Evidence for the Propositions of the Interpersonal Theory of Suicide Among a Military Sample

Peer-Written Caring Letters for Veterans after a Suicidal Crisis

OBJECTIVE

In the evidence-based suicide prevention intervention, Caring Letters, healthcare providers send brief, caring messages to patients following psychiatric inpatient care, a time of elevated suicide risk. However, recent studies with military populations have found mixed results. An adaptation of Caring Letters employed a peer framework in which veterans from the community wrote brief caring messages to veterans discharging from psychiatric inpatient treatment after a suicidal crisis.

METHODS

The present study utilized content analysis to assess 90 caring messages generated by 15 peer veterans recruited from veteran service organizations (e.g., American Legion).

RESULTS

Three themes emerged: (1) Shared Military Service, (2) Care, and (3) Overcoming Adversity. Peer-generated content varied in how the coded themes were expressed in the messages.

CONCLUSION

These veteran-to-veteran caring messages may bolster belongingness, social support, and destigmatize mental health struggles, and have the potential to augment existing Caring Letters effects and interventions.

A Psychometric Evaluation of the Interpersonal Hopelessness Scale Among Individuals With Elevated Suicide Risk

The interpersonal theory of suicide hypothesizes that suicide ideation (SI) emerges specifically in the context of hopelessness about the immutability of thwarted belongingness (TB) and perceived burdensomeness (PB; i.e., interpersonal hopelessness). The psychometrics of the Interpersonal Hopelessness Scale (IHS), which could be used to test this hypothesis directly, have not been rigorously evaluated. Participants (U.S. adults reporting past-year SI) completed online self-report assessments at Waves 1 (W1; N = 595) and 2 (W2; N = 215), 1 week apart. Confirmatory factor analyses supported a two-factor structure, IHS-TB and IHS-PB. Correlations indicated strong concurrent validity. Hurdle negative binomial regressions indicated that W1 IHS-TB and IHS-PB scores were associated with SI presence and severity at both waves, but this was inconsistent when adjusting for other W1 variables. IHS-TB and IHS-PB demonstrated excellent internal consistency and moderate to good test-retest reliability. The IHS could improve theory testing and suicide risk assessment and management.

The Prevalence of Nonsuicidal Self-Injury in Military Personnel: A Systematic Review and Meta-Analysis

Military service members and veterans (SMVs) are at risk for self-directed violence, including nonsuicidal self-injury (NSSI). While NSSI is an important construct worthy of independent study, it is understudied among SMVs and, when included in research, typically examined in the context of suicide risk. Consequently, lifetime prevalence rate estimates of NSSI among SMVs vary. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review and meta-analysis estimated the average lifetime NSSI prevalence among SMVs and explored demographic and methodological factors that may account for observed variability. Based on a search of Ovid MEDLINE, Embase, PsycINFO, and Web of Science, 47 samples from 42 articles across five countries met inclusion criteria. Results revealed an average NSSI lifetime prevalence rate of 15.76% among SMVs. Significantly higher prevalence rates were observed among clinical (28.14%) versus community (11.28%) samples and studies using interviews to assess NSSI (23.56%) versus self-report (13.44%) or chart review (7.84%). Lifetime prevalence increased as publication year increased and decreased as sample size increased. In contrast to prior literature, prevalence rates were comparable between active-duty SMVs, and studies collecting data anonymously versus those that did not. Lifetime prevalence was not moderated by age, gender, race, country, primary research focus, quality of NSSI operationalization, or whether NSSI methods were assessed. Findings suggest NSSI is a pervasive problem among military personnel, particularly within clinical settings, highlighting the need for systematic assessment of this important but understudied clinical phenomenon among SMVs. Further research is necessary to elucidate additional risk factors for NSSI among SMVs, including trauma exposure.

