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(p. 1) Foundations of Prolonged Exposure 

(p. 1) Foundations of Prolonged Exposure
(p. 1) Foundations of Prolonged Exposure

Edna B. Foa

, Elizabeth A. Hembree

, Barbara Olasov Rothbaum

, and Sheila A. M. Rauch

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date: 14 October 2019

This therapist guide of prolonged exposure (PE) treatment is accompanied by the patient workbook, Reclaiming Your Life from a Traumatic Experience. The treatment and manuals are designed for use by a therapist who is familiar with cognitive behavioral therapy (CBT) and who underwent an intensive training workshop for PE by experts in this therapy. The guide will instruct therapists to implement this brief CBT program that targets individuals who are diagnosed with posttraumatic stress disorder (PTSD) or who manifest PTSD symptoms that cause distress and/or dysfunction following various types of trauma.

Background Information and Purpose of Emotional Processing Therapy

The overall aim of the treatment is to help trauma survivors emotionally process their traumatic experiences to diminish or eliminate PTSD and other trauma-related symptoms. The term “prolonged exposure” reflects the fact that the treatment program emerged from the long tradition of exposure therapy for anxiety disorders in which patients are helped to confront safe but anxiety-evoking situations to overcome their unrealistic, excessive fear and anxiety. At the same time, PE has emerged from the adaption and extension of Emotional Processing Theory (EPT) to PTSD, which emphasizes the central role of successfully processing the traumatic memory in the amelioration of PTSD symptoms. Throughout this guide, we highlight that emotional processing is the mechanism underlying successful reduction of PTSD symptoms.

(p. 2) PE includes the following key components:

  • Education about common reactions to trauma, what maintains trauma-related symptoms, and how PE reduces PTSD symptoms.

  • Repeated in vivo confrontation with situations, people, or objects that the patient is avoiding because they are trauma-related and cause emotional distress, such as anxiety, shame, or guilt.

  • Repeated, prolonged imaginal exposure to the trauma memories (i.e., revisiting and recounting the trauma memory in imagery) followed by processing the details of the event, the emotions, and the thoughts that the patient experienced during the trauma. This is accomplished through discussion of the experience of recounting the trauma memories.

The education component of PE begins in Session 1 with presenting to the patient the overall rationale for treatment (Handout 1: Rationale for Treatment by Prolonged Exposure). In addition to providing an overview of the treatment, we introduce the view that avoidance of trauma reminders maintains PTSD symptoms and trauma-related distress and that PE aims at reducing or eliminating avoidance. This rationale is repeated and elaborated in the next two sessions with the introduction of the core interventions of PE: in vivo and imaginal exposure. Psychoeducation continues in Session 2 with a discussion of “Common Reactions to Trauma,” in which the therapist reviews with the patient common symptoms, emotions, and behaviors that occur in the wake of traumatic experiences, with the aim of eliciting and discussing the patient’s own reactions to the traumatic experiences and understanding these reactions in the context of PTSD (Handout 3: Common Reactions to Trauma).

In vivo exposure to safe or low-risk situations, activities, places, and objects that the patient is avoiding because of trauma-related distress and anxiety is introduced in Session 2 (Handout 4: In Vivo Exposure Hierarchy and Handout 5: In Vivo Exposure Homework Recording Form). In each session thereafter, the therapist and patient choose which exposure exercises the patient should practice, taking into consideration the patient’s anticipated level of distress and ability to schedule and complete the assignments successfully. For the most part, the patient conducts the in vivo exercises as homework between sessions, but if an exercise is particularly difficult, the therapist and the patient may do it together at least once.

(p. 3) Imaginal exposure, revisiting the trauma memory in imagination, is initiated in Session 3 (Handout 7: Imaginal Exposure Homework Recording Form; Appendix C). It consists of the patient visualizing and recounting the traumatic event aloud followed by processing and discussing the emotions, thoughts, and details of the trauma that emerge during the revisiting of the traumatic memory. Imaginal exposure is conducted in each of the remaining treatment sessions. The session is audio-recorded, and the patient is instructed to listen to the recording from that week’s session for homework. As noted earlier, these two interventions—imaginal and in vivo exposure—comprise the core procedures of PE.

