Correction to: Are personnel with a past history of mental disorders disproportionately vulnerable to the effects of deployment-related trauma? A cross-sectional study of Canadian military personnel.

Following publication of the original article [1], we have been notified that the copyright holder needs to be changed from ©The Author(s) to ©Crown.

Are personnel with a past history of mental disorders disproportionately vulnerable to the effects of deployment-related trauma? A cross-sectional study of Canadian military personnel.

BACKGROUND: Past mental disorders predict future disorders, both in the presence and absence of trauma exposure. However, it is not clear whether those with past mental disorders are disproportionately vulnerable to the negative effects of a given level of trauma. METHODS: The data source was the 2013 Canadian Forces Mental Health Survey (CFMHS), of which 1820 respondents had deployed only once in their military careers-all in support of the mission in Afghanistan. The primary outcomes were past 12-month depression and past 12-month PTSD. Multivariate logistic regression was performed for each outcome variable, looking primarily for differences in the marginal effect of deployment-related trauma in those with and without a pre-deployment history of each disorder. RESULTS: A history of each pre-deployment disorder did indeed interact with deployment-related trauma with respect to the corresponding past 12-month disorder. In addition, pre-deployment history of depression and of PTSD interacted with each other, though only for the outcome of past 12-month PTSD. The average marginal effect of deployment-related trauma on past 12-month PTSD was highest in those with a pre-deployment history of depression in the absence of a pre-deployment history of PTSD. This group was twice as vulnerable to post-deployment PTSD relative to those without a pre-deployment history of both disorders and four times as vulnerable to post-deployment PTSD relative to those with a pre-deployment history of both disorders. No significant differences were seen in the marginal effects of trauma on past 12-month depression in the presence or absence of a pre-deployment history of that disorder. CONCLUSION: There is modest differential vulnerability to past 12-month PTSD as a function of deployment-related trauma in those who had a pre-deployment history of PTSD or depression when compared to those who did and did not have a pre-deployment history of one or both disorders.

Mental Health Service Utilization in Depressed Canadian Armed Forces Personnel.

BACKGROUND: Major depression is prevalent, impactful, and treatable in military populations, but not all depressed personnel seek professional care in a given year. Care-seeking patterns (including the use of primary vs. specialty care) and factors associated with the likelihood of mental health service utilization in depressed military personnel are poorly understood. METHODS: Our sample included 520 Regular Force respondents to the 2013 Canadian Forces Mental Health Survey. All study participants had past-year major depression. Subjects reported whether they had spoken about their mental health with at least one health professional in the past 12 months. We used multivariate Poisson regression to explore factors associated with past-year mental health service use. RESULTS: Three-quarters of Canadian military personnel with past-year depression had sought mental health care in the previous 12 months. Among care-seeking personnel, 70% had seen a psychologist or psychiatrist, while 5% had exclusively received care from a primary care physician. Belief in the effectiveness of mental health care was the factor most strongly associated with care seeking. Female gender, functional impairments, and psychiatric comorbidities were also associated with care seeking. Surprisingly, stigma perceptions had no independent association with care seeking. CONCLUSIONS: The proportion of depressed Canadian Armed Forces personnel who seek professional care and who access specialty mental health care is higher than in most other populations. However, an important minority of patients are not accessing health services. Efforts to further increase mental health service utilization in the Canadian military should continue to target beliefs about the effectiveness of mental health care.

Comorbidity Patterns of Psychiatric Conditions in Canadian Armed Forces Personnel.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is often accompanied by other mental health conditions, including major depressive disorder (MDD), substance misuse disorders, and anxiety disorders. The objective of the current study is to delineate classes of comorbidity and investigate predictors of comorbidity classes amongst a sample of Canadian Armed Forces (CAF) Regular Force personnel. METHODS: Latent class analyses (LCAs) were applied to cross-sectional data obtained between April and August 2013 from a nationally representative random sample of 6700 CAF Regular Force personnel who deployed to the mission in Afghanistan. RESULTS: MDD was the most common diagnosis (8.0%), followed by PTSD (5.3%) and generalized anxiety disorder (4.7%). Of those with a mental health condition, LCA revealed 3 classes of comorbidity: a highly comorbid class (8.3%), a depressed-only class (4.6%), and an alcohol use-only class (3.1%). Multinomial logit regression showed that women (adjusted relative risk ratio [ARRR] = 2.77; 95% CI, 2.13 to 3.60; P < 0.01) and personnel reporting higher trauma exposure (ARRR = 4.18; 95% CI, 3.13 to 5.57; P < 0.01) were at increased risk of membership in the comorbid class compared to those without a mental health condition. When compared to those with no mental health condition, experiencing childhood abuse increased the risk of being in any comorbidity class. CONCLUSIONS: Results provide further evidence to support screening for and treatment of comorbid mental health conditions. The role of sex, childhood abuse, and combat deployment in determining class membership may also prove valuable for clinicians treating military-related mental health conditions.

