Cannabis use disorder and suicide attempts in Iraq/Afghanistan-era veterans

Genome-wide DNA methylation analysis of cannabis use disorder in a veteran cohort enriched for posttraumatic stress disorder

Cannabis use has been increasing over the past decade, not only in the general US population, but particularly among military veterans. With this rise in use has come a concomitant increase in cannabis use disorder (CUD) among veterans. Here, we performed an epigenome-wide association study for lifetime CUD in an Iraq/Afghanistan era veteran cohort enriched for posttraumatic stress disorder (PTSD) comprising 2,310 total subjects (1,109 non-Hispanic black and 1,201 non-Hispanic white). We also investigated CUD interactions with current PTSD status and examined potential indirect effects of DNA methylation (DNAm) on the relationship between CUD and psychiatric diagnoses. Four CpGs were associated with lifetime CUD, even after controlling for the effects of current smoking (AHRR cg05575921, LINC00299 cg23079012, VWA7 cg22112841, and FAM70A cg08760398). Importantly, cg05575921, a CpG strongly linked to smoking, remained associated with lifetime CUD even when restricting the analysis to veterans who reported never smoking cigarettes. Moreover, CUD interacted with current PTSD to affect cg05575921 and cg23079012 such that those with both CUD and PTSD displayed significantly lower DNAm compared to the other groups. Finally, we provide preliminary evidence that AHRR cg05575921 helps explain the association between CUD and any psychiatric diagnoses, specifically mood disorders.

Development of Mobile Contingency Management for Cannabis Use Reduction

Many interventions for cannabis use disorder (CUD) are associated with decreases in frequency and quantity of use but fail to increase overall rates of sustained abstinence. It is currently unknown whether reductions in use (in the absence of sustained abstinence) result in clinically significant improvements in functioning. The objective of this study was to refine a mobile contingency management approach to reduce cannabis use to ultimately evaluate whether reductions in frequency and quantity of cannabis are related to improvements in functional and mental health status. Three cohorts of participants (n = 18 total, n = 10 women) were enrolled and completed 2 weeks of ecological momentary assessment (EMA) during a baseline ad lib cannabis use period, followed by a 6-week reduction period. Participants completed EMA assessments multiple times per day and were prompted to provide videotaped saliva cannabis testing 2-3 times daily. Data from participants who were at least 80% adherent to all EMA prompts were analyzed (13 out of 18). During the ad lib phase, participants were using cannabis on 94% of the days and reported using a mean of 1.42 grams daily. The intervention was a mobile application that participants used to record cannabis use by saliva tests to bioverify abstinence and participants completed electronic diaries to report their grams used. During the 6-week intervention phase, participants reported reducing their use days to 47% of the days with a reported mean of .61 grams daily. In the last cohort, at least 50% of the heavy users were able to reduce their cannabis use by at least 50%. The effect of cannabis reduction (versus abstinence) is largely unknown. Observations suggest that it is possible to develop a mobile intervention to reduce cannabis use among heavy users, and this paradigm can be utilized in future work to evaluate whether reductions in cannabis use among heavy users will result in improvements in functional and mental health status.

Suicide Attempts in an Italian Population with Cannabis Use Disorders: Results of a Follow-Up Study

The relationship between cannabis use and suicidal behavior is complex, with no consensus in the literature. We used electronic health records of national health services to identify individuals who received a diagnosis of Cannabis Use Disorder in the Metropolitan area of Bologna from 2009 to 2019. In this cohort we identified accesses to Emergency Departments for suicide attempts from 2009 to 2019. The Crude Suicide Rate for 1,000 Person Years was 2.5, higher in females, in patients with Alcohol Use Disorders, with any psychiatric diagnosis, within one year from the first visit, and during the COVID-19 period. The risk was over 22 times higher than in the general population. Considering the high prevalence of cannabis use in the general population and the consequent risk of Cannabis Use Disorders, these data suggest the importance of a clinical evaluation for suicidal risk.