The aim of in vivo and imaginal exposure is to enhance emotional processing of traumatic events by helping the patient face the trauma memories and reminders and process the emotions and thoughts as well as the details of the trauma that emerge during revisiting experiences. In doing so, patients learn that talking and thinking about the trauma are not the same as being in the trauma. They learn that they can safely experience these trauma reminders, that the distress that initially results from confrontations with these reminders decreases over time, and that they can tolerate this distress. They also learn to examine their negative emotions and thoughts about themselves such as anxiety, shame, and guilt and their emotions and thoughts about the world as an entirely dangerous place, determine if they are unrealistic and thus should be abandoned or modified. Ultimately, the treatment helps patients reclaim their lives from the devastating consequences of PTSD symptoms.

Diagnostic Criteria for Posttraumatic Stress Disorder

PTSD is included in the current Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM5; American Psychological Association [APA], 2013) as a trauma- and stressor-related disorder.

DSM5 Criteria for Posttraumatic Stress Disorder

PTSD requires being exposed to a criterion A event, defined as an event that involves actual or threatened death, serious injury, or sexual (p. 4) violence. According to DSM5 (APA, 2013), such exposure can occur through direct personal experience; witnessing it happen to others; or learning about the violent or accidental, actual or threatened death of a family member or friend. In addition, a traumatic event can include repeated exposure to the details of traumatic events, such as hearing details of accounts of child abuse or handling human remains after a disaster.

Following exposure to the criterion A event or events, the symptoms of PTSD fall into four symptom clusters (see APA, 2013, for a comprehensive account of diagnostic criteria).

  • The first cluster, intrusive symptoms, includes recurrent and distressing images, nightmares, and thoughts of the event. These symptoms are experienced as out of control and intense and may come on in response to reminders of the event or come out of the blue.

  • The second cluster, avoidance symptoms, includes effortful avoidance of thoughts, feelings, and memories or reminders of people, places, or things associated with the trauma. Patients describe avoidance as making their life and functioning increasingly smaller as they avoid more and more activities that they used to enjoy. In addition, family and friends often do not understand why they are not engaging with social activities and may take this as rejection.

  • The third cluster, negative mood, includes thoughts and feelings of self-blame and guilt related to the trauma as well as the belief that the whole world is dangerous. Such beliefs are often unrealistic, persistent, and exaggerated. These symptoms may also include feeling detached from others and difficulty experiencing positive emotions. Individuals with PTSD often feel sad and defeated, leading to high rates of comorbid depression along with the negative mood cluster symptoms.

  • Finally, the hyperarousal cluster of symptoms includes problems sleeping, outbursts of anger, self-destructive behavior, feeling constantly on guard, problems with concentration, and exaggerated startle response. Patients often describe a sense that their life is constantly in danger and that they need to be ready to respond in any situation. Importantly, the DSM5 emphasizes that PTSD involves not only fear but also other emotions such as self-blame, guilt, and anger.

(p. 5) Prevalence

Traumatic events occur quite frequently, with up to 60% of the US population exposed to at least one traumatic event in their lifetime (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). The National Comorbidity Survey (2005) found lifetime rates of PTSD in the general US population of 3.6% for men and 9.7% for women and a 12-month prevalence of 1.8% among men and 5.2% among women (Kessler et al., 2005; McLean, Asnaani, & Foa, 2015).

Development of This Treatment Program and Evidence Base

PE has been developed over the past 30 years through well-controlled studies and clinical practice in which PE was provided to thousands of patients. In addition, thousands of therapists in a variety of settings and countries have been trained to implement the treatment. Our clinical experiences and the results of numerous studies over these years have guided the evolution of PE to its current form, which is detailed in the chapters that follow. In addition, our experience as trainers has attuned us to the questions and concerns therapists have regarding the effective implementation of PE.

PE has become one of the most studied psychotherapeutic interventions, with hundreds of completed efficacy and effectiveness trials using gold standard randomized clinical trials methodologies. Studies have compared PE’s impact with other treatments including medications, cognitive processing therapy (CPT), eye movement desensitization and reprocessing (EMDR), and counseling, and have examined the value of adding other techniques such as cognitive restructuring, relaxation, and stress inoculation training (SIT). These studies have truly pushed the boundaries to explore where PE can be used with efficacy, effectiveness, and safety, and this guide provides the application of the sum of what has been learned. PE is a highly effective, flexible, and robust treatment for PTSD that can be safely and effectively applied with even the most complex patient presentations and comorbidities. Research began with a study of 45 female rape victims with chronic PTSD who received nine sessions of PE, SIT, or supportive counseling (SC), compared to wait list control (offered delayed treatment; Foa, Rothbaum, Riggs, & Murdock, (p. 6) 1991). Twice weekly, 90-minute treatment sessions were completed with master’s- or PhD-level psychologists. At the end of treatment, those receiving PE and SIT, and to a lesser extent those receiving SC, significantly improved, while those on the wait list did not. At a 1-year follow-up, those who received PE continued to improve on PTSD symptoms, while the other groups maintained their gains. Although the sample was small, the results energized our continued development of the treatment.