Contribution of traumatic deployment experiences to the burden of mental health problems in Canadian Armed Forces personnel: exploration of population attributable fractions.

PURPOSE: Mental health problems are prevalent after combat; they are also common in its absence. Estimates of deployment-attributability vary. This paper quantifies the contribution of different subtypes of occupational trauma to post-deployment mental health problems. METHODS: Participants were a cohort of 16,193 Canadian personnel undergoing post-deployment mental health screening after return from the mission in Afghanistan. The screening questionnaire assessed post-traumatic stress disorder, depression, panic disorder, generalized anxiety disorder, and exposure to 30 potentially traumatic deployment experiences. Logistic regression estimated adjusted population attributable fractions (PAFs) for deployment-related trauma, which was treated as count variables divided into several subtypes of experiences based on earlier factor analytic work. RESULTS: The overall PAF for overall deployment-related trauma exposure was 57.5% (95% confidence interval 44.1, 67.7) for the aggregate outcome of any of the four assessed problems. Substantial PAFs were seen even at lower levels of exposure. Among subtypes of trauma, exposure to a dangerous environment (e.g., receiving small arms fire) and to the dead and injured (e.g., handling or uncovering human remains) had the largest PAFs. Active combat (e.g., calling in fire on the enemy) did not have a significant PAF. CONCLUSIONS: Military deployments involving exposure to a dangerous environment or to the dead or injured will have substantial impacts on mental health in military personnel and others exposed to similar occupational trauma. Potential explanations for divergent findings in the literature on the extent to which deployment-related trauma contributes to the burden of mental disorders are discussed.

Validation of a brief measure of combat exposure among Canadian Armed Forces personnel.

BACKGROUND: Exposure to military combat is associated with mental health problems, including posttraumatic stress disorder (PTSD) and depression. To understand the effects of combat on adverse health outcomes, the sound measurement of combat experiences is required; however, many scales used in past research are lengthy. A brief measure of combat exposure benefits militaries by reducing the burden on respondents as well as administration time in post-deployment settings and large population-based health surveys. DATA AND METHODS: The current study sought to describe the psychometric properties of a brief measure of combat exposure among Canadian Armed Forces (CAF) personnel. Data from post-deployment screening were used to compare the psychometric properties of an 8-item scale with the full scale that it was derived from. RESULTS: The 8-item measure did not fit a one-factor solution well and did not offer a statistically significant improvement in model fit over the full 30-item measure. However, its association with increased odds of a number of health outcomes indicates that it could be useful as a brief measure of combat exposure in settings where using the full scale is not feasible. DISCUSSION: Brief measures of combat exposure are valuable for assessing events experienced during deployment among military personnel. Although the 8-item Combat Exposure Scale assessed in the current study represents a potentially useful measure for CAF personnel, further research is necessary to improve its fit.

Mental Disorder, Psychological Distress, and Functional Status in Canadian Military Personnel.

OBJECTIVE: We examined the overlap between mood and anxiety disorders and psychological distress and their associations with functional status in Canadian Armed Forces (CAF) personnel. METHOD: Data on Regular Forces personnel ( N = 6700) were derived from the 2013 Canadian Forces Mental Health Survey, a nationally representative survey of the CAF personnel. Current psychological distress was assessed using the Kessler K10 scale. Past-month mood and anxiety disorders were assessed using the World Health Organization World Mental Health Composite Diagnostic Interview. RESULTS: The prevalence of psychological distress was the same as that of any past-month mood or anxiety disorder (7.1% for each). A total of 3.8% had both distress and past-month mood or anxiety disorder, 3.3% had past-month disorder without psychological distress, while another 3.3% had psychological distress in the absence of a past-month mood or anxiety disorder. After adjusting for age, sex, marital, education, income, language, element, rank, and alcohol use disorder, individuals with both psychological distress and past-month mood and anxiety disorders exhibited the highest levels of disability, days out of role, and work absenteeism relative to those with neither mental disorders nor psychological distress. Relative to individuals with both disorder and distress, those who endured distress in the absence of mental disorder exhibited lower, but meaningful, levels of disability compared with those with neither disorder nor distress. CONCLUSIONS: Disability is most severe among CAF personnel with both distress and past-month mood and anxiety disorders. Nevertheless, distress in the absence of disorder is prevalent and is associated with meaningful levels of disability.

