Temporal sequencing of change in trauma-related beliefs and therapeutic alliance during prolonged exposure and sertraline for chronic PTSD.

OBJECTIVE: Changes in trauma-related beliefs and therapeutic alliance have been found to temporally precede symptom reduction; however, it is likely these processes do not act in isolation but rather in interactive ways. METHODS: The present study examined the temporal relationships between negative posttraumatic cognitions (PTCI) and therapeutic alliance (WAI) in 142 patients who were part of a randomized trial comparing prolonged exposure (PE) to sertraline for chronic PTSD. RESULTS: Using time-lagged mixed regression models, improvements in the therapeutic alliance predicted subsequent improvements in trauma-related beliefs (d = 0.59), an effect accounted for by between-patient variability (d = 0.64) compared to within-patient variability (d = .04) giving weaker support to the causal role of alliance on outcome. Belief change did not predict improvements in alliance and neither model was moderated by treatment type. CONCLUSION: Findings suggest alliance may not be an independent driver of cognition change and point to the need for additional study of the impact of patient characteristics on treatment processes.

Rare copy number variation in posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is a heritable (h2 = 24-71%) psychiatric illness. Copy number variation (CNV) is a form of rare genetic variation that has been implicated in the etiology of psychiatric disorders, but no large-scale investigation of CNV in PTSD has been performed. We present an association study of CNV burden and PTSD symptoms in a sample of 114,383 participants (13,036 cases and 101,347 controls) of European ancestry. CNVs were called using two calling algorithms and intersected to a consensus set. Quality control was performed to remove strong outlier samples. CNVs were examined for association with PTSD within each cohort using linear or logistic regression analysis adjusted for population structure and CNV quality metrics, then inverse variance weighted meta-analyzed across cohorts. We examined the genome-wide total span of CNVs, enrichment of CNVs within specified gene-sets, and CNVs overlapping individual genes and implicated neurodevelopmental regions. The total distance covered by deletions crossing over known neurodevelopmental CNV regions was significant (beta = 0.029, SE = 0.005, P = 6.3 × 10-8). The genome-wide neurodevelopmental CNV burden identified explains 0.034% of the variation in PTSD symptoms. The 15q11.2 BP1-BP2 microdeletion region was significantly associated with PTSD (beta = 0.0206, SE = 0.0056, P = 0.0002). No individual significant genes interrupted by CNV were identified. 22 gene pathways related to the function of the nervous system and brain were significant in pathway analysis (FDR q < 0.05), but these associations were not significant once NDD regions were removed. A larger sample size, better detection methods, and annotated resources of CNV are needed to explore this relationship further.

WhatsApp supervision for a lay-led Islamic trauma-focused intervention in Somaliland: Qualitative content analysis.

Clinical supervision is critical for the uptake of psychotherapy but difficult to facilitate in countries with limited providers, resources, and internet infrastructure. Innovative supervision approaches are needed to increase access to mental health treatments in low-to-middle income countries (LMICs). This study examined the content and feasibility of remote WhatsApp text supervision conducted as part of an open clinical trial in Somaliland. Islamic Trauma Healing ITH) is a brief, group, lay-lead, trauma-focused, mosque-based intervention that has demonstrated initial efficacy in pilot studies in the United States and Somaliland. After a 2-day, in-person training, lay leaders led four groups of five to seven members focused on trauma-related psychopathology and community reconciliation. Somali lay leaders trained in ITH (n = 9) and the research team (n = 6) attended weekly WhatsApp supervision during the intervention. Content was logged and subjected to qualitative analysis by two coders. Comments related to intervention implementation indicated that lay leaders understood the treatment rationale, adhered to treatment procedures, and believed the intervention components to be helpful and culturally relevant. Themes related to engagement suggested perfect attendance across groups and high levels of participation. Lay leader psychoeducation and skill development; supervisor praise, support, and encouragement; and supervisee gratitude emerged as additional themes. Remote text supervision conducted via WhatsApp was technologically feasible and may have facilitated skill development and the effective implementation of this lay-led intervention. When tailored to the local context, remote supervision approaches hold promise for increasing access to services in LMICs with limited resources.

The effect of perceived life stress on posttraumatic stress disorder treatment outcome.