The next study included a larger sample of 97 female rape and nonsexual assault survivors with chronic PTSD who received nine twice-weekly 90-minute sessions of PE, SIT, or a combination of the two compared to wait list control (offered delayed treatment; Foa, Dancu et al., 1999). All patients assigned to active treatment showed substantial reduction in PTSD severity and depression, whereas those on the wait list showed no improvement. In fact, immediately after treatment ended, only 35% of the women receiving PE, 42% of those receiving SIT, and 46% of those receiving PE/SIT retained a diagnosis of PTSD. Contrary to our expectation that combined treatment would show the most improvement, PE alone was superior to SIT and PE/SIT on several indices of benefit from treatment. Specifically, the magnitude of change in treatment (effect size) was considerably larger for PE alone than for SIT and PE/SIT. Furthermore, more patients in PE showed good end state function as measured by remission of PTSD, general anxiety, and depression. Similar results were obtained at a 1-year follow-up. The failure of the combination of PE and SIT to provide more benefit than PE alone was puzzling. One explanation was that SIT included several techniques and, in combination with PE, might have overloaded the patient. Patients in the PE/SIT combination may have less time to do PE homework because they have to also do homework related to SIT. Our conclusion from this study was to recommend “pure” PE rather than adding any other techniques.

This pattern of failing to find that combining PE with other treatment components improves outcome over PE alone was found across subsequent studies in our and other clinical research centers. Foa and colleagues (2005) compared PE alone with PE combined with cognitive restructuring (CR) in 179 women with chronic PTSD resulting from rape, nonsexual assault, and/or childhood sexual abuse. Participants received (p. 7) between 9 and 12 sessions of therapy, 90 minutes each, delivered once per week. Results demonstrated comparable efficacy for both PE and PE/CR because they resulted in greater reductions in symptoms of PTSD, anxiety, and depression than those on the wait list both at posttreatment and at a 1-year follow-up. Of note, effect sizes were again larger in PE alone than in PE combined with CR. Moreover, studies from multiple research groups have found that adding various CBT techniques to PE did not enhance the benefit of PE alone (Foa et al., 2005). Marks et al. in England found a similar pattern of results when they compared PE, CR, their combination, and relaxation; PE achieved more responders compared to the other three treatments (Marks, Lovell, Noshirvani, Livanou, & Thrasher, 1998). In a Swedish study, Paunovic and Ost compared PE to PE/CR; no differences emerged between treatments (Paunovic & Öst, 2001). In the one exception that we are aware of, Bryant et al. (2008) found that imaginal and in vivo exposure combined with CR resulted in greater improvement in PTSD and depression compared to exposure alone in a sample of civilian trauma survivors. However, the study omitted the processing after imaginal exposure. Given the preponderance of evidence, we have abandoned the inclusion of other formal CBT techniques with PE and focused more on how to tailor the intervention to setting through modification of treatment duration (shorter sessions), treatment site (telehealth, primary care, deployed settings), and mode of delivery (massed sessions, group vs. individual).

In comparative efficacy trials, PE has shown similar efficacy to other interventions. For example, Resick et al. (2002) compared PE alone with CPT, a form of cognitive therapy, in women with rape-related PTSD. In comparison to the wait list, both PE and CPT yielded significant improvement in PTSD symptoms and depression, with gains maintained through long-term follow-up of 5–10 years (Resick et al., 2012). In a more sensitive analysis of relapse among those remitted at posttreatment, only 6% of PE remitters relapsed versus 21% of CPT remitters (Resick, Williams, Suvak, Monson, & Gradus, 2012).

When compared to EMDR (Shapiro, 1989, 1995) and wait list control, Rothbaum, Astin, and Marsteller (2005) found that women with sexual assault–related PTSD showed similar and significant reductions in PTSD, depression, and anxiety with both PE and EMDR exhibiting (p. 8) larger reductions than the wait list condition. However, the PE group was superior to the EMDR group on a composite measure of functioning taken at a follow-up assessment 6 months after the end of treatment. In Vancouver, Taylor et al. compared PE, EMDR, and relaxation and found no differences between EMDR and relaxation (the control group); PE showed more benefit than relaxation (Taylor et al., 2003).