Deployment-Related Traumatic Events and Suicidal Behaviours in a Nationally Representative Sample of Canadian Armed Forces Personnel.

OBJECTIVE: Worldwide, there has been substantial controversy with respect to whether military deployment is a risk factor for suicidal behaviour. The present study examined the relationship between lifetime exposure to deployment and deployment-related traumatic events (DRTEs) and past-year suicidal ideation (SI), suicidal plans (SP), and suicidal attempts (SA). METHOD: Data were analysed from the 2013 Canadian Forces Mental Health Survey (8161 respondents; response rate, 79.8%; aged 18-60 years). A total of 12 individual items assessed exposure to DRTEs (e.g., combat, witnessing human atrocities, feeling responsible for the death of Canadian or ally personnel, knowing someone who was injured or killed). We examined each individual DRTE type as well as the number of types of DRTEs in relation to suicidal behaviour. RESULTS: Lifetime deployment was not significantly associated with suicidal behaviour. In models adjusted for sociodemographic variables, most of the individual DRTE items and the DRTE count variable were significantly associated with suicidal behaviours (adjusted odds ratio ranged between 1.10 and 5.32). When further adjusting for child abuse exposure, these associations were minimally attenuated, and some became nonsignificant. In models adjusting for mental disorders and child abuse, most DRTEs and number of types of DRTEs became nonsignificant in relation to SI, SP, and SA. CONCLUSIONS: Active military personnel exposed to increasing number of DRTEs are at increased risk for SI, SP, and SA. However, most of the association between DRTEs and suicidal behaviour is accounted for by child abuse exposure and mental disorders.

Trends in suicidal behaviour and use of mental health services in Canadian military and civilian populations.

BACKGROUND: In the context of the Canadian mission in Afghanistan, substantial media attention has been placed on mental health and lack of access to treatment among Canadian Forces personnel. We compared trends in the prevalence of suicidal behaviour and the use of mental health services between Canadian military personnel and the general population from 2002 to 2012/13. METHODS: We obtained data for respondents aged 18-60 years who participated in 4 nationally representative surveys by Statistics Canada designed to permit comparisons between populations and trends over time. Surveys of the general population were conducted in 2002 (n = 25 643) and 2012 (n = 15 981); those of military personnel were conducted in 2002 (n = 5153) and 2013 (n = 6700). We assessed the lifetime and past-year prevalence of suicidal ideation, plans and attempts, as well as use of mental health services. RESULTS: In 2012/13, but not in 2002, military personnel had significantly higher odds of both lifetime and past-year suicidal ideation than the civilian population (lifetime: adjusted odds ratio [OR] 1.32, 95% confidence interval [CI] 1.17-1.50; past year: adjusted OR 1.34, 95% CI 1.09-1.66). The same was true for suicidal plans (lifetime: adjusted OR 1.64, 95% CI 1.35-1.99; past year: adjusted OR 1.66, 95% CI 1.18-2.33). Among respondents who reported past-year suicidal ideation, those in the military had a significantly higher past-year utilization rate of mental health services than those in the civilian population in both 2002 (adjusted OR 2.02, 95% CI 1.31-3.13) and 2012/13 (adjusted OR 3.14, 95% CI 1.86-5.28). INTERPRETATION: Canadian Forces personnel had a higher prevalence of suicidal ideation and plans in 2012/13 and a higher use of mental health services in 2002 and 2012/13 than the civilian population.

Military Occupational Outcomes in Canadian Armed Forces Personnel with and without Deployment-Related Mental Disorders.