Life stress following trauma exposure is a consistent predictor of the development of posttraumatic stress disorder (PTSD). However, there is a dearth of research on the effect of life stress on PTSD treatment outcomes. The current study examined the effects of pretreatment levels of perceived life stress on treatment outcome in a sample of 200 individuals with PTSD who were randomized to receive either prolonged exposure (PE) therapy or sertraline as part of a clinical trial. Life stress over the year prior to treatment significantly interacted with treatment type to predict higher residual PTSD symptom severity, as assessed using the PTSD Symptom Scale-Interview, among participants who received sertraline but not those who received PE, ß = .24, p = .017, ∆R2 = .03. These findings were similar for self-reported depression severity, ß = .27, p = .008, ∆R2 = .04. Adherence to either PE homework or sertraline compliance did not mediate this association nor did life stress predict treatment retention for either treatment arm. Higher levels of perceived life stress may serve as a prescriptive predictor of PTSD treatment outcome, with PE remaining efficacious regardless of heightened pretreatment life stress. These findings encourage clinician confidence when providing PE to individuals with higher levels of life stress. Future researchers should examine the impact of PTSD treatment on perceived and objective measures of life stress to improve treatment for individuals who experience chronic stress.

Bridging the science-practice gap in treatment for posttraumatic stress disorder: Testing strategies to enhance beliefs toward exposure therapy.

OBJECTIVE: Exposure therapies (e.g., prolonged exposure [PE]), are first-line interventions for posttraumatic stress disorder but remain underutilized, partially due to providers' negative beliefs about these interventions. We examined two experimental strategies aimed at enhancing beliefs towards PE and subsequent utilization. METHOD: Clinicians (N = 155) were randomized to one of three conditions presenting a PE rationale: basic, empirically-based, or emotionally-based description. Participants were rerandomized to write or not write arguments for utilizing PE. Before and after PE rationales and 1-month later, participants completed questions about PE beliefs and utilization. RESULTS: Participants reported small yet durable belief change across all rationale conditions, with greatest change following the empirically-based description. Across conditions, belief change was not impacted by writing condition or associated with utilization. CONCLUSION: Addressing negative beliefs with empirical information may be a brief, cost-effective strategy to improve clinicians' beliefs toward PE. Complementary strategies that leverage belief modification to increase utilization are needed.

Islamic Trauma Healing: Integrating Faith and Empirically Supported Principles in a Community-Based Program.

Access to adequate, much less state-of-the-art, mental health care is a global problem. Natural disasters, civil war, and terrorist conflict have forcibly displaced millions of Muslims and have resulted in a remarkable level of individual and communitywide trauma exposure. As a result, many are at risk for posttraumatic stress and other trauma-related disorders. Many religiously oriented Muslims traditionally rely on Islamic principles and teachings, as well as their community, to cope with and address trauma-related distress. Islamic Trauma Healing is a six-session, lay-led group intervention developed within a Somali Muslim community that integrates evidence-based trauma-focused cognitive-behavioral therapy principles with cultural and religious practices aimed to enhance uptake and create an easily up-scalable intervention for a wide range of trauma. In sessions, narratives of prophets who have undergone trauma (e.g., Prophet Ayyub, faith during hard times) present Islamic principles and facilitate cognitive shifts. Group members spend individual time turning to Allah in dua (i.e., informal prayer), focused on exposure to trauma memories. Program themes arc across suffering to healing to growth following trauma. This paper describes the core theoretical principles and methods in the Islamic Trauma Healing program. We also describe leader perspectives and the program's train-the-trainer model, in which lay leaders are trained to further disseminate the program and allow Islamic Trauma Healing to be owned and sustained by the Muslim community.

Prolonged Exposure and Sertraline Treatments for Posttraumatic Stress Disorder Also Improve Multiple Indicators of Social Functioning.

Trauma survivors with posttraumatic stress disorder (PTSD) frequently also suffer from difficulties in social functioning that range across emotional, cognitive, and environmental domains. A detailed evaluation of the differential impacts of effective PTSD treatments on social functioning is needed. Men and women (N = 200) with chronic PTSD received 10 weeks of prolonged exposure (PE) or sertraline in a randomized clinical trial and were followed for 24 months. A secondary data analysis examined changes in social functioning with regard to fear of intimacy; receipt of social support; and distress, avoidance, and negative cognitions in social situations. Effects were examined between treatments over time, controlling for baseline functioning. There were large, durable improvements across all indices. Compared to sertraline, PE was more efficient at reducing fear of intimacy and distress from negative social cognitions by posttreatment, ds = 0.94-1.14. Patients who received sertraline continued to improve over the course of follow-up, ds = 0.54-1.17. The differential speed of therapeutic effects may argue for more direct mechanisms in cognitive behavioral interventions versus cascade effects in serotonin reuptake inhibitors. Notably, both treatments produced substantial social benefits for trauma survivors with social functioning difficulties, and effect sizes were comparable to typical reductions in PTSD, depression, and anxiety.

