Prevalence, correlates, and clinical features of delayed-onset posttraumatic stress disorder in a nationally representative military sample

Using Machine Learning Algorithms to Enhance the Management of Suicide Ideation

Combat veterans; especially those with mental health conditions are an at risk group for suicidal ideation and behaviour. This study attempts to use machine learning algorithm to predict suicidal ideation (SI) in a treatment seeking veteran population. Questionnaire data from 738 patients consisting of veterans, still serving members of the Canadian Forces (CF) and Royal Canadian Mountain Police (RCMP) were examined to determine the likelihood of suicide ideation and to identify key variables for tracking the risk of suicide. Unlike conventional approaches we use pattern recognition methods, known collectively as machine learning (ML), to examine multivariate data and identify patterns associate with suicidal ideation. Our findings show that accurate prediction of SI of over 84.4% can be obtained with 25 variables, and 81% using as little as 10 variables primarily obtained from the patient health questionnaire (PHQ). Surprisingly the best identifiers for SI did not come from occupational experiences but rather the patient quality of health, signifying that these findings could be applied to the general population. Our results suggest that ML could assist clinicians to develop a better screening aid for suicidal ideation and behaviour.

Delayed unpaired extinction as a treatment for hyperarousal of the rabbit nictitating membrane response and its implications for treating PTSD

Treatment for PTSD (Post-traumatic stress disorder) is rarely available immediately after trauma and often delayed for weeks or months after an event. In a rabbit eyeblink conditioning model of PTSD, we have previously shown that presentations of a tone conditioned stimulus (CS) and shock unconditioned stimulus (US) in an explicitly unpaired manner known as unpaired extinction is effective in reducing CS responding and US hyperarousal even if shock intensity is reduced eight-fold and elicits only minimal responding. Here we determined if delayed delivery of unpaired extinction would still be effective in extinguishing hyperarousal. Rabbits were tested for sensitivity to shock before CS-US pairings and after six days of unpaired extinction presented a day, a week or a month after CS-US pairings. Hyperarousal was extinguished a day and a week after conditioning but not after a month suggesting a significant delay in "treatment" can make hyperarousal persist. We next assessed if this persistence of hyperarousal was associative by comparing rabbits given CS-US pairings to those given explicitly unpaired CS and US presentations, measuring hyperarousal a day and a month later, followed by unpaired extinction and hyperarousal assessment. After four weeks, there was an increase in responding for all rabbits but only rabbits receiving CS-US pairings showed a significant increase in associatively-mediated hyperarousal. Importantly, both paired and unpaired groups showed increased levels of responding after unpaired extinction suggesting treatment delayed for too long may no longer be effective and could cause generalized hyperarousal.

Out of the shadows: mental health of Canadian armed forces veterans

In the past 15 years in Canada, as in other nations, the mental health of veterans has emerged as a key concern for both government and the public. As mental health service enhancement unfolded, the need for wider population studies became apparent. This paper describes the renewal of services and key findings from national surveys of serving personnel and veterans.

Genome to Phenome: A Systems Biology Approach to PTSD Using an Animal Model

Post-traumatic stress disorder (PTSD) is a debilitating illness that imposes significant emotional and financial burdens on military families. The understanding of PTSD etiology remains elusive; nonetheless, it is clear that PTSD is manifested by a cluster of symptoms including hyperarousal, reexperiencing of traumatic events, and avoidance of trauma reminders. With these characteristics in mind, several rodent models have been developed eliciting PTSD-like features. Animal models with social dimensions are of particular interest, since the social context plays a major role in the development and manifestation of PTSD.For civilians, a core trauma that elicits PTSD might be characterized by a singular life-threatening event such as a car accident. In contrast, among war veterans, PTSD might be triggered by repeated threats and a cumulative psychological burden that coalesced in the combat zone. In capturing this fundamental difference, the aggressor-exposed social stress (Agg-E SS) model imposes highly threatening conspecific trauma on naïve mice repeatedly and randomly.There is abundant evidence that suggests the potential role of genetic contributions to risk factors for PTSD. Specific observations include putatively heritable attributes of the disorder, the cited cases of atypical brain morphology, and the observed neuroendocrine shifts away from normative. Taken together, these features underscore the importance of multi-omics investigations to develop a comprehensive picture. More daunting will be the task of downstream analysis with integration of these heterogeneous genotypic and phenotypic data types to deliver putative clinical biomarkers. Researchers are advocating for a systems biology approach, which has demonstrated an increasingly robust potential for integrating multidisciplinary data. By applying a systems biology approach here, we have connected the tissue-specific molecular perturbations to the behaviors displayed by mice subjected to Agg-E SS. A molecular pattern that links the atypical fear plasticity to energy deficiency was thereby identified to be causally associated with many behavioral shifts and transformations.PTSD is a multifactorial illness sensitive to environmental influence. Accordingly, it is essential to employ the optimal animal model approximating the environmental condition that elicits PTSD-like symptoms. Integration of an optimal animal model with a systems biology approach can contribute to a more knowledge-driven and efficient next-generation care management system and, potentially, prevention of PTSD.

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.

Mental health of Canadian Armed Forces Veterans: review of population studies

Introduction. The mental health of Canadian Armed Forces (CAF) populations emerged as an important concern in the wake of difficult CAF deployments in the 1990s. This article is the first comprehensive summary of findings from subsequent surveys of mental health and well-being in CAF Veterans, undertaken to inform mental health service renewals by CAF Health Services and Veterans Affairs Canada (VAC). Methods. Epidemiological findings in journal publications and government reports were summarized from four cross-sectional national surveys: a survey of Veterans participating in VAC programs in 1999 and three surveys of health and well-being representative of whole populations of Veterans in 2003, 2010, and 2013. Results. Although most Veterans had good mental health, many had mental health problems that affected functioning, well-being, and service utilization. Recent Veterans had a higher prevalence of mental health problems than the general Canadian population, earlier-era Veterans, and possibly the serving population. There were associations between mental health conditions and difficult adjustment to civilian life, physical health, and multiple socio-demographic factors. Mental health problems were key drivers of disability. Comparisons with other studies were complicated by methodological, era, and cultural differences. Discussion. The survey findings support ongoing multifactorial approaches to optimizing mental health and well-being in CAF Veterans, including strong military-to-civilian transition support and access to effective mental and physical health services. Studies underway of transitioning members and families in the peri-release period of the military-to-civilian transition and longitudinal studies of mental health in Veterans will address important knowledge gaps.

Predictors of treatment utilization and unmet treatment need among individuals with posttraumatic stress disorder from a national sample

OBJECTIVE

Posttraumatic stress disorder (PTSD) is a chronic psychiatric condition associated with significant disability that often remains untreated. Sociodemographic and family-level factors may serve as predictors of unmet treatment need, identifying groups that would most benefit from policies aimed at increasing access to the mental health care system.

METHOD

Data from the nationally representative Collaborative Psychiatric Epidemiologic Surveys were used to identify predictors of mental health treatment utilization, both with a mental health specialist and with a general health practitioner, and self-reported unmet treatment need among individuals who endorsed past-year PTSD. We defined unmet treatment need as self-reporting a mental health problem and not accessing mental health care in the general or specialty mental health care system.

RESULTS

Among 600 participants, predictors of unmet treatment need included being non-Latino black [odds ratio (OR) 2.11, 95% confidence interval (CI) 1.25-3.54], having a high school education versus some college (OR 2.45, 95% CI 1.34-4.48), and being employed or unemployed versus not being in the workforce (OR 1.74, 95% CI 1.00-3.02 and OR 4.95, 95% CI 1.60-15.34, respectively). Recursive partitioning identified younger age and being married as predictors of low treatment utilization.

CONCLUSIONS

Future research should elucidate barriers to accessing treatment among those with PTSD in these underserved groups.

Sleep and REM sleep disturbance in the pathophysiology of PTSD: the role of extinction memory

Post-traumatic stress disorder (PTSD) is accompanied by disturbed sleep and an impaired ability to learn and remember extinction of conditioned fear. Following a traumatic event, the full spectrum of PTSD symptoms typically requires several months to develop. During this time, sleep disturbances such as insomnia, nightmares, and fragmented rapid eye movement sleep predict later development of PTSD symptoms. Only a minority of individuals exposed to trauma go on to develop PTSD. We hypothesize that sleep disturbance resulting from an acute trauma, or predating the traumatic experience, may contribute to the etiology of PTSD. Because symptoms can worsen over time, we suggest that continued sleep disturbances can also maintain and exacerbate PTSD. Sleep disturbance may result in failure of extinction memory to persist and generalize, and we suggest that this constitutes one, non-exclusive mechanism by which poor sleep contributes to the development and perpetuation of PTSD. Also reviewed are neuroendocrine systems that show abnormalities in PTSD, and in which stress responses and sleep disturbance potentially produce synergistic effects that interfere with extinction learning and memory. Preliminary evidence that insomnia alone can disrupt sleep-dependent emotional processes including consolidation of extinction memory is also discussed. We suggest that optimizing sleep quality following trauma, and even strategically timing sleep to strengthen extinction memories therapeutically instantiated during exposure therapy, may allow sleep itself to be recruited in the treatment of PTSD and other trauma and stress-related disorders.

Eyeblink classical conditioning and post-traumatic stress disorder - a model systems approach

Not everyone exposed to trauma suffers flashbacks, bad dreams, numbing, fear, anxiety, sleeplessness, hyper-vigilance, hyperarousal, or an inability to cope, but those who do may suffer from post-traumatic stress disorder (PTSD). PTSD is a major physical and mental health problem for military personnel and civilians exposed to trauma. There is still debate about the incidence and prevalence of PTSD especially among the military, but for those who are diagnosed, behavioral therapy and drug treatment strategies have proven to be less than effective. A number of these treatment strategies are based on rodent fear conditioning research and are capable of treating only some of the symptoms because the extinction of fear does not deal with the various forms of hyper-vigilance and hyperarousal experienced by people with PTSD. To help address this problem, we have developed a preclinical eyeblink classical conditioning model of PTSD in which conditioning and hyperarousal can both be extinguished. We review this model and discuss findings showing that unpaired stimulus presentations can be effective in reducing levels of conditioning and hyperarousal even when unconditioned stimulus intensity is reduced to the point where it is barely capable of eliciting a response. These procedures have direct implications for the treatment of PTSD and could be implemented in a virtual reality environment.