OBJECTIVE: Mental disorders are common in military organizations, and these frequently lead to functional impairments that can interfere with duties and lead to costly attrition. In Canada, the military mental health system has received heavy investment to improve occupational outcomes. We investigated military occupational outcomes of diagnosed mental disorders in a cohort of 30,513 personnel who deployed on the Afghanistan mission. METHODS: Cohort members were military personnel who deployed on the Afghanistan mission from 2001 to 2008. Mental disorder diagnoses and their attribution to the Afghanistan mission were ascertained via medical records in a stratified random sample (n = 2014). Career-limiting medical conditions (that is, condition-associated restrictions that reliably lead to medically related attrition) were determined using administrative data. Outcomes were assessed from first Afghanistan-related deployment return. RESULTS: At 5 years of follow-up, the Kaplan-Meier estimated cumulative fraction with career-limiting medical conditions was 40.9% (95% confidence interval [CI] 35.5 to 46.4) among individuals with Afghanistan service-related mental disorders (ARMD), 23.6% (CI 15.5 to 31.8) with other mental disorders, and 11.1% (CI 8.9 to 13.3) without mental disorders. The adjusted Cox regression hazard ratios for career-limiting medical condition risk were 4.89 (CI 3.85 to 6.23) among individuals with ARMD and 2.31 (CI 1.48 to 3.60) with other mental disorders, relative to those without mental disorders. CONCLUSIONS: Notwithstanding the Canadian military's mental health system investments, mental disorders (particularly ARMD) still led to a high risk of adverse military occupational outcomes. Such investments have intrinsic value but may not translate into reduced medically related attrition without improvements in prevention and treatment effectiveness.

Contribution of the Mission in Afghanistan to the Burden of Past-Year Mental Disorders in Canadian Armed Forces Personnel, 2013.

OBJECTIVE: The purpose of this study was to estimate the contribution of the mission in Afghanistan to the burden of mental health problems in the Canadian Armed Forces (CAF). METHODS: Data were obtained from the 2013 Canadian Forces Mental Health Survey, which assessed mental disorders using the World Health Organization's Composite International Diagnostic Interview. The sample consisted of 6696 Regular Force (RegF) personnel, 3384 of whom had deployed in support of the mission. We estimated the association of past-year mental health problems with Afghanistan deployment status, adjusting for covariates using logistic regression; population attributable fractions (PAFs) were also calculated. RESULTS: Indication of a past-year mental disorder was identified in 18.4% (95% confidence interval [CI], 17.0% to 19.7%) of Afghanistan deployers compared with 14.6% (95% CI, 13.3% to 15.8%) in others. Afghanistan-related deployments contributed to the burden of a past-year disorder (PAF = 8.7%; 95% CI, 3.0% to 14.2%), with the highest PAFs being seen for panic disorder (34.7%) and posttraumatic stress disorder (32.1%). The PAFs for individual alcohol use disorders and suicide ideation were not different from zero. Child abuse, however, had a much greater PAF for any past-year disorder (28.7%; 95% CI, 23.4% to 33.7%) than did the Afghanistan mission. CONCLUSIONS: The mission in Afghanistan contributed significantly to the burden of mental disorders in the CAF RegF in 2013. However, the much stronger contribution of child abuse highlights the need for strong military mental health systems, even in peacetime, and the need to target the full range of determinants of mental health in prevention and control efforts.

Perceived Need for and Perceived Sufficiency of Mental Health Care in the Canadian Armed Forces: Changes in the Past Decade and Comparisons to the General Population.

OBJECTIVES: Failure to perceive need for care (PNC) is the leading barrier to accessing mental health care. After accessing care, many individuals perceive that their needs were unmet or only partially met, an additional problem related to perceived sufficiency of care (PSC). The Canadian Armed Forces (CAF) invested heavily in workplace mental health in the past decade to improve PNC/PSC; yet, the impact of these investments remains unknown. To assess the impact of these investments, this study 1) captures changes in PNC/PSC over the past decade in the CAF and 2) compares current PNC/PSC between the CAF and civilians. METHODS: Data were drawn from the 2013 and 2002 CAF surveys and the 2012 civilian mental health survey (total N = ∼40 000), conducted by Statistics Canada using similar methodology. Exclusions were applied to the civilian sample to make them comparable to the military sample. Prevalence rates for No need, Need met, Need partially met, and Need unmet categories across service types (Information, Medication, Counselling and therapy, Any services) were calculated and compared between 1) the 2 CAF surveys and 2) the 2013 CAF and 2012 civilian surveys after sample matching. RESULTS: Reports of Any need and Need met were higher in the CAF in 2013 than in 2002 by approximately 6% to 8% and 2% to 8%, respectively, and higher in the CAF than in civilians by 3% to 10% and 2% to 8%, respectively. CONCLUSIONS: These results suggest that investments in workplace mental health, such as those implemented in the CAF, can lead to improvements in recognizing the need for care (PNC) and subsequently getting those needs met (PSC).

