Validation of the four-item very brief University of California at Los Angeles Posttraumatic Stress Disorder Reaction Index screening tool for children and adolescents.

OBJECTIVE: Experiencing traumatic events places children and adolescents at risk for developing posttraumatic stress disorder (PTSD), often leading to adverse mental health consequences. Although well-validated measures of PTSD are available, very brief screening tools are needed to assess PTSD when resources are limited. This study was conducted to develop and validate the four-item University of California at Los Angeles (UCLA) PTSD Reaction Index for DSM-5-Very Brief Form (RI-5-VBF) to be used in settings requiring rapid and efficient screening. METHOD: Item response theory (IRT) models were used to derive RI-5-VBF scores from the UCLA PTSD Reaction Index for DSM-5 and assess its internal consistency using a sample of 1,785 youth (Mage = 12.32 years, SD = 2.78) seeking support at an academic medical center clinic or bereavement center. Receiver operating characteristic (ROC) analyses and diagnostic efficiency statistics were used to assess discriminant groups validity and screening utility of the RI-5-VBF scores. Differential item functioning (DIF) analyses were used to examine possible bias across age, gender, race, ethnicity, and clinical setting versus bereavement center setting. RESULTS: IRT models identified four items with the highest discrimination within each PTSD subscale. The RI-5-VBF scores exhibited acceptable internal consistency (α = .74). ROC analyses indicated that an RI-5-VBF score of 9 maximized sensitivity and specificity. DIF analyses did not find evidence of bias across age, gender, race, ethnicity, or clinical versus bereavement center settings. CONCLUSION: These findings provide support for the reliability and validity of the RI-5-VBF. Findings highlight the utility of the RI-5-VBF as a brief screening measure for PTSD in children and adolescents. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Five Essential Elements of Immediate and Mid-Term Mass Trauma Intervention: Empirical Evidence.

Given the devastation caused by disasters and mass violence, it is critical that intervention policy be based on the most updated research findings. However, to date, no evidence-based consensus has been reached supporting a clear set of recommendations for intervention during the immediate and the mid-term post mass trauma phases. Because it is unlikely that there will be evidence in the near or mid-term future from clinical trials that cover the diversity of disaster and mass violence circumstances, we assembled a worldwide panel of experts on the study and treatment of those exposed to disaster and mass violence to extrapolate from related fields of research, and to gain consensus on intervention principles. We identified five empirically supported intervention principles that should be used to guide and inform intervention and prevention efforts at the early to mid-term stages. These are promoting: 1) a sense of safety, 2) calming, 3) a sense of self- and community efficacy, 4) connectedness, and 5) hope.

Measurement Invariance of the Persistent Complex Bereavement Disorder Checklist With Respect to Youth Gender, Race, Ethnicity, and Age.

The Persistent Complex Bereavement Disorder (PCBD) Checklist was constructed to facilitate the developmentally sensitive assessment of proposed PCBD criteria in bereaved children and adolescents 8-18 years of age. Initial analyses of the PCBD Checklist provided support for the hypothesized two-factor model. The purpose of the present study was to evaluate the measurement invariance of the PCBD Checklist with respect to gender (boys and girls), race/ethnicity (White, Black, and Hispanic youth), and age (school age, preadolescent, and adolescent youth). Participants were 594 youth (50.4% female) aged 7-18 years (M = 11.91, SD = 2.80) who were evaluated as part of standard care at a community-based grief support center. Youth self-identified as Hispanic (n = 184, 30.8%), non-Hispanic white (n = 179, 30.0%), and African American/Black (n = 136, 22.8%). A series of stepwise, multigroup confirmatory factor analyses provided evidence in support of the PCBD Checklist's measurement invariance for all three groups concerning configural invariance, metric invariance, and scalar invariance. These results suggest that PCBD Checklist Criterion B and C scores are measuring similar latent variables, to a similar degree, across gender, race/ethnicity, and age. Establishing the cross-group equivalence of the PCBD Checklist is an important endorsement of its generalizability and clinical utility in that it can be administered to diverse populations with confidence that it is measuring proposed PCBC diagnostic criteria similarly across subgroups.

Implementing an emotional support and mental health response plan for healthcare workers during the COVID-19 pandemic.

