In the sections that follow, the committee provides a detailed summary of the studies it reviewed using the following
Sources of information: the VA Health Services Research and Development database, the National Institutes of Health (NIH) Research Portfolio Online Reporting Tools (RePORT) database, ClinicalTrials.gov, and information provided from the Department of Defense (DoD).1 After identification of relevant research projects, it categorized those projects based on 10 research categories that parallel the major topics of the committee’s phase 1 report and Table 9-2 in this report. The committee tried to qualitatively describe the kind of posttraumatic stress disorder (PTSD) research currently being funded and who is funding that research. For each research target in the categories below, the committee presents the percentage of studies undertaken (and in some instances funded) by DoD, the Department of Veterans Affairs (VA), the National Institute of Mental Health (NIMH), other NIH institutes, or other
Sources (Other). The studies are described to the extent possible, given the available information in each database. Some studies could have been considered under multiple categories but were counted only in the most relevant category to avoid an overestimation of studies. There were also numerous studies that were funded by more than one organization. The committee tried to identify the main funding
Source so that the study would be counted only once, but this was not always possible and some studies, particularly studies funded jointly by DoD and VA, were counted twice. A
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1 A list of these studies can be obtained by contacting the National Academies Public Access Records Office.
detailed discussion of the committee’s approach and search strategy can be found in Chapter 9.
PHYSIOLOGY, NEUROBIOLOGY, AND BEHAVIOR
Target A: Mechanistic Research on the Process
from Trauma Exposure to PTSD
Target A.1: Neural Circuitry, Neural Connectivity, Brain Regions
Involved in PTSD Pathogenesis, and Neuronal Plasticity
DoD = 9; VA = 0; NIMH = 28; Other NIH Institutes = 6; Other = 10
The committee identified numerous studies that were a mix of research across species and methodologic designs including:
Target A.2: Neuropeptides, Neurotransmitters, Cytokines, and Specific Receptors that Play a Role in PTSD Pathology and Symptoms
DoD = 4; VA = 1; NIMH = 38; Other NIH Institutes = 4; Other = 3
A large number of the studies funded under this category and target area were focused on basic mechanisms by which stress interacts with fear memories and resilience. A range of tools were used, including standard molecular tools, lesions and electrophysiology, and optogenetics. The experimental procedures used most often were fear conditioning and extinction, exposure to predators, and other stress models.
Target A.3: Pathways to Understand Comorbidities and Overlapping Pathways Between PTSD and Comorbidities
DoD = 7; VA = 4; NIMH = 4; Other NIH Institutes = 11; Other = 1
A quarter of the studies in this section examined the mechanisms that underlie alcoholism and PTSD, and one examined cocaine. A few examined the relationship between stress, PTSD, and depression. Others examined the relationship between the neural circuitry or traumatic brain injury (TBI) and fear control techniques in PTSD. Additional projects examined overlap in the circuitry between stress and chronic fatigue syndrome and stress and sleep impairments. Most of the projects funded by DoD under this category were focused on the interactions between TBI and blast injuries, with few exceptions (one on depression and PTSD and another on epilepsy and PTSD). Individual studies in this area included the following:
Target A.4: Memory, Fear Memory, and Memory Processing
DoD = 4; VA = 1; NIMH = 33; Other NIH Institutes = 5; Other = 1
Some of the projects in this section overlap with those captured under Target A.1 because some fear control techniques are essentially manipulating learning and memory. For instance, projects on reconsolidation were included under this target area because they involved memory manipulation, whereas projects on extinction were included under both this target area and target area A.1. Both the extinction and reconsolidation studies mostly examined models of conditioned fear as the learning task. Other studies under this category with no overlap included the following:
techniques from studies of cellular and molecular mechanisms to animal models of neural circuits to human systems.
Several projects that examined basic memory processes that were not specifically related to fear, emotion, trauma, or stress were identified. However, many of them investigated topics such as mechanisms of memory plasticity or altering memory consolidation that could be relevant to PTSD, including creating and understanding new interventions.
Target A.5: Neurobiology Underlying Gender Differences
DoD = 0; VA = 1; NIMH = 5; Other NIH Institutes = 1; Other = 0
There were a few studies that could be categorized under this target research area. The studies that did fall into this area focused on the influence of stress and norepinephrine on fear responses; sex differences in corticotrophin releasing factor in the prefrontal cortex; adenylate cyclase-activity polypeptide, its antagonists, and its interaction with the bed nucleus of the stria terminalis during fear learning; and morphological differences (gross differences or at the synaptic levels in the prefrontal cortex) between males and females.