Insomnia and the Interpersonal Theory of suicide among civilians, service members, and veterans

BACKGROUND

Insomnia is associated with suicide risk in civilian and military populations. Thwarted belongingness is proposed as a mediator of this relationship under the Interpersonal Theory of Suicide (IPTS). The present study explored how insomnia relates to suicidal ideation in conjunction with thwarted belongingness among civilians, Service members, and Veterans.

METHODS

Data from the Military Suicide Research Consortium for N = 6556 individuals (6316 with non-missing suicidal ideation status) were divided into 4 subgroups: civilians, never deployed Service members, previously deployed Service members, and Veterans. Robust Poisson models evaluated the associations between insomnia severity/subtype and current suicidal ideation, with bootstrap mediation models assessing thwarted belongingness as a mediator.

RESULTS

A 5-point increase in insomnia severity was associated with a 38% increased risk for current suicidal ideation among civilians, a 56% greater risk among never deployed Service members, an 83% greater risk among previously deployed Service members, and a 37% greater risk among Veterans. Moreover, active Service members showed greater associations between difficulty falling asleep and staying asleep with suicidal ideation than civilians. These associations were independent of covariates and only mediated by thwarted belongingness among Veterans.

CONCLUSIONS

The relationship between insomnia and suicide is not purely explained by thwarted belongingness except among Veterans. Future research should explore additional psychological and neurobiological mechanisms connecting insomnia and suicidality.

Qualitatively Exploring Mental Health Attitude Changes among Emerging Adult Motivational Interviewing after One Motivational Enhanced Interview

Emerging adult military members and veterans (MMV) are experiencing many transitions (e.g., adulthood, military). The sum of these changes can cause stress, anxiety, and mental health challenges. Stigma of mental health and treatment exists, and military populations are often not seeking or engaging in appropriate care. Recent research emphasizes the need to uncover mental health attitudes and self-stigma barriers regarding help seeking. We evaluated the impact of a single motivational-interviewing enhanced interview with 26 MMV, all who reported high risk substance use. In 75-minute interviews with the primary focus of discussing their experiences regarding mental health, substance use, and identity development, the interviewer incorporated motivational interviewing strategies (e.g., affirmations, complex reflections). Participants shared their developmental experiences, stressors transitioning, and barriers and stigma around mental health treatment. Participants completed a survey which included a variety of standardized measures and open-ended questions two weeks before and after the interview. Qualitative follow-up data via open ended questions shows the session was well received by participants as they could share their stories, think critically about their military experiences, and brainstorm solutions for mental health care. We conclude that using individual, confidential interviews to discuss sensitive topics for data collection with MMV is an area to continue developing. Conducting qualitative research with motivational interviewing strategies has the potential to be twofold: advance scholarship and inform practitioners, but also serve as a therapeutic platform for some participants.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10615-022-00837-z.

Social exclusion, thwarted belongingness, and perceived burdensomeness: construct validity and psychometric properties of the Interpersonal Needs Questionnaire among patients with sexually transmitted infections in Shanghai, China

Background

Sexually transmitted infections (STIs) are a serious public health problem worldwide. Patients with STIs have a high rate of psychosocial problems and may perceive unmet interpersonal needs, which is considered a proximal and sufficient cause of suicidal thoughts and behaviors. The present study examined the construct validity and psychometric properties of the 15-item Interpersonal Needs Questionnaire among patients with STIs in Shanghai, China.

Methods

We recruited 910 patients with STIs (438 males and 472 females; mean age = 38.72, standard deviation [SD] = 13.034) from the Shanghai Skin Disease Hospital using accidental sampling. Baseline descriptive statistics were calculated using R 4.0.0, and a latent variable model was developed using Mplus 7.4.

Results

The construct validity results supported a latent variable measurement model with three distinct but related constructs (thwarted belongingness, perceived burdensomeness, and social exclusion) (p < 0.001, χ2/df = 2.475, root mean square error of approximation = 0.057, comparative fit index = 0.931, Tucker–Lewis index = 0.916, standardized root mean residual = 0.044). The Cronbach’s α and McDonald’s ω values were 0.849 and 0.767 for the total scale, 0.888 and 0.889 for perceived burdensomeness, 0.764 and 0.777 for social exclusion, and 0.892 and 0.893 for thwarted belongingness. Interpersonal needs were significantly associated with low self-esteem (r = 0.539), loneliness (r = 0.573), depression (r = 0.338), entrapment (r = 0.420), defeat (r = 0.579), and low perceived social support (r = 0.424).

