Using iterative random forest to find geospatial environmental and Sociodemographic predictors of suicide attempts

IntroductionDespite a recent global decrease in suicide rates, death by suicide has increased in the United States. It is therefore imperative to identify the risk factors associated with suicide attempts to combat this growing epidemic. In this study, we aim to identify potential risk factors of suicide attempt using geospatial features in an Artificial intelligence framework.MethodsWe use iterative Random Forest, an explainable artificial intelligence method, to predict suicide attempts using data from the Million Veteran Program. This cohort incorporated 405,540 patients with 391,409 controls and 14,131 attempts. Our predictive model incorporates multiple climatic features at ZIP-code-level geospatial resolution. We additionally consider demographic features from the American Community Survey as well as the number of firearms and alcohol vendors per 10,000 people to assess the contributions of proximal environment, access to means, and restraint decrease to suicide attempts. In total 1,784 features were included in the predictive model.ResultsOur results show that geographic areas with higher concentrations of married males living with spouses are predictive of lower rates of suicide attempts, whereas geographic areas where males are more likely to live alone and to rent housing are predictive of higher rates of suicide attempts. We also identified climatic features that were associated with suicide attempt risk by age group. Additionally, we observed that firearms and alcohol vendors were associated with increased risk for suicide attempts irrespective of the age group examined, but that their effects were small in comparison to the top features.DiscussionTaken together, our findings highlight the importance of social determinants and environmental factors in understanding suicide risk among veterans

Mechanisms of Moral Injury Following Military Sexual Trauma and Combat in Post-9/11 U.S. War Veterans

Objective: Moral injury may result from perpetration-based and betrayal-based acts that violate deeply held norms; however, researchers and clinicians have little guidance about the moral injury syndrome's specific developmental pathways following morally injurious events. The present study's objective was to examine the direct and indirect pathways proposed in a frequently cited model of moral injury (1) in relation to two types of military-related traumas [experiencing military sexual trauma (MST) and combat exposure].Methods: Secondary analyses were conducted within a sample of post-9/11 veterans at a Southwestern Veterans Health Care System (N = 310) across two time-points. Structural equation modeling tested the direct and indirect pathways from MST and combat to a PTSD-depression factor via betrayal, perpetration, guilt, and shame.Results: Betrayal accounted for the association between MST and PTSD-depression (β = 0.10, p < 0.01, 95% CI = 0.01 − 0.11) and perpetration accounted for the association between combat and PTSD-depression (β = 0.07, p < 0.05, 95% CI = 0.02 − 0.14). The indirect path from combat to shame to PTSD-depression was significant (β = 0.16, p < 0.01, 95% CI = 0.07 − 0.28) but the path through guilt was not. The specific indirect paths through perpetration or betrayal to shame or guilt were non-significant.Conclusions: Betrayal and perpetration are associated with PTSD-depression following MST and combat. Results suggest multiple pathways of moral injury development following different military traumas and morally injurious events. Implications for moral injury conceptualization and treatment are discussed

The factor structure of psychiatric comorbidity among Iraq/Afghanistan-era veterans and its relationship to violence, incarceration, suicide attempts, and suicidality

The present research examined how incarceration, suicide attempts, suicidality, and difficulty controlling violence relate to the underlying factor structure of psychiatric comorbidity among a large sample of Iraq/Afghanistan-era veterans (N = 1897). Diagnostic interviews established psychiatric diagnoses; self-report measures assessed history of incarceration, difficulty controlling violence, suicide attempts, and suicidality. A 3-factor measurement model characterized by latent factors for externalizing-substance-use disorders (SUD), distress, and fear provided excellent fit to the data. Alcohol-use disorder, drug-use disorder, and nicotine dependence were indicators on the externalizing-SUD factor. Posttraumatic stress disorder and depression were indicators on the distress factor. Panic disorder, social phobia, specific phobia, and obsessive-compulsive disorder were indicators on the fear factor. Incarceration was exclusively predicted by the externalizing-SUD factor. Difficulty controlling violence, suicidality, and suicide attempts were exclusively predicted by the distress factor. Contrary to hypotheses, the path from the externalizing/SUD factor to difficulty controlling violence was not significant. Taken together, these findings suggest that the distress factor of psychiatric comorbidity is a significant risk factor for suicidality, suicide attempts, and difficulty controlling violence and could help to explain the frequent co-occurrence of these critical outcomes among returning Iraq/Afghanistan veterans

Mental Health Treatment Involvement and Religious Coping among African American, Hispanic, and White Veterans of the Wars of Iraq and Afghanistan

Although racial/ethnic differences have been found in the use of mental health services for depression in the general population, research among Veterans has produced mixed results. This study examined racial/ethnic differences in the use of mental health services among 148 Operation Enduring/Iraqi Freedom (OEF/OIF) Veterans with high levels of depression and posttraumatic stress disorder (PTSD) symptoms and evaluated whether religious coping affected service use. No differences between African American, Hispanic, and Non-Hispanic white Veterans were found in use of secular mental health services or religious counseling. Women Veterans were more likely than men to seek secular treatment. After controlling for PTSD symptoms, depression symptom level was a significant predictor of psychotherapy attendance but not medication treatment. African American Veterans reported higher levels of religious coping than whites. Religious coping was associated with participation in religious counseling, but not secular mental health services

Self-Reported Pain in Male and Female Iraq/Afghanistan-Era Veterans: Associations with Psychiatric Symptoms and Functioning

