Interventions provided before, upon, or shortly after trauma exposure, and aiming to reduce the consequent incidence of posttraumatic stress disorder (PTSD) have been intensively studied in the past 20 years.1,2 To efficiently meet their goal, such interventions must identify survivors with risk factors, target modifiable pathogenic mechanisms, and be acceptable, scalable, and cost-efficient. This article examines generic and practical aspects of survivors' risk assessment, trauma exposure mitigation, and interventions' proper timing. Its structure follows the above-mentioned prerequisites: identifying target populations, timely engagement of modifiable pathogens, and reducing barriers to care.
Aspects of PTSD prevention have generated significant intervention research that is published and summarized as treatment guidelines, meta-analyses, and systematic reviews,1–3 most of which have identified major knowledge gaps leaving many clinically pertinent questions unanswered. A 2013 report4 by the Agency for Healthcare Research and Quality found convincing evidence to discard debriefing, validate cognitive-behavioral therapy, and tentatively recommend collaborative care (CC), but at the same time concluded that “evidence supporting the effectiveness of most interventions used to prevent PTSD is lacking.”
Therefore, a gap between conclusive evidence from controlled clinical trials and clinicians' practical needs exists. Significant advances in understanding PTSD etiology and pathogenesis, however, can inform intervention principles and fill some of those gaps. This article distills the extant evidence toward carefully guiding the approach of clinicians and service providers to those who have been recently traumatized.
Identifying Survivors at Risk
Survivors at risk can be identified based on trauma exposure, immediate response, or early PTSD symptoms. Additionally, preexposure risk factors should be considered as moderators of exposure- and reaction-based risk estimates.4
Exposure to a Traumatic Event
Examples of exposure-based identifiers of PTSD risk include an admission to acute care services after trauma, experiencing or witnessing acts of violence, serving in military conflicts, or surviving natural or man-made disasters. People exposed to any of these conditions incur a risk of developing PTSD.
A weakness of exposure-based identifiers is the variety of experiences occurring under each exposure category. A car accident could alternatively result in devastating loss of life or limb, or in minor bodily harm without life threat. Similarly, warzone exposure may extend from immersion in death and horror to prolonged rear echelon deployment with manageable stress. Exposure categories, therefore, provide a first approximation of risk-likelihood via preliminary group-level, event-specific PTSD conditional probability scores illustrated in Figure 1.6
Conditional probability of posttraumatic stress disorder by trauma type and sex.
As can be seen, the conditional probabilities of PTSD vary by sex and trauma category. They are also 2 to 5 times higher among residents of high-income countries compared with low-income countries.7 Adverse socioeconomic factors such as poverty, lower education, and lifetime exposure to interpersonal trauma similarly increase the likelihood of PTSD upon trauma exposure.5
A pertinent finding across conditional probability studies is that, under most circumstances, the majority of those exposed to a potentially traumatic event do not develop PTSD. This has implications for providing early interventions for all those exposed, a practice optimally reserved for events involving higher prior odds of PTSD (eg, rape, school shooting, torture).
To somewhat improve exposure-based risk prediction, care providers can determine whether specific exposure dimensions that aggravate the effect of trauma were present. Exposure to interpersonal violence, uncontrollable stress, grotesque disfiguration, and death, as well as multiple events or sexual assault similarly increase one's odds of developing PTSD and other deleterious mental health outcomes.8
Chaotic events, blatant injustice or evil intent, breakdown of social bonds, loneliness, degradation, and dehumanization are equally important risk components of traumatic events. Finally, any circumstance that prolongs trauma exposure or aggravates it (such as lingering pain, forced relocation, or forced separation) can significantly add to survivors' long-term psychological sequelae9,10 and should be included in an event-based risk assessment.
Protective factors affecting a trauma exposure outcome include group cohesion, a sense of purpose or responsibility (such as rescuing, or leading others), and perceived success in coping with the effect of trauma (eg, successful escape to safety, or protecting children and relatives). Soothing human presence and rescuers' beneficence are the beginning of Psychological First Aid (PFA), which is described below.
Exposure and Early Responses
Second to evaluating exposure-based risk, survivors immediate reactions to the event (also known as “peritraumatic reactions”) are important risk indicators. PTSD diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV),11 PTSD required a peritraumatic reaction of fear, horror, or helplessness to infer a traumatic exposure. The removal of that requirement in Diagnostic and Statistical Manual of Mental Disorders, fifth edition,12 illustrates the problems of using this risk indicator (indeed, any risk indicator) as a mandatory inclusion criterion rather than as an additive or incremental contributor to PTSD likelihood; numerous survivors develop PTSD without salient peritraumatic responses (eg, suppressing emotions during combat action is frequent, and arguably ensures better functioning and ultimately survival). Similarily, DSM-IV's11 use of dissociation symptoms as a required diagnostic criterion of acute stress disorder, a forerunner of PTSD, was similarly challenged by studies showing that most PTSD cases do not express initial dissociation symptoms.13
Thus, the following decision rule applies to evaluating peritraumatic and early response; they neither categorically predict nor preclude PTSD and should rather be used as incremental arguments in estimating PTSD likelihood.
For clinicians, therefore, traumatic events that evoke overwhelming psychological or physiological responses, such as dissociation, derealization, or shock, and those involving traumatic brain injury,14 are associated with higher PTSD likelihood. The appraisal of a potentially traumatic event as threatening or harmful15 and the subjective experience of panic, fear, helplessness, or horror16 have both been demonstrated as potent risk factors. Additionally, events with a higher likelihood of eliciting shame (eg, participation in war or violence17) have been linked with PTSD, particularly when those events became central to one's identity.18 Clinicians can safely assume that that any overwhelming, uncontrollable, paralyzing, and protracted reaction to an event should be considered an indicator of severity and PTSD risk.
Milder bodily reactions to trauma (eg, peritraumatic heart rate or stress hormones levels) have been extensively studied as risk indicators. However, these responses rarely exceed normal physiological boundaries and frequently overlap with values obtained in survivors who do not develop PTSD. Consequently, while arguably informing PTSD etiology and potential interventions, their measurement shortly after trauma exposure has not yet yielded efficient risk prediction.19,20 Specific physiological alterations, however, may contribute to PTSD risk in subsets of survivors (eg, lower cortisol excretion among survivors with past history of childhood trauma21) but such heterogeneities have not been convincingly explored and integrated into predictive models of PTSD.
Trauma Exposure and Early PTSD Symptoms
The third and most important layer of PTSD risk assessment involves early PTSD symptom severity. PTSD symptoms are often present shortly after trauma exposure and their initial severity is indicative of prolonged PTSD risk. PTSD symptoms, therefore, must be evaluated in a risk assessment of early survivors.
A limitation to using PTSD symptoms as predictors is that some of them require time to be properly experienced, reported, and eventually quantified (eg, the extent of insomnia, avoidance, or negative emotions may only become clear days or weeks after trauma exposure) and thus cannot be reliably evaluated during acute care admission or rescue team contact. Another limitation is that early PTSD symptoms rapidly decline in the majority of those expressing them (Figure 2)22 and thus their very early assessment captures numerous survivors likely to recover without intervention.
Posttraumatic stress disorder (PTSD) symptom trajectories after emergency department admission for traumatic injury in 957 adults. The X axis indicates PTSD symptoms' severity and the Y axis represents time since trauma exposure (from 10 to 420 days). The graph illustrates the frequency (17%) of nonremitting participants in this cohort. Reprinted (permission is not required) under the Creative Commons Attribution License (CC BY) from Galatzer-Levy et al.22
Tracking early PTSD symptoms is nonetheless important. In one's clinical practice, one is often asked by survivors, families, and care providers how long it is normal and acceptable to express early symptoms, and when should one seek help. Studies to date indicate that evaluations conducted 1 month after trauma exposure are reasonably predictive of longer-term PTSD.5 A recent multinational study of over 2,400 survivors admitted to acute care centers in six countries5 was able to generate a PTSD likelihood estimate scale (Figure 3) currently available for clinicians ( https://wvdmei.shinyapps.io/PTSD_Risk_Lookup/) as a decision-support tool. That study5 has equally shown that risk indicators preceding the traumatic event, such as female gender, less than high school education, and lifetime exposure to interpersonal trauma interact with early PTSD symptoms to increase PTSD likelihood.
Probability of chronic posttraumatic stress disorder (PTSD) given baseline PTSD symptoms severity. The X axis expresses a likelihood estimate (0 to 1) of developing chronic PTSD. The Y axis expresses CAPS (Clinicians Administered PTSD Scale) obtained within 60 days of trauma exposure. Reprinted from Shalev et al.5 with permission of John Wiley and Sons.
Biological and Physiological Risk Indicators
Recent studies23,24 have addressed biological and physiological risk indicators of PTSD, the most promising of which are dynamic provocation tests, such as measuring physiological responses to recalling the traumatic event. If confirmed, these studies may allow a more accurate detection of risk shortly after trauma exposure, before PTSD symptoms develop. Another risk indicator under development is an assessment of sleep quality after trauma exposure.25 However, if research to date has any lesson to teach, and considering the multiplicity and codependency of known risk indicators, efficient risk estimation of PTSD will likely require a combination of risk indicators.
Summary of Early Risk Assessment
Identifying survivors' risk is possible and can be done efficiently using tools and information readily available to clinicians and service providers. It requires information about pretrauma risk indicators, event type and severity, peritraumatic reactions (if available), and early PTSD symptoms (critical). Importantly, predicting who will develop PTSD can be successfully superseded by estimating PTSD likelihood given initial risk indicators. Several psychometric instruments (Table 1) may assist clinicians in evaluating PTSD risk. Finally, some risk indicators are more closely predictive of PTSD (eg, emerging PTSD symptoms), whereas others may predict a wider array of outcomes. This has important implications for what one can reasonably expect to predict, treat, or prevent at each stage of the response to traumatic events.
Instruments for Early Assessment
Timely Addressing Pathogenic Mechanisms
Understanding Trauma Timeline and Stage-Specific Interventions
Schematically, traumatic events imprint on the brain and behavior represents a summation of pathogenic factors that include pre-exposure vulnerability (eg, emotional threat bias), traumatic experiences' memory imprint (acquisition, early consolidation), postexposure elaboration (extinction failure, generalization), and posttraumatic psychopathology stabilization.24 Conceptualizing PTSD pathogenesis as a sequence of overlaid processes implies stage-specific intervention, defined by an optimal timeframe, specific goals, and targets. Table 2 presents a list of stage-specific intervention types and their targets.
Phase-Based Taxonomy and Interventions
Stage-specific interventions, however, must be judged by both their effect on specifically targeted proximal processes and their long-term effect on PTSD likelihood. A salient example of a discrepancy between the two are studies of critical incidents' stress debriefing (CISD), a treatment modality that aimed to educate survivors about normal reactions to trauma, encourage them to share and normalize their experiences and emotional responses, and teach coping skills. CISD was generally well received and perceived as helpful by participants but failed as a prevention of PTSD.26
Similarly, studies of early interventions using benzodiazepines, while producing a “proximal” reduction of anxiety and insomnia coincided with an increased risk of subsequent PTSD.27 These examples illustrate the frequent incongruence between immediate reactions and downstream psychopathology. Although it is the clinician's first responsibility to mitigate harm and reduce distress among traumatized patients, clinicians must take care that their well-intentioned actions do not inadvertently increase the risk of subsequent psychological impairment. Finally, early interventions may differentially affect a subset of survivors, but only a few recent studies28 have addressed predictors of treatment responses.
Reducing The Effect of Traumatic Events
Much of the burden of managing the effect of traumatic events falls on critical incident managers, first responders, rescuers, and acute care personnel. Mental health professionals have a limited yet important supportive role in reducing the effect of trauma. Given the variety of traumatic circumstances, their role is better defined by intervention principles shown in the following examples.
In a seminal expert consensus article, Hobfoll et al.29 formulated five “essential elements of mass trauma interventions” that are critical to the establishment of a recovery environment that fosters adaptation and resilience. These elements include (1) providing a sense of safety, (2) calming, (3) promoting self-efficacy and community efficacy, (4) promoting social connectedness, and (5) instilling hope.
Translated to trauma mitigation practice, these principles become (1) creating a safe environment and engaging in nonintrusive, noninquisitive dialogue with survivors; (2) identifying and alleviating sources of distress and worries by providing accurate information, responding to survivors' concerns, and mitigating secondary stressors (eg, lingering pain, disconnection from attachment figures); (3) allowing and encouraging survivors to engage in their preferred, culturally sanctioned way of handling adversity; (4) supporting and enhancing the survivor's connection with significant others; and (5) instilling hope.
Overlapping with the above, PFA30 offers a systematic set of helping actions aimed at reducing initial posttrauma distress and supporting short- and long-term adaptive functioning. PFA is designed as an initial component of a comprehensive disaster or trauma response. It is constructed around eight core actions: (1) contact and engagement, (2) safety and comfort, (3) stabilization, (4) information gathering, (5) practical assistance, (6) connection with social supports, (7) information on coping support, and (8) linkage with collaborative services. PFA's implementation requires assessment and clinical judgment by the provider and as such is intended for use by trained disaster mental health responders. It can be delivered anywhere (eg, shelters, schools, hospitals, homes, or other community settings).
A bridge between PFA and psychiatric treatment is offered by the CC interventions,31 a method applied to hospital inpatients after traumatic injury and combining individual case management, multidisciplinary integration, and psychopharmacological or psychotherapeutic treatments. A typical CC team includes a case manager, trauma support specialist, psychiatrist, and psychologist. The intervention starts formulating a comprehensive postinjury care plan with the patient that simultaneously addresses his or her medical and psychosocial needs. Patients' case management may continue for up to 6 months after injury and include treatment referral, relapse prevention, and community integration support. CC, therefore, combines attending concrete needs (eg, medical, surgical or interpersonal) with early distress mitigation and, for those identified with PTSD or other disorders, and evidence-based therapies for those with early PTSD. CC has been shown to reduce PTSD symptoms relative to treatment as usual control.31
Reducing Barriers to Care
Despite a widespread recognition of chronic PTSD's persistence, severity, and disabling nature, many symptomatic survivors do not seek help. The median time for initiating mental health care in combat veterans with PTSD, for example, is 2 years after return from deployment.32 Delays in the general population are even longer.33 A survey of deployed US Army and Marine Corps personnel34 found that only 19.5% of the soldiers who met screening criteria for PTSD saw a mental health professional. Similarly, in a large outreach and prevention study,35 49% of 1,501 civilian trauma survivors, contacted by telephone, assessed, and found to have 17. acute stress disorder symptoms declined a face-to-face assessment with a clinician, and 27% of those seen by clinicians and diagnosed as having acute PTSD declined an offer of early treatment. Thus, deferring and avoiding care are the major barriers to efficient prevention of PTSD and worth including in one's “prevention” toolbox and addressing upon contacts with survivors.
Modifiable reasons for delayed care include no perceived need,36 concerns related to stigma, shame or rejection, lack of knowledge about PTSD, treatment-related doubts, fear of negative social consequences, and, for some survivors, concerns about a painful reexperiencing of the traumatic events during therapies.37 Addressing these concerns during early contacts might be an important step toward reducing trauma-triggered morbidity. Finally, in incidents involving high risk of PTSD (eg, terror, rape, mass shooting), proactive follow-up, monitoring, and eventual referral to care are recommended.