 895 patients assessed over a seven-year period. Admixture analysis was used to determine the best fitting theoretical model for distribution of age at first attempt that divided the sample. Subsequently, multivariate analysis was performed to identify variables that distinguished the subgroups identified.

RESULTS

The theoretical solution that best explained the observed distribution of age at first suicide attempt was a mixture of two Gaussian distributions with a cut-off of 31 years for the two subgroups. In logistic regression analysis, male gender (Odds ratios [OR] 3.047, 95% Confidence Interval (CI) 1.818-5.106), fewer years of formal schooling (OR 3.384, 95% CI 1.701-6.734) and being married (OR 23.36, 95% CI 10.753-50.000), were more commonly associated with the late onset subgroup (age at first attempt >31 years). Further, the late onset subgroup had poorer global functioning (OR 0.980, 95% CI 0.962 to 0.998).

CONCLUSION

Age at onset of first suicide attempt is a useful candidate marker to delineate an early and late onset subgroup among suicide attempters. These results are likely to inform customization of suicide prevention strategies.

Digital phenotyping of suicidal thoughts

BACKGROUND

To examine whether there are subtypes of suicidal thinking using real-time digital monitoring, which allows for the measurement of such thoughts with greater temporal granularity than ever before possible.

METHODS

We used smartphone-based real-time monitoring to assess suicidal thoughts four times per day in two samples: Adults who attempted suicide in the past year recruited from online forums (n = 51 participants with a total of 2,889 responses, surveyed over 28 days; ages ranged from 18 to 38 years) and psychiatric inpatients with recent suicidal ideation or attempts (n = 32 participants with a total of 640 responses, surveyed over the duration of inpatient treatment [mean stay = 8.79 days], ages ranged 23-68 years). Latent profile analyses were used to identify distinct phenotypes of suicidal thinking based on the frequency, intensity, and variability of such thoughts.

RESULTS

Across both samples, five distinct phenotypes of suicidal thinking emerged that differed primarily on the intensity and variability of suicidal thoughts. Participants whose profile was characterized by more severe, persistent suicidal thoughts (i.e., higher mean and lower variability around the mean) were most likely to have made a recent suicide attempt.

CONCLUSIONS

Suicidal thinking has historically been studied as a homogeneous construct, but using newly available monitoring technology we discovered five profiles of suicidal thinking. Key questions for future research include how these phenotypes prospectively relate to future suicidal behaviors, and whether they represent remain stable or trait-like over longer periods.

The development of a novel high-precision major depressive disorder screening system using transient autonomic responses induced by dual mental tasks

12.6% of major depressive disorder (MDD) patients have suicide intent, while it has been reported that 43% of patients did not consult their doctors for MDD, automated MDD screening is eagerly anticipated. Recently, in order to achieve automated screening of MDD, biomarkers such as multiplex DNA methylation profiles or physiological method using near infra-red spectroscopy (NIRS) have been studied, however, they require inspection using 96-well DNA ELIZA kit after blood sampling or significant cost. Using a single-lead electrocardiography (ECG), we developed a high-precision MDD screening system using transient autonomic responses induced by dual mental tasks. We developed a novel high precision MDD screening system which is composed of a single-lead ECG monitor, analogue to digital (AD) converter and a personal computer with measurement and analysis program written by LabView programming language. The system discriminates MDD patients from normal subjects using heat rate variability (HRV)-derived transient autonomic responses induced by dual mental tasks, i.e. verbal fluency task and random number generation task, via linear discriminant analysis (LDA) adopting HRV-related predictor variables (hear rate (HR), high frequency (HF), low frequency (LF)/HF). The proposed system was tested for 12 MDD patients (32 ± 15 years) under antidepressant treatment from Shizuoka Saiseikai General Hospital outpatient unit and 30 normal volunteers (37 ± 17 years) from Tokyo Metropolitan University. The proposed system achieved 100% sensitivity and 100% specificity in classifying 42 examinees into 12 MDD patients and 30 normal subjects. The proposed system appears promising for future HRV-based high-precision and low-cost screening of MDDs using only single-lead ECG.

Male Depression Subtypes and Suicidality: Latent Profile Analysis of Internalizing and Externalizing Symptoms in a Representative Canadian Sample

Assessment of men's externalizing symptoms has been theorized to assist in the identification of those at risk of suicide. A nationally representative sample of Canadian men (N = 1000; mean, 49.63 years) provided data on internalizing and externalizing symptoms, and history of recent suicide planning and attempt (previous 4 weeks). Latent profile analysis indicted three classification subtypes. Robust effects were observed regarding history of recent suicide planning and attempt. Men with a marked externalizing profile (12.7% of sample), which included substance use, anger, and risk taking, were significantly more likely to have had a recent suicide plan (risk ratio, 14.47; p < 0.001) or to have attempted suicide within the previous 4 weeks (risk ratio, 21.32; p < 0.001) relative to asymptomatic men (67.7% of sample). Because recent suicide attempt was a rare event in the present sample (n = 13), findings need to be replicated in higher-risk populations. Results support primary care screening for both men's internalizing and externalizing depression symptoms.

Subtypes of suicide attempters based on longitudinal childhood profiles of co-occurring depressive, anxious and aggressive behavior symptoms

Because suicide attempts are multi-determined events, multiple pathways to suicidal behaviors exist. However, as a low-frequency behavior, within group differences in trajectories to attempts may not emerge when examined in samples including non-attempters. We used longitudinal latent profile analysis to identify subtypes specific for suicide attempters based on longitudinal trajectories of childhood clinical symptoms (i.e., depression, anxiety, and aggression measured in 2nd, 4th-7th grades) for 161 young adults (35.6% male; 58.6% African American) who attempted suicide between ages 13-30 from a large, urban community-based, longitudinal prevention trial (n = 2311). Differences in psychiatric diagnoses, suicide attempt characteristics, criminal history and traumatic stress history were studied. Three subtypes emerged: those with all low (n = 32%), all high (n = 16%), and high depressive/anxious, but low aggressive (n = 52%) symptoms. Those with the highest levels of all symptoms were significantly more likely to report a younger age of suicide attempt, and demonstrate more substance abuse disorders and violent criminal histories. Prior studies have found that childhood symptoms of depression, anxiety and aggression are malleable targets; interventions directed at each reduce future risk for suicidal behaviors. Our findings highlight the link of childhood aggression with future suicidal behaviors extending this research by examining childhood symptoms of aggression in the context of depression and anxiety.