Mechanisms of Change in Written Exposure Treatment of Posttraumatic Stress Disorder

Heart rate reactivity during trauma recall as a predictor of treatment outcome in cognitive processing therapy for PTSD

Emotional engagement when recollecting a trauma memory is considered a key element of effective trauma-focused therapy. Research has shown that reduced physiological reactivity during trauma recall is associated with worse treatment outcomes for posttraumatic stress disorder (PTSD), but this has yet to be examined in a cognitively oriented treatment. This study examined whether pretreatment heart rate (HR) reactivity during trauma recall predicts PTSD symptom improvement and treatment dropout during Cognitive Processing Therapy (CPT) for PTSD. Participants were 142 women with PTSD secondary to interpersonal violence enrolled in one of two clinicals trials. HR reactivity reflected the mean increase in HR after listening to two 30-s scripts of the trauma memory prior to treatment. Linear mixed-effects models showed the effect of HR reactivity on change in total PTSD symptoms was not significant, but lower HR reactivity predicted less improvement in reexperiencing and avoidance and was associated with increased dropout. Findings suggest pretreatment physiological reactivity to the trauma memory may be a prognostic indicator of some elements of treatment response in CPT. Results tentatively support the importance of emotional activation during trauma recall in cognitive treatment of PTSD, though more research is needed to clarify how low HR reactivity impacts treatment.

A systematic review of literature examining mediators and mechanisms of change in empirically supported treatments for posttraumatic stress disorder

Despite the availability of empirically supported treatments (ESTs) for posttraumatic stress disorder (PTSD), relatively little is known regarding these treatments' mechanisms of change. This systematic review moves beyond previous reviews by summarizing the findings and reviewing the methodological quality of literature that specifically examined mediators/mechanisms of change in ESTs for PTSD. Studies were included if they were written in English, empirical, peer-reviewed, claimed to study mediators/mechanisms of a recommended PTSD treatment, measured the mediator/mechanism during or before and after treatment, and included a posttreatment PTSD or global outcome (e.g., functioning). PsycINFO and PubMed were searched on October 7, 2022. Two coders screened and coded studies. Sixty-two eligible studies were identified. The most consistent mediator/mechanism was reduction in negative posttraumatic cognitions, followed by between-session extinction and decreased depression. Only 47% of studies measured the mediator/mechanism before the outcome and measured the mediator/mechanism and outcome at least three times, and 32% also used growth curve modeling to establish temporal precedence of change in the mediator/mechanism and outcome. Many of the mediators/mechanisms examined had weak or no empirical support. Results highlight the need for improved methodological rigor in treatment mediator and mechanism research. Implications for clinical care and research are discussed. PROSPERO ID: 248088.

Does fear reduction predict treatment response to exposure for social anxiety disorder?

BACKGROUND AND OBJECTIVES

Fear activation and reduction have traditionally been considered important mechanisms of exposure therapy. Evidence to date is mixed and impeded by inadequate methodology. This study examined the extent to which fear activation and reduction within and across exposures predicted treatment outcomes for social anxiety disorder within a paradigm suitable for their measurement.

METHODS

Sixty-eight adults with social anxiety disorder and fear of public speaking completed seven exposure sessions, each consisting of seven speeches conducted in virtual reality. Exposures were identical in duration, task requirements, and virtual public speaking situation. Fear was measured with skin conductance and subjective distress ratings. At baseline and post-treatment, participants completed a public speaking behavioral approach test with a panel of confederate judges; subjective fear was measured. A standardized questionnaire of anxiety symptoms was administered at baseline, post-treatment, and one-month follow-up.

RESULTS

No indices of within- or between-session fear reduction, measured by subjective distress and skin conductance response, predicted treatment outcome. One measure of fear activation was associated with outcomes such that less activation predicted greater symptom reduction; remaining indices did not predict outcomes.

LIMITATIONS

Data were collected in the context of a randomized controlled trial of scopolamine; drug group was included in analytic models to account for drug influence. VR exposures elicited mild levels of distress that may underestimate levels of distress in clinical settings.

CONCLUSIONS

Findings failed to support fear activation or reduction within or across exposure sessions as significant predictors of treatment outcome for social anxiety. Treatment implications are discussed.