Prevalence Comparison of Past-year Mental Disorders and Suicidal Behaviours in the Canadian Armed Forces and the Canadian General Population.

OBJECTIVE: Military personnel in Canada and elsewhere have been found to have higher rates of certain mental disorders relative to their corresponding general populations. However, published Canadian data have only adjusted for age and sex differences between the populations. Additional differences in the sociodemographic composition, labour force characteristics, and childhood trauma exposure in the populations could be driving these prevalence differences. Our objective is to compare the prevalence of past-year mental disorders and suicidal behaviours in the Canadian Armed Forces Regular Force with the rates in a representative, matched sample of Canadians in the general population (CGP). METHODS: Data sources were the 2013 Canadian Forces Mental Health Survey and the 2012 Canadian Community Health Survey-Mental Health. CGP sample was restricted to match the age range, employment status, and history of chronic conditions of Regular Force personnel. An iterative proportional fitting method was used to approximate the marginal distribution of sociodemographic and childhood trauma variables in both samples. RESULTS: Relative to the matched CGP, Regular Force personnel had significantly higher rates of past-year major depressive episode, generalized anxiety disorder, and suicide ideation. However, lower rates of alcohol use disorder were seen in Regular Force personnel relative to the matched CGP sample. CONCLUSIONS: Factors other than differences in sociodemographic composition and history of childhood trauma account for the excess burden of mental disorders and suicidal behaviours in the Canadian Armed Forces. Explanations to explore in future research include occupational trauma, selection effects, and differences in the context of administration of the 2 surveys.

Disability and Mental Disorders in the Canadian Armed Forces.

OBJECTIVES: The initial goal was to validate the use of a self-report measure of disability in the Canadian Armed Forces (CAF). The main goal was to document the extent of disability in personnel with and without mental disorders. METHODS: Data were obtained from the 2013 Canadian Forces Mental Health Survey; the sample included 6700 Regular Forces personnel. Disability was measured with the 12-item version of the World Health Organization Disability Assessment Schedule (WHODAS-2); established cut points were used to demarcate severe, moderate, minimal, and no disability. The following recent (past-year) and remote (lifetime but not past-year) disorders were assessed with diagnostic interviews: posttraumatic stress disorder, major depressive episode, generalized anxiety disorder, panic disorder, and alcohol use disorder. RESULTS: The WHODAS-2 showed good internal consistency (α = 0.89) and a 1-factor structure. Most personnel had no disability (59.2%) or minimal disability (30.8%). However, an important minority had moderate or severe disability (8.4% and 1.6%, respectively). Individuals with recent disorders reported greater disability than those without lifetime disorders, although many had minimal or no disability (41.2% and 24.7%, respectively). Disability increased with the number of recent disorders. Relative to those without lifetime disorders, individuals with remote disorders showed slightly greater disability, but most had no disabilty (57.1%) or minimal disability (35.0%). CONCLUSIONS: The 12-item WHODAS-2 is a valid measure of disability in the CAF. Mental disorders may be important drivers of disability in this population, although limited residual disability is seen in individuals with remote disorders.

The 2013 Canadian Forces Mental Health Survey: Background and Methods.

OBJECTIVE: The 2013 Canadian Forces Mental Health Survey (CFMHS) collected detailed information on mental health problems, their impacts, occupational and nonoccupational determinants of mental health, and the use of mental health services from a random sample of 8200 serving personnel. The objective of this article is to provide a firm scientific foundation for understanding and interpreting the CFMHS findings. METHODS: This narrative review first provides a snapshot of the Canadian Armed Forces (CAF), focusing on 2 key determinants of mental health: the deployment of more than 40,000 personnel in support of the mission in Afghanistan and the extensive renewal of the CAF mental health system. The findings of recent population-based CAF mental health research are reviewed, with a focus on findings from the very similar mental health survey done in 2002. Finally, key aspects of the methods of the 2013 CFMHS are presented. RESULTS: The findings of 20 peer-reviewed publications using the 2002 mental health survey data are reviewed, along with those of 25 publications from other major CAF mental health research projects executed over the past decade. CONCLUSIONS: More than a decade of population-based mental health research in the CAF has provided a detailed picture of its mental health and use of mental health services. This knowledge base and the homology of the 2013 survey with the 2002 CAF survey and general population surveys in 2002 and 2012 will provide an unusual opportunity to use the CFMHS to situate mental health in the CAF in a historical and societal perspective.