High expectancy and early response produce optimal effects in sertraline treatment for post-traumatic stress disorder.

BACKGROUND: Better indicators of prognosis are needed to personalise post-traumatic stress disorder (PTSD) treatments.AimsWe aimed to evaluate early symptom reduction as a predictor of better outcome and examine predictors of early response. METHOD: Patients with PTSD (N = 134) received sertraline or prolonged exposure in a randomised trial. Early response was defined as 20% PTSD symptom reduction by session two and good end-state functioning defined as non-clinical levels of PTSD, depression and anxiety. RESULTS: Early response rates were similar in prolonged exposure and sertraline (40 and 42%), but in sertraline only, early responders were four times more likely to achieve good end-state functioning at post-treatment (Number Needed to Treat = 1.8, 95% CI 1.28-3.00) and final follow-up (Number Needed to Treat = 3.1, 95% CI 1.68-16.71). Better outcome expectations of sertraline also predicted higher likelihood of early response. CONCLUSIONS: Higher expectancy of sertraline coupled with early response may produce a cascade-like effect for optimal conditions for long-term symptom reduction. Therefore, assessing expectations and providing clear treatment rationales may optimise sertraline effects. DECLARATION OF INTEREST: None.

Effects of treatment, choice, and preference on health-related quality-of-life outcomes in patients with posttraumatic stress disorder (PTSD).

PURPOSE: Health outcomes may depend on which treatment is received, whether choice of treatment is given, and whether a received treatment is the preferred therapy. We examined the effects of these key factors on the EuroQol-5D (EQ-5D-3L) in patients with PTSD. METHODS: Two hundred patients aged 18-65 years with PTSD diagnosis enrolled in a doubly randomized preference trial (DRPT) examining treatment, choice of treatment, and treatment-preference effects of prolonged exposure therapy (PE) and pharmacotherapy with sertraline (SER) (clinicaltrials.gov Identifier: NCT00127673). We performed difference-in-difference analysis to estimate the treatment effects of prolonged exposure therapy (PE) as compared to pharmacotherapy with sertraline (SER), receipt of choice versus no-choice of treatment, and receipt of preferred versus non-preferred treatment on health-related quality-of-life (HRQOL) outcome using the EQ-5D-3L completed at baseline and 10-week post-treatment. RESULTS: The treatment effects of PE on the EQ-5D scores in overall patients and subgroup of patients who preferred PE were 0.150 (p = 0.025) and 0.223 (p < 0.001), respectively. The effects of treatment choice were 0.088 (p = 0.050) and 0.156 (p = 0.043) in overall patients and subgroup of patients received SER, respectively. The effects of treatment preference were 0.101 (p = 0.038) and 0.249 (p = 0.004) in overall patients and subgroup of patients SER, respectively. CONCLUSIONS: Overall, PE is associated with better improved HRQOL, especially in patients who prefer it. Independently, allowing patients to choose their preferred treatment resulted in better HRQOL than either assigning them a treatment or giving them a treatment that is not preferred.

Assessing for suicidal behavior in youth using the Achenbach System of Empirically Based Assessment.

This study investigated the clinical utility of the Achenbach System of Empirically Based Assessment (ASEBA) for identifying youth at risk for suicide. Specifically, we investigated how well the Total Problems scores and the sum of two suicide-related items (#18 "Deliberately harms self or attempts suicide" and #91 "Talks about killing self") were able to distinguish youth with a history of suicidal behavior. Youth (N = 1117) aged 5-18 were recruited for two studies of mental illness. History of suicidal behavior was assessed by semi-structured interviews (K-SADS) with youth and caregivers. Youth, caregivers, and a primary teacher each completed the appropriate form (YSR, CBCL, and TRF, respectively) of the ASEBA. Areas under the curve (AUCs) from ROC analyses and diagnostic likelihood ratios (DLRs) were used to measure the ability of both Total Problems T scores, as well as the summed score of two suicide-related items, to identify youth with a history of suicidal behavior. The Suicide Items from the CBCL and YSR performed well (AUCs = 0.85 and 0.70, respectively). The TRF Suicide Items did not perform better than chance, AUC = 0.45. The AUCs for the Total Problems scores were poor-to-fair (0.33-0.65). The CBCL Suicide Items outperformed all other scores (ps = 0.04 to <0.0005). Combining the CBCL and YSR items did not lead to incremental improvement in prediction over the CBCL alone. The sum of two questions from a commonly used assessment tool can offer important information about a youth's risk for suicidal behavior. The low burden of this approach could facilitate wide-spread screening for suicide in an increasingly at-risk population.

Repeated trauma exposure does not impair distress reduction during imaginal exposure for posttraumatic stress disorder.

BACKGROUND: Based on experimental research on threat extinction, individuals exposed to repeated traumatic events may have impaired outcome in exposure therapy compared to those who have experienced a single trauma (Lang & McTeague, ). This study examined whether repeated trauma exposure predicts smaller changes in self-reported distress during imaginal exposure and worse outcomes for patients with posttraumatic stress disorder (PTSD). METHODS: Adults (N = 116) with chronic PTSD received up to 10 sessions of prolonged exposure (PE) therapy. Trauma exposure was assessed via interview and number of traumatic events were summed for each participant. To examine reductions in distress during treatment, mean and peak values of distress during imaginal exposure were calculated for the first imaginal session (initial distress activation) and subsequent sessions (between-session change in distress). Change in PTSD symptoms from pre- to posttreatment and follow-up provided an additional index of outcome. RESULTS: In-session distress during imaginal exposure decreased over the course of treatment. PTSD symptoms also decreased over treatment, with gains being maintained through follow-up. Repeated trauma exposure was not significantly correlated with initial distress activation. Additionally, linear mixed-model analyses showed no significant association between repeated trauma exposure and between-session change in distress or PTSD symptoms. CONCLUSIONS: Contrary to recent speculation, repeated trauma exposure did not predict less change in self-reported distress during imaginal exposure or worse PTSD outcomes. The bench-to-bedside linkage of threat extinction to exposure therapy is discussed, noting strengths and weaknesses. Patients with repeated trauma exposure show reductions in distress with exposure treatment and benefit from PE as much as patients with single-exposure trauma histories.

A multi-level modeling approach examining PTSD symptom reduction during prolonged exposure therapy: moderating effects of number of trauma types experienced, having an HIV-related index trauma, and years since HIV diagnosis among HIV-positive adults.

People living with HIV (PLWH) have extensive interpersonal trauma histories and higher rates of posttraumatic stress disorder (PTSD) than the general population. Prolonged exposure (PE) therapy is efficacious in reducing PTSD across a variety of trauma samples; however, research has not examined factors that influence how PTSD symptoms change during PE for PLWH. Using multi-level modeling, we examined the potential moderating effect of number of previous trauma types experienced, whether the index trauma was HIV-related or not, and years since HIV diagnosis on PTSD symptom reduction during a 10-session PE protocol in a sample of 51 PLWH. In general, PTSD symptoms decreased linearly throughout the PE sessions. Experiencing more previous types of traumatic events was associated with a slower rate of PTSD symptom change. In addition, LOCF analyses found that participants with a non-HIV-related versus HIV-related index trauma had a slower rate of change for PTSD symptoms over the course of PE. However, analyses of raw data decreased this finding to marginal. Years since HIV diagnosis did not impact PTSD symptom change. These results provide a better understanding of how to tailor PE to individual clients and aid clinicians in approximating the rate of symptom alleviation. Specifically, these findings underscore the importance of accounting for trauma history and index trauma type when implementing a treatment plan for PTSD in PLWH.

Comparing the Diagnostic Accuracy of Five Instruments for Detecting Posttraumatic Stress Disorder in Youth.

The purpose of the study was to compare diagnostic accuracy of five posttraumatic stress disorder (PTSD) measures in a large outpatient sample of youths 11-18 years of age. Index tests included a parent report (a rationally derived scale from the Child Behavioral Checklist), a teacher report (the Teacher Report Form), and three youth reports-a PTSD scale from the Youth Self Report (YSR), Child PTSD Symptom Scale, and Child and Adolescent Trauma Survey. Interviews with the youth and caregiver using Schedule for Affective Disorders and Schizophrenia for School-Age Children generated criterion diagnoses of PTSD. Diagnoses were blind to scores on the index tests. Based on consensus diagnoses (N = 458), 10% of youth had PTSD. Area under the curve (AUC) from receiver operating characteristic analyses and multilevel likelihood ratios evaluated test performance. All youth reports (AUCs .67-.73) outperformed the teacher report (AUCs .42-.48) at identifying PTSD. The YSR outperformed the caregiver reports (AUCs .57-.58). Combining tests did not improve prediction of PTSD. The YSR predicted PTSD even after controlling for a self-reported traumatic event, but checklist ratings of traumatic events had no incremental value after controlling for YSR scores. When a youth endorsed few symptoms, the likelihood of the youth having PTSD was low. Very high scores on the YSR were associated with a moderate increase in the likelihood of PTSD diagnosis. The YSR appeared to be a useful diagnostic aid for youth PTSD and could facilitate differential diagnosis of youth PTSD in outpatient settings.

CRITICAL ANALYSIS OF THE CURRENT TREATMENT GUIDELINES FOR COMPLEX PTSD IN ADULTS.

According to current treatment guidelines for Complex PTSD (cPTSD), psychotherapy for adults with cPTSD should start with a "stabilization phase." This phase, focusing on teaching self-regulation strategies, was designed to ensure that an individual would be better able to tolerate trauma-focused treatment. The purpose of this paper is to critically evaluate the research underlying these treatment guidelines for cPTSD, and to specifically address the question as to whether a phase-based approach is needed. As reviewed in this paper, the research supporting the need for phase-based treatment for individuals with cPTSD is methodologically limited. Further, there is no rigorous research to support the views that: (1) a phase-based approach is necessary for positive treatment outcomes for adults with cPTSD, (2) front-line trauma-focused treatments have unacceptable risks or that adults with cPTSD do not respond to them, and (3) adults with cPTSD profit significantly more from trauma-focused treatments when preceded by a stabilization phase. The current treatment guidelines for cPTSD may therefore be too conservative, risking that patients are denied or delayed in receiving conventional evidence-based treatments from which they might profit.

An Investigation of Depression, Trauma History, and Symptom Severity in Individuals Enrolled in a Treatment Trial for Chronic PTSD.

OBJECTIVE: To explore how factors such as major depressive disorder (MDD) and trauma history, including the presence of childhood abuse, influence diverse clinical outcomes such as severity and functioning in a sample with posttraumatic stress disorder (PTSD). METHOD: In this study, 200 men and women seeking treatment for chronic PTSD in a clinical trial were assessed for trauma history and MDD and compared on symptom severity, psychosocial functioning, dissociation, treatment history, and extent of diagnostic co-occurrence. RESULTS: Overall, childhood abuse did not consistently predict clinical severity. However, co-occurring MDD, and to a lesser extent a high level of trauma exposure, did predict greater severity, worse functioning, greater dissociation, more extensive treatment history, and additional co-occurring disorders. CONCLUSION: These findings suggest that presence of co-occurring depression may be a more critical marker of severity and impairment than history of childhood abuse or repeated trauma exposure. Furthermore, they emphasize the importance of assessing MDD and its effect on treatment seeking and treatment response for those with PTSD.

The impact of PTSD treatment on the cortisol awakening response.

BACKGROUND: Posttraumatic stress disorder (PTSD) is associated with abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis; however, limited research has examined whether cortisol levels change following successful PTSD treatment. The current study examined the impact of successful PTSD treatment on the cortisol awakening response (CAR). METHOD: Twenty-nine adults participating in a treatment trial for chronic PTSD provided saliva samples (upon waking, and 30-, 45-, and 60 min postwaking) before and after receiving either prolonged exposure therapy or sertraline. PTSD responder status (i.e., loss or retention of a PTSD diagnosis) served as the predictor variable. Outcome measures included area under the curve with respect to ground and increase, reflecting total cortisol output and HPA axis reactivity, respectively. RESULTS: A series of hierarchical regressions revealed no significant main effects of PTSD responder status for either CAR outcome. However, a significant gender by treatment response interaction for cortisol reactivity revealed that female treatment nonresponders displayed higher cortisol reactivity following treatment than female responders, whereas cortisol reactivity did not change pre- to posttreatment for male responders. Findings remained after controlling for age, trauma history, baseline medication status, baseline PTSD, and baseline depressive symptoms. CONCLUSION: Loss of a PTSD diagnosis may contribute to decreased cortisol reactivity in females. Neuroendocrine changes following treatment may emerge only for specific subgroups, highlighting the importance of exploring treatment moderators.