Across the research to date, several meta-analyses of PE have indicated that PE is highly effective at ameliorating the symptoms of PTSD, depression, anxiety, guilt, suicidal ideation, and self-injurious behavior, and, in comparison with other forms of CBT, it achieved comparable outcomes (Cusack et al., 2016; Lee et al., 2016; Watts et al., 2013).

Dissemination and Implementation of PE Across the United States and Abroad to Community Clinicians

Can community clinicians deliver PE effectively? The Foa et al. (2005) study described earlier was designed not only to examine the augmenting effects of CR, but also to answer this important question by comparing the treatment outcome of patients who received their treatment from community rape crisis center (Women Organized Against Rape [WOAR]) MA-level counselors with those who received their treatment from PhD-level clinicians in the Center for the Treatment and Study of Anxiety (CTSA). The results indicated that with a 5-day workshop and ongoing consultation for all providers of PE, no differences in treatment outcome were apparent between the two groups of patients. This was the first study to show that PE can be successfully transported to a community setting and implemented effectively by non-CBT experts, with the patients self-referred to WOAR.

Since the initial studies, PE workshops are now being conducted around the world. PE was first disseminated to Israel and was successful in treating PTSD primarily in male combat veterans. A randomized, controlled study that compared PE with treatment as usual in Israel demonstrated results similar to those in the open studies (Nacasch et al., 2011).

Dissemination to Japan has also shown success (Asukai, Saito, Tsuruta, Ogami, & Kishimoto, 2008). In a systematic review of research and (p. 9) clinical dissemination efforts on PE, Foa, Gillihan, and Bryant (2013) summarized the many international efforts to disseminate PE and the success of moving this effective clinical practice around the world. With large efforts, PE is now practiced in many languages and cultures around the globe, and this PE guide has been translated into many languages. While noting this success, Foa and colleagues (2013) also discussed many barriers and facilitators to dissemination including treatment facility and training leadership support for the new practice and logistical support through billing and other practices to support sustainability. Indeed, system change is hard, and integrating new practices into existing mental healthcare systems is a challenge that needs to be overcome to provide the best care to those who suffer from PTSD.

In 2007, the Veterans Health Administration (VHA) implemented a large-scale effort to train thousands of VA mental health providers in PE. To date, more than 2,000 VA mental health providers have been trained in PE, with a huge increase in its use. As a result, research on the efficacy and effectiveness of PE in veterans has exploded. The training initiative and VHA PTSD Clinics have demonstrated PE efficacy with large effect sizes in clinical care similar to clinical trials and retention rates similar to other psychotherapies and medication for PTSD in this population (Eftekhari et al., 2011, 2013, 2015; Rauch, Eftekhari, & Ruzek, 2012; Rauch et al., 2009, 2015; Tuerk et al., 2012, 2013). PE has shown efficacy across veterans of different eras and is effective with comorbidities that are common in this population, including traumatic brain injury, psychotic disorder, alcohol and substance use disorders, borderline personality disorder and characteristics, and depression (Grubaugh et al., 2016; Harned, Jackson, Comtois, & Linehan, 2010; Sripada et al., 2013; van den Berg et al., 2016; Wolf et al., 2015; Yoder et al., 2012).

As a result of the large body of research supporting the effectiveness of PE, the treatment program was awarded a 2001 Exemplary Substance Abuse Prevention Program Award by the US Department of Health and Human Services, Substance Abuse and Mental Health Services Administration (SAMHSA), and was designated as a Model Program for national dissemination.

(p. 10) PE Treatment Mechanisms Research

Examination of the processes underlying the efficacy of treatments for pathological anxiety has shown significant progress over the 12 years since the last edition of this guide. Numerous studies have been conducted to better understand how treatments such as PE work, with the aim of further refining and improving the efficacy and efficiency of the treatment and of better understanding the psychopathology of anxiety disorders. These will be briefly summarized. Emotional Processing Theory, EPT, posits two necessary conditions for emotional processing: (1) the fear structure must be activated in order to modify it, and (2) new information must be incorporated into the fear structure. This new information is encoded during exposure, altering the fear structure and leading to a general pattern of reduction in negative affect (habituation/extinction) as the same or similar stimuli are encountered, thereby resulting in symptom reduction. Thus, three potential indicators of emotional processing include (1) activation of the fear, (2) within-session extinction, and (3) between-session extinction. Accordingly, from EPT we hypothesize that the degree of fear activation, the degree of fear reduction within sessions, and the lower peak responses in successive exposure sessions will all be positively associated with improvement in PTSD symptom severity. Negative cognitions were hypothesized to impede recovery after a traumatic experience, and reduction of these cognitions is viewed as a key mechanism of emotional processing and the resultant recovery (Foa & Rothbaum, 1998; Foa & Cahill, 2001; Rauch & Foa, 2006). Next, we will consider these hypotheses, beginning with the role of negative cognitions.