Prevalence of Past-Year Mental Disorders in the Canadian Armed Forces, 2002-2013.

OBJECTIVE: More than 40,000 Canadian Armed Forces (CAF) personnel have deployed in support of the mission in Afghanistan since 2002. Over the same period, the CAF strengthened its mental health system. This article explores the effect of these events on the prevalence of past-year mental disorders over the period 2002-2013. METHOD: The data sources were 2 highly comparable population-based mental health surveys of CAF Regular Force personnel done in 2002 and 2013 (n = 5155 and 6996, respectively). Data were collected via in-person interviews with Statistics Canada personnel using the World Health Organization's Composite International Diagnostic Interview to assess past-year disorders. RESULTS: In 2013, 16.5% had 1 or more of the 6 past-year disorders assessed in the survey, with the most common conditions being major depressive episode (MDE), posttraumatic stress disorder (PTSD), and generalized anxiety disorder (GAD), which affected 8.0%, 5.3%, and 4.7%, respectively. The prevalence of PTSD, GAD, and panic disorder has increased significantly since 2002 (adjusted odds ratios from logistic regression models = 2.1, 3.0, and 1.9, respectively), while no change was seen for MDE. The comorbidity of mood and anxiety disorders increased significantly over time, being seen in 27.4% and 41.0% of those with mental disorders in 2002 and 2013, respectively. CONCLUSION: There has been an increase in the prevalence of PTSD and other anxiety disorders and of the extent of comorbidity of mood and anxiety disorders in CAF personnel over the period 2002-2013.

Psychosocial Pathways Linking Adverse Childhood Experiences to Mental Health in Recently Deployed Canadian Military Service Members.

Multiple pathways have been suggested to account for the relationship of adverse childhood experiences (ACEs) and well-being in adulthood, including interpersonal difficulties, the underestimation of one's sense of mastery, and a greater propensity to experience stressors later in life. This study was conducted to examine the association between ACEs and mental health in Canadian Armed Forces (CAF) personnel, and the possible mediating roles of social support, mastery, and combat stressors in that relationship. The study consisted of a prospective analysis involving 3,319 CAF members upon their return from an overseas deployment. Results were that ACEs were associated with poorer mental health (ß = -.14, p < .001) and that approximately 42.6% of this relationship could be explained by the mediating effects of low social support, low mastery, and a greater number of combat stressors. The full model, including the covariates, ACEs, social support, mastery, and combat stressors as correlates of postdeployment mental health, was statistically significant with adjusted R(2) = .28, F(9, 3309) = 141.96, p < .001. On the whole, results suggested that social support, mastery, and life stressors may be possible targets for interventions to minimize the impact of ACEs on later mental health in military personnel.

Prospective Analysis of Premilitary Mental Health, Somatic Symptoms, and Postdeployment Postconcussive Symptoms.

OBJECTIVES: Many recent studies of service members returning from deployment have focused on the health impacts of mild traumatic brain injury (mTBI), including persistent postconcussive symptoms (PCS). However, cross-sectional study designs have made it difficult to understand the role of mental health in the etiology of persistent PCS. METHODS: Participants were 3319 military personnel (primarily men [90%] of 25-34 years [54%]) who had completed health surveys at basic training and after deployment, on average, 4.6 years later. Negative binomial regression was used to assess the association of PCS with demographic covariates, premilitary mental health and somatic symptoms, combat experiences and mTBI during deployment, in addition to postdeployment mental health and non-PCS somatic symptoms. RESULTS: Premilitary mental health and somatic symptoms predicted PCS even when adjusting for other variables, yielding an elevated incidence rate ratio (IRR) for posttraumatic stress disorder (PTSD; IRR = 1.23, 95% confidence interval [CI] = 1.06-1.41) and somatic symptoms (mild versus minimal somatic symptoms: IRR = 1.43, 95% CI = 1.31-1.55; moderate/severe versus minimal somatic symptoms: IRR = 1.69, 95% CI = 1.43-2.06), but not for depressive symptoms. When postdeployment mental health and somatic symptom measures were added to the model, the effect of premilitary somatic symptoms remained significant. CONCLUSIONS: Findings point to potential etiological contributions of premilitary characteristics, particularly a tendency to experience somatic symptoms and PTSD, as well as mTBI and combat experiences, to the development of PCS. PCS were also strongly related to concurrent postdeployment mental health.