Conclusions

This was the first study to highlight social exclusion as a distinct but related dimension of interpersonal needs. This finding indicates that patients with STIs perceive high social exclusion. Therefore, health providers should consider the psychological status of these patients and implement strategies to support their integration into society.

Preferences in Information Processing: Understanding Suicidal Thoughts and Behaviors among Active Duty Military Service Members

The present study examined Preferences in Information Processing (PIP), an emerging model of understanding suicidal thoughts and behaviors (STBs), in a clinical military sample for the first time. Constructs of need for affect (NFA; i.e., extent to which one engages or avoids emotional content) and need for cognition (NFC; i.e., extent of preference for and enjoyment of cognitive effort) are central individual differences of the PIP model hypothesized to be associated with STBs. Data (n = 200 active duty personnel) were drawn from medical records and self-report questionnaires from two outpatient treatment settings in a military hospital. Primary findings include: (1) moderate positive bivariate associations of NFA avoidance with mental health symptoms and lifetime STBs; (2) consistent patterns in which NFA approach buffers the negative associations of depression with life STBs, clinical suicide risk, perceived burdensomeness and thwarted belonging. Recommendations are offered for military suicide prevention, and future suicide theory testing.

The suicide of Private Danny Chen: An interpersonal theory perspective

Despite considerable prevention and intervention efforts, military suicide rates have increased. Although most research on active-duty military suicide has focused on combat exposure, evidence shows that bullying, hazing, and race are understudied risk factors for military suicide. According to the interpersonal theory of suicide, thwarted belongingness, perceived burdensomeness, and acquired capability are necessary components for enacting a suicide death. In this theoretically-based interpersonal case analysis of the suicide death of Private Danny Chen, an American soldier of Chinese descent, we explore how bullying, hazing, and race may have intersected with other vulnerabilities to result in his death.

Pulling Together - The Protective Role of Belongingness for Depression, Suicidal Ideation and Behavior Among Suicide-Bereaved Individuals

Background: While belongingness has frequently been investigated in the general population as an antidote to experiencing depression, suicidal thoughts, and suicidal behavior, it has rarely been evaluated as a protective factor among individuals bereaved by suicide. Aims: We examined whether perceived belongingness could moderate the differences between suicide-bereaved, suicide-exposed, and nonexposed respondents regarding depression, suicide ideation, and suicide attempts. Method: We conducted an online survey of the adult Israeli population (N = 806), with 203 suicide-bereaved, 266 suicide-exposed, and 377 nonexposed respondents. Participants completed several questionnaires tapping depression and suicidality as well as perceived belongingness levels. Results: Individuals bereaved by suicide reported the highest levels of depression, suicide ideation, and suicide attempts in comparison with suicide-exposed and nonexposed individuals. However, belongingness was found to moderate these distinctions concerning suicide ideation and suicide attempts. Limitations: Belongingness was assessed by only a single question, and the online survey suffered from a relatively high nonresponse rate. Conclusion: Our results suggest that belongingness may act as a potent antidote to the adverse mental health consequences among individuals bereaved by suicide. Clinicians should accord adequate attention to fostering social connectedness among their clients bereaved by suicide.

Veteran peer suicide prevention: A community-based peer prevention model

OBJECTIVE

The purpose of this study was to develop a conceptual model of community-based veteran peer suicide prevention.

METHOD

We conducted a qualitative study in which semi-structured interviews were followed by three focus groups. Participants (n = 17) were chosen from community-based organizations who had peers working on veteran suicide prevention; the sample included veteran peers, non-peers, program managers, and community stakeholders. Interview data were analyzed thematically and inductively to identify key components and subcomponents of veteran peer suicide prevention. A draft model was shared with each focus group to elicit feedback and refine key concepts.