Negative Trauma-Related Cognitions

The unhelpful, negative cognitions that “the world is extremely dangerous” and “I am extremely weak and incompetent” mediate the development and maintenance of PTSD by promoting avoidance that prevents disconfirmation. Accordingly, treatment that aims to ameliorate PTSD symptoms should correct these erroneous cognitions by introducing new information that disconfirms these erroneous, negative cognitions (Foa, Huppert, & Cahill, 2006). Several lines of research support the hypothesis that negative trauma-related cognitions (most often (p. 11) measured via patient self-report inventories, such as the Posttraumatic Cognitions Inventory [Foa et al., 1999]) are a key mechanism of recovery from PTSD (e.g., Foa, Tolin, Ehlers, Clark, & Orsillo, 1999; Foa & Rauch, 2004; Kleim et al., 2013; Moser, Hajcak, Simons, & Foa, 2007; Rauch et al., 2015; Smith et al., 2007). Providing strongest support for change in cognitions as a possible causative mechanism, research examining the temporal sequencing of change has shown that reductions in negative trauma-related cognitions temporally precede decreases in PTSD symptoms during PE (Kumpula et al., 2017; Foa & Mclean, 2015; McLean, Su, & Foa, 2014; McLean, Yeh, Rosenfield, & Foa, 2015; Zalta et al., 2014), whereas PTSD symptom reduction did not precede reduction in negative cognitions. These findings are consistent with the EPT supposition that change in negative cognitions is involved in PTSD recovery, whether it be natural recovery or therapeutic recovery, whether it is due to PE or to another PTSD treatment (Foa, Huppert, & Cahill, 2006).

Fear Activation (Emotional Engagement)

The role of emotional engagement in PTSD treatment has been examined by Foa and colleagues using several methods. One study that operationalized emotional engagement as facial fear expression during the first session of imaginal exposure found that higher fear expression was associated with superior treatment outcome after PE (Foa, Riggs, Massie, & Yarczower, 1995). Research findings from extinction learning paradigms (often conceptualized as an analogue to exposure therapy) in animals lend support to the hypothesis that greater fear activation during exposure therapy is associated with greater reductions in PTSD symptoms. Benzodiazepine medications reduce arousal and are not recommended for patients with PTSD. Indeed, in one study they were found to impede response to PE in veterans with PTSD (Rothbaum et al., 2014).

Within- and Between-Session Extinction (Habituation)

As noted earlier, EPT originally proposed that the gradual reduction of anxiety within a session is an indicator of emotional processing, which (p. 12) is the process by which pathological anxiety is reduced. Although anxiety does typically decline from the beginning to the end of an exposure session, the role of within-session extinction in treatment outcomes has not received strong support (Jaycox, Foa, & Morral, 1998; van Minnen & Hagenaars, 2002; see Craske et al., 2008, for a review). Indeed, since PE was first developed, a robust literature related to extinction learning in animals and humans has indicated that within-session fear reduction is not related to fear extinction (i.e., long-term fear reduction). These findings have clinical implications because they suggest that shortening exposure sessions may be feasible without reducing treatment efficacy. Indeed, although longer exposures have been shown to promote greater within-session extinction than shorter exposures (e.g., van Minnen & Foa, 2006), the fact that within-session fear reduction does not predict treatment outcome suggests that the length of PE sessions can be shortened if necessary without compromising efficacy. Two studies to date have examined this issue within the context of PTSD in humans.

In a nonrandomized study, van Minnen and Foa (2006; N = 92) found that 60-minute imaginal exposures within 90-minute sessions did not produce superior outcomes to 30-minute imaginal exposures within 60-minute sessions, despite greater within-session extinction in the longer exposures. Following this study, Nacasch et al. (2015) conducted a small randomized trial (N = 39) comparing 20-minute imaginal exposures (during 60-minute sessions) with 40-minute imaginal exposures (during 90-minute sessions). The results replicated the van Minnen and Foa study finding no differences in outcome between the two groups. Long sessions resulted in greater within-session reduction of distress, but no group differences emerged in reduction of negative cognitions.