Perturbation of 3D nuclear architecture, epigenomic aging and dysregulation, and cannabinoid synaptopathy reconfigures conceptualization of cannabinoid pathophysiology: part 2-Metabolome, immunome, synaptome

The second part of this paper builds upon and expands the epigenomic-aging perspective presented in Part 1 to describe the metabolomic and immunomic bases of the epigenomic-aging changes and then considers in some detail the application of these insights to neurotoxicity, neuronal epigenotoxicity, and synaptopathy. Cannabinoids are well-known to have bidirectional immunomodulatory activities on numerous parts of the immune system. Immune perturbations are well-known to impact the aging process, the epigenome, and intermediate metabolism. Cannabinoids also impact metabolism via many pathways. Metabolism directly impacts immune, genetic, and epigenetic processes. Synaptic activity, synaptic pruning, and, thus, the sculpting of neural circuits are based upon metabolic, immune, and epigenomic networks at the synapse, around the synapse, and in the cell body. Many neuropsychiatric disorders including depression, anxiety, schizophrenia, bipolar affective disorder, and autistic spectrum disorder have been linked with cannabis. Therefore, it is important to consider these features and their complex interrelationships in reaching a comprehensive understanding of cannabinoid dependence. Together these findings indicate that cannabinoid perturbations of the immunome and metabolome are important to consider alongside the well-recognized genomic and epigenomic perturbations and it is important to understand their interdependence and interconnectedness in reaching a comprehensive appreciation of the true nature of cannabinoid pathophysiology. For these reasons, a comprehensive appreciation of cannabinoid pathophysiology necessitates a coordinated multiomics investigation of cannabinoid genome-epigenome-transcriptome-metabolome-immunome, chromatin conformation, and 3D nuclear architecture which therefore form the proper mechanistic underpinning for major new and concerning epidemiological findings relating to cannabis exposure.

Epidemiology and Clinical-Demographic Characteristics of Suicide Attempts in Alcohol Use Disorders in an Italian Population

Suicide is a leading cause of morbidity worldwide. Among the known risk factors, alcohol use disorders (AUDs) are particularly relevant, but data on the epidemiology and characteristics of suicide attempts (SA) in this group are lacking. We used electronic health records of national health services to identify individuals who received a diagnosis of AUD in the Metropolitan area of Bologna from 2009 to 2019. In this cohort we identified accesses to Emergency Departments for SA from 2009 to 2020. The Crude Suicide Rate (CSR) for 1,000 Person Years was 2.93, higher than the general population. The CSR was higher in females, within one year from receiving the diagnosis of AUD, in patients with psychiatric comorbidities, concomitant abuse of cannabis or benzodiazepines. As for Covid-19 pandemic, the risk ratio of SA was significantly higher in 2020 compared to 2019 in females. Our results are relevant to identify clinical risk factors for SA in patients with AUDs, which are strongly associated with suicide risk but with scarce data in the previous literature and paucity of evidence-based therapeutic interventions.

