Mechanisms of symptom reduction in a combined treatment for comorbid posttraumatic stress disorder and alcohol dependence

Childhood-related PTSD: the role of cognitions in EMDR and imagery rescripting

Background: The relationship between trauma-related negative cognitions and post-traumatic stress disorder (PTSD) symptoms has been studied frequently. Several studies found a mediating effect of trauma-related negative cognitions on symptom reduction in studies on different psychotherapeutic treatments, however, this relationship has never been studied in imagery rescripting (ImRs) or eye movement desensitization and reprocessing (EMDR).Objective: To analyse the role of trauma-related negative cognitions in the treatment of PTSD due to childhood trauma with EMDR and ImRs.Method: N = 155 patients with PTSD due to childhood trauma aged between 18 and 65 (M = 38.54) participated in a randomized clinical trial and were treated with either EMDR or ImRs in Australia, Germany, and the Netherlands between October 2014 and June 2019. We analysed the relationship between PTSD symptoms (Clinician-administered PTSD Scale for DSM-5, CAPS-5 and Impact of Event Scale revised; IES-R, completed twice for index trauma and for all other traumas) and trauma-related negative cognitions (Post-Traumatic Cognitions Inventory, PTCI) using Granger Causality analyses with linear mixed models on person-centered variables. Assessments were conducted pre-treatment, post-treatment (12 sessions in 6 weeks), eight weeks post-treatment, and one year after the pre-treatment assessment.Results: Changes in negative cognitions (PTCI) preceded changes in PTSD symptoms (unidirectional) as measured by the CAPS and the IES-R for index trauma. For the IES-R related to all other traumas, a unidirectional relationship was found in which changes in PTSD symptoms preceded changes in negative cognitions. No moderating effect of treatment was found. On the level of PTCI subscales only changes in cognitions about oneself preceeded changes in PTSD symptoms.Conclusions: The results support the idea of a general role of trauma-related negative cognitions in the treatment of PTSD. The analyses should be replicated with a higher frequency of assessments.

From alcohol and other drug treatment mediator to mechanism to implementation: A systematic review and the cases of self-efficacy, social support, and craving

Research designed to establish alcohol and other drug (AOD) mechanisms of behavioral change (MOBC) has centered on what variables mediate the relation between AOD treatment and outcomes. The purpose of this paper was to review this research evidence to identify empirically supported mediators of alcohol and other drug use and related outcomes and then to evaluate their potential as being AOD treatment MOBC. The first phase was a systematic review of reviews (2008-2023) to identify the variables with the strongest empirical support as mediators of AOD treatment effects. Eligible reviews focused on AOD treatment modalities, included empirically tested mediators, and targeted adult samples. The second phase was a systematic review of empirical studies (1990-2023) testing the hypothesis that variables identified in phase one were AOD treatment mediators/mechanisms and then evaluating each eligible stage two study according to the Kazdin and Nock (Journal of Child Psychology and Psychiatry, 44, 1116) criteria. Eligible articles included empirical studies with adult samples attending AOD treatment and empirically tested one of the three treatment mechanisms as a mediator of an AOD-related outcome. Databases were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. This systematic review was not preregistered. The first review of 11 eligible review articles identified self-efficacy, social support, and craving as having the strongest empirical support. The second review captured 48 individual studies. An evaluation of each of these studies by the Kazdin and Nock criteria suggested that they likely are MOBC and therefore are ready for implementation. The implementation of self-efficacy, social support, and craving into clinical practice and training is warranted. Six directions for future research to solidify and generalize empirical support for the case that self-efficacy, social support, and craving are MOBC are presented, as are five implications for clinical practice and training.

Changes in cognitive processes and coping strategies precede changes in symptoms during cognitive therapy for posttraumatic stress disorder

Theories of posttraumatic stress disorder (PTSD) highlight the role of cognitive and behavioral factors in its development, maintenance, and treatment. This study investigated the relationship between changes in factors specified in Ehlers and Clark's (2000) model of PTSD and PTSD symptom change in 217 patients with PTSD who were treated with cognitive therapy for PTSD (CT-PTSD) in routine clinical care. Bivariate latent change score models (LCSM) of session-by-session changes in self-report measures showed that changes in PTSD symptoms were preceded by changes in negative appraisals, flashback characteristics of unwanted memories, safety behaviours, and unhelpful responses to intrusions, but not vice versa. For changes in trauma memory disorganization and PTSD symptoms we found a bidirectional association. This study provides evidence that cognitive and behavioral processes proposed in theoretical models of PTSD play a key role in driving symptom improvement during CT-PTSD.

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.

Changes in trauma-related cognitions predict subsequent symptom improvement during prolonged exposure in patients with childhood abuse-related PTSD

Change in negative posttraumatic cognitions is a proposed mechanism through which Prolonged Exposure (PE) leads to symptom reduction of posttraumatic stress disorder (PTSD). A strong case for posttraumatic cognitions as a change mechanism in PTSD treatment can be made by establishing temporal precedence of change in cognitions. The current study examines the temporal relationship between change in posttraumatic cognitions and PTSD symptoms during PE, using the Posttraumatic Cognitions Inventory. Patients with DSM-5 defined PTSD following childhood abuse (N = 83) received a maximum of 14-16 sessions of PE. Clinician-rated PTSD symptom severity and posttraumatic cognitions were assessed at baseline, week 4, 8, and 16 (post-treatment). Using time-lagged mixed effect regression models, we found that posttraumatic cognitions predicted subsequent PTSD symptom improvement. Notably, when using the items of an abbreviated version of the PTCI (PTCI-9), we found a mutual relationship between posttraumatic cognitions and PTSD symptom improvement. Crucially, the effect of change in cognitions on PTSD symptom change was greater than the reverse effect. The current findings corroborate change in posttraumatic cognitions as a change process during PE, but cognitions and symptoms cannot be completely separated. The PTCI-9 is a short instrument that appears suitable to track cognitive change over time.

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.

Evaluating changes in negative posttrauma cognition as a mechanism of PTSD severity changes in two separate intensive treatment programs for veterans

BACKGROUND

A wealth of evidence has illustrated that reductions in negative posttrauma cognitions (NPCs) predict improvement in posttraumatic stress disorder (PTSD) symptoms during treatment. Yet, the specific temporal arrangement of changes in these constructs is less well understood. This study examined the temporal association between NPC changes and PTSD symptom changes in two distinct intensive PTSD treatment samples.

METHODS

Data from 502 veterans who completed a 3-week CPT-based intensive PTSD treatment program was used to test the extent to which lagged NPC measurement predicted the next occurring PTSD severity measurement using linear mixed effects regression models. PTSD severity was assessed every other day during treatment. NPCs were assessed at three treatment timepoints. A second sample of 229 veterans who completed a 2-week CPT-based intensive PTSD treatment program was used to replicate these findings.

RESULTS

Across both intensive PTSD treatment programs, NPCs generally increased from intake the end of the first treatment week, which was followed by gradual decreases in NPCs throughout the rest of both programs. Change in NPCs during both the 3-week (b = .21, p < .001, R2 = .38) and the 2-week programs (b = 0.20, p < .001, R2 = .24) were significant predictors of change in PTSD symptom severity. However, the reverse was true as well, with change in PTSD severity predicting latter change in NPCs during both the 3-week (b = 1.51, p < .001, R2 = .37) and 2-week (b = 1.37, p < .001, R2 = .33) programs, further raising questions about temporality of the association between NPCs and PTSD symptom severity during treatment.

CONCLUSIONS

The present study demonstrated that changes in NPCs may not temporally precede changes in PTSD symptom severity in PTSD treatment samples. Instead, we observed earlier PTSD symptom changes and a bidirectional association between the two constructs across both samples. Clinically, the study supports the continued focus on NPCs as an important treatment target as they are an important indicator of successful PTSD treatment, even if they may not be a direct mechanism of treatment-based changes in PTSD severity. Future research should attempt to identify alternative mechanisms of change in CPT.

Changes in Alcohol Consumption following Direct-Acting Antiviral Treatment for Hepatitis C in VA Patients with Comorbid Alcohol Use Disorder and PTSD

OBJECTIVE

To investigate whether direct-acting antivirals (DAA) for hepatitis C viral infection (HCV): glecaprevir/pibrentasvir (GLE/PIB), ledipasvir/sofosbuvir (LDV/SOF), and sofosbuvir/velpatasvir (SOF/VEL) are associated with reduced alcohol consumption among veterans with alcohol use disorder (AUD) and co-occurring post-traumatic stress disorder (PTSD).

METHODS

We measured change in Alcohol Use Disorder Identification Test-Consumption Module (AUDIT-C) scores in a retrospective cohort of veterans with PTSD and AUD receiving DAAs for HCV.

RESULTS

One thousand two hundred and eleven patients were included (GLE/PIB n = 174, LDV/SOF n = 808, SOF/VEL n = 229). Adjusted frequencies of clinically meaningful improvement were 30.5% for GLE/PIB, 45.5% for LDV/SOF, and 40.5% for SOF/VEL. The frequency was lower for GLE/PIB than for LDV/SOF (OR = 0.59; 95% CI [0.40, 0.87]) or SOF/VEL (OR = 0.66; 95% CI [0.42, 1.04]).

CONCLUSIONS

DAA treatment for HCV was associated with a substantial reduction in alcohol use in patients with AUD and co-occurring PTSD. Further exploration of the role of DAAs in AUD treatment is warranted.

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.

Evaluating treatments for posttraumatic stress disorder, alcohol and other drug use disorders using meta-analysis of individual patient data: Design and methodology of a virtual clinical trial

This paper describes Project Harmony, a Virtual Clinical Trial (VCT) funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) to harmonize and analyze data from over 40 independent psychological, pharmacologic and/or combined pharmacological treatment studies for posttraumatic stress disorder and comorbid alcohol and other drug use disorders (PTSD/AOD). The study attends to three distinct analysis challenges: (1) variation in measurement of PTSD/AOD across studies, time, populations and reporters, (2) cross-study variation in treatment effect sizes and (3) non-randomized, cross-study variation in the classification of treatments (despite within-study randomization of treatment arms). To address these challenges, the study combines meta-analysis of individual patient data (MIPD), integrative data analysis (IDA) and propensity score weighting (PSW) to integrate raw data from these clinical trials. This protocol shows how this VCT analytic framework was used to (1) develop commensurate scale scores of PTSD and AOD severity when measures vary across studies, (2) compare the efficacy of evidence-based treatment models for PTSD/AOD, (3) test for potential mediators of treatment effects on AOD and PTSD across treatment models, and (4) explore individual- and study-level moderators to inform for whom each of the treatment models works best. The advantages of the general VCT approach are juxtaposed against the limitations of single randomized controlled trials and conventional meta-analysis.

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.

Processes of Change in Trauma-Focused Cognitive Behavioral Therapy for Youth: An Emotional Processing Theory Informed Approach

This study examines processes of change in trauma-focused cognitive behavioral therapy (TF-CBT) delivered to a community sample of 81 youth. Emotional processing theory (EPT) is used as an organizational framework. EPT highlights activating and changing pathological trauma-related responses and increasing adaptive responses across cognitive, emotional, behavioral, and physiological domains. We coded sessions during the trauma processing phase of TF-CBT to examine the extent to which pathological and adaptive trauma-related responses were activated across domains. Higher scores indicate that more domains (0-4) were activated at a threshold of moderate to high intensity. Curvilinear change (inverted U, increase then decrease) in multimodal negative response scores across sessions predicted improvement in internalizing and PTSD symptoms at posttreatment. Linear increases in multimodal positive responses predicted improvement in externalizing symptoms. Findings suggest value in activating and changing both pathological and adaptive trauma responses across multiple domains and examining nonlinear patterns of change.

Trauma-related cognitions predict treatment response in smokers with PTSD: Evidence from cross-lagged panel analyses

OBJECTIVE

Compared to smokers without posttraumatic stress disorders (PTSD), smokers with PTSD smoke more heavily and are less successful in quitting smoking. However, limited research has examined the cognitive pathways underlying this heightened comorbidity. The current study is the first to simultaneously model the cross-sectional and lagged relationships between trauma-related cognitions and cigarette smoking, as well as between trauma-related cognitions and PTSD severity, in smokers with comorbid PTSD receiving treatment.

METHOD

Participants (n = 142) were seeking treatment for smoking cessation and PTSD as part of a randomized controlled trial of varenicline and smoking cessation counseling with or without adjunctive Prolonged Exposure (varenicline + PE vs. varenicline only) (Foa et al., 2017). Data were available for both baseline and end-of-treatment assessments of trauma cognitions severity of cigarette smoking and PTSD symptoms. We conducted both cross-sectional and lagged analysis to simultaneously examine the bidirectional relationship from trauma cognitions and 1) cigarette smoking and 2) PTSD symptoms.

RESULTS

Trauma cognitions (specifically, negative beliefs about the self and the world) were significantly associated with cigarette/day at the end of treatment for participants who received varenicline only. However, baseline trauma cognitions did not predict post-treatment cigarettes/day. Baseline trauma cognitions (specifically negative beliefs about the self and world) were associated with PTSD severity at both baseline and end of treatment; furthermore, these negative cognitions at baseline positively and prospectively predicted end-of-treatment PTSD severity, but not vice versa. Wald tests revealed that there were no treatment effects on these cross-lagged relationships. Conclusions These findings provide novel empirical support for the importance of addressing trauma-related cognitions in the smoking cessation treatment efforts for patients with comorbid PTSD and cigarette smoking.

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.

Mechanisms of change in psychological interventions for posttraumatic stress symptoms: A systematic review with recommendations

Psychological interventions can alleviate posttraumatic stress symptoms (PTSS). However, further development of treatment approaches calls for understanding the mechanisms of change through which diverse interventions affect PTSS. We systematically searched the literature for controlled studies of mechanisms of change in psychological interventions for PTSS. We aimed to detect all empirically studied mechanisms and evaluate the level of evidence for their role in the alleviation of PTSS. We identified 34 studies, of which nine were among children. We found evidence for improvements in maladaptive posttraumatic cognitions as a general mechanism of change involved in diverse interventions, among both adults and children. We also found some preliminary evidence for increases in mindfulness as a mechanism of change in mindfulness- and spiritually-oriented interventions among adults. We found scant, mixed empirical evidence for other mechanisms of change. Notably, studies on changes in traumatic memories as a mechanism of change were lacking, despite clinical emphasis on their importance. A major limitation across reviewed studies was that most could not establish temporal order of changes in mechanisms and PTSS. Including thorough analyses of mechanisms of change beyond cognitions in all future trials and improving the reporting of findings would aid the development and implementation of even more effective interventions.

Trauma-Related Cognitions and Cognitive Emotion Regulation as Mediators of PTSD Change Among Treatment-Seeking Active-Duty Military Personnel With PTSD

Trauma-related cognitions about the self and the world have been identified as a mediator of posttraumatic stress disorder (PTSD) change during prolonged exposure (PE) therapy. However, the extent to which negative cognitions mediate PTSD change in other PTSD treatments is unclear. In addition, previous studies have not tested alternate mediators of PTSD change during PE. In a sample of 216 treatment-seeking active-duty military personnel with PTSD, the present study examined the specificity of the negative cognition mediation effect in both PE and present-centered therapy (PCT). In addition, we examined another possible mediator, cognitive emotion regulation. Lagged mediational analyses indicated that negative cognitions about the self and world and the unhelpful cognitive emotion regulation strategy of catastrophizing each significantly mediated change in PTSD from baseline to 6-month follow-up. In a combined model, the mediating effect of catastrophizing was greater than negative cognitions about the world, and similar to negative cognitions about the self. Moderated mediation analyses revealed that the effect of catastrophizing was greater in PE than in PCT. Findings show that trauma-related cognitions and, to a greater degree, the emotion regulation strategy catastrophizing, both mediate PTSD change. Further research is needed to determine whether these mediating variables represent mechanisms of therapeutic change.

A cognitive processing therapy-based treatment program for veterans diagnosed with co-occurring posttraumatic stress disorder and substance use disorder: The relationship between trauma-related cognitions and outcomes of a 6-week treatment program

Dysfunctional trauma-related cognitions are important in the emergence and maintenance of posttraumatic stress disorder (PTSD) and the modification of such cognitions is a proposed mechanism of trauma treatment. However, the authors are not aware of any research examining trauma-related cognitions as a treatment mechanism in a sample of individuals with comorbid PTSD and substance use disorder (SUD). Accordingly, the present study sought to address this gap in the literature and examined the relationship between trauma-related cognitions and treatment outcomes within a sample of seventy-two veterans diagnosed with PTSD and SUD. Veterans completed a 6-week day CPT-based treatment program that included cognitive processing therapy as a central component. Measures of trauma-related cognitions, PTSD symptoms, depressive symptoms, and trauma-cued substance craving were completed at pre- and post-treatment. As expected, trauma-related cognitions were associated with several PTSD-related variables prior to treatment. Furthermore, results of a within-subjects mediational analysis indicated that maladaptive trauma-related cognitions decreased during the treatment program and accounted for a significant portion of the variance in the reduction of PTSD and depressive symptoms at post-treatment. This study provides support for the position that attempts to modify dysfunctional trauma-related cognitions among veterans with co-occurring PTSD and SUD can lead to desirable treatment outcomes.

Testing Mediators of Reduced Drinking for Veterans in Alcohol Care Management

INTRODUCTION

Alcohol Care Management (ACM) is a manualized treatment provided by behavioral health providers working in a primary care team aimed at increasing patients' treatment engagement and decreasing their alcohol use. Research has shown that ACM is effective in reducing alcohol consumption; however, the mechanisms of ACM are unknown. Therefore, the purpose of this study is to examine the mechanisms of change in ACM in the context of a randomized clinical trial evaluating the effectiveness of ACM.

MATERIALS AND METHODS

This study performed secondary data analysis of existing data from a larger study that involved a sample of U.S. veterans (N = 163) who met criteria for current alcohol dependence. Upon enrollment into the study, participants were randomized to receive either ACM or standard care. ACM was delivered in-person or by telephone within the primary care clinic and focused on the use of oral naltrexone and manualized psychosocial support. According to theory, we hypothesized several ACM treatment components that would mediate alcohol consumption outcomes: engagement in addiction treatment, reduced craving, and increased readiness to change. Parallel mediation models were performed by the PROCESS macro Model 4 in SPSS to test study hypotheses. The institutional review boards at each of the participating facilities approved all study procedures before data collection.

RESULTS

As hypothesized, results showed that treatment engagement mediated the relation between treatment and both measures of alcohol consumption outcomes, the percentage of alcohol abstinent days, and the percentage of heavy drinking days. Neither craving nor readiness to change mediated the treatment effect on either alcohol consumption outcome.

CONCLUSIONS

Findings suggest that ACM may be effective in changing drinking patterns partially due to an increase in treatment engagement. Future research may benefit from evaluating the specific factors that underlie increased treatment engagement. The current study provides evidence that alcohol use disorder interventions should aim to increase treatment engagement and reduce barriers to care.

Confounding in statistical mediation analysis: What it is and how to address it

Psychology researchers are often interested in mechanisms underlying how randomized interventions affect outcomes such as substance use and mental health. Mediation analysis is a common statistical method for investigating psychological mechanisms that has benefited from exciting new methodological improvements over the last 2 decades. One of the most important new developments is methodology for estimating causal mediated effects using the potential outcomes framework for causal inference. Potential outcomes-based methods developed in epidemiology and statistics have important implications for understanding psychological mechanisms. We aim to provide a concise introduction to and illustration of these new methods and emphasize the importance of confounder adjustment. First, we review the traditional regression approach for estimating mediated effects. Second, we describe the potential outcomes framework. Third, we define what a confounder is and how the presence of a confounder can provide misleading evidence regarding mechanisms of interventions. Fourth, we describe experimental designs that can help rule out confounder bias. Fifth, we describe new statistical approaches to adjust for measured confounders of the mediator-outcome relation and sensitivity analyses to probe effects of unmeasured confounders on the mediated effect. All approaches are illustrated with application to a real counseling intervention dataset. Counseling psychologists interested in understanding the causal mechanisms of their interventions can benefit from incorporating the most up-to-date techniques into their mediation analyses. (PsycINFO Database Record

Do changes in trauma-related beliefs predict PTSD symptom improvement in prolonged exposure and sertraline?

OBJECTIVE

Negative trauma-related belief change has been found to predict subsequent improvement in symptoms of posttraumatic stress disorder (PTSD) in prolonged exposure (PE) and other therapies, consistent with several psychological theories of treatment change (e.g., Foa & Kozak, 1986). However, belief change has not been examined in selective serotonin reuptake inhibitors such as sertraline. We examined processes associated with symptom improvement in 2 treatments for PTSD, hypothesizing that belief change would robustly predict PTSD improvement in patients treated with PE but not those treated with sertraline, reflecting moderation by treatment.

METHOD

Patients with chronic PTSD (N = 134; 78% women, 71.6% Caucasian, M = 38.1 years, SD = 11.8) received 10 weeks of PE or sertraline in a randomized, controlled trial. Patients reported PTSD and depression symptoms, and trauma-related beliefs (Post-Traumatic Cognitions Inventory; Foa, Ehlers, Clark, D Tolin, & Orsillo, 1999) at pretreatment, every treatment session, and posttreatment.

RESULTS

Using time-lagged mixed regression models, change in trauma-related beliefs predicted subsequent PTSD symptom improvement, an effect moderated by treatment and particularly strong in PE (d = 0.93) compared with sertraline (d = 0.35). Belief change also predicted depressive symptom improvement but more modestly and bidirectionally, with no difference by treatment modality.

CONCLUSIONS

Trauma-related belief change precedes PTSD improvement more robustly in PE than in sertraline and with greater specificity compared with depressive symptoms. These findings highlight potentially divergent processes contributing to symptom change in these PTSD treatments, with belief change as a key mechanism of PE. (PsycINFO Database Record

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.

Temporal Sequencing of Change in Posttraumatic Cognitions and PTSD Symptom Reduction During Prolonged Exposure Therapy

Prolonged exposure (PE) effectively reduces negative cognitions about self, world, and self-blame associated with posttraumatic stress disorder (PTSD), with changes in posttraumatic cognitions being associated with reductions in PTSD symptoms (Foa & Rauch, 2004). Further, recent research has demonstrated that cognitive change is a likely mechanism for PTSD symptom reduction in PE (Zalta et al., 2014). The present study examines temporal sequencing of change in three domains of posttraumatic cognitions (i.e., negative cognitions about the self, negative cognitions about the world, and self-blame) and PTSD symptoms during the course of PE. Adult outpatients meeting diagnostic criteria for PTSD were recruited at 4 sites. Participants (N=46) received 8 sessions of PE over 4 to 6weeks. PTSD symptoms and posttraumatic cognitions were assessed at pretreatment and Sessions 2, 4, 6, and 8. PTSD symptom severity and negative cognitions about the self and the world each decreased significantly from pre- to posttreatment, while self-blame cognitions were unchanged. Examination of temporal sequencing of changes during the course of PE via time-lagged mixed effects regression modeling revealed that preceding levels of negative cognitions about the world drove successive severity levels of PTSD symptoms, whereas preceding PTSD symptom severity did not drive subsequent negative cognitions about the world. Reductions in negative cognitions about the self led to subsequent improvement in PTSD. Improvement in PTSD symptoms in prior sessions was related to later reduction in negative cognitions about the self, though the impact of negative cognitions in influencing subsequent symptom change demonstrated a stronger effect. Results support that reductions in negative cognitions about the self and world are mechanisms of change in PE, which may have valuable implications for maximizing treatment effectiveness.

Trauma cognitions are related to symptoms up to 10 years after cognitive behavioral treatment for posttraumatic stress disorder

OBJECTIVES

This study examined (a) relationships between trauma-related cognitions and posttraumatic stress disorder (PTSD) symptoms from pretreatment through a long-term period after cognitive-behavioral therapy (CBT) for PTSD and (b) whether these relationships were impacted by treatment type.

METHOD

Participants were 171 women randomized into treatment for PTSD after rape. Measures of self-reported trauma-related cognitions and interviewer-assessed PTSD symptoms (i.e., Posttraumatic Maladaptive Beliefs Scale, Trauma-Related Guilt Inventory, and Clinician-Administered PTSD Scale) were obtained at pretreatment, posttreatment, and 3-month, 9-month, and 5-10 year follow-ups. Multilevel regression analyses were used to examine relationships between trauma-related cognitions and PTSD symptoms throughout the study period and whether these relationships differed as a function of treatment type (i.e., Cognitive Processing Therapy or Prolonged Exposure).

RESULTS

Initial multilevel regression analyses that examined mean within-participant associations suggested that beliefs regarding Reliability and Trustworthiness of Others, Self-Worth and Judgment, Threat of Harm, and Guilt were related to PTSD symptoms throughout follow-up. Growth curve modeling suggested that patterns of belief change throughout follow-up were similar to those previously observed in PTSD symptoms over the same time period. Finally, multilevel mediation analyses that incorporated time further suggested that change in beliefs was related to change in symptoms throughout follow-up. With 1 minor exception, relationships between beliefs and symptoms were not moderated by treatment type.

CONCLUSIONS

These data suggest that trauma-related cognitions are a potential mechanism for long-term maintenance of treatment gains after CBT for PTSD. Moreover, these cognitions may be a common, rather than specific, treatment maintenance mechanism. (PsycINFO Database Record

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

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.

Treating Posttraumatic Stress Symptoms Among People Living with HIV: a Critical Review of Intervention Trials

The prevalence rate of posttraumatic stress disorder (PTSD) among people living with HIV (PLWH) is significantly higher than the rate among the general population. Moreover, PTS symptoms have been linked with numerous negative health-related outcomes in PLWH. While these findings suggest that studies evaluating the efficacy of treatments for PTS symptoms among PLWH are sorely needed, according to prior reviews, such studies are lacking. The purpose of the present systematic review was to provide an updated critical evaluation of treatment studies that targeted PTS among PLWH. Following PRIMSA guidelines, we searched PubMed and PsycINFO and identified eight articles (representing seven studies) evaluating the impact of various individual and group treatments on PTS symptoms. The limited evidence base to date precludes clinical recommendations for this population. Future studies should examine the efficacy of existing evidence-based treatments for PTSD among PLWH and then, if necessary, evaluate the impact of any treatment modifications for this population.

Cognitive Mediation of Symptom Change in Exposure and Response Prevention for Obsessive-Compulsive Disorder

This study examined cognitive mediators of symptom change during exposure and response prevention (EX/RP) for obsessive-compulsive disorder (OCD). Based on cognitive models of OCD, obsessive beliefs were hypothesized as a mediator of symptom change. Participants were 70 patients with primary OCD receiving EX/RP either as part of a randomized controlled trial (n=38) or in open treatment following nonresponse to risperidone or placebo in the same trial (n=32). Blinded evaluations of OCD severity and self-report assessments of three domains of obsessive beliefs (i.e., responsibility/threat of harm, importance/control of thoughts, and perfectionism/intolerance of uncertainty) were administered during acute (Weeks 0, 4 and 8) and maintenance treatment (Weeks 12 and 24). Study hypotheses were examined using cross-lagged multilevel modeling. Contrary to predictions, the obsessive beliefs domains investigated did not mediate subsequent OCD symptom reduction. In addition, OCD symptoms did not significantly mediate subsequent change in obsessive beliefs. The present study did not find evidence of cognitive mediation during EX/RP for OCD, highlighting the need to investigate other plausible mediators of symptom improvement.

Psychological therapies for post-traumatic stress disorder and comorbid substance use disorder

BACKGROUND

Post-traumatic stress disorder (PTSD) is a debilitating mental health disorder that may develop after exposure to traumatic events. Substance use disorder (SUD) is a behavioural disorder in which the use of one or more substances is associated with heightened levels of distress, clinically significant impairment of functioning, or both. PTSD and SUD frequently occur together. The comorbidity is widely recognised as being difficult to treat and is associated with poorer treatment completion and poorer outcomes than for either condition alone. Several psychological therapies have been developed to treat the comorbidity, however there is no consensus about which therapies are most effective.

OBJECTIVES

To determine the efficacy of psychological therapies aimed at treating traumatic stress symptoms, substance misuse symptoms, or both in people with comorbid PTSD and SUD in comparison with control conditions (usual care, waiting-list conditions, and no treatment) and other psychological therapies.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Group's Specialised Register (CCDANCTR) all years to 11 March 2015. This register contains relevant randomised controlled trials from the Cochrane Library (all years), MEDLINE (1950 to date), EMBASE (1974 to date), and PsycINFO (1967 to date). We also searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov, contacted experts, searched bibliographies of included studies, and performed citation searches of identified articles.

SELECTION CRITERIA

Randomised controlled trials of individual or group psychological therapies delivered to individuals with PTSD and comorbid substance use, compared with waiting-list conditions, usual care, or minimal intervention or to other psychological therapies.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 14 studies with 1506 participants, of which 13 studies were included in the quantitative synthesis. Most studies involved adult populations. Studies were conducted in a variety of settings. We performed four comparisons investigating the effects of psychological therapies with a trauma-focused component and non-trauma-focused interventions against treatment as usual/minimal intervention and other active psychological therapies. Comparisons were stratified for individual- or group-based therapies. All active interventions were based on cognitive behavioural therapy. Our main findings were as follows.Individual-based psychological therapies with a trauma-focused component plus adjunctive SUD intervention was more effective than treatment as usual (TAU)/minimal intervention for PTSD severity post-treatment (standardised mean difference (SMD) -0.41; 95% confidence interval (CI) -0.72 to -0.10; 4 studies; n = 405; very low-quality evidence) and at 3 to 4 and 5 to 7 months' follow-up. There was no evidence of an effect for level of drug/alcohol use post-treatment (SMD -0.13; 95% CI -0.41 to 0.15; 3 studies; n = 388; very low-quality evidence), but there was a small effect in favour of individual psychological therapy at 5 to 7 months (SMD -0.28; 95% CI -0.48 to -0.07; 3 studies; n = 388) when compared against TAU. Fewer participants completed trauma-focused therapy than TAU (risk ratio (RR) 0.78; 95% CI 0.64 to 0.96; 3 studies; n = 316; low-quality evidence).Individual-based psychological therapy with a trauma-focused component did not perform better than psychological therapy for SUD only for PTSD severity (mean difference (MD) -3.91; 95% CI -19.16 to 11.34; 1 study; n = 46; low-quality evidence) or drug/alcohol use (MD -1.27; 95% CI -5.76 to 3.22; 1 study; n = 46; low-quality evidence). Findings were based on one small study. No effects were observed for rates of therapy completion (RR 1.00; 95% CI 0.74 to 1.36; 1 study; n = 62; low-quality evidence).Non-trauma-focused psychological therapies did not perform better than TAU/minimal intervention for PTSD severity when delivered on an individual (SMD -0.22; 95% CI -0.83 to 0.39; 1 study; n = 44; low-quality evidence) or group basis (SMD -0.02; 95% CI -0.19 to 0.16; 4 studies; n = 513; low-quality evidence). There were no data on the effects on drug/alcohol use for individual therapy. There was no evidence of an effect on the level of drug/alcohol use for group-based therapy (SMD -0.03; 95% CI -0.37 to 0.31; 4 studies; n = 414; very low-quality evidence). A post-hoc analysis for full dose of a widely established group therapy called Seeking Safety showed reduced drug/alcohol use post-treatment (SMD -0.67; 95% CI -1.14 to -0.19; 2 studies; n = 111), but not at subsequent follow-ups. Data on the number of participants completing therapy were not for individual-based therapy. No effects were observed for rates of therapy completion for group-based therapy (RR 1.13; 95% CI 0.88 to 1.45; 2 studies; n = 217; low-quality evidence).Non-trauma-focused psychological therapy did not perform better than psychological therapy for SUD only for PTSD severity (SMD -0.26; 95% CI -1.29 to 0.77; 2 studies; n = 128; very low-quality evidence) or drug/alcohol use (SMD 0.22; 95% CI -0.13 to 0.57; 2 studies; n = 128; low-quality evidence). No effects were observed for rates of therapy completion (RR 0.91; 95% CI 0.68 to 1.20; 2 studies; n = 128; very low-quality evidence).Several studies reported on adverse events. There were no differences between rates of such events in any comparison. We rated several studies as being at 'high' or 'unclear' risk of bias in multiple domains, including for detection bias and attrition bias.

AUTHORS' CONCLUSIONS

We assessed the evidence in this review as mostly low to very low quality. Evidence showed that individual trauma-focused psychological therapy delivered alongside SUD therapy did better than TAU/minimal intervention in reducing PTSD severity post-treatment and at long-term follow-up, but only reduced SUD at long-term follow-up. All effects were small, and follow-up periods were generally quite short. There was evidence that fewer participants receiving trauma-focused therapy completed treatment. There was very little evidence to support use of non-trauma-focused individual- or group-based integrated therapies. Individuals with more severe and complex presentations (e.g. serious mental illness, individuals with cognitive impairment, and suicidal individuals) were excluded from most studies in this review, and so the findings from this review are not generalisable to such individuals. Some studies suffered from significant methodological problems and some were underpowered, limiting the conclusions that can be drawn. Further research is needed in this area.

The Efficacy of Exposure Therapy for Anxiety-Related Disorders and Its Underlying Mechanisms: The Case of OCD and PTSD

In this review we describe the intricate interrelationship among basic research, conceptualization of psychopathology, treatment development, treatment outcome research, and treatment mechanism research and how the interactions among these areas of study further our knowledge about psychopathology and its treatment. In describing the work of Edna Foa and her colleagues in anxiety disorders, we demonstrate how emotional processing theory of anxiety-related disorders and their treatment using exposure therapy have generated hypotheses about the psychopathology of posttraumatic stress disorder and obsessive-compulsive anxiety disorder that have informed the development and refinement of specific treatment protocols for these disorders: prolonged exposure and exposure and response (ritual) prevention. Further, we have shown that the next step after the development of theoretically driven treatment protocols is to evaluate their efficacy. Once evidence for a treatment's efficacy has accumulated, studies of the mechanisms involved in the reduction of the targeted psychopathology are conducted, which in turn inform the theory and further refine the treatments. We conclude our review with a discussion of how the knowledge derived from Foa and colleagues' programmatic research together with knowledge emerging from basic research on extinction learning can inform future research on the psychopathology of anxiety disorders and their treatments.

Are 60-minute prolonged exposure sessions with 20-minute imaginal exposure to traumatic memories sufficient to successfully treat PTSD? A randomized noninferiority clinical trial

The study aims to determine whether 60-minute sessions of prolonged exposure (PE) that include 20 minutes of imaginal exposure (IE) are noninferior to the standard 90-minute sessions that include 40 minutes of IE in treating posttraumatic stress disorder (PTSD) and to explore the relationship of treatment outcome to within- and between-session habituation and change in negative cognitions. Thirty-nine adult veterans with chronic PTSD were randomly assigned to 90-minute (n=19) or 60-minute (n=20) sessions of PE. PTSD symptoms were assessed by an unaware independent evaluator before and after treatment and at 6-month follow-up. Self-reports of depression and negative cognitions were assessed before and after treatment. Participants in both conditions showed significant reductions in PTSD symptoms. Sixty-minute sessions were found to be noninferior to 90-minute sessions in reducing PTSD symptoms, as the upper bound of the 95% confidence interval for the difference between conditions in the PTSD Symptom Scale-Interview (posttreatment: 6.00; follow-up: 6.77) was below the predefined noninferiority margin (7.00). Participants receiving shorter sessions showed less within- and between-session habituation than those receiving longer sessions, but no group differences in reductions in negative cognitions were found. The current findings indicate that the outcomes of 60-minute sessions of PE do not differ from those of 90-minute sessions. In addition, change in trauma-related cognitions and between-session habituation are both potential mechanisms of PE.

Changes in negative cognitions mediate PTSD symptom reductions during client-centered therapy and prolonged exposure for adolescents

OBJECTIVE

To assess whether changes in negative trauma-related cognitions play an important role in reducing symptoms of posttraumatic stress disorder (PTSD) and depression during prolonged exposure therapy for adolescents (PE-A).

METHOD

Secondary analysis of data from a randomized controlled trial comparing PE-A with client-centered therapy (CCT) for PTSD. Participants were 61 adolescent female sexual assault survivors ages 13-18 who received 8-14 weekly sessions of PE-A or CCT at a community rape crisis center. PTSD severity was assessed at baseline, mid-treatment, post-treatment, and 3-months post-treatment. Participants also completed self-report measures of negative posttraumatic cognitions and depressive symptoms at the same assessment points.

RESULTS

Cross lag panel mediation analyses showed that change in negative trauma-related cognitions mediated change in PTSD symptoms and depressive symptoms whereas change in PTSD and depressive symptoms did not mediate change in negative cognitions.

CONCLUSION

Our findings support EPT and suggest that change in negative trauma-related cognitions is a mechanism of both PE-A and CCT.