Using Client Narratives to Identify Predictors of Outcome in Written Exposure Therapy and Cognitive Processing Therapy

Written exposure therapy (WET) is a brief, five-session treatment for posttraumatic stress disorder (PTSD) that aims to improve access to care. WET has been demonstrated to be an efficacious PTSD treatment with lower rates of dropout and noninferior PTSD symptom outcome compared to cognitive processing therapy (CPT), a 12-session, gold-standard treatment. To identify predictors of treatment outcome in both WET and CPT, the current study examined the content of participants' written narratives. Participants were 123 adults with PTSD who were randomly assigned to receive WET (n = 61) or CPT (n = 62). The Change and Growth Experiences Scale (CHANGE) coding system was used to code all available narratives in both treatment conditions for variables hypothesized to be relevant to therapeutic change. Linear regression analyses revealed that in WET, higher average levels of accommodated (healthy, balanced) beliefs and an increase in accommodated beliefs from the first to the final impact statement predicted better PTSD symptom outcome at 12 weeks postrandomization. In CPT, higher average levels of overgeneralized and accommodated beliefs and lower levels of avoidance expressed in the narratives predicted better PTSD outcome. There were no significant predictors of outcome in analyses of change from the first to final impact statement in CPT. These findings add to research identifying predictors of change in WET and CPT by highlighting the importance of low avoidance in CPT and of trauma-related cognitions in both CPT and WET, even though WET is a brief written intervention that does not explicitly target cognitive change.

Comparing Heart Rate Analytical Methods to Examine Engagement During Imaginal Prolonged Exposure Therapy: Multicase Study

OBJECTIVE

As mobile health technologies proliferate, their use during exposure-based therapies has the potential to illuminate treatment mechanisms. The primary purpose of this study was to examine three approaches to using continuously collected physiological data of patients with posttraumatic stress disorder during prolonged exposure (PE) therapy, in an effort to examine physiological markers of treatment response.

METHODS

Photoplethysmogram-measured heart rates from three non-Hispanic White male veterans, during clinic-based PE therapy sessions, were analyzed to assess three potential therapeutic mechanisms: emotional engagement (examined via correlation analysis between self-reported peak distress ratings and objectively measured peak heart rate in the minute prior to distress ratings), initial emotion activation (examined through time to peak heart rate and peak self-reported distress), and extinction processes within and between therapy sessions (examined via multilevel modeling of within- and between-person changes in heart rate over time and across imaginal PE therapy sessions).

RESULTS

Results for each analytical approach with each patient are presented, and benefits and limitations of each approach are discussed. Treatment outcomes were as follows: one participant with overengagement did not benefit from PE, one participant with initial underengagement demonstrated clinical improvement, and one participant with optimal engagement had associated clinical improvements.

CONCLUSIONS

Mobile health technologies may provide a new avenue toward unveiling treatment mechanisms in psychotherapy. Use of standardized analytical approaches will enable cross-study comparison and greater understanding of treatment mechanisms, ultimately leading to increased treatment response.

Temporal Relationship Between Change in Subjective Distress and PTSD Symptom Decrease During Prolonged Exposure Therapy for Posttraumatic Stress Disorder

There is growing evidence that change in distress is an indicator of change during Prolonged Exposure (PE) for posttraumatic stress disorder (PTSD). However, temporal sequencing studies investigating whether change in distress precedes PTSD symptom decline are lacking. These studies are essential since the timeline between indicators of change and treatment outcome is a key assumption for mediation. The aim of the present study was to assess the temporal relationship between within- and between-session change in subjective distress and PTSD symptom decrease. We analyzed session data from 86 patients with PTSD. Data were analyzed using dynamic panel models. We distinguished temporal effects (within-persons) from averaged effects (between-persons). Results regarding the temporal effect showed that within-session change in subjective distress preceded PTSD symptom improvement while the reversed effect was absent. Averaged within-session change in subjective distress was also related to PTSD symptom improvement. Results regarding the temporal effect of between-session change in subjective distress showed that it did not precede PTSD symptom improvement. Averaged between-session change in subjective distress was related to PTSD symptom improvement. This study provides evidence for within- but not between-session change in subjective distress as indicator of change during PE. We also found that the way of modeling potential indicators of change affects results and implications. We recommend future studies to analyze mediators during treatment using temporal rather than averaged effects.