In contrast to within-session extinction, between-session extinction has been associated with therapeutic recovery in many (e.g., Rauch et al., 2004; Sripada & Rauch, 2014; van Minnen & Foa, 2006) but not all studies (e.g., Pitman, Orr, et al., 1996). Using cluster analysis, Jaycox, Foa, and Morral (1998) found three distinct patterns of change among female assault victims during PE: (1) high distress in the first session followed by a gradual decline in distress over subsequent sessions, (2) high distress in the first session and no decline across sessions, and (3) moderate distress in the first session and no change across sessions. (p. 13) At posttreatment, participants in the first group showed superior improvement compared to participants in either of the other groups. These findings are consistent with the proposition that emotional engagement and habituation are involved in recovery. Thus, while within-session reductions in fear are no longer considered critical for improvement (Foa et al., 2006), extinction across therapy sessions appears to be important for treatment success. Consequently, EPT has shifted away from a focus on within-session extinction toward a model emphasizing emotional engagement, disconfirmation (i.e., change in negative cognitions), and between-session extinction.

Benefits and Risks of This Treatment Program


Thirty years of research on PE, as partially summarized earlier, has yielded findings that clearly support the robust and versatile efficacy of PE as a treatment for PTSD resulting from a wide range of traumatic experiences and when delivered to complex patients. Nearly all studies have found that PE reduces not only PTSD but also other trauma-related problems, including depression, general anxiety, anger, self-injurious behaviors, and guilt. PE provides an avenue for transformative change in helping people to reclaim their lives from PTSD.


The primary risks associated with PE therapy are temporary discomfort and emotional distress when confronting anxiety-provoking images, memories, and situations in the course of treatment. The procedures of PE are intended to promote engagement with the range of emotions associated with the traumatic memory (e.g., anxiety, fear, sadness, anger, shame, guilt) to help the patient process the traumatic memories. As will be described in detail in Chapter 8, during PE the therapist not only should be supportive and empathic in guiding the patient through the processing of the trauma memory but also should monitor the patient’s distress and intervene when necessary to modulate the level of emotional (p. 14) engagement and associated discomfort. When recommending PE to a trauma survivor, the therapist should explain that disclosing trauma-related information and working to emotionally process these painful experiences in therapy may lead to increased emotional distress and, for some people, a temporary exacerbation of PTSD, anxiety, and depression. This is described to patients as “feeling worse before you feel better.” However, in a sample of 75 women receiving PE for assault-related PTSD, this temporary exacerbation occurred in a small subset of patients and was not associated with worse outcome or with premature termination of treatment (Foa, Zoellner, Feeny, Hembree, & Alvarez-Conrad, 2002). Moreover, while some patients fail to benefit from this therapy, there are only a handful of case reports of symptoms worsening after exposure therapy. In fact, recent studies have shown that individuals who drop out of PE before completion do not show significant increases in severity of PTSD and depression (Tuerk et al., 2011).

Alternative Treatments

Although an extensive review of studies investigating CBT treatments for PTSD is beyond the scope of this therapist guide, our own research findings are neither unique nor isolated. In general, many studies over the past 30 years have found exposure therapy effective in reducing PTSD and other trauma-related pathology, rendering it the most empirically validated approach among the psychosocial treatments for PTSD and one designated by expert treatment guidelines as a first-line treatment (Foa, Keane, Friedman, & Cohen, 2009; Institute of Medicine [IOM], 2007; VA/DOD, 2017). In addition to PE and other variants of exposure therapy, the CBT programs that have been empirically examined and found effective include CPT, SIT, cognitive therapy (CT), and EMDR. For recent meta-analyses comparing interventions, see Lee et al. (2016) and Watts et al. (2013).

The Role of Medications

The VA/DOD and American Psychological Association’s 2017 PTSD practice guidelines recommend the selective serotonergic reuptake (p. 15) inhibitors (SSRIs) sertraline (Zoloft), paroxetine (Paxil), and fluoxetine (Prozac) and the serotonin norepinephrine reuptake inhibitor (SNRI) venlafaxine (Effexor) as pharmacological treatments for PTSD (VA/DOD Clinical Practice Guideline for the management of PTSD and ASD, 2017; APA Clinical Practice Guideline, 2017). Of these, the only medications to receive indications for treatment of PTSD from the US Food and Drug Administration are two SSRIs: sertraline and paroxetine. A number of randomized controlled trials have found SSRIs to be superior to placebo, and most studies of SSRIs have generally found a significant reduction in all DSM-IV symptom clusters of PTSD: reexperiencing, avoidance, and arousal. They are also considered useful agents because of their efficacy in improving comorbid disorders such as depression, panic disorder, and obsessive-compulsive disorder and because of their relatively low side-effect profile.