Clinical Epidemiology of Alcohol Use Disorders in Military Personnel versus the General Population in Canada.

OBJECTIVES: Research suggests a high prevalence of problematic alcohol use among military personnel relative to civilians. Our primary objectives were to compare the prevalence, correlates, help-seeking behaviors, perceived need for care, and barriers to care for alcohol use disorders (AUDs) in the Canadian Armed Forces (CAF) and the Canadian general population (CGP). METHODS: Data were from 2 nationally representative surveys collected by Statistics Canada: (1) the Canadian Community Health Survey on Mental Health collected in 2012 (N = 25,113; response rate = 68.9%) and (2) the Canadian Forces Mental Health Survey collected in 2013 (N = 8,161; response rate = 79.8%). Descriptive statistics and logistic regression were used to examine differences in outcomes of interest associated with AUDs in the CAF and CGP. RESULTS: The prevalence of lifetime AUDs was significantly higher in the CAF (32.0%) than the CGP (20.3%; adjusted odds ratio [AOR] = 1.14, 95% confidence interval [CI, 1.02 to 1.27]) after adjustment for sociodemographic covariates. In contrast, the past-year prevalence of AUDs was significantly lower among CAF personnel (4.5%) than civilians (3.8%; AOR = 0.78, 95% CI [0.61 to 0.99]) after adjustment for sociodemographic covariates. Child abuse history and comorbid mental disorders were strongly associated with past-year AUDs in both populations. CAF personnel compared to the CGP were more likely to perceive a need for care (AOR = 4.15, 95% CI [2.56 to 6.72]) and engage in help-seeking behaviors (significant AORs ranged from 1.85 to 5.54). CAF personnel and civilians with past-year AUDs reported different barriers to care. CONCLUSIONS: Findings argue for the value of different approaches to address unmet need for AUD care in the CAF and CGP.

Deployment-related mild traumatic brain injury, mental health problems, and post-concussive symptoms in Canadian Armed Forces personnel.

BACKGROUND: Up to 20% of US military personnel deployed to Iraq or Afghanistan experience mild traumatic brain injury (mTBI) while deployed; up to one-third will experience persistent post-concussive symptoms (PCS). The objective of this study was to examine the epidemiology of deployment-related mTBI and its relationship to PCS and mental health problems (MHPs) in Canadian Armed Forces (CAF) personnel. METHODS: Participants were 16153 personnel who underwent post-deployment screening (median =136 days after return) following deployment in support of the mission in Afghanistan from 2009 - 2012. The screening questionnaire assessed mTBI and other injuries while deployed, using the Brief Traumatic Brain Injury Screening Tool. Current MHPs and PCS were assessed using items from the Patient Health Questionnaire, the Patient Checklist for PTSD, and the Cognitive Failures Questionnaire. Log-binomial regression explored the association of mTBI, other injuries, and MHPs with PCS, using the presence of 3 or more of 7 PCS as the outcome. Results are expressed as adjusted prevalence ratios (PR). RESULTS: mTBI while deployed was reported in 843 respondents (5.2%). Less severe forms of mTBI (associated only with having been dazed or confused or having "seen stars") predominated. Blast was reported as a mechanism of injury in half of those with mTBI. Multiple PCS were present in 21% of those with less severe forms of mTBI and in 27% of those with more severe forms of mTBI (i.e., mTBI associated with loss of consciousness or post-traumatic amnesia). After adjustment for confounding, mTBI had no statistically significant association with PCS relative to non-TBI injury. In contrast, MHPs had a strong association with reporting 3 or more PCS (adjusted prevalence ratio (PR) =7.77). CONCLUSION: Deployment-related mTBI prevalence was lower than in many US reports; most of those who had had mTBI were free of multiple PCS. PCS was strongly associated with MHPs but not with mTBI. Careful assessment of MHPs is essential in personnel with a history of combat-related mTBI and PCS.