Target B: Genomics of PTSD
DoD = 6; VA = 6; NIMH = 20; Other NIH Institutes = 3; Other = 1
Examples of studies under this target included those to identify genes or epigenetic modifications or changes in gene expression after trauma that are associated with an increased or decreased risk for developing PTSD. Studies were carried out in vitro, in rodent models, and in humans.
In vitro studies included the following:
Most of the rodent animal models under this research target were concerned with identifying and understanding mechanisms of resilience, memory formation, fear responses, and learned fear.
The studies in adult humans include both civilian and military populations. One goal of many of those studies was to understand the way in which candidate genes may or may not be associated with the development of PTSD. A futher goal was to gain a better understanding of the relationship between genetics and the environment and how that relationship could be influenced by the development of PTSD. Many of the studies integrated information from a variety of
Sources such as brain imaging, human genotyping, neuropsychological measurements, and clinical assessments. Three genome-wide association studies of PTSD were identified, one of which was used primarily in a veteran population. Some additional studies included the following:
Target C: Differential Responses to Treatment
DoD = 6; VA = 2; NIMH = 1; Other NIH Institutions = 0; Other = 6
The goal of the studies that were categorized under this category was to examine how people respond to PTSD treatment.
Target D: Preclinical Studies of New Pharmacotherapies
DoD = 4; VA = 3; NIMH = 5; Other NIH Institutes = 2; Other = 1
In its search of upcoming PTSD research, the committee found several novel and promising preclinical studies of new pharmacotherapies.
PREVENTION
DoD = 21; VA = 9; NIMH = 18; Other NIH Institutions = 4; Other = 8
The committee identified several studies that investigated the prevention of PTSD through stress-management interventions and pharmacological interventions. Some of those studies included the following:
In addition to the above studies that focused on preventing PTSD by administering interventions before trauma exposure or immediately following trauma exposure, the committee identified several studies that focused on identifying early markers of the development of PTSD after trauma. Those studies examined general biomarkers for stress (sweat and saliva) and epigenetic markers for PTSD. Two studies explored potential genetic, neuroanatomical, and behavioral markers of resilience and one looked at neuroimaging and cerebrospinal fluid markers to distinguish PTSD from TBI and neurodegeneration following TBI. Others studies described the development of tools using single-photon emission computed tomography imaging and novel positron emission tomography tracers that may be used in the future to explore biomarkers for PTSD. Of those studies, there was one study that was focused on developing biomarkers that are specific to women. The committee also identified several studies that investigated modifiable factors that promote or prevent the development of PTSD. Some of the specific studies in this area include the following:
SCREENING
DoD = 4; VA = 5; NIMH = 3; Other NIH Institutes = 0; Other = 0
The studies in this target area were mostly focused on screening for PTSD, mild TBI, PTSD comorbid with substance abuse, cognitive symptoms of PTSD, interpersonal violence, or exposure to military sexual trauma. Most of the studies were conducted in veterans of OEF and OIF, with a small number in Gulf War veterans. A few were gender specific
(that is, restricted to women or men). Methods of screening included computer-assisted testing, health information technology, automated telephone screening, use of administrative data to develop algorithms, and use of compensation and pension reports to develop concept-based indexing. Four studies specifically examined the following:
DIAGNOSIS AND DETERMINING SYMPTOM SEVERITY
DoD = 5; VA = 5; NIMH = 1; Other NIH Institutes = 0; Other = 0
In this target area, several studies were identified that investigated tools for diagnosing PTSD and determining PTSD symptom severity.
TREATMENT
Target A.1: Pharmacotherapy
DoD = 11; VA = 13; NIMH = 2; Other NIH Institutes = 1; Other = 33
The pharmaceutical studies identified by the committee involved a broad spectrum of drugs with different mechanisms of action and novel methods of administration. The following types of studies were categorized under this target area:
Target A.2: Somatic Treatments
DoD = 2; VA = 2; NIMH = 0; Other NIH Institutes = 0; Other = 6
The committee identified several studies that explored surgical treatment approaches or the use of stimulatory devices. Examples include the following:
Target A.3: Psychotherapies
DoD = 4; VA = 12; NIMH = 6; Other NIH Institutes = 2; Other = 20
The committee found numerous treatment studies that were psychotherapy-specific. The following types of studies were identified in this target area:
through practice as a way to reduce PTSD via better cognitive modulation of emotion.
Target A.4: Combining Psychotherapy and Pharmacotherapy
DoD = 4; VA = 4; NIMH = 8; Other NIH Institutes = 0; Other = 6
A few studies were identified that investigated the effectiveness of combining psychotherapy and pharmacotherapy treatments for PTSD.