RESULTS

A conceptual model containing nine components and twenty-six subcomponents was developed. Participants emphasized key organizational, relational, and practical elements needed to achieve positive outcomes. In addition, they described critical contextual and cultural factors that impacted veteran peers' ability to prevent suicide and promote overall wellness.

CONCLUSIONS

Community-based veteran peer efforts are a promising public health approach to preventing veteran suicide. Provided veteran peers are supported and fully allowed to contribute, these efforts can complement existing clinic-based efforts. Future research on community-based veteran peer suicide prevention should document a range of outcomes (e.g., clinical, wellness, financial) and allow for considerable flexibility in peer approaches.

Perceived burdensomeness, but not thwarted belongingness, mediates the impact of PTSD symptom clusters on suicidal ideation modeled longitudinally

BACKGROUND

Studies examining Posttraumatic Stress Disorder symptom clusters, suicidal ideation, and variables described in the Joiner's interpersonal theory of suicidal behavior were cross-sectional.

METHODS

We tested whether the relation between the Posttraumatic Stress Disorder symptom clusters and suicidal ideation is mediated by perceived burdensomeness and thwarted belongingness (variables of the interpersonal theory of suicidal behavior) in military personnel with current suicidal ideation using longitudinal design. DSM-IV model with reexperiencing, avoidance, numbing, and hyperarousal clusters was used. Structural equation modelling was used to test separate models for each symptom cluster with a symptom cluster at baseline, month 1 perceived burdensomeness and thwarted belongingness, and month 3 suicidal ideation, controlling for baseline values of the month 1 and month 3 variables.

RESULTS

Analysis of direct non-mediation models showed that baseline reexperiencing (p = .08) and avoidance (p = .07) symptom clusters marginally predicted month 3 suicidal ideation. The mediation analyses showed indirect effects from baseline reexperiencing, avoidance, and hyperarousal to suicidal ideation at month 3 through perceived burdensomeness at month 1. Thwarted belongingness did not mediate the relations between symptom clusters and suicidal ideation.

LIMITATIONS

The mechanism driving development of suicidal ideation in military personnel with PTSD may be different from the mechanism in other samples. Doing a phone interview limited us to use questionnaires instead of a clinical interview.

CONCLUSIONS

Our findings suggest that interventions targeting perceived burdensomeness in military personnel with reexperiencing, avoidance, and hyperarousal symptoms may be beneficial to reduce suicidal ideation.

A test of the interpersonal theory of suicide in a large, representative, retrospective and prospective study: Results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS)

The interpersonal theory of suicide hypothesizes that perceived burdensomeness, thwarted belongingness, and hopelessness lead to active suicidal thoughts and individuals with active suicidal thoughts and elevated capability for suicide are most likely to attempt suicide. We retrospectively and prospectively tested this theory in a large sample of 7677 U.S. Army soldiers followed post-deployment for up to nine months. The interaction of perceived burdensomeness and hopelessness (OR = 2.59) was significantly associated with lifetime suicidal thoughts; however, the interactions of thwarted belongingness and perceived burdensomeness and of thwarted belongingness and hopelessness were not. Consistent with the theory, capability for suicide prospectively predicted suicide attempts during and following deployment (OR = 1.22); however, among soldiers reporting lifetime suicidal thoughts, capability did not predict attempts, only perceived burdensomeness did (OR = 1.36). Results supported some, but not all, theory hypotheses, suggesting that additional constructs may be needed to better identify the psychological factors that lead soldiers to attempt suicide.

Use of the acquired capability for suicide scale (ACSS) among United States military and Veteran samples: A systematic review

BACKGROUND

Military personnel and Veterans are at increased risk for suicide. Theoretical and conceptual arguments have suggested that elevated levels of acquired capability (AC) could be an explanatory factor accounting for this increased risk. However, empirical research utilizing the Acquired Capability for Suicide Scale (ACSS) in military populations has yielded mixed findings.