Suicidal behavior across a broad range of psychiatric disorders

Suicide is a leading cause of death worldwide. In 2020, some 12.2 million Americans seriously contemplated suicide, 3.2 million planned suicide attempts, and 1.2 million attempted suicide. Traditionally, the approach to treating suicidal behavior (SB) has been to treat the "underlying" psychiatric disorder. However, the number of diagnoses associated with SB is considerable. We could find no studies describing the range of disorders reported to be comorbid with SB. This narrative review summarizes literature documenting the occurrence of SB across the lifespan and the full range of psychiatric diagnoses, not only BPD and those that comprise MDE, It also describes the relevance of these observations to clinical practice, research, and nosology. The literature searches contained the terms "suicid*" and each individual psychiatric diagnosis and identified 587 studies. We did not include case reports, case series, studies only addressing suicidal ideation or non-suicidal self-injury (NSSI), studies on self-harm, not distinguishing between SB and NSSI and studies that did not include any individuals that met criteria for a specific DSM-5 diagnosis (n = 366). We found that SB (suicide and/or suicide attempt) was reported to be associated with 72 out of 145 diagnoses, although data quality varied. Thus, SB is not exclusively germane to Major Depressive Episode (MDE) and Borderline Personality Disorder (BPD), the only conditions for which it is a diagnostic criterion. That SB co-occurs with so many diagnoses reinforces the need to assess current and past SB regardless of diagnosis, and supports the addition of charting codes to the DSM-5 to indicate current or past SB. It also comports with new data that specific genes are associated with SB independent of psychiatric diagnoses, and suggests that SB should be managed with specific suicide prevention interventions in addition to treatments indicated for co-occurring diagnoses. SB diagnostic codes would help researchers and clinicians document and measure SB's trajectory and response to treatment over time, and, ultimately, help develop secondary and tertiary prevention strategies. As a separate diagnosis, SB would preclude situations in which a potentially life-threatening behavior is not accounted for by a diagnosis, a problem that is particularly salient when no mental disorder is present, as is sometimes the case.

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.

Clinical Epigenomic Explanation of the Epidemiology of Cannabinoid Genotoxicity Manifesting as Transgenerational Teratogenesis, Cancerogenesis and Aging Acceleration

As global interest in the therapeutic potential of cannabis and its' derivatives for the management of selected diseases increases, it is increasingly imperative that the toxic profile of cannabinoids be thoroughly understood in order to correctly assess the balance between the therapeutic risks and benefits. Modern studies across a number of jurisdictions, including Canada, Australia, the US and Europe have confirmed that some of the most worrying and severe historical reports of both congenital anomalies and cancer induction following cannabis exposure actually underestimate the multisystem thousand megabase-scale transgenerational genetic damage. These findings from teratogenic and carcinogenic literature are supported by recent data showing the accelerated patterns of chronic disease and the advanced DNA methylation epigenomic clock age in cannabis exposed patients. Together, the increased multisystem carcinogenesis, teratogenesis and accelerated aging point strongly to cannabinoid-related genotoxicity being much more clinically significant than it is widely supposed and, thus, of very considerable public health and multigenerational impact. Recently reported longitudinal epigenome-wide association studies elegantly explain many of these observed effects with considerable methodological sophistication, including multiple pathways for the inhibition of the normal chromosomal segregation and DNA repair, the inhibition of the basic epigenetic machinery for DNA methylation and the demethylation and telomerase acceleration of the epigenomic promoter hypermethylation characterizing aging. For cancer, 810 hits were also noted. The types of malignancy which were observed have all been documented epidemiologically. Detailed epigenomic explications of the brain, heart, face, uronephrological, gastrointestinal and limb development were provided, which amply explained the observed teratological patterns, including the inhibition of the key morphogenic gradients. Hence, these major epigenomic insights constituted a powerful new series of arguments which advanced both our understanding of the downstream sequalae of multisystem multigenerational cannabinoid genotoxicity and also, since mechanisms are key to the causal argument, inveighed strongly in favor of the causal nature of the relationship. In this introductory conceptual overview, we present the various aspects of this novel synthetic paradigmatic framework. Such concepts suggest and, indeed, indicate numerous fields for further investigation and basic science research to advance the exploration of many important issues in biology, clinical medicine and population health. Given this, it is imperative we correctly appraise the risk-benefit ratio for each potential cannabis application, considering the potency, severity of disease, stage of human development and duration of use.