Target A.5: Complementary and Alternative Treatments
DoD = 15; VA = 14; NIMH = 0; Other NIH Institutes = 4; Other = 12
The committee identified a range of complementary and alternative medicine studies, including those that focused on mindfulness, relaxation, yoga, mantram repetition, acupuncture, acupressure, biofeedback, and guitar music therapy. Specific studies in this category included
Target A.6: Different Models for the Delivery of PTSD Care
DoD = 24; VA = 19; NIMH = 4; Other NIH Institutions = 2; Other = 10
The committee identified several projects that tested new technologies to deliver telehealth using a remotely located clinician, to provide supplementary self-help material via websites, to monitor patient reactions using patient-worn sensors connected to mobile devices between sessions, and to use interactive voice response telephone monitoring systems to maintain patient engagement. Some of the studies in this area included the following:
individuals with PTSD and to specifically address comorbid mild TBI. All of these cognitive remediation therapy projects test the rationale that computer-delivered cognitive training programs will promote access via home-based practice.
Target A.7: Modality of the Treatment Intervention
DoD = 4; VA = 6; NIMH = 2; Other NIH Institutions = 0; Other = 3
The committee identified a few studies that investigated the modality of the treatment intervention—that is, treatments that are given in group, couple, or individual settings.
of which were with veterans. A mix of treatment approaches was used, including mindfulness training
Target A.8: Treating Different Gender and Racial Groups
DoD = 2; VA = 3; NIMH = 4; Other NIH Institutions = 3; Other = 1
The committee identified a few research studies that were focused on women and minority populations.
Target A.9: Concurrent Treatment of Comorbidities
DoD = 12; VA = 28; NIMH = 5; Other NIH Institutes = 14; Other = 13
Most of the studies in this target area focused on PTSD and alcohol or substance use. Other areas of research were PTSD and depression, suicide, other mental health disorders, interpersonal violence, sleep disturbances, pain, and irritable bowel syndrome. Some of the treatment approaches in this research category were tailored exposure, imagery rehearsal with or without CBT, and cognitive behavior social rhythm therapy in groups. There were also a few studies related to pharmaceutical agents, technological applications, and yoga. Examples of specific studies included the following:
BARRIERS
DoD = 10; VA = 37; NIMH = 5, Other NIH Institutes = 2; Other = 0
Fifty-four projects refer to barriers to care. Several studies focused on barriers as the main purpose of the project and others included them as subsidiary goals (for example, in studies of treatment or the design of a new procedure to enhance care).
With respect to target populations, the largest group was of OEF and OIF veterans. There were also two studies of predominantly Vietnam-era veterans, nine that either did not specify the population of interest or studied veterans of all eras, and six that were limited to National Guard and reserve service members. Some examples of studies categorized in this area included the following:
Nearly all studies appropriately pertained to research on individual, family, provider, and institutional barriers to the delivery of evidence-based care. However, there were two studies that investigated variations in institutional review board functioning, one study that focused on transitioning care from DoD to VA, and two studies that were focused on identifying barriers for delivering novel treatments, such as acupuncture.
LONG-TERM OUTCOMES ASSOCIATED WITH PTSD
DoD = 9; VA = 10; NIMH = 4; Other NIH Institutes = 5; Other = 0
The committee identified several studies that investigated long-term health outcomes in people who had a diagnosis of PTSD. The studies varied widely and some considered such topics as the following:
INTIMATE PARTNER VIOLENCE
DoD = 0; VA = 4; NIMH = 2; Other NIH Institutes = 2; Other = 1
The committee identified a few studies that included reference to associations between PTSD and intimate partner violence.
intimate partner violence on PTSD and depression; and to assess the additive or interactive effects of maternal attachment on PTSD and depression symptoms and biomarkers of allostatic load.
TRAINING
Target A: Training Providers
DoD = 6; VA = 2; NIMH = 4; Other NIH Institutes = 0; Other = 3
The research in this target area included of primary care providers; mental health clinicians and trainees; clinical psychology graduate students; military, VA, and community mental health care providers; and primary care physicians. Some of the studies in this area included the following:
Target B: Research or Training Grants for Career Development
DoD = 0; VA = 1; NIMH = 13; Other NIH Institutions = 8; Other = 0
The committee identified several k-awards or training grants in the NIH RePORT database. Some of the major topic areas of these awards and grants included the impact of PTSD on older veterans; laboratory methods for PTSD; the molecular basis of emotional learning; the use of fMRI for emotional memory research in PTSD; olfaction and PTSD; the neural basis of safety learning and fear inhibition by safety; and the genetic and environmental etiology of depression, anxiety disorders; s and PTSD. The impact of individual career development awards cannot be determined from the committee’s review of the databases. However, the committee acknowledges that grants aimed at training the next generation of researchers and clinicians in empirically supported methods are of utmost importance.