METHODS

To better ascertain what factors are associated with AC, and whether methodological limitations may be contributing to mixed findings, a systematic review was conducted.

RESULTS

A total of 31 articles utilized the ACSS to examine factors associated with AC, including combat history, in United States (U.S.) military personnel and Veterans. Nearly all studies (96.8%) were rated high risk of bias. Use of the ACSS varied, with seven different iterations utilized. Nearly all studies examined correlations between the ACSS and sample characteristics, mental health and clinical factors, Interpersonal Theory of Suicide constructs, and/or suicide-specific variables. Results of higher-level analyses, dominated by cross-sectional designs, often contradicted correlational findings, with inconsistent findings across studies.

LIMITATIONS

Included studies were non-representative of all U.S. military and Veteran populations and may only generalize to these populations.

CONCLUSIONS

Due to the high risk of bias, inconsistent use of the ACSS, lack of sample heterogeneity, and variability in factors examined, interpretation of current ACSS empirical data is cautioned. Suggestions for future research, contextualized by these limitations, are discussed.

Leader provided purpose: Military leadership behavior and its association with suicidal ideation

Suicide in U.S. Army Soldiers is of major concern as it is estimated that over 100 Soldiers die by suicide each year. Examining risk and protective factors is essential to develop both an understanding of Soldier suicide as well as inform systemic interventions to reduce suicide. One potential systemic approach is to embed preventive mechanisms within the structure of the military rather than the typical administration of primary intervention through mandatory training. To examine potential mechanisms of leader-based interventions, several leadership behaviors were assessed in a cross-sectional sample of n = 1,096 active duty Soldiers. Soldiers completed self-report measures of interpersonal predictors of suicide, suicidal ideation (SI), leadership behaviors, and unit cohesion. Logistic regression was used to identify leadership behaviors related to SI. Only the leader behavior attempting to foster a sense of purpose predicted SI. Leader provided purpose (LPP) was then entered into indirect effect analyses to evaluate the mechanisms of this relationship. Analyses revealed that LPP predicted SI through unit cohesion, thwarted belongingness, and perceived burdensomeness. Results demonstrate that specific aspects of military leadership such as fostering Soldier purpose may enhance resilience and reduce risk for SI.

Perceived burdensomeness, bullying, and suicidal ideation in suicidal military personnel

OBJECTIVE

Suicide is a major public health concern among military servicemembers and previous research has demonstrated an association between bullying and suicide. This study evaluated the association between workplace bullying and suicidal ideation via perceived burdensomeness and thwarted belongingness which were hypothesized to mediate this association.

METHOD

Four hundred and seventy-one suicidal Army Soldiers and U.S. Marines completed self-report measures of suicidal ideation, thwarted belongingness, perceived burdensomeness, and bullying. A series of regressions were used to test the hypothesized mediation model using the baseline data from a larger clinical trial.

RESULTS

Perceived burdensomeness was a significant mediator of the association between bullying and the level of suicidal ideation, but thwarted belongingness was not a significant mediator.

CONCLUSIONS

Perceived burdensomeness may represent a malleable target for intervention to prevent suicide among military service members, and should be evaluated further as an intervening variable with regard to suicidality in the setting of bullying victimization.

Lack of Emotional Awareness is Associated with Thwarted Belongingness and Acquired Capability for Suicide in a Military Psychiatric Inpatient Sample

OBJECTIVE

To examine potential links between facets of impulsivity and emotion dysregulation to components of the Interpersonal-Psychological Theory of Suicide (thwarted belongingness, perceived burdensomeness, and acquired capability) among U.S. military personnel.

METHOD

The current study performed secondary data analysis from a randomized control trial testing the efficacy of a cognitive therapy for 134 service members (71.64% male, 68.66% Caucasian; mean age: 30.14) admitted to a psychiatric inpatient unit for a suicide-related crisis. We utilized the Difficulties in Emotion Regulation Scale, the Barratt Impulsivity Scale, the Acquired Capability for Suicide Scale, and the Interpersonal Needs Questionnaire.