Perceived Need for a Faith-Based Trauma-Focused Treatment in a Sample of Forcibly Displaced Muslims.

Forcibly displaced Muslims, including refugees, internally displaced persons, and asylum seekers who have fled their homes to escape violence, conflict, and persecution, often have inequitable access to quality mental health services, despite substantial trauma exposure and high rates of posttraumatic stress disorder (PTSD). Understanding factors associated with domains of perceived need (i.e., community, individual, friends/family) for culturally-responsive, trauma-focused mental health interventions among forcibly displaced Muslims may provide insight into those most likely to seek psychological treatment. A sample of 108 forcibly displaced Muslims endorsed moderate to high perceived need across all three domains for a trauma healing group tailored for Muslim refugees. PTSD severity related to perceived individual need, regardless of locus of displacement. Among participants with minimal PTSD symptoms, those who were externally displaced had higher perceived community and friends or family need than those who were internally displaced. Findings highlight a need for culturally responsive, trauma-focused mental health services to facilitate access to mental health care for forcibly displaced Muslims.

Islamic trauma healing (ITH): A scalable, community-based program for trauma: Cluster randomized control trial design and method.

Background: Somalia has long been in a state of humanitarian crisis; trauma-related mental health needs are extremely high. Access to state-of-the-art mental health care is limited. Islamic Trauma Healing (ITH) is a manualized mosque-based, lay-led group intervention aimed at healing the individual and communal mental wounds of war and refugee trauma. The 6-session intervention combines Islamic principles with empirically-supported exposure and cognitive restructuring principles for posttraumatic stress disorder (PTSD). ITH reduces training time, uses a train the trainers (TTT) model, and relies on local partnerships embedded within the strong communal mosque infrastructure. Methods: We will conduct a hybrid effectiveness-implementation randomized control trial (RCT) in the Somaliland, with implementation in the cities of Hargeisa, Borama, and Burao. In this study, a lay-led, mosque-based intervention, Islamic Trauma Healing (ITH), to promote mental health and reconciliation will be examined in 200 participants, randomizing mosques to either immediate ITH or a delayed (waitlist; WL) ITH conditions. Participants will be assessed by assessors masked to condition at pre, 3 weeks, 6 weeks, and 3-month follow-up. Primary outcome will be assessor-rated posttraumatic stress symptoms (PTSD), with secondary outcomes of depression, somatic symptoms, and well-being. A TTT model will be tested, examining the implementation outcomes. Additional measures include potential mechanisms of change and cost effectiveness. Conclusion: This trial has the potential to provide effectiveness and implementation data for an empirically-based principle trauma healing program for the larger Islamic community who may not seek mental health care or does not have access to such care. Clinical trial registration number: ClinicalTrials.gov NCT05890482. World health organization trial registration data set information: See Supplemental Appendix 1.

Sudden gains in prolonged exposure and sertraline for chronic PTSD.

BACKGROUND: Sudden gains are significant, rapid improvements in symptoms, larger than typical between-session symptom reduction.([8]) Sudden gains in a large sample of individuals with posttraumatic stress disorder (PTSD) have not been studied, and only one study has looked at it in pharmacotherapy, but not in PTSD. In the present study, we examined the occurrence of sudden gains in psychotherapy, specifically prolonged exposure (PE), and pharmacotherapy, specifically sertraline, for chronic PTSD. METHOD: Sudden gains in PTSD symptoms (PTSD symptom scale self-report([25]) ) were assessed in 200 individuals with PTSD during 10 weeks of PE or sertraline. RESULTS: Individuals in both PE (42.2%) and sertraline (31%) exhibited sudden gains. Individuals in PE made more gains toward the end of treatment (7.2%) than sertraline (2%, OR = 3.82). However, individuals in sertraline made larger gains during early treatment (M = 18.35, SD = 8.15) than PE (M = 12.53, SD = 5.16, d = .85). Notably, those on sertraline were more likely to exhibit a reversal of sudden gains than those in PE (OR = .23). Pointing to clinical significance, the presence of a sudden gain was associated with better reduction in symptoms from pre- to posttreatment (ß = -.49). CONCLUSIONS: Individuals in both PE and sertraline experienced gains, though sertraline was associated with earlier large but reversible gains, and PE was associated with later gains. This differential pattern of discontinuous change highlights potential differential mechanism for these therapies and marks important transition points for further detailed analyses of change mechanisms.