Objective. To examine pain symptoms and co-occurring psychiatric and functional indices in male and female Iraq/Afghanistan-era veterans. Design. Self-reported data collection and interviews of Iraq/Afghanistan-era veterans who participated in a multisite study of postdeployment mental health. Setting. Veterans were enrolled at one of four participating VA sites. Subjects. Two thousand five hundred eighty-seven male and 662 female Iraq/Afghanistan-era veterans. Methods. Nonparametric Wilcoxon rank tests examined differences in pain scores between male and female veterans. Chi-square tests assessed differences between male and female veterans in the proportion of respondents endorsing moderate to high levels of pain vs no pain. Multilevel regression analyses evaluated the effect of pain on a variety of psychiatric and functional measures. Results. Compared with males, female veterans reported significantly higher mean levels of headache (P \u3c 0.0001), muscle soreness (P \u3c 0.008), and total pain (P \u3c 0.0001), and were more likely to report the highest levels of headache (P \u3c 0.0001) and muscle soreness (P \u3c 0.0039). The presence of pain symptoms in Iraq/Afghanistan-era veterans was positively associated with psychiatric comorbidity and negatively associated with psychosocial functioning. There were no observed gender differences in psychiatric and functional indices when levels of pain were equated. Conclusions. Although female Iraq/Afghanistan-era veterans reported higher levels of pain than male veterans overall, male and female veterans experienced similar levels of psychiatric and functional problems at equivalent levels of reported pain. These findings suggest that pain-associated psychological and functional impacts are comparable and consequential for both male and female veterans

Large epigenome-wide association study identifies multiple novel differentially methylated CpG sites associated with suicidal thoughts and behaviors in veterans

Introduction The U.S. suicide mortality rate has steadily increased during the past two decades, particularly among military veterans; however, the epigenetic basis of suicidal thoughts and behaviors (STB) remains largely unknown. Methods To address this issue, we conducted an epigenome-wide association study of DNA methylation (DNAm) of peripheral blood samples obtained from 2,712 U.S. military veterans. Results Three DNAm probes were significantly associated with suicide attempts, surpassing the multiple testing threshold (FDR q-value <0.05), including cg13301722 on chromosome 7, which lies between the genes SLC4A2 and CDK5; cg04724646 in PDE3A; and cg04999352 in RARRES3. cg13301722 was also found to be differentially methylated in the cerebral cortex of suicide decedents in a publicly-available dataset (p = 0.03). Trait enrichment analysis revealed that the CpG sites most strongly associated with STB in the present sample were also associated with smoking, alcohol consumption, maternal smoking, and maternal alcohol consumption, whereas pathway enrichment analysis revealed significant associations with circadian rhythm, adherens junction, insulin secretion, and RAP-1 signaling, each of which was recently associated with suicide attempts in a large, independent genome-wide association study of suicide attempts of veterans. Discussion Taken together, the present findings suggest that SLC4A2, CDK5, PDE3A, and RARRES3 may play a role in STB. CDK5, a member of the cyclin-dependent kinase family that is highly expressed in the brain and essential for learning and memory, appears to be a particularly promising candidate worthy of future study; however, additional work is still needed to replicate these finding in independent samples

Genomewide association studies of suicide attempts in US soldiers

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139960/1/ajmgb32594.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139960/2/ajmgb32594_am.pd

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci.

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations

Epigenomeâ wide association of PTSD from heterogeneous cohorts with a common multiâ site analysis pipeline

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138305/1/ajmgb32568.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138305/2/ajmgb32568_am.pd

Posttraumatic Stress Disorder Symptom Network Analysis in U.S. Military Veterans: Examining the Impact of Combat Exposure

Recent work inspired by graph theory has begun to conceptualize mental disorders as networks of interacting symptoms. Posttraumatic stress disorder (PTSD) symptom networks have been investigated in clinical samples meeting full diagnostic criteria, including military veterans, natural disaster survivors, civilian survivors of war, and child sexual abuse survivors. Despite reliable associations across reported networks, more work is needed to compare central symptoms across trauma types. Additionally, individuals without a diagnosis who still experience symptoms, also referred to as subthreshold cases, have not been explored with network analysis in veterans. A sample of 1,050 Iraq/Afghanistan-era U.S. military veterans (851 males, mean age = 36.3, SD = 9.53) meeting current full-criteria PTSD (n = 912) and subthreshold PTSD (n = 138) were assessed with the Structured Clinical Interview for DSM-IV Disorders (SCID). Combat Exposure Scale (CES) scores were used to group the sample meeting full-criteria into high (n = 639) and low (n = 273) combat exposure subgroups. Networks were estimated using regularized partial correlation models in the R-package qgraph, and robustness tests were performed with bootnet. Frequently co-occurring symptom pairs (strong network connections) emerged between two avoidance symptoms, hypervigilance and startle response, loss of interest and detachment, as well as, detachment and restricted affect. These associations replicate findings reported across PTSD trauma types. A symptom network analysis of PTSD in a veteran population found significantly greater overall connectivity in the full-criteria PTSD group as compared to the subthreshold PTSD group. Additionally, novel findings indicate that the association between intrusive thoughts and irritability is a feature of the symptom network of veterans with high levels of combat exposure. Mean node predictability is high for PTSD symptom networks, averaging 51.5% shared variance. With the tools described here and by others, researchers can help refine diagnostic criteria for PTSD, develop more accurate measures for assessing PTSD, and eventually inform therapies that target symptoms with strong network connections to interrupt interconnected symptom complexes and promote functional recovery