RESULTS

All emotion dysregulation dimensions and one impulsivity facet (attentional) were positively correlated with perceived burdensomeness and thwarted belongingness. Lack of emotional awareness was positively associated with acquired capability. After controlling for depression, hopelessness, and demographic covariates, lack of emotional awareness was significantly associated with both thwarted belongingness and acquired capability, but not perceived burdensomeness, and impulsivity dimensions did not link to any variable of interest.

CONCLUSIONS

Findings imply that individuals with reduced emotional awareness may have difficulty cultivating interpersonal bonds and be more vulnerable to elevated acquired capability. Lack of emotional awareness may be a potential contributor to both suicidal desire and capability.

A Matter of Life and Death: Integrating Mattering into the Interpersonal-Psychological Theory of Suicide

OBJECTIVE

This paper advocates for a more robust sense of mattering into the interpersonal-psychological theory of suicide (IPTS) constructs of perceived burdensomeness and thwarted belongingness. According to IPTS, suicide is precipitated in part by the presence of these twin constructs. IPTS theorists rely on mattering, or feeling significant to others, to undergird theoretical constructs. This is not surprising, as mattering theorists herald "significance to others" as essential to one's will to live. However, IPTS theorists solely leverage mattering to explain perceived burdensomeness.

METHOD

This paper summarizes the existing suicide literature on IPTS and mattering. Further, this paper extensively reviews how mattering has been incorporated into IPTS to date, and possibilities for how mattering could be more fully integrated into the theory.

RESULTS

IPTS theorists rely on select mattering elements to define perceived burdensomeness. Strong theoretical overlap exists between mattering and thwarted belongingness.

CONCLUSION

Mattering can play central role in understanding both perceived burdensomeness and thwarted belongingness. Implications for future research and use of mattering-enriched IPTS are discussed.

Relations Between Thwarted Belongingness, Perceived Burdensomeness, and History of Suicide Attempts and Readiness for Mental Health Treatment in High-Risk Veterans, Reserves, and Active Duty Service Members

Suicide rates for service members and veterans are growing rapidly in the United States. Despite availability of evidence-based approaches, a large number of high-risk individuals are reluctant to seek out treatment. The present study used the interpersonal theory of suicide, involving 3 primary predictors of death by suicide to investigate treatment readiness in high-risk U. S. veterans, reserves, and active duty service members. Four hundred and two service members were recruited. Inclusion criteria involved (a) reporting active suicidal ideation and (b) denying active behavioral health treatment. All participants completed a self-report battery that assessed burdensomeness, thwarted belongingness, lifetime suicide attempts, and perceptions about treatment. Regression analyses revealed that thwarted belongingness was significantly predictive of treatment perceptions and readiness, in that higher or more severe scores on the thwarted belongingness scale were significantly related to lower or less likely treatment perceptions and readiness scores. The findings suggested that, in high-risk service members, thwarted belongingness is predictive of lower treatment readiness, and contributes to the growing literature on perceived stigmas, treatment barriers and readiness, and suicidal behaviors and risk factors.

The Military Suicide Research Consortium Common Data Elements: An Examination of Measurement Invariance Across Current Service Members and Veterans

Suicide rates within the U.S. military are elevated, necessitating greater efforts to identify those at increased risk. This study utilized a multigroup confirmatory factor analysis to examine measurement invariance of the Military Suicide Research Consortium Common Data Elements (CDEs) across current service members ( n = 2,015), younger veterans (<35 years; n = 377), and older veterans (≥35 years; n = 1,001). Strong factorial invariance was supported with adequate model fit observed for current service members, younger veterans, and older veterans. The structures of all models were generally comparable with few exceptions. The Military Suicide Research Consortium CDEs demonstrate at least adequate model fit for current military service members and veterans, regardless of age. Thus, the CDEs can be validly used across military and veteran populations. Given similar latent structures, research findings in one group may inform clinical and policy decision making for the other.

Army Soldiers and Suicidal Thoughts: The Impact of Negative Relationship Dynamics Moderated by the Dissolution of Romantic Relationships

Suicide among United States active-duty Army soldiers rapidly increased over the past two decades. Using a sample of 322 soldiers from the Army STARRS study, the researchers examined if romantic relationship factors (i.e., hostile disagreements and relationship distress) were linked with suicidal thoughts in Army soldiers, and if these associations were moderated by a recent separation or divorce. Hostile disagreements and relational distress were both significantly associated with higher rates of suicidal ideation. These associations were significantly amplified in magnitude when in the context of a recent separation or divorce. Implications include novel assessment, prevention, and treatment efforts focused on romantic relationships that may reduce the likelihood of soldiers experiencing thoughts of suicide.

Mechanisms of Action Contributing to Reductions in Suicide Attempts Following Brief Cognitive Behavioral Therapy for Military Personnel: A Test of the Interpersonal-Psychological Theory of Suicide

Brief cognitive behavioral therapy (BCBT) is associated with significant reductions in suicide attempts among military personnel. However, the underlying mechanisms of action contributing to reductions in suicide attempts in effective psychological treatments remain largely unknown. The present study conducted a secondary analysis of a randomized controlled trial of BCBT versus treatment as usual (TAU) to examine the mechanisms of action hypothesized by the interpersonal-psychological theory of suicide (IPT): perceived burdensomeness, thwarted belongingness, and fearlessness about death. In a sample of 152 active duty U.S. Army personnel with recent suicide ideation or attempts, there were significantly fewer suicide attempts in BCBT, but there were no differences between treatment groups from baseline to 6 months postbaseline on any of the 3 IPT constructs or their interactions. Tests of the moderated mediation failed to support an indirect effect for the IPT model, regardless of which IPT variables were specified as mediators or moderators. Results suggest that the IPT's hypothesized mechanisms of action do not account for reductions in suicide attempts in BCBT. Implications for clinical practice and research are discussed.

Sex Differences in Suicide-Related Symptoms in a Large Military Sample

Little research has focused on suicide-related symptoms in female servicemembers, despite high rates of suicidal behaviors. This study examined sex differences in suicide-related risk factors in 3,374 U.S. Army Recruiters (91.9% male). Female servicemembers had a greater number of past major depressive and suicidal ideation episodes than males; there were no differences in suicide attempt histories or mental health visits. Females reported significantly fewer symptoms of current suicidal ideation, perceived burdensomeness, and acquired capability. No significant sex differences emerged for thwarted belongingness, insomnia, or agitation. Our findings provide evidence for sex differences in rates of suicide-related symptoms among military personnel.

The Life Span Model of Suicide and Its Neurobiological Foundation

The very incomprehensibility of the suicidal act has been occupying the minds of researchers and health professionals for a long time. Several theories of suicide have been proposed since the beginning of the past century, and a myriad of neurobiological studies have been conducted over the past two decades in order to elucidate its pathophysiology. Both neurobiology and psychological theories tend to work in parallel lines that need behavioral and empirical data respectively, to confirm their hypotheses. In this review, we are proposing a "Life Span Model of Suicide" with an attempt to integrate the "Stress-Diathesis Model" and the "Interpersonal Model of Suicide" into a neurobiological narrative and support it by providing a thorough compilation of related genetic, epigenetic, and gene expression findings. This proposed model comprises three layers, forming the capability of suicide: genetic factors as the predisposing Diathesis on one side and Stress, characterized by epigenetic marks on the other side, and in between gene expression and gene function which are thought to be influenced by Diathesis and Stress components. The empirical evidence of this model is yet to be confirmed and further research, specifically epigenetic studies in particular, are needed to support the presence of a life-long, evolving capability of suicide and identify its neurobiological correlates.