More research needs to be conducted to expand our knowledge of pharmacological treatments for PTSD. Research is needed to compare the relative efficacy of medications, psychosocial therapies, and their combination. Three studies have been published to date combining SSRIs and PE in three different orders:

  • One study started patients on the SSRI sertraline, then added PE or wait list (Rothbaum et al., 2006). Outpatient men and women with chronic PTSD completed 10 weeks of open-label sertraline and then were randomly assigned to 5 additional weeks of sertraline alone (n = 31) or sertraline plus 10 sessions of twice-weekly PE (n = 34). Results indicated that sertraline led to a significant reduction in PTSD severity after 10 weeks but was associated with no further reductions after 5 more weeks. Participants who received PE showed further reduction in PTSD severity. This augmentation effect was observed only for participants who showed a partial response to medication. Thus, the addition of PE to sertraline for PTSD improved the outcome for individuals experiencing a less than full response to the medication (Rothbaum et al., 2006).

  • Another study delivered PE to all patients and then randomized them to receive paroxetine or placebo while continuing to receive PE (Simon et al., 2008). They did not find a benefit of PE plus paroxetine over PE plus placebo.

  • (p. 16) A third study started World Trade Center survivors on paroxetine (or placebo) and PE simultaneously for 10 weeks and was the only one to find an additive effect: paroxetine plus PE was more effective than placebo plus PE (Schneier et al., 2012). We should note that in both the VA/DOD and APA 2017 clinical guidelines, there was insufficient evidence to suggest any augmentation strategy for nonresponders to a monotherapy (APA, 2017; VA/DOD, 2017).

There has been interest in combining more novel medications with psychotherapy, particularly for patients who are considered treatment resistant. These medications include d-cycloserine (Mataix-Cols et al., 2017; Rothbaum et al., 2014), 3,4-methylenedioxymethamphetamine (MDMA) (Mithoefer, Wagner, Mithoefer, Jerome, & Doblin, 2011), cannabinoids (Rabinak et al., 2014), and methylene blue (Zoellner et al., 2017). Note that these novel medications are not recommended by either treatment guideline (APA, 2017; VA/DOD, 2017).

In our clinical practice, it is common for patients to enter PE treatment already taking an SSRI or other appropriate medication for their PTSD and/or depression. For study purposes, we merely require that the person be on a stable dose of the medication for at least 2–4 weeks prior to commencing treatment. For PTSD patients presenting with severe, comorbid depression, ongoing pharmacotherapy may be quite helpful and allow them to participate fully in the PE treatment.

Outline of This Treatment Program

The PE treatment program consists of 8–15 weekly or twice-weekly treatment sessions that are generally 90 minutes each. Since the first edition of the guide, additional clinical experience and research has supported the use of PE sessions in massed sessions provided every day for 2 weeks and in brief versions of the therapy (Blount, Cigrang, Foa, Ford, & Peterson, 2014) and in a brief form in primary care (Cigrang et al., 2017).

This guide is divided into chapters that provide instructions about how to conduct each session and how to present the material to the patient, with a focus on the most widely used format of 8–15 weekly sessions. (p. 17) Each session includes an outline of what is to be accomplished (with suggested time frames), the information that you will convey to your patient, the techniques you will use and how to use them, and what homework to assign to your patient. The patient will receive a workbook that contains all necessary handouts and homework forms (Rothbaum, Foa, Hembree, & Rauch, 2019). Each session should be recorded for the patient to review as part of the homework each week. In addition, a separate recording will be made during the breathing retraining in Session 1 for the patient to use at home to practice the breathing skill. We record the breathing practice for several minutes and give it to the patient for practice at home. Finally, beginning in Session 3, two recordings will be made in each session, one with the imaginal exposure (revisiting and recounting the traumatic memory) alone to facilitate the homework of listening to the exposure once a day. The other recording has everything up to the onset of imaginal exposure and also the processing discussion that follows imaginal exposure. These recordings can be made with audiotape or digital recording, or the patient may prefer to use her cell phone. Recently, the VA and DOD developed the PE Coach App that provides an excellent interface for digitally recording the sessions. PE Coach can be used with Android or iPhone and also helps the patient to progress through the whole PE protocol, including presentation of treatment rationale, support for monitoring the Subjective Unit of Discomfort Scale (SUDS), and scheduling in vivo and other appointments. In addition to resources for patient use, the Medical University of South Carolina, with funding from the VA and DOD, has created an online training resource for PE providers that includes didactic resources and training videos illustrating key concepts in effective use of PE for PTSD (

As will be described in the next chapter, monitoring the patient’s progress throughout treatment is an important aspect of PE. This is accomplished in part by having the patient complete self-report measures of PTSD and depression every other session. You will review these forms briefly at the beginning of the sessions in which they are completed.