Sudden Gains in Two Trauma-Focused Treatments for Posttraumatic Stress Disorder

In the current study, we examined the degree to which sudden gains (large, rapid, and stable symptom reduction in a one-session interval) predicted treatment outcome in adults randomized to two different trauma-focused treatments. Adults diagnosed with PTSD were randomized to either written exposure therapy (WET; n = 63), a brief, exposure-based treatment for posttraumatic stress disorder (PTSD), or the more time-intensive Cognitive Processing Therapy (CPT; n = 63). Findings showed that 20.6% of participants who received WET and 17.5% of participants who received CPT experienced sudden gains. Sudden gains occurred earlier in WET (M session = 2.69, SD = 0.75) than in CPT (M session = 5.64, SD = 3.01). However, there were no treatment condition differences in the magnitude of the sudden gains. Treatment outcomes were significantly better for those who experienced sudden gains compared with those who did not, regardless of treatment assignment. Exploratory analyses of participants' trauma narratives revealed that expressing more negative emotion predicted the occurrence of sudden gains in both treatment conditions. Negative beliefs about the self and others did not predict sudden gains. The findings are discussed in terms of how they may help identify individual early response patterns that predict outcomes in trauma-focused treatments.

Relevance of Objective Measures in Psychiatric Disorders-Rest-Activity Rhythm and Psychophysiological Measures

PURPOSE OF REVIEW

We present a review of recent methods of objective measurement in psychiatry and psychology with a focus on home monitoring and its utility in guiding treatment.

RECENT FINDINGS

For individualized diagnostics and treatment of insomnia, actigraphy can generate clinically useful graphical presentations of sleep timing and patterns. Psychophysiological measures may complement psychometrics by tracking parallel changes in physiological responses and emotional functioning, especially during therapy for trauma symptoms and emotion regulation. It seems that rather than defining universal cut-offs, an individualised range of variability could characterize treatment response. Wearable actigraphy and psychophysiological sensors are promising devices to provide biofeedback and guide treatment. Use of feasible and reliable technology during experimental and clinical procedures may necessitate defining healthy and abnormal responses in different populations and pathological states. We present a "call for action" towards further collaborative work to enable large scale use of objective measures.

The temporal sequence of change in PTSD symptoms and hypothesized mediators in Cognitive Processing Therapy and Written Exposure Therapy for PTSD

We examined whether extinction or changes negative trauma-related beliefs occur either prior to or concurrently with changes in posttraumatic stress symptoms among individuals who received either Cognitive Processing Therapy (CPT) or Written Exposure Therapy (WET) using statistical methods that permit proper discernment of temporal sequence. Community participants with PTSD (N = 126) were evenly randomized to 12 sessions of CPT or 5 sessions of WET. We assessed within- and between-session changes in arousal and valence and changes in trauma-related beliefs 6-, 12-, 24-, 36- and 60-weeks following the first treatment session. Between-session change in post-session emotional valence temporally preceded PTSD symptom reduction among participants who received WET but did not predict subsequent symptom reduction. Although negative trauma-related beliefs changed in parallel with and correlated with PTSD symptom reduction in both conditions, this change did not temporally precede symptom reduction. Our results are inconsistent with those from prior studies and suggest these constructs may more appropriately be characterized as correlates, rather than mediators, of symptom reduction. These results highlight the value of discernment of the temporal sequence of change between hypothesized mediators and symptoms and underscore that we still have much to learn about how evidence-based treatments reduce PTSD symptoms.

Culturally Adapted Cognitive Behavioral Therapy Plus Problem Management (CA-CBT+) With Afghan Refugees: A Randomized Controlled Pilot Study

Culturally adapted cognitive behavioral therapy (CA-CBT) is a well-evaluated, transdiagnostic group intervention for refugees that uses psychoeducation, meditation, and stretching exercises. In the current study, we added problem-solving training to CA-CBT and evaluated this treatment (i.e., CA-CBT+) in a randomized controlled pilot trial with a sample of Farsi-speaking refugees. Participants (N = 24) were male refugees diagnosed with DSM-5 PTSD, major depressive disorder, and anxiety disorders who were randomly assigned to either a treatment or waitlist control (WLC) condition. Treatment components were adapted both to the specific cultural background and the current social problems of asylum seekers. Assessments were performed pretreatment, 12-weeks posttreatment, and 1-year follow-up. The primary treatment outcome was the General Health Questionnaire (GHQ-28); secondary outcome measures included the Posttraumatic Stress Disorder Checklist, Patient Health Questionnaire, Somatic Symptom Scale, World Health Organization Quality of Life, and Emotion Regulation Scale. Eleven of 12 participants were randomized to CA-CBT+ completed treatment. Based on intent-to-treat data, large between-group effect sizes were seen at posttreatment in the GHQ-28, d = 3.0, and for most secondary outcome measures. Improvements for individuals in the treatment group decreased at 1-year follow-up, but effect sizes demonstrated continued large improvements on all measures as compared to pretreatment levels. In summary, CA-CBT+ led to large improvements in general psychopathological distress and quality of life, which were maintained in the long term. In addition, the dropout rate was very low, with delivery in group format. Thus, problem-solving training appears to be a promising addition to CA-CBT.