Institutions across the world are working to develop initiatives aimed at supporting the well-being of healthcare workers (HCWs) facing the psychological impacts of the novel coronavirus (COVID-19) pandemic. This Commentary identifies risks that HCWs are experiencing, reviews sources of fear and stress, and describes the implementation of a three-tiered model for the provision of emotional support and mental health services for clinical and nonclinical HCWs. The model recognizes the fluid, ever-evolving nature of the COVID-19 pandemic and includes proactive, visible, and easy-to-access supportive psychological services that expand the safety net and help address immediate and future mental health challenges of HCWs. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The UCLA PTSD Reaction Index for DSM-5 Brief Form: A Screening Tool for Trauma-Exposed Youths.

OBJECTIVE: Children and adolescents who experience potentially traumatic events are at risk for developing posttraumatic stress disorder (PTSD). Although psychometrically sound measures are now available to assess these youths, brief tools are currently needed for screening purposes. Two studies were conducted to develop and validate the UCLA PTSD Reaction Index for DSM-5-Brief Form (RI-5-BF). METHOD: Study 1 used item response theory models to derive the RI-5-BF from the UCLA PTSD Reaction Index for DSM-5 and assess its internal consistency using a sample of 486 trauma-exposed youths (mean age = 13.32 years, SD = 2.90) recruited through a practice research network. Study 2 used receiver operating characteristic analyses and diagnostic efficiency statistics to assess the discriminant-groups validity and clinical utility of the RI-5-BF in identifying children at different levels of PTSD risk using a sample of 41 treatment-seeking youths (mean age = 12.44 years, SD = 2.99). RESULTS: In study 1, item response theory models identified the 11 most informative items across their respective subscales. The RI-5-BF exhibited excellent internal consistency in both studies (α > .93). In study 2, receiver operating characteristic analyses indicated that an RI-5-BF score of 21 maximized sensitivity and specificity. Moreover, diagnostic likelihood ratios across multiple levels of scores provided support for the measure's clinical utility in identifying different levels of PTSD risk. CONCLUSION: These findings provide support for both the psychometric properties of the RI-5-BF as a brief screening measure for PTSD in children and adolescents and its utility for identifying youths meriting further assessment and consideration for treatment.

Trauma-informed measurement-based care for children: Implementation in diverse treatment settings.

Ongoing and comprehensive assessment is a critical part of the implementation of evidence-based care; yet, most providers fail to routinely incorporate measurement into their clinical practice. Few studies have focused on the complex application of routine assessment or measurement-based care (MBC) with children. This pilot examined the acceptability, appropriateness, adoptability, and feasibility of an MBC effort, the Clinical Improvement through Measurement Initiative (CIMI), across several child-serving settings (e.g., community mental health center, residential treatment facility). CIMI includes a comprehensive mental health assessment protocol and combines a mobile technology platform with implementation support. Survey and focus group information, assessing implementation constructs and outcomes, was collected from 44 clinicians and staff. Overall, participants agreed that the implementation process and technology were acceptable, appropriate, and feasible for use in child mental health and that CIMI can be used to guide case conceptualization, facilitate treatment planning, and monitor outcomes. Strategies that supported the implementation process were identified as were recommendations to enhance adoption. Significant differences were observed by Community versus Specialized settings with respect to feasibility and appropriateness, likely because of factors associated with inner setting (climate, compatibility), outer setting (patient needs), and the phase of implementation achieved by sites. Implications and recommendations for tailoring MBC implementation by characteristics related to setting are discussed. MBC across child service settings are discussed in the context of implementation frameworks. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Validation of the UCLA PTSD Reaction Index for DSM-5: A Developmentally Informed Assessment Tool for Youth.

OBJECTIVE: To describe the test construction procedure and evaluate the internal consistency, criterion-referenced validity, and diagnostic accuracy of the Child/Adolescent Self-Report Version of the UCLA PTSD Reaction Index for DSM-5 (RI-5) across 2 independent samples. METHOD: Study 1 examined the clarity, developmental appropriateness, acceptability of individual RI-5 items, and internal consistency and criterion-referenced validity of the full test. The study 1 sample included 486 youth recruited from 2 major US cities who completed the RI-5 and a measure of depression. Study 2 evaluated the reliability and diagnostic accuracy of the RI-5 in 41 treatment-seeking youth who completed the RI-5 and a "gold standard" structured diagnostic interview, the Clinician-Administered PTSD Scale for DSM-5-Child/Adolescent Version. RESULTS: RI-5 total scale scores showed excellent internal consistency in the 2 samples. Study 1 provided evidence of criterion-referenced validity, in that total scale scores correlated positively with depressive symptoms. Study 2 provided evidence of diagnostic accuracy (including discriminant-groups validity). RI-5 total scores discriminated youth with from youth without PTSD as benchmarked against the structured diagnostic interview. Further, receiver operating characteristic analyses using a total score of 35 provided excellent diagnostic classification accuracy (area under the curve 0.94). CONCLUSION: The developmental appropriateness and diagnostic accuracy of the RI-5 support its utility for clinical assessment, case conceptualization, and treatment planning in different child-serving systems, including schools, juvenile justice, child welfare, and mental health.

Pediatrician's Practical Approach to Sleep Disturbances in Children Who Have Experienced Trauma.

Sleep difficulties are a common challenge among children who have experienced trauma. Pediatricians are best positioned to work with families to address sleep challenges after traumatic events and help families return to healthy sleep patterns. In this article, we review the underlying concepts that connect trauma to disturbed sleep, types of sleep difficulties seen in children exposed to trauma, and explore ways in which pediatricians can support families as they help their child return to a normal sleep cycle, including the identification of co-occurring conditions and the use of medications. [Pediatr Ann. 2019;48(7):e280-e285.].

Benefits of Treatment Completion Over Premature Termination: Findings from the National Child Traumatic Stress Network.

Objective: To evaluate potential differences in therapeutic outcomes between youths who completed a full course of treatment as planned compared to youths who terminated treatment prematurely. Method: Using longitudinal data from the National Child Traumatic Stress Network (NCTSN) Core Data Set, the present study examined demographic characteristics, trauma history, scores on standardized measures, and ratings of functional impairment and behavior problems in a large clinical sample of children and adolescents exposed to trauma who received treatment at NCTSN centers across the United States. Baseline and follow-up data were used to compare treatment completers (n= 3,108) and noncompleters (n = 4,029). Results: Both treatment completers and noncompleters received benefits from treatment by NCTSN mental health providers in that both groups showed significant decreases in mean scores from baseline to follow-up on all standardized measures. However, compared to noncompleters, treatment completers showed three types of significantly greater benefit at follow-up. These included: (a) greater rates of decline (i.e., steeper slopes) on all outcome measures; (b) greater reductions in the odds of falling within the clinical range on standardized measures; and (c) greater reductions in the odds of exhibiting functional impairment and behavior problems at follow-up. In contrast, compared to treatment completers, noncompleters reported significantly higher rates of lifetime exposure to community violence, psychological maltreatment, physical abuse, neglect, sexual abuse, and sexual assault. Conclusion: These findings underscore the value of incorporating engagement and retention strategies in treatments for traumatized youths to maximize therapeutic benefit and raise the standard of care.

Evaluating referral, screening, and assessment procedures for middle school trauma/grief-focused treatment groups.

There is a need to delineate best practices for referring, assessing, and retaining students suspected of posttraumatic stress (PTS) and maladaptive grief (MG) in school-based treatment. Evidence-based risk-screening procedures should accurately include students who are appropriate for group treatment and exclude students who do not require treatment or who are better served by other forms of intervention and support. We described and evaluated the sequence of steps used to screen 7th- and 8th-grade students (N = 89) referred by school staff as candidates for an open trial of group-based Trauma and Grief Component Therapy for Adolescents (TGCTA; Saltzman et al., in press). We used t tests to compare included versus excluded students on PTS symptom and MG reaction scores (University of California at Los Angeles Posttraumatic Stress Disorder Reaction Index; Grief Screening Scale) during the group screen, individual interview, and treatment-implementation phases. Logistic regressions tested the incremental utility of including measures of both trauma exposure and related emotional and conduct problems (Strengths and Difficulties Questionnaire) in the screening battery. Results suggest that the group screen helped to detect mental health needs and that the individual interview further identified students with PTS and emotional problems. Conduct problems and trauma exposure predicted attrition among students who qualified for treatment. MG incrementally predicted students who advanced from the group screening to the individual interview, and trauma exposure incrementally predicted attrition from treatment. Findings yield implications for improving research and practice, including procedures for enhancing school-based referral, screening, assessment, and selection procedures. (PsycINFO Database Record

Civilization and its discontented: Links between youth victimization, beliefs about government, and political participation across seven American presidencies.

Promoting trust in public officials and active political engagement is vital to sustaining a well-functioning democracy. Developmental psychologists propose that youths' beliefs about government and participation in politics are rooted in personal experiences within their communities. Previous studies have focused on how positive experiences within youths' families, schools, and communities facilitate greater social trust and political participation. However, less is known about how negative interpersonal experiences-such as criminal victimization-intersect with youths' beliefs about the trustworthiness, competence, and knowledge of government officials, and their participation in political activity. Using data from 39 waves of the Monitoring the Future study, the current study examined associations among youth victimization, beliefs about government, and participation in various political activities. Adolescents (N = 109,574; 50.9% female) enrolled in 12th grade across the United States reported on whether they had experienced various types of victimization during the previous year, their beliefs about government, and their participation in multiple forms of political activity. Adolescents who reported more frequent victimization experiences endorsed significantly greater discontent with government and were significantly more engaged in various forms of political activity. The magnitude and direction of these effects were generally consistent across different types of victimization, different demographic subgroups of youth, and different sociohistorical periods. Findings are interpreted from a social contract theory perspective, followed by a discussion of implications for building psychological theory and informing public policy. (PsycINFO Database Record

Impaired Caregiving, Trauma Exposure, and Psychosocial Functioning in a National Sample of Children and Adolescents.

Impairments in Caregiving (ICG) secondary to mental illness and substance use have been linked to adverse outcomes in children. Little is known, however, about whether outcomes vary by type of ICG, exposure to co-occurring traumas, or mechanisms of maladaptive outcomes. Clinic-referred youth age 7-18 years (n = 3988) were compared on ICG history, demographics, trauma history, and mental health symptoms. Child trauma exposure was tested as a mediator of ICG and child symptoms. Youth with ICG were at heightened risk for trauma exposure, PTSD, internalizing symptoms, total behavioral problems, and attachment problems, particularly youth with multiple types of ICG. Effect sizes were moderate to large for PTSD, internalizing symptoms, and total behavioral problems. Number of trauma types mediated the relationship between ICG and child symptoms. ICG was related to trauma exposure within and outside the family context. Understanding these links has important implications for interrupting intergenerational trauma and psychopathology.

Predicting Grief Reactions One Year Following a Mass University Shooting: Evaluating Dose-Response and Contextual Predictors.

This study identifies risk factors for grief following a mass school shooting. Participants (N = 1,013) completed online questionnaires 3-4 months (Time 1) and 1 year (Time 2) post-shootings. We tested models predicting Time 2 grief reactions, exploring direct and indirect predictive effects of exposure variables (physical and social proximity) through hypothesized peritraumatic mediators (peritraumatic perceived threat to self or others) while controlling for Time 1 grief and posttraumatic stress (PTS) reactions, pretrauma vulnerabilities. Findings demonstrate that closer social proximity predicted higher levels of Time 2 grief, directly and indirectly through increasing peritraumatic perceived threat to others' safety. Physical proximity and peritraumatic threat to self did not predict Time 2 grief reactions. Implications for grief screening instruments and theory building research through identifying risk factors and causal mechanisms are discussed.

PTSD prevalence and symptom structure of DSM-5 criteria in adolescents and young adults surviving the 2011 shooting in Norway.

BACKGROUND: Diagnostic criteria for Posttraumatic Stress Disorder (PTSD) have been revised for DSM-5. Two key changes include alteration of the clustering of PTSD symptoms and new PTSD symptom criteria related to negative alterations in cognition and mood. In this study, we empirically investigated these changes. METHODS: We interviewed 325 adolescents and young adults who survived the 2011 youth camp shooting at Utøya Island, Norway. The UCLA PTSD Reaction Index for DSM-IV was used to assess symptoms of PTSD. In addition, 11 questions were added to assess the four new symptom criteria within the new DSM-5 symptom categories. RESULTS: PTSD prevalence did not differ significantly whether DSM-IV (11.1%) or DSM-5 (11.7%) criteria were used and the Cohen׳s Kappa for consistency between the diagnoses was 0.061. Confirmatory factor analyses showed that the four-factor structure of the DSM-5 fit the data adequately according to the conceptual model outlined. LIMITATIONS: The homogeneity of this sample of highly exposed subjects may preclude generalization to less severely exposed groups. Also, we did not assess criterion G in regard to symptoms causing clinically significant distress and functional impairment. CONCLUSION: The prevalence of PTSD was quite similar regardless of diagnostic system. The relatively low concordance between the diagnoses has implications for eligibility for a diagnosis of PTSD.

Using the core curriculum on childhood trauma to strengthen clinical knowledge in evidence-based practitioners.

The high prevalence of trauma exposure in mental health service-seeking populations, combined with advances in evidence-based practice, competency-based training, common-elements research, and adult learning make this an opportune time to train the mental health workforce in trauma competencies. The Core Curriculum on Childhood Trauma (CCCT) utilizes a five-tiered conceptual framework (comprising Empirical Evidence, Core Trauma Concepts, Intervention Objectives, Practice Elements, and Skills), coupled with problem-based learning, to build foundational trauma knowledge and clinical reasoning skills. We present findings from three studies: Study 1 found that social work graduate students' participation in a CCCT course (N = 1,031) was linked to significant pre-post increases in self-reported confidence in applying core trauma concepts to their clinical work. Study 2 found significant pre-post increases in self-reported conceptual readiness (N = 576) and field readiness (N = 303) among social work graduate students participating in a "Gold Standard Plus" educational model that integrated classroom instruction in core trauma concepts, training in evidence-based trauma treatment (EBTT), and implementation of that EBTT in a supervised field placement. Students ranked the core concepts course as an equivalent or greater contributor to field readiness compared to standard EBTT training. Study 3 used qualitative methods to "distill" common elements (35 intervention objectives, 59 practice elements) from 26 manualized trauma interventions. The CCCT is a promising tool for educating "next-generation" evidence-based practitioners who possess competencies needed to implement modularized, individually tailored trauma interventions by strengthening clinical knowledge, clinical reasoning, and familiarity with common elements.

Traumatic childhood experiences in the 21st century: broadening and building on the ACE studies with data from the National Child Traumatic Stress Network.

The study objectives were to (a) examine the association between total number of trauma types experienced and child/adolescent behavioral problems and (b) determine whether the number of trauma types experienced predicted youth behavioral problems above and beyond demographic characteristics, using a diverse set of 20 types of trauma. Data came from the National Child Traumatic Stress Network's (NCTSN) Core Data Set (CDS), which includes youth assessed and treated for trauma across the United States. Participants who experienced at least one type of trauma were included in the sample (N = 11,028; age = 1½-18 years; 52.3% girls). Random effects models were used to account for possible intraclass correlations given treatment services were provided at different NCTSN centers. Logistic regression analyses were used to investigate associations among demographic characteristics, trauma, and emotional and behavioral problems as measured by the Child Behavior Checklist (CBCL). Significant dose-response relations were found between total number of trauma types and behavior problems for all CBCL scales, except Sleep, one of the subscales only administered to 1½- to 5-year-olds. Thus, each additional trauma type endorsed significantly increased the odds for scoring above the clinical threshold. Results provide further evidence of strong associations between diverse traumatic childhood experiences and a diverse range of behavior problems, and underscore the need for a trauma-informed public health and social welfare approach to prevention, risk reduction, and early intervention for traumatized youth.

Trauma histories among justice-involved youth: findings from the National Child Traumatic Stress Network.

BACKGROUND: Up to 90% of justice-involved youth report exposure to some type of traumatic event. On average, 70% of youth meet criteria for a mental health disorder with approximately 30% of youth meeting criteria for post-traumatic stress disorder (PTSD). Justice-involved youth are also at risk for substance use and academic problems, and child welfare involvement. Yet, less is known about the details of their trauma histories, and associations among trauma details, mental health problems, and associated risk factors. OBJECTIVE: This study describes detailed trauma histories, mental health problems, and associated risk factors (i.e., academic problems, substance/alcohol use, and concurrent child welfare involvement) among adolescents with recent involvement in the juvenile justice system. METHOD: The National Child Traumatic Stress Network Core Data Set (NCTSN-CDS) is used to address these aims, among which 658 adolescents report recent involvement in the juvenile justice system as indexed by being detained or under community supervision by the juvenile court. RESULTS: Age of onset of trauma exposure was within the first 5 years of life for 62% of youth and approximately one-third of youth report exposure to multiple or co-occurring trauma types each year into adolescence. Mental health problems are prevalent with 23.6% of youth meeting criteria for PTSD, 66.1% in the clinical range for externalizing problems, and 45.5% in the clinical range for internalizing problems. Early age of onset of trauma exposure was differentially associated with mental health problems and related risk factors among males and females. CONCLUSIONS: The results indicate that justice-involved youth report high rates of trauma exposure and that this trauma typically begins early in life, is often in multiple contexts, and persists over time. Findings provide support for establishing trauma-informed juvenile justice systems that can respond to the needs of traumatized youth.

Using multidimensional grief theory to explore the effects of deployment, reintegration, and death on military youth and families.

To date, the US military has made major strides in acknowledging and therapeutically addressing trauma and post-traumatic stress disorder (PTSD) in service members and their families. However, given the nature of warfare and high rates of losses sustained by both military members (e.g., deaths of fellow unit members) and military families (e.g., loss of a young parent who served in the military), as well as the ongoing threat of loss that military families face during deployment, we propose that a similar focus on grief is also needed to properly understand and address many of the challenges encountered by bereaved service members, spouses, and children. In this article, we describe a newly developed theory of grief (multidimensional grief theory) and apply it to the task of exploring major features of military-related experiences during the phases of deployment, reintegration, and the aftermath of combat death--especially as they impact children. We also describe implications for designing preventive interventions during each phase and conclude with recommended avenues for future research. Primary aims are to illustrate: (1) the indispensable role of theory in guiding efforts to describe, explain, predict, prevent, and treat maladaptive grief in military service members, children, and families; (2) the relevance of multidimensional grief theory for addressing both losses due to physical death as well as losses brought about by extended physical separations to which military children and families are exposed during and after deployment; and (3) a focus on military-related grief as a much-needed complement to an already-established focus on military-related PTSD.

Enhancing family resilience through family narrative co-construction.

We draw upon family resilience and narrative theory to describe an evidence-based method for intervening with military families who are impacted by multiple wartime deployments and psychological, stress-related, or physical parental injuries. Conceptual models of familial resilience provide a guide for understanding the mechanics of how families respond and recover from exposure to extreme events, and underscore the role of specific family processes and interaction patterns in promoting resilient capabilities. Leading family theorists propose that the family's ability to make meaning of stressful and traumatic events and nurture protective beliefs are critical aspects of resilient adaptation. We first review general theoretical and empirical research contributions to understanding family resilience, giving special attention to the circumstances, challenges, needs, and strengths of American military families. Therapeutic narrative studies illustrate the processes through which family members acquire meaning-making capacities, and point to the essential role of parents' in facilitating discussions of stressful experiences and co-constructing coherent and meaningful narratives. This helps children to make sense of these experiences and develop capacities for emotion regulation and coping. Family-based narrative approaches provide a structured opportunity to elicit parents' and children's individual narratives, assemble divergent storylines into a shared family narrative, and thereby enhance members' capacity to make meaning of stressful experiences and adopt beliefs that support adaptation and growth. We discuss how family narratives can help to bridge intra-familial estrangements and re-engage communication and support processes that have been undermined by stress, trauma, or loss. We conclude by describing a family-based narrative intervention currently in use with thousands of military children and families across the USA.

A systematic review of PTSD prevalence and trajectories in DSM-5 defined trauma exposed populations: intentional and non-intentional traumatic events.

OBJECTIVE: We conducted a systematic review of the literature to explore the longitudinal course of PTSD in DSM-5-defined trauma exposed populations to identify the course of illness and recovery for individuals and populations experiencing PTSD. METHODS: We reviewed the published literature from January 1, 1998 to December 31, 2010 for longitudinal studies of directly exposed trauma populations in order to: (1) review rates of PTSD in the first year after a traumatic event; (2) examine potential types of proposed DSM-5 direct trauma exposure (intentional and non-intentional); and (3) identify the clinical course of PTSD (early onset, later onset, chronicity, remission, and resilience). Of the 2537 identified articles, 58 articles representing 35 unique subject populations met the proposed DSM-5 criteria for experiencing a traumatic event, and assessed PTSD at two or more time points within 12 months of the traumatic event. RESULTS: The mean prevalence of PTSD across all studies decreases from 28.8% (range =3.1-87.5%) at 1 month to 17.0% (range =0.6-43.8%) at 12 months. However, when traumatic events are classified into intentional and non-intentional, the median prevalences trend down for the non-intentional trauma exposed populations, while the median prevalences in the intentional trauma category steadily increase from 11.8% to 23.3%. Across five studies with sufficient data, 37.1% of those exposed to intentional trauma develop PTSD. Among those with PTSD, about one third (34.8%) remit after 3 months. Nearly 40% of those with PTSD (39.1%) have a chronic course, and only a very small fraction (3.5%) of new PTSD cases appears after three months. CONCLUSIONS: Understanding the trajectories of PTSD over time, and how it may vary by type of traumatic event (intentional vs. non-intentional) will assist public health planning and treatment.