The influence of cannabis use disorder on post-traumatic stress disorder symptoms, depression symptoms, and non-suicidal self-injury among college students

Objective: The interrelationships between cannabis use disorder (CUD), post-traumatic stress disorder (PTSD) and depressive symptoms, and non-suicidal self-injury (NSSI) were examined. Participants: Undergraduates (N = 363) who reported using cannabis within the past six months were recruited. Method: Mediation analyses was conducted to examine if CUD symptoms were indirectly associated with greater risk for engagement in current NSSI through more severe PTSD and depression symptoms. A factor comprised of PTSD-depression symptoms was created given PTSD and depression symptoms were highly correlated. Results: Greater CUD symptom severity indirectly increased risk for current NSSI via more severe PTSD-depression symptoms, after accounting for gender and alcohol use disorder symptoms. Conclusion: The current study provides preliminary evidence for the negative consequences of CUD on college students' mental health symptoms and engagement in NSSI, and future longitudinal research is needed to examine the dynamic relationships between CUD, PTSD-depression symptoms, and NSSI over time.

Cannabis use and suicide risk among Gulf War veterans

Cannabis use has been indicated as a risk factor for suicide in veterans. This study of Gulf War veterans tested the relationship between self-report past year cannabis use and (a) past year suicidal ideation and (b) risk for suicidal behavior. Data were from a national sample (N = 1126) of Gulf War veterans. Logistic regression models indicated cannabis use was associated with past year suicidal ideation and elevated risk for suicidal behavior, independent of key covariates. In corroboration with research on other military populations, this study indicates a potentially concerning association between cannabis use and suicide risk in Gulf War veterans.

Demographic risk factors for co-occurring suicidality and cannabis use disorders: Findings from a nationally representative United States sample

OBJECTIVE

Burgeoning research suggests a link between suicidality (i.e., ideation, attempts) and cannabis use; however, little is known about which demographic groups are at increased risk of co-occurring suicidality and cannabis use disorders (CUD). This study tested differences in suicidality, CUD, and their co-occurrence by gender, age, race/ethnicity, and sexual orientation in a nationally representative U.S.

SAMPLE

METHOD

Five years (2015-2019) of National Survey of Drug Use and Heath surveys were combined. Multinomial logistic regressions tested demographic differences in odds of suicidality only, CUD only, and co-occurring CUD and suicidality, relative to neither suicidality nor CUD. Covariates included survey year, major depressive episode, and other substance use disorders.

RESULTS

Men had higher odds of co-occurring suicidal ideation and CUD than women (AOR = 2.06). All older age groups reported lower odds of co-occurring suicidal ideation and CUD and co-occurring suicide attempts and CUD than emerging adults (AORs = 0.06-0.39). Black/African American (AOR = 1.42) and Native (AOR = 2.16) adults reported higher odds of co-occurring suicidal ideation and CUD than White adults. Black/African American (AOR = 4.05) and Hispanic/Latinx (AOR = 2.49) adults reported higher odds of co-occurring CUD and suicide attempts than White adults. Gay/lesbian (AOR = 2.04) and bisexual (AOR = 3.16) adults reported higher odds of co-occurring suicidal ideation and CUD than heterosexual adults.

CONCLUSIONS

Men, emerging adults, Black/African American, Native, and sexual minority groups had elevated risk of co-occurring suicidal ideation and CUD. Emerging adults, Black/African American, and Hispanic/Latinx groups had elevated risk of co-occurring suicide attempts and CUD.

Effect of cannabis use on PTSD treatment outcomes in veterans

Introduction

Researchers have found anandamide (an endocannabinoid) and cannabinoid type 1 receptor activation encourages extinction of aversive memories. Some theorize cannabinoids such as those in cannabis may provide a new treatment approach for PTSD, while others suggest it may worsen symptomology. The objective of the current study was to determine if cannabis use impacts the success of evidence-based intensive outpatient PTSD treatment in a veteran population.

Methods

A list of veterans enrolled in the Battle Creek Veterans' Affairs Medical Center outpatient PTSD Clinical Team Clinic between October 1st, 2008 and October 1st, 2016 was obtained, and a random sample was identified. Study participants were veterans aged 18 to 85 years, with at least 2 PTSD Checklist scores, and a diagnosis of PTSD. Data collected included mental health medications, type and number of evidence-based psychotherapy used, and presence of co-occurring behavioral health diagnoses. The cannabis use group was compared to the no-cannabis-use group, and differences in variables pertaining to the relative number of treatment successes and failures was evaluated for statistical and clinical significance.

Results

The majority of patients were white (87.1%) and male (95%). The success rate was similar between the cannabis and no-cannabis-use groups (51.9% and 51.4%, respectively).

Discussion

The current study did not show that a predominantly white male veteran sample diagnosed with PTSD differed in intensive PTSD treatment success or failure based on cannabis use.

Cannabis use among military veterans: A great deal to gain or lose?

Policy changes have resulted in dramatic increases in access to cannabis for medical purposes. Veterans are disproportionately affected by conditions for which medical cannabis is often pursued, making an evidence-based perspective on risks versus benefits of high priority. The current review sought to examine the state of the evidence on the correlates and consequences of cannabis use among veterans. Using a comprehensive search strategy, 501 articles were identified and 86 studies met criteria for inclusion. The literature was predominated by cross-sectional studies (67%) of male veterans (71.4%-100% male) from the United States (93.0%). Three overarching themes emerged, comprising cannabis associations with other substance use, mental health, and physical health outcomes. The balance of the evidence associated cannabis use with negative health outcomes, with consistent positive associations with other substance use, psychiatric disorders, and self-harm/suicidality. Few studies examined the therapeutic effects of cannabis, thus limiting the potential to evaluate evidence of efficacy. Priority areas for future research are studies using designs that can examine the directionality of links between cannabis and health in veterans more conclusively, and studies directly examining therapeutic efficacy of cannabis-based therapies in veterans. Methodologically rigorous design will be essential to inform clinical recommendations and practices guidelines in an era of burgeoning access to cannabis.

Comparative associations of problematic alcohol and cannabis use with suicidal behavior in U.S. military veterans: A population-based study

Alcohol use disorder (AUD) and cannabis use disorder (CUD) are each associated with increased suicidal behavior, but it is unclear how their comorbidity relates to suicide risk. Understanding these associations in U.S. military veterans is especially important, given their heightened risk for suicide, high prevalence of AUD, and increasing access to cannabis. We compared associations of probable AUD, CUD, and AUD/CUD with suicide ideation, plan(s), and attempt(s) in a nationally representative sample of 4,069 veterans surveyed in 2019-2020 as part of the National Health and Resilience in Veterans Study. Among veterans who screened positive for current AUD, 8.7% also screened positive for current CUD. Among veterans who screened positive for current CUD, 33.3% screened positive for current AUD. Current and lifetime positive screens for AUD, CUD, and AUD/CUD were each strongly and independently associated with past-year suicide ideation and lifetime suicide ideation, plan(s), and attempt(s) [odds ratios (ORs) = 1.6-8.7]. Relative to veterans who screened positive for AUD only, veterans who screened positive for AUD/CUD and CUD only had higher odds of past-year suicide ideation (AUD/CUD: OR = 3.3; CUD only: OR = 2.4), lifetime suicide ideation (AUD/CUD: OR = 1.9; CUD only: OR = 2.6) and lifetime suicide plan(s) (AUD/CUD: OR = 1.7; CUD only: OR = 6.1). Collectively, findings suggest that screening positive for CUD might be an especially strong indicator of suicide ideation and planning in veterans with and without AUD, independent of sociodemographic, military, trauma, and other psychiatric factors. These findings underscore the importance of routine screening for CUD in suicide prevention efforts, especially as cannabis becomes more widely available.

Burden of cannabis use and disorder in the U.S. veteran population: Psychiatric comorbidity, suicidality, and service utilization

BACKGROUND

Cannabis use is associated with psychiatric illness and suicidality, which are prevalent among U.S. military veterans. However, the psychiatric burden of cannabis use and cannabis use disorder (CUD) among veterans is unclear. Using data from a nationally representative sample of veterans, we evaluated associations of lifetime cannabis use and CUD with psychiatric problems, suicidality, and treatment utilization.

METHODS

Participants were 3,157 veterans aged 21 to 96 years from the National Health and Resilience in Veterans Study (NHRVS). Cannabis use and CUD were assessed using the Mini International Neuropsychiatric Interview. Psychiatric morbidities, suicidal ideation and attempts, and treatment utilization were assessed and compared between three cannabis groups: [1] no lifetime cannabis use (never-use); [2] lifetime cannabis use but never met criteria for CUD (non-CUD cannabis use); [3] lifetime CUD (CUD).

RESULTS

Relative to the never-use group, veterans who used cannabis had elevated odds of current and lifetime posttraumatic stress disorder (PTSD), mood, anxiety, and substance use disorders, current suicidal ideation, lifetime suicide attempts, and current and lifetime mental health treatment utilization [odds ratios (ORs)=1.5-8.3]. Veterans with CUD had higher odds of current and lifetime PTSD, mood, and anxiety disorders, lifetime nicotine and alcohol dependence, and current suicidal ideation, relative to veterans who used cannabis but never met criteria for CUD (ORs=1.6-2.7).

LIMITATIONS

The cross-sectional design of this study precludes causal inference.

CONCLUSIONS

Cannabis use and CUD are associated with substantial psychiatric and suicide-related burden among veterans, highlighting the need for screening, education, and treatment to mitigate potential cannabis-related harm.

Co-occurrence across time and space of drug- and cannabinoid- exposure and adverse mental health outcomes in the National Survey of Drug Use and Health: combined geotemporospatial and causal inference analysis

BACKGROUND

Whilst many studies have linked increased drug and cannabis exposure to adverse mental health (MH) outcomes their effects on whole populations and geotemporospatial relationships are not well understood.

METHODS

Ecological cohort study of National Survey of Drug Use and Health (NSDUH) geographically-linked substate-shapefiles 2010-2012 and 2014-2016 supplemented by five-year US American Community Survey. Drugs: cigarettes, alcohol abuse, last-month cannabis use and last-year cocaine use. MH: any mental illness, major depressive illness, serious mental illness and suicidal thinking.

DATA ANALYSIS

two-stage, geotemporospatial, robust generalized linear regression and causal inference methods in R.

RESULTS

410,138 NSDUH respondents. Average response rate 76.7%. When drug and sociodemographic variables were combined in geospatial models significant terms including tobacco, alcohol, cannabis exposure and various ethnicities remained in final models for all four major mental health outcomes. Interactive terms including cannabis were related to any mental illness (β-estimate = 1.97 (95%C.I. 1.56-2.37), P <  2.2 × 10^- 16), major depressive episode (β-estimate = 2.03 (1.54-2.52), P = 3.6 × 10^- 16), serious mental illness (SMI, β-estimate = 2.04 (1.48-2.60), P = 1.0 × 10^- 12), suicidal ideation (β-estimate = 1.99 (1.52-2.47), P <  2.2 × 10^- 16) and in each case cannabis alone was significantly associated (from β-estimate = - 3.43 (- 4.46 - -2.42), P = 3.4 × 10^- 11) with adverse MH outcomes on complex interactive regression surfaces. Geospatial modelling showed a monotonic upward trajectory of SMI which doubled (3.62 to 7.06%) as cannabis use increased. Extrapolated to whole populations cannabis decriminalization (4.26%, (4.18, 4.34%)), Prevalence Ratio (PR) = 1.035(1.034-1.036), attributable fraction in the exposed (AFE) = 3.28%(3.18-3.37%), P < 10^- 300) and legalization (4.75% (4.65, 4.84%), PR = 1.155 (1.153-1.158), AFE = 12.91% (12.72-13.10%), P < 10^- 300) were associated with increased SMI vs. illegal status (4.26, (4.18-4.33%)).

CONCLUSIONS

Data show all four indices of mental ill-health track cannabis exposure across space and time and are robust to multivariable adjustment for ethnicity, socioeconomics and other drug use. MH deteriorated with cannabis legalization. Cannabis use-MH data are consistent with causal relationships in the forward direction and include dose-response and temporal-sequential relationships. Together with similar international reports and numerous mechanistic studies preventative action to reduce cannabis use is indicated.

Posttraumatic Stress Disorder, Suicidal Ideation, and Suicidal Self-Directed Violence Among U.S. Military Personnel and Veterans: A Systematic Review of the Literature From 2010 to 2018

Rates of suicide and posttraumatic stress disorder remain high among United States military personnel and veterans. Building upon prior work, we conducted a systematic review of research published from 2010 to 2018 regarding: (1) the prevalence of suicidal ideation, suicide attempt, and suicide among United States military personnel and veterans diagnosed with posttraumatic stress disorder; (2) whether posttraumatic stress disorder was associated with suicidal ideation, suicide attempt, and suicide among United States military personnel and veterans. 2,106 titles and abstracts were screened, with 48 articles included. Overall risk of bias was generally high for studies on suicidal ideation or suicide attempt and low for studies on suicide. Across studies, rates of suicidal ideation, suicide attempt, and suicide widely varied based on study methodology and assessment approaches. Findings regarding the association between posttraumatic stress disorder diagnosis with suicidal ideation and suicide were generally mixed, and some studies reported that posttraumatic stress disorder was associated with lower risk for suicide. In contrast, most studies reported significant associations between posttraumatic stress disorder and suicide attempt. These findings suggest complex associations between posttraumatic stress disorder and suicidal ideation, suicide attempt, and suicide, which are likely influenced by other factors (e.g., psychiatric comorbidity). In addition, most samples were comprised of veterans, rather than military personnel. Further research is warranted to elucidate associations between posttraumatic stress disorder and suicidal ideation, suicide attempt, and suicide, including identification of moderators and mediators of this relationship. Addressing this among United States military personnel, by gender, and in relation to different trauma types is also necessary.

Cannabis Use as a Risk Factor for Depression, Anxiety, and Suicidality: Epidemiological Associations and Implications for Nurses

Psychiatric disorders and substance use disorders commonly co-occur and are major public health concerns given the morbidity and mortality associated with them. Globally, cannabis is among the most commonly used drugs, and cannabis use frequently begins in adolescence or emerging adulthood, both important periods of development and periods in which psychiatric symptoms and disorders frequently emerge. Thus, the relationships between cannabis use and mental illnesses are essential for nurses and other healthcare professionals and researchers to explore and understand. This literature review examines the relationships between cannabis use and depression, anxiety, and suicide. It includes a primer on the neurobiology of cannabis effects; an overview on the epidemiological evidence on the associations between cannabis use and depression, anxiety, and suicide; and a discussion of implications for nurses, particularly important given changes in the medical and recreational cannabis legislation in North America. Overall, this review found consistent evidence showing a cross-sectional association between recreational cannabis use and depression, anxiety, and suicide, despite some limitations and conflicts in the literature. In addition, most evidence from longitudinal or case control studies suggested cannabis use preceded the development of depressive symptoms and suicidal behaviors, although the quality of this evidence was mixed. Implications for future research and nursing practice are discussed.

Endogenous cannabinoid levels and suicidality in combat veterans

Combat veterans are at elevated suicide risk. The goal of this study was to test the hypothesis that combat veterans who have made a suicide attempt post-deployment can be distinguished from combat veterans who have never made a suicide attempt based on differences in psychological and biological variables. For the latter, we focused on endogenous cannabinoids, neuroendocrine markers that are associated with stress. Demographic and clinical parameters of suicide attempters and non-attempters were assessed. Blood samples were assayed for anandamide (AEA), 2-arachidonoylglycerol (2-AG), and cortisol. Suicide attempters had higher Scale for Suicidal Ideation (SSI) scores in comparison to non-attempters. Controlling for gender, 2-AG levels were higher among suicide attempters in comparison to non-attempters. Cortisol levels positively correlated with 2-AG levels and negatively correlated with SSI scores among non-attempters but not among attempters. AEA levels negatively correlated with SSI scores among attempters but not among non-attempters. Our results indicate that there are psychological and biological differences between combat veterans with or without a history of suicidal attempt. Our findings also suggest that clinically observed differences between the groups may have a neurobiological basis.

The Influence of Substance Use on Engagement in Non-Suicidal Self-Injury (NSI) in Adults

Background: Adults engaging in non-suicidal self-injurious (NSI) behaviors often report the use of substances; however, little research explores the relationship between substance abuse and NSI. Thus, this study examined the influence of substance use on patterns of NSI among adults. Objectives: This study seeks to answer the following questions: (a) Is AOD use predictive of more frequent self-injurious behaviors? and (b) Does the use of AODs predict injuring more severely than expected? Methods: An observational cross-sectional design was used to examine the relationship between drug use and NSI behaviors. Participants were recruited through Amazon Mechanical Turk (Mturk). Results: Results indicated opiates, barbiturates and sedatives all had a small but statistically significant influence on the frequency of NSI behaviors, while marijuana, PCP and anti-anxiety medications had a small but statistically significant relationship to severity. Conclusion/Importance: This study indicates that future research should take into account substance use patterns in adults engaging in NSI behaviors.

Interactive effects of PTSD and substance use on suicidal ideation and behavior in military personnel: Increased risk from marijuana use

BACKGROUND

The current study examines the unique and interactive effects of posttraumatic stress disorder (PTSD) symptoms and days using alcohol, opioids, and marijuana on PTSD symptoms, suicidal ideation, and suicidal behavior up to 1 year, later in a high-risk sample of military personnel not active in mental health treatment.

METHODS

Current and former military personnel at risk for suicide (N = 545; M age = 31.91 years, standard deviation = 7.27; 88.2% male) completed self-report measures of PTSD symptoms, past 30 days heavy alcohol use, opioid use, marijuana use, and current suicidal ideation via telephone at baseline and 1, 3, 6, and 12 months later. PTSD symptoms and the substance use variables (and relevant covariates) were entered as predictors of changes in PTSD symptoms, the likelihood of suicidal ideation, suicidal ideation severity, and the likelihood of suicidal behavior during the 11-month follow-up period.

RESULTS

PTSD symptoms predicted PTSD symptoms 1 month later. PTSD symptoms and marijuana use predicted the likelihood of suicidal ideation 1 month later and suicidal behavior during the 11-month follow-up period. The interaction between PTSD symptoms and marijuana use significantly predicted increased PTSD symptoms over time and suicidal behavior. At high, but not low levels of PTSD symptoms, more days using marijuana predicted increased PTSD symptoms over time and the likelihood of suicidal behavior.

CONCLUSIONS

Results suggest marijuana, especially for military personnel experiencing elevated PTSD symptoms may negatively impact suicidal thoughts and behavior. These results are relevant to suggestions that medical marijuana could be used in treating or augmenting treatment for PTSD.

Cannabis Use Disorder and Post-Deployment Suicide Attempts in Iraq/Afghanistan-Era Veterans

The objective of the present study was to use retrospective data to test the hypothesis that cannabis dependence would be associated with an increased rate of post-deployment suicide attempts. Participants included 319 veterans who had deployed to either Iraq or Afghanistan. Study procedures involved completion of a structured clinical interview and a battery of self-report questionnaires. As expected, lifetime cannabis dependence was significantly associated with post-deployment suicide attempts, AOR = 7.963, p = .014, even after controlling for the effects of pre-deployment suicide attempts, posttraumatic stress disorder, depression, pain, non-cannabis substance use disorder, and gender. Although preliminary, our findings provide the first evidence to date that heavy cannabis use may be a unique risk factor for post-deployment suicide attempts among veterans.