The efficacy of written exposure therapy versus imaginal exposure delivered online for posttraumatic stress disorder: Design of a randomized controlled trial in Veterans

Adapting evidence-based treatments for online delivery has potential to significantly increase the reach of effective care to Veterans with posttraumatic stress disorder (PTSD). This paper describes the rationale for and methods of a randomized controlled trial comparing the efficacy and efficiency of written exposure therapy versus imaginal exposure for PTSD delivered in a novel online and variable length format. Participants will be 300 Veterans seeking treatment for clinically significant symptoms of PTSD. Participants will be randomly assigned to either written exposure or imaginal exposure via verbal recounting and will complete between 4 and 8 online therapy sessions facilitated by trained peer support specialists. Treatment is terminated before session 8 if the PTSD symptom improvement criterion is met. Assessments will be conducted at baseline, post-treatment, and at 3-month follow-up. The primary hypotheses are that written exposure therapy will be noninferior to imaginal exposure with respect to treatment efficacy and efficiency. Secondary hypotheses relate to identifying and comparing potential mediators of PTSD treatment outcome, including trauma-related cognitions and emotion regulation.

Addressing Diversity in PTSD Treatment: Clinical Considerations and Guidance for the Treatment of PTSD in LGBTQ Populations

Purpose of review

Trauma exposure is widespread but is especially common among lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals. LGBTQ individuals also experience higher rates of discrimination, victimization, and minority stress which can complicate posttraumatic stress disorder (PTSD) treatment but also represent independent intervention targets. In this review, we highlight existing evidence-based practices, current limitations, and provide recommendations for care in the absence of established guidelines for treatment PTSD among LGBTQ patients.

Recent findings

Trauma-focused therapies (e.g., CPT, PE) and medications (e.g., SSRIs, SNRIs) have shown benefit for people with PTSD. However, evaluations of these interventions have failed to examine the role of LGBTQ identities in recovery from trauma, and existing PTSD treatments do not account for ongoing threat to safety or the pervasive minority stress experienced by LGBTQ patients. In addition, many LGBTQ patients report negative experiences with healthcare, necessitating increased education and cultural awareness on the part of clinicians to provide patient-centered care and, potentially, corrective mental health treatment experiences.

Summary

Providers should routinely assess trauma exposure, PTSD, and minority stress among LGBTQ patients. We provide assessment and screening recommendations, outline current evidence-based treatments, and suggest strategies for integrating existing treatments to treat PTSD among LGBTQ patients.

Adapting Evidence-Based Treatments for Digital Technologies: a Critical Review of Functions, Tools, and the Use of Branded Solutions

PURPOSE OF REVIEW

We provide a critical review of digital technologies in evidence-based treatments (EBTs) for mental health with a focus on the functions technologies are intended to serve. The review highlights issues related to clarity of purpose, usability, and assumptions related to EBT technology integration, branding, and packaging.

RECENT FINDINGS

Developers continue to use technology in creative ways, often combining multiple functions to convey existing EBTs or to create new technology-enabled EBTs. Developers have a strong preference for creating and investigating whole-source, branded solutions related to specific EBTs, in comparison to developing or investigating technology tools related to specific components of behavior change, or developing specific clinical protocols that can be delivered via existing technologies. Default assumptions that new applications are required for each individual EBT, that EBTs are best served by the use of only one technology solution rather than multiple tools, and that an EBT-specific technology product should include or convey all portions of an EBT slow scientific progress and increase risk of usability issues that negatively impact uptake. We contend that a purposeful, functions-based approach should guide the selection, development, and application of technology in support of EBT delivery.

Brief novel therapies for PTSD: Written Exposure Therapy

PURPOSE OF REVIEW

Written Exposure Therapy (WET) is a 5-session exposure-based intervention for the treatment of posttraumatic stress disorder (PTSD). WET was developed through a series of systematic evaluations of the expressive writing procedure. It is an efficient intervention, requiring limited patient and therapist time and no between-session assignments. The treatment results in statistically and clinically significant symptom change among individuals, including veterans, with PTSD.

RECENT FINDINGS

WET has been shown to be non-inferior to Cognitive Processing Therapy (CPT), a more intensive form of PTSD treatment. Additionally, WET resulted in substantially lower rates of treatment dropout compared to CPT (6% versus 39%). Moderator analyses of the rate of symptom change during treatment indicated that WET performed equally well for participants regardless of age, gender, comorbid depression, or estimated full scale IQ.

SUMMARY

WET represents a viable option for the efficacious, brief treatment of PTSD and may have significant strengths compared to other manualized psychotherapeutic approaches.

Effect of expressive and neutral writing on respiratory sinus arrhythmia response over time

BACKGROUND AND OBJECTIVES

Parasympathetic activity, as indexed by respiratory sinus arrhythmia (RSA), underlies key aspects of emotional and cognitive self-regulation. Examining time-varying RSA response during expressive writing about trauma may help inform theory about mechanisms of this intervention. The present study investigated changes in RSA during expressive writing.

METHODS

Participants (N = 246, M_age = 21.5 years, 72% female) were randomly assigned to expressive or neutral writing conditions and wrote for three 20-min sessions. RSA was measured continuously during the first and third writing session.

RESULTS

Linear mixed model analyses of RSA changes within and across sessions by writing groups found that neutral writers, but not expressive writers, exhibited change in RSA. The overall RSA changes during expressive and neutral writing are consistent with theory about the relationship between cognitive and emotional processing mechanisms and vagal activation.

LIMITATIONS

As the present study was not a clinical sample selected on trauma exposure, findings should be considered preliminary. Additionally, engagement of affective and cognitive processes was only hypothesized, as manipulation checks were not performed.

CONCLUSIONS

The present study illustrates the benefits of examining changes in RSA over time. Future work with clinical samples should include additional measures and tasks to better define these mechanisms and rule out alternative hypotheses.

An empirical review of potential mediators and mechanisms of prolonged exposure therapy

Prolonged exposure (PE) is an empirically-supported treatment for posttraumatic stress disorder (PTSD), but the precise mechanism(s) by which PE promotes symptom change are not well established. Understanding how PE works is critical to improving clinical outcomes, advancing dissemination efforts, and enhancing transdiagnostic models of psychopathology. However, mechanisms research conducted in clinical treatment settings is complex, and findings may be difficult to interpret without appropriate context. This is the first review of potential mechanisms of PE to provide such context, by rigorously evaluating empirical findings in line with essential criteria for effective research on mechanisms (or mediators). We begin by describing six putative mechanisms identified by emotional processing theory and contemporary models of fear extinction, before thoroughly reviewing empirical findings from clinical research on PE and similar PTSD treatments. We provide a detailed description of each study and mechanism test, as well as ratings of strength of evidence and quality of evaluation based on a novel rating scheme. We highlight variables with strong evidence (belief change and between-session habituation), intermediate evidence (inhibitory learning and emotional engagement), and minimal support (narrative organization and within-session habituation). After discussing limitations of the extant literature and this review, we summarize specific challenges for research on PE mechanisms and highlight directions for future study based on clinical and research implications.

Trauma-related emotions and radical acceptance in dialectical behavior therapy for posttraumatic stress disorder after childhood sexual abuse

BACKGROUND

Posttraumatic Stress Disorder (PTSD) related to childhood sexual abuse (CSA) is often associated with a wide range of trauma-related aversive emotions such as fear, disgust, sadness, shame, guilt, and anger. Intense experience of aversive emotions in particular has been linked to higher psychopathology in trauma survivors. Most established psychosocial treatments aim to reduce avoidance of trauma-related memories and associated emotions. Interventions based on Dialectical Behavior Therapy (DBT) also foster radical acceptance of the traumatic event.

METHODS

This study compares individual ratings of trauma-related emotions and radical acceptance between the start and the end of DBT for PTSD (DBT-PTSD) related to CSA. We expected a decrease in trauma-related emotions and an increase in acceptance. In addition, we tested whether therapy response according to the Clinician Administered PTSD-Scale (CAPS) for the DSM-IV was associated with changes in trauma-related emotions and acceptance. The data was collected within a randomized controlled trial testing the efficacy of DBT-PTSD, and a subsample of 23 women was included in this secondary data analysis.

RESULTS

In a multilevel model, shame, guilt, disgust, distress, and fear decreased significantly from the start to the end of the therapy whereas radical acceptance increased. Therapy response measured with the CAPS was associated with change in trauma-related emotions.

CONCLUSIONS

Trauma-related emotions and radical acceptance showed significant changes from the start to the end of DBT-PTSD. Future studies with larger sample sizes and control group designs are needed to test whether these changes are due to the treatment.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT00481000.

Constructive and Unproductive Processing of Traumatic Experiences in Trauma-Focused Cognitive-Behavioral Therapy for Youth

Although there is substantial evidence to support the efficacy of cognitive-behavioral treatments (CBT) for posttraumatic stress disorder (PTSD), there is some debate about how these treatments have their effects. Modern learning theory and cognitive and emotional processing theories highlight the importance of reducing avoidance, facilitating the constructive processing of feared experiences, and strengthening new inhibitory learning. We examined variables thought to be associated with unproductive and constructive processing of traumatic experiences in a sample of 81 youth with elevated PTSD symptoms, who received Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) for abuse or traumatic interpersonal loss. Sessions during the trauma narrative phase of TF-CBT were coded for indicators of unproductive processing (overgeneralization, rumination, avoidance) and constructive processing (decentering, accommodation of corrective information), as well as levels of negative emotion. In previous analyses of this trial (Ready et al., 2015), more overgeneralization during the narrative phase predicted less improvement in internalizing symptoms at posttreatment and a worsening of externalizing symptoms over the 12-month follow-up. In contrast, more accommodation predicted improvement in internalizing symptoms and also moderated the negative effects of overgeneralization on internalizing and externalizing symptoms. The current study examined correlates of overgeneralization and accommodation. Overgeneralization was associated with more rumination, less decentering, and more negative emotion, suggesting immersion in trauma-related material. Accommodation was associated with less avoidance and more decentering, suggesting a healthy distance from trauma-related material that might allow for processing and cognitive change. Decentering also predicted improvement in externalizing symptoms at posttreatment. Rumination and avoidance showed important associations with overgeneralization and accommodation, respectively, but did not predict treatment outcomes. This study identifies correlates of overgeneralization and accommodation that might shed light on how these variables relate to unproductive and constructive processing of traumatic experiences.

Psychological Mechanisms of PTSD and Its Treatment

Psychological mechanisms can be defined as processes or events that are responsible for specific changes in psychological outcomes. In psychotherapy research, mechanisms are the factors through which interventions produce change. In this article, we explain the importance of identifying psychological mechanisms, describe methods for identifying them, and analyze recent literature on the psychological mechanisms underlying the development and treatment of posttraumatic stress disorder (PTSD). Based on the findings of recent investigations (from 2013 to present), we focus on four putative mechanisms: emotional engagement, extinction and contextualization, distress tolerance, and negative posttraumatic cognitions. Future directions for psychological mechanism research are also outlined, including possible opportunities for capitalizing on the most promising mechanisms identified to date.

Brief treatment for PTSD: A non-inferiority trial

Prior studies have identified several psychosocial treatment approaches as effective for posttraumatic stress disorder (PTSD). Unfortunately, a substantial minority of individuals who receive these treatments drop out prematurely. Moreover, a considerable number of individuals in need of PTSD treatment do not present for treatment due to time constraints and other barriers to care. Thus, there is a need to develop alternative evidence-based PTSD treatments that have lower treatment dropout rates and address current barriers to receiving care. One recently developed PTSD treatment that has demonstrated efficacy and potentially meets these criteria is Written Exposure Therapy (WET), a 5-session treatment protocol that promotes recovery through writing about the trauma event as well as one's thoughts and feelings about it without any assigned homework. In an ongoing randomized controlled trial (RCT) we are investigating whether WET is equally efficacious as Cognitive Processing Therapy (CPT), a treatment that typically requires more therapist training and more therapy sessions. The study sample consists of 126 adults diagnosed with PTSD who are randomly assigned to either WET (n=63) or CPT (n=63). Participants are assessed prior to treatment and 6-, 12-, 24-, 36-, and 60-weeks after the first treatment session. The primary outcome measure is PTSD symptom severity assessed with the Clinician Administered PTSD Scale for DSM-5. Given the prevalence of PTSD and the aforementioned limitations of currently available first-line PTSD treatments, the identification of a brief, efficacious treatment that is associated with reduced patient dropout would represent a significant public health development.