We cannot overemphasize the importance of building a good foundation for treatment that is based on a strong therapeutic alliance and a clear and compelling rationale for treatment. It takes practice to implement (p. 18) a manualized treatment like PE and at the same time provide empathy, support, and consistent attention to the therapeutic alliance that is so important in psychotherapy. It is a misconception that following treatment manuals dehumanizes the therapy process, but tailoring the interventions of a treatment manual to the individual patient—while simultaneously “being a therapist”—requires practice and skill.

Structure of Sessions

Session 1 begins by presenting the patient with an overview of the treatment program and a general rationale for PE (Handout 1: Rationale for Treatment by Prolonged Exposure). The second part of the session is devoted to collecting information about the trauma, the patient’s reactions to the trauma, and pretrauma stressful experiences. The Trauma Interview in Appendix A of this guide was developed to assist you in obtaining information that will be useful in designing the patient’s treatment program. Importantly, during the trauma interview, you and the patient need to identify the trauma that is currently most upsetting to the patient (the index trauma) as well as the beginning and end points of this trauma memory. This will be the trauma memory that will be revisited in imaginal exposure in Session 3. Session 1 ends with the introduction of breathing retraining (Handout 2: Breathing Retraining Technique). Breathing retraining is introduced to provide the patient with a useful and handy skill to reduce general tension and anxiety that may interfere with daily functioning (e.g., at work or with difficulty falling asleep). In our experience, some patients find this technique extremely useful and use it often, while others do not. With a few exceptions, we instruct PE patients not to use breathing retraining during exposure exercises because we want them to experience their ability to cope with trauma-related memories and situations without special devices. In our view, the breathing skill is not critical to the process and outcome of PE. For homework, the patient is instructed to review Handout 1: Rationale for Treatment by Prolonged Exposure, listen to the session recording one time before the next session, and practice the breathing retraining on a daily basis (Handout 2: Breathing Retraining Technique, will facilitate the practice of this exercise). (p. 19)

Therapist Note

It is a good idea to familiarize yourself with the Trauma Interview (Appendix A: Trauma Interview) before the first session so you are comfortable asking questions about the trauma and the patient’s history. If you are conducting PE with a patient whose history you are familiar with, you may not need to ask all of the questions on the Trauma Interview and should modify it accordingly.

Session 2 begins with reviewing the patient’s experience of homework: listening to the recording of Session 1, reviewing the treatment rationale, and practicing the breathing skill. It next presents patients with an opportunity to talk in detail about their reactions to traumatic experiences and their effect on them. Common reactions to trauma are discussed and are also described in the workbook (Handout 3: Common Reactions to Trauma). This discussion will be didactic and interactive. Next, the rationale for in vivo exposure is presented. Finally, during Session 2, you and the patient together construct a hierarchy of situations or activities and places that the patient is avoiding (Handout 4: In Vivo Exposure Hierarchy). The patient will begin confronting situations for in vivo exposure homework after this session (Handout 5: In Vivo Homework Recording Form). Session 2 concludes by identifying specific in vivo assignments for that week’s homework. The patient is also encouraged to continue to practice the breathing exercises, listen to the session recording one time before the next session, and read the Common Reactions to Trauma daily. (p. 20)

Therapist Note

We note that in some clinical and research settings, Session 2 as described in this guide is broken into two separate sessions. The first is devoted to the discussion of common reactions and the patient’s experience of these, and the second to the in vivo exposure portion of Session 2. This procedure has been done to reduce the length and amount of material presented in the standard Session 2.

Session 3 begins with a homework review. You then present the rationale for imaginal exposure, followed by the patient’s first imaginal revisiting of the trauma memory. During this imaginal exposure, you instruct the patient to recount the trauma for 40–45 minutes (Appendix C: Therapist Imaginal Exposure Recording Form). This is followed by 15–20 minutes of discussion aimed at helping the patient to continue processing thoughts and feelings associated with the trauma. The assigned homework is to listen to the recording of the imaginal exposure on a daily basis, listen to the entire session recording one time, and continue with in vivo exposure.

Intermediate Sessions (4 to up to 14) consist of homework review, followed by up to 30–45 minutes of imaginal exposure, 15–20 minutes of postexposure processing of thoughts and feelings, