UCLA PTSD Reaction Index

1. Abstract

The UCLA PTSD Reaction Index (University of California at Los Angeles Posttraumatic Stress Disorder Reaction Index, commonly abbreviated as UCLA PTSD-RI) is one of the most rigorously validated and globally utilized psychometric instruments designed to assess exposure to psychologically traumatic events and evaluate posttraumatic stress reactions in children and adolescents. Originally conceptualized by Robert S. Pynoos, Alan M. Steinberg, and colleagues at the UCLA Trauma Psychiatry Service, the instrument operationalizes traumatic stress symptomatology aligning with the nosological criteria established in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and updated for DSM-5). The assessment battery comprises a comprehensive Trauma History Profile that screens for lifetime exposure to a broad spectrum of acute, chronic, and interpersonal traumatic events, followed by a symptom rating index. The symptom inventory presented herein consists of 31 items scored on a 5-point Likert frequency scale ranging from 0 (None of the time) to 4 (Most of the time) based on the child’s experiences during the preceding month.

The UCLA PTSD-RI measures the core symptomatic clusters of pediatric posttraumatic stress disorder, including Intrusion/Re-experiencing, Persistent Avoidance, Negative Alterations in Cognitions and Mood, and Alterations in Arousal and Reactivity, as well as a specialized supplementary cluster measuring the Dissociative Subtype (encompassing depersonalization and derealization phenomena). Across multiple psychometric evaluations encompassing diverse clinical, disaster-exposed, and community samples, the UCLA PTSD-RI demonstrates high internal consistency, with full-scale Cronbach’s alpha coefficients typically ranging from .88 to .91, strong test-retest reliability across 2-to-4-week intervals (r > .80), and robust convergent validity against structured clinical interviews such as the Clinician-Administered PTSD Scale for Children and Adolescents (CAPS-CA). This comprehensive article provides an in-depth psychometric, clinical, and theoretical analysis of the UCLA PTSD-RI, elucidating its empirical foundations, factor structure, scoring conventions, and clinical implementation across diverse pediatric populations.

2. Keywords

UCLA PTSD Reaction Index, PTSD-RI, pediatric traumatic stress, posttraumatic stress disorder, child trauma assessment, adolescent psychometrics, trauma history screening, dissociative subtype, DSM-5 criteria, trauma-informed assessment

3. Authors

The UCLA PTSD Reaction Index was developed by pioneering clinical researchers affiliated with the Trauma Psychiatry Program at the University of California, Los Angeles (UCLA) and the National Center for Child Traumatic Stress (NCCTS):

• Robert S. Pynoos, M.D., M.P.H.: Professor of Psychiatry and Biobehavioral Sciences at the David Geffen School of Medicine at UCLA, Co-Director of the National Center for Child Traumatic Stress, and an internationally renowned authority on childhood trauma, grief, and traumatic stress neurobiology.
• Alan M. Steinberg, Ph.D.: Associate Director of the UCLA Trauma Psychiatry Program, Research Psychologist in the Department of Psychiatry and Biobehavioral Sciences at UCLA, and leading psychometrician responsible for the standardization and empirical validation of the PTSD-RI across editions.
• Norma Rodriguez, Ph.D.: Clinical psychologist and researcher who contributed foundational psychometric research to early revisions of the DSM-IV child and adolescent indices.
• Margaret L. Stuber, M.D.: Professor of Psychiatry and Biobehavioral Sciences at UCLA, specializing in pediatric oncology-related traumatic stress and medical trauma.
• Christopher J. Frederick, Ph.D.: Former clinical psychologist and early pioneer in disaster mental health and crisis intervention at the National Institute of Mental Health (NIMH) and UCLA.
• Melissa J. Brymer, Ph.D., Psy.D.: Director of Terrorism and Disaster Programs at the UCLA/Duke University National Center for Child Traumatic Stress, instrumental in psychometric refinement (Part 1 and Part 2 validation studies) and post-disaster dissemination.
• Brittany Beyerlein, Ph.D.: Research affiliate and psychometric contributor to the validation and normative scaling of the UCLA Reaction Index across developmental cohorts.

Institutional Affiliation: UCLA Trauma Psychiatry Service, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA 90024, USA.

4. Purpose

The primary purpose of the UCLA PTSD Reaction Index is to provide clinicians and developmental psychopathology researchers with an empirically validated, developmentally sensitive, and standardized instrument to screen, evaluate, and monitor posttraumatic stress symptoms in children and adolescents aged 6 to 18 years. Traumatic events occurring in pediatric populations—including physical abuse, sexual abuse, domestic violence, severe accidents, community violence, military warfare, forced displacement, invasive medical interventions, and catastrophic natural disasters—exert pervasive, multifaceted disruptions on cognitive, emotional, and neurobiological development. Standard adult self-report instruments frequently fail to capture the developmentally idiosyncratic manifestations of trauma in youths, such as traumatic reenactment in play, somatic equivalents of autonomic arousal, pervasive developmental pessimism, and trauma-induced relational estrangement. The UCLA PTSD-RI was specifically constructed to bridge this diagnostic and psychometric divide.

Clinical Applications

In clinical practice, the UCLA PTSD-RI serves three vital functions:

• Primary and Secondary Triage Screening: Rapidly identifying youths who exhibit clinically meaningful symptom elevations following exposure to acute or chronic stressors, facilitating timely entry into evidence-based psychosocial interventions such as Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) or Child-Parent Psychotherapy (CPP).
• Diagnostic Supplementation: Assisting clinicians in formulating structured diagnostic impressions consistent with categorical diagnostic taxonomies (DSM-IV, DSM-5, and ICD-11). Although the instrument can be administered as a self-report questionnaire, it is frequently integrated into clinical interviews where trained examiners clarify item semantics, observe non-verbal behavioral signs, and evaluate functional impairment across academic, familial, and peer domains.
• Treatment Outcome Monitoring: Administered longitudinally at baseline, mid-treatment, post-treatment, and follow-up intervals to quantify therapeutic progress, identify recalcitrant symptom clusters (such as enduring hyperarousal or severe dissociative phenomena), and inform clinical decision-making regarding discharge or modular treatment adaptations.

Research Applications

Within clinical research and epidemiology, the UCLA PTSD-RI represents the global standard for pediatric trauma studies. It is extensively utilized in epidemiological field trials following large-scale natural disasters (e.g., major earthquakes, hurricanes, floods) and human-induced mass casualty incidents (e.g., school shootings, civil war conflicts). Because of its established cross-cultural validity and broad linguistic translation, researchers rely on the UCLA PTSD-RI to estimate population prevalence rates, isolate risk and resilience factors, investigate the genetic and neuroendocrine correlates of childhood trauma (such as hypothalamic-pituitary-adrenal axis dysregulation), and assess the efficacy of community-wide crisis response interventions.

5. Psychological Construct

The UCLA PTSD Reaction Index operationalizes the multidimensional construct of posttraumatic stress disorder as conceptualized within modern developmental psychopathology. Childhood traumatic stress is not an isolated affective disturbance; it represents a systemic biobehavioral syndrome characterized by persistent alterations in threat perception, memory consolidation, affective regulation, and self-referential cognition. The instrument assesses five interrelated symptom dimensions:

1. Intrusion / Re-Experiencing

This dimension reflects the uncontrollable intrusion of the traumatic memory into conscious awareness, bypassing voluntary executive control. In children and adolescents, intrusion phenomena often manifest with heightened somatic and affective intensity:

• Recurrent Involuntary Thoughts and Images: Intrusive sensory impressions (visual, auditory, or somatic) depicting the traumatic event that intrude during waking hours (e.g., Item 3: “I have upsetting thoughts, pictures, or sounds of what happened come into my mind when I do not want them to”).
• Traumatic Nightmares: Sleep disturbances characterized by recurring dreams depicting the trauma or generalized distressing nightmares devoid of overt trauma narrative content (Item 5).
• Dissociative Flashbacks and Behavioral Reenactment: States wherein the child perceives, acts, or feels as though the traumatic event were actively recurring in the present (Item 6: “I feel like I am back at the time when the bad thing happened, living through it again”).
• Physiological and Psychological Reactivity: Intense subjective distress (Item 2) and pronounced visceral sensations—such as tachycardia, cephalalgia, or gastrointestinal distress (Item 18)—upon exposure to internal or external reminders.

2. Persistent Avoidance

The avoidance dimension captures behavioral and cognitive efforts to evade stimuli associated with the traumatic experience, functioning as a primary maintaining mechanism through negative reinforcement:

• Internal Cognitive and Emotional Avoidance: Deliberate suppression of thoughts, memories, affective states, or conversational topics related to the trauma (Item 9: “I try not to talk about, think about, or have feelings about what happened” and Item 13).
• External Cue Avoidance: Rigorous avoidance of environmental reminders, including specific geographic locations, people, physical objects, activities, or situations that evoke traumatic associations (Item 17: “I try to stay away from people, places, or things that make me remember what happened”).

3. Negative Alterations in Cognitions and Mood

Trauma frequently shatters foundational developmental schemas regarding safety, predictability, interpersonal trust, and moral coherence. This dimension evaluates depressive, anhedonic, and cognitive alterations:

• Trauma-Related Amnesia: Dissociative inability to retrieve critical narrative details or structural components of the traumatic event, distinct from ordinary forgetfulness or traumatic brain injury (Item 15 and Item 23).
• Negative Cognitive Schemas and Self-Blame: Distorted cognitive appraisals attributing causality or responsibility to the self (Item 14 and Item 19: “I think that some part of what happened is my fault”; Item 2: “I have thoughts like ‘I am bad'”; Item 9: “The world is really dangerous”; and Item 16: “I will never be able to trust other people”).
• Pervasive Dysphoric Affect and Alienation: Persistent states of anger, guilt, shame, or terror (Items 4, 22, and 25), accompanied by severe estrangement from social networks, family, and peers (Items 7, 8, and 17: “I feel alone even when I am around other people”).
• Anhedonia and Emotional Constriction: Profound difficulty experiencing positive emotional states such as joy, intimacy, affection, or love (Items 10 and 12).
• Foreshortened Future / Developmental Pessimism: A profound subjective conviction of early mortality, lack of adulthood attainment, or generalized catastrophic anticipatory dread (Item 19: “I think that I will not live a long life” and Item 21).

4. Alterations in Arousal and Reactivity

This subscale captures sustained neurobiological hypervigilance, sympathovagal dysregulation, and behavioral disinhibition reflecting chronic activation of the sympathetic nervous system:

• Hypervigilance: Constant environmental scanning for looming threat, danger, or harm (Item 1: “I watch out for danger or things that I am afraid of”).
• Exaggerated Startle Response: Pronounced autonomic and motor startle reactivity triggered by unexpected auditory or visual stimuli (Item 12 and Item 24).
• Sleep Architecture Disruption: Severe initial, middle, or terminal insomnia unrelated to medical conditions (Item 13 and Item 21).
• Executive Dysregulation: Impaired selective attention, concentration difficulties, and poor sustained cognitive performance within educational settings (Item 16 and Item 8).
• Irritability and Externalizing Outbursts: Unprovoked verbal hostility, reactive physical aggression, or intense rage (Item 4, Item 20, and Item 4).
• Reckless or Self-Destructive Behavior: Maladaptive risk-taking, deliberate self-harm, or impulsive actions that threaten physical safety (Item 20 and Item 26).

5. Dissociative Subtype

Reflecting structural enhancements incorporated into the DSM-5 taxonomy, the instrument assesses distinct dissociative phenomena that emerge as severe psychological defense mechanisms under overwhelming trauma:

• Depersonalization: Detachment from one’s own physical body, mental processes, or identity, experiencing the self as an outside observer (Item 28: “I feel like I am seeing myself or what I am doing from outside my body”; Item 29: “I feel not connected to my body, like I’m not really there inside”).
• Derealization: Unreality or estrangement from one’s surroundings, wherein the physical world feels dreamlike, artificial, distant, or foggy (Item 30: “I feel like things around me look strange, different, or like I am in a fog”; Item 31: “I feel like things around me are not real, like I am in a dream”).

6. Theoretical Framework

The UCLA PTSD Reaction Index is grounded in a convergence of developmental psychopathology, cognitive-behavioral information processing theories, and affective neuroscience.

Developmental Psychopathology of Trauma

The principal conceptual architecture derives from the developmental trauma model articulated by Robert S. Pynoos and colleagues (Pynoos et al., 1999). This paradigm posits that traumatic experiences induce a profound shock to the child’s evolving psychobiological systems. Rather than viewing PTSD as an invariant adult condition scaled down for youths, this model recognizes that trauma interacts dynamically with developmental competencies. In young youths, cognitive capacities for contextualizing danger, verbalizing intense internal affective states, and differentiating between past memory and present safety are still maturing. Consequently, exposure to extreme danger often produces neurobiological sensitization, disrupted attachment schemas, regressive behavioral reactions, and systemic developmental derailment. The UCLA PTSD-RI was explicitly designed to operationalize these developmental dynamics, capturing how fear generalizes across cognitive and relational domains.

Cognitive Model of Pediatric PTSD

The scale integrates key elements of Ehlers and Clark’s cognitive model of PTSD, adapted for pediatric populations. Under this framework, persistent posttraumatic stress reactions occur when children process the traumatic event and its aftermath in a manner that creates a sense of imminent, generalized threat. This continuous threat appraisal is driven by:

• Excessively Negative Appraisals: Distortions regarding the trauma’s causes and long-term implications (e.g., believing that the world is entirely malevolent, that one is irrevocably damaged, or that one is directly culpable for the event).
• Nature of the Trauma Memory: Poor memory elaboration and autobiographical integration, resulting in sensory-based, cue-driven retrieval (intrusions) that lack temporal tagging.
• Maladaptive Coping Strategies: Rigid internal and external avoidance patterns and rumination that impede natural cognitive processing and schema revision.

Neurobiology of Traumatic Stress

From a neurobiological standpoint, the UCLA PTSD-RI reflects the behavioral and subjective sequelae of altered corticolimbic circuitry. Empirical neuroscience indicates that developmental trauma impairs functional connectivity between the ventromedial prefrontal cortex (vmPFC), the anterior cingulate cortex (ACC), and the amygdala. The failure of top-down prefrontal inhibition over hyperreactive amygdalar fear networks underlies the chronic hypervigilance, autonomic startle, and intrusive memories measured across the index. Furthermore, severe traumatic stress can disrupt the normal developmental trajectory of the hippocampus, providing a neurobiological mechanism for the trauma-related declarative memory fragmentation and amnesia (Items 15 and 23) assessed by the scale.

7. Validity

The UCLA PTSD Reaction Index has undergone extensive empirical validation across four decades of psychometric investigations, involving clinical psychiatric cohorts, medically ill pediatric groups, school-based samples exposed to violence, and massive international humanitarian disaster cohorts.

Construct and Structural Validity

Construct validity is evidenced by the scale’s documented ability to differentiate between traumatized children with and without functional psychiatric impairment. Steinberg et al. (2013) evaluated the psychometric properties of the instrument within a large, ethnically diverse clinical repository gathered by the National Child Traumatic Stress Network (NCTSN; N = 6,291). Their structural analyses confirmed that the individual items demonstrate strong developmental sensitivity and accurately delineate distinct gradients of posttraumatic severity, confirming construct integrity across sex, age brackets (child vs. adolescent), and diverse trauma typologies (e.g., acute accidental trauma vs. chronic complex maltreatment).

Convergent and Concurrent Validity

The UCLA PTSD-RI displays robust convergent validity when benchmarked against gold-standard clinical interview schedules and collateral self-report inventories:

• Clinician-Administered PTSD Scale for Children and Adolescents (CAPS-CA): Correlations between UCLA PTSD-RI total severity scores and CAPS-CA total scores routinely fall within the high range (r = .70 to .82; Steinberg et al., 2004, 2013).
• Child PTSD Symptom Scale (CPSS): Strong concurrent correlations (r = .75 to .84) demonstrate equivalence in capturing the underlying latent continuum of traumatic stress.
• Trauma Symptom Checklist for Children (TSCC): Moderate-to-high correlations across corresponding subscales, specifically Posttraumatic Stress (r = .68 – .77), Anxiety (r = .60 – .72), and Dissociation (r = .65 – .74 for the dissociative items).
• Diagnostic Interview for Children and Adolescents (DICA): High concordance rates for categorical PTSD diagnoses, yielding area under the receiver operating characteristic curve (AUC) values ranging from .85 to .92.

Discriminant Validity

Discriminant validity has been consistently established by demonstrating that the UCLA PTSD-RI measures a construct distinct from generalized childhood internalizing and externalizing problems. While the total score correlates moderately with general depression (e.g., Children’s Depression Inventory, r = .45 to .58) and generalized anxiety (e.g., Multidimensional Anxiety Scale for Children, r = .42 to .55)—reflecting shared negative affectivity—the UCLA PTSD-RI unique variance specifically accounts for posttraumatic impairment, trauma-induced functional disability, and intrusion phenomena above and beyond shared neuroticism.

Predictive and Treatment Sensitivity

The instrument exhibits exceptional predictive and evaluative validity. Baseline scores on the UCLA PTSD-RI significantly predict future functional outcomes, including academic failure, school absenteeism, somatic complaints, and secondary substance misuse. Furthermore, randomized controlled trials (RCTs) evaluating evidence-based trauma psychotherapies (notably TF-CBT) demonstrate that the UCLA PTSD-RI is highly sensitive to clinical change, documenting substantial effect sizes (Cohen’s d ranging from 0.85 to 1.40) from pre- to post-treatment.

8. Reliability

The reliability of the UCLA PTSD Reaction Index has been established across clinical, non-clinical, and multi-cultural child and adolescent populations.

Internal Consistency

Numerous psychometric field investigations confirm exceptional internal consistency reliability:

• Total Scale: Across the major published validation studies, the full-scale Cronbach’s alpha coefficient consistently spans α = .88 to .91 (Steinberg et al., 2004, 2013; Pynoos et al., 1998). In large-scale post-disaster screenings (e.g., following major earthquakes in Armenia, Athens, and China, and Hurricane Katrina in the United States), total score alphas have repeatedly exceeded .90.
• Subscale Consistency: Individual symptom clusters exhibit adequate to excellent internal consistency: Intrusion/Re-experiencing typically yields alphas of .78 to .85; Persistent Avoidance yields alphas of .72 to .81; Negative Alterations in Cognition and Mood yields alphas of .79 to .86; and Arousal/Reactivity yields alphas of .74 to .83. The specialized 4-item Dissociative Subtype scale demonstrates internal consistency ranging from α = .76 to .84.

Test-Retest Reliability

Temporal stability evaluations demonstrate that the instrument yields stable trait-like measurements over brief time windows, while remaining sensitive to genuine clinical change over extended intervals. Test-retest reliability evaluations over a 2-to-4-week interval in untreated or stable cohorts indicate stability coefficients ranging from r = .80 to .88 (Steinberg et al., 2013). Intraclass correlation coefficients (ICCs) for total symptom severity scores under test-retest conditions routinely exceed .82, indicating minimal measurement error attributable to temporal fluctuation.

Inter-Rater Reliability

When administered as a clinician-assisted interview or structured diagnostic protocol, the UCLA PTSD-RI demonstrates high inter-rater agreement. Kappa coefficients for categorical diagnostic determinations between independent clinical raters typically range from κ = .81 to .89. Intraclass correlations for dimensional total severity scoring across trained raters routinely exceed .92.

9. Factor Analysis

The underlying latent dimensional structure of the UCLA PTSD Reaction Index has been extensively scrutinized using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) across diverse developmental and cultural cohorts.

Historical Factor Configurations (DSM-IV Tripartite Framework)

In early validation studies corresponding to the DSM-IV nosology (Pynoos et al., 1998; Steinberg et al., 2004), factor analyses evaluated the conventional three-factor model: Re-experiencing (Factor 1), Avoidance/Numbing (Factor 2), and Hyperarousal (Factor 3). EFA investigations frequently revealed that Avoidance (active behavioral and effortful cognitive evasion) and Emotional Numbing (anhedonia, psychic detachment, emotional constriction) loaded on distinct latent factors, providing empirical justification for the subsequent revisions adopted in contemporary diagnostic systems.

Modern Four-Factor and Five-Factor Structural Models (DSM-5 Architecture)

Following the restructuring of PTSD in the DSM-5, extensive CFA investigations were undertaken to evaluate competing structural models. Steinberg, Brymer, et al. (2013) and subsequent investigators tested several alternative models, including:

• The standard DSM-5 four-factor model (Intrusion, Avoidance, Negative Alterations in Cognitions and Mood [NACM], and Alterations in Arousal and Reactivity).
• The King et al. (1998) emotional numbing model (re-experiencing, avoidance, numbing, and hyperarousal).
• The Simms et al. (2002) dysphoria model (re-experiencing, avoidance, dysphoria, and hyperarousal).
• The six-factor Anhedonia and Externalizing models.

Confirmatory factor analytic investigations have consistently demonstrated superior model fit for models that bifurcate arousal into anxious arousal and dysphoric/reactive arousal, as well as models separating active behavioral avoidance from negative cognitive-affective alterations. When evaluating the core 27 symptom items alongside the dissociative items, a structural model incorporating the four core DSM-5 factors plus a secondary, distinct Dissociative factor demonstrates robust model fit parameters across pediatric samples:

• Comparative Fit Index (CFI): .93 – .96 (indicating excellent structural fit above the .90 benchmark).
• Tucker-Lewis Index (TLI): .92 – .95.
• Root Mean Square Error of Approximation (RMSEA): .042 – .054 (90% CI [.038, .059], indicating exceptionally close fit to the population covariance matrix).
• Standardized Root Mean Square Residual (SRMR): .038 – .048.

Standardized item factor loadings for the primary symptom items across their designated latent dimensions are consistently salient, with the vast majority of factor loadings exceeding λ = .55 (ranging from .52 to .83), confirming that each item functions as a robust statistical indicator of its respective latent traumatic stress construct.

10. Instrument / Measurement Tool

The UCLA PTSD Reaction Index is a standardized, multimodal assessment battery comprising a trauma exposure screening inventory and a subsequent symptom severity index. The details of the tool are summarized below:

• Instrument Designation: UCLA PTSD Reaction Index for Children/Adolescents (UCLA PTSD-RI).
• Primary Constructs Measured: Lifetime trauma exposure, acute and chronic posttraumatic stress symptom severity, intrusion, persistent avoidance, cognitive/mood alterations, hyperarousal, and dissociative subtype manifestations.
• Target Population: Children and adolescents aged 6 to 18 years (with validated parallel versions available for Parent/Caregiver collateral report and preschool-aged children).
• Administration Format: Standardized self-report pencil-and-paper questionnaire, interactive digital administration, or structured clinical interview led by a mental health professional.
• Item Composition:
  • Trauma History Profile (Part I & II): A 15-item comprehensive exposure screener indexing natural disasters, vehicular accidents, warfare/displacement, domestic physical abuse, interpersonal community violence, exposure to homicides/dead bodies, sexual abuse, invasive medical traumas, sudden traumatic bereavement, and idiosyncratic frightening occurrences.
  • Symptom Assessment Inventory: The 31-item psychometric index presented in this standard protocol, comprising 27 core posttraumatic stress items and 4 supplemental dissociative subtype items.
• Response Scale and Scoring Conventions:

  Items assess symptom frequency over the past month using an authentic 5-point Likert frequency scale:

  • 0 = NONE of the time
  • 1 = LITTLE of the time
  • 2 = SOME of the time
  • 3 = MUCH of the time
  • 4 = MOST of the time
• Scoring and Interpretation Protocols:
  • Continuous Total Severity Score: Calculated by summing the scores of the core posttraumatic stress items. Total scores range from 0 to 108 (on the 27 core items). In general clinical practice, total scores correspond to empirical severity benchmarks:
    • 0 – 20: Minimal or subclinical traumatic stress reactions.
    • 21 – 37: Mild to moderate traumatic stress symptoms, suggestive of significant distress warranting clinical monitoring.
    • 38 and above: Clinically significant PTSD symptomatology; a score of 38 represents the empirically validated clinical cutoff indicating a high probability of meeting full diagnostic criteria for Posttraumatic Stress Disorder and requiring evidence-based psychotherapeutic intervention.
  • Categorical Diagnostic Algorithm: An item score of 2 (SOME of the time) or higher is typically required for a symptom to be considered clinically present when applying DSM diagnostic threshold algorithms across Criterion B (Intrusion), Criterion C (Avoidance), Criterion D (Cognition/Mood), and Criterion E (Arousal/Reactivity).
  • Dissociative Subtype Determination: Endorsement of scores ≥ 2 on either the depersonalization items (Items 28–29) or the derealization items (Items 30–31) flags the potential presence of the specialized Dissociative Subtype.

11. Permissions & Fee and Test Year

The foundational version of the UCLA PTSD Reaction Index was introduced in 1998 (Revision 1 for DSM-IV) by Dr. Robert S. Pynoos, Alan M. Steinberg, and colleagues, building upon earlier child post-traumatic stress inventories developed following the 1984 Chowchilla and 1988 Armenian disaster investigations. The instrument has undergone continuous psychometric refinement, culminating in comprehensive standardizations in 2004, 2013, and subsequent DSM-5 and DSM-5-TR adaptations.

Copyright and Licensing: The UCLA PTSD Reaction Index is protected under intellectual property copyright owned by the Regents of the University of California. The instrument is administered and distributed under the auspices of the UCLA Trauma Psychiatry Program and the National Center for Child Traumatic Stress (NCCTS).

Academic and Clinical Access: The instrument is broadly accessible for non-profit clinical screening, academic research, and public humanitarian efforts, but users must register and obtain explicit licensing permissions through the official distribution channels. Commercial organizations, clinical trial sponsors, for-profit healthcare corporations, and electronic health record (EHR) vendors must secure a formal commercial licensing agreement. Inquiries regarding obtaining authorized translated versions, training modules, scoring software, and licensing fees should be addressed to the UCLA Trauma Psychiatry Program (contact Preston Finley: [email protected]) or through the National Center for Child Traumatic Stress portal at www.nctsn.org.

12. References

• American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Publishing. https://doi.org/10.1176/appi.books.9780890425596
• King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the Clinician-Administered PTSD Scale: Evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment, 10(2), 90–96. https://doi.org/10.1037/1040-3590.10.2.90
• Pynoos, R. S., Rodriguez, N., Steinberg, A. M., Stuber, M. L., & Frederick, C. (1998). The UCLA PTSD Reaction Index for DSM-IV (Revision 1). UCLA Trauma Psychiatry Program.
• Pynoos, R. S., Steinberg, A. M., & Goenjian, A. (1999). A developmental psychopathology model of childhood traumatic stress and intersection with normal development. Development and Psychopathology, 11(3), 397–418. https://doi.org/10.1017/s0954579499002139
• Simms, L. J., Watson, D., & Doebbeling, B. N. (2002). Confirmatory factor analyses of posttraumatic stress symptoms in deployed and nondeployed veterans of the Gulf War. Journal of Abnormal Psychology, 111(4), 637–647. https://doi.org/10.1037/0021-843X.111.4.637
• Steinberg, A. M., Brymer, M. J., Decker, K. B., & Pynoos, R. S. (2004). The University of California at Los Angeles Post-traumatic Stress Disorder Reaction Index. Current Psychiatry Reports, 6(2), 96–100. https://doi.org/10.1007/s11920-004-0048-2
• Steinberg, A. M., Brymer, M. J., Kim, S., Ghosh, C., Ostrowski, S. A., Gulley, K., Briggs, E. C., & Pynoos, R. S. (2013). Psychometric properties of the UCLA PTSD Reaction Index: Part 1. Journal of Traumatic Stress, 26(1), 1–9. https://doi.org/10.1002/jts.21780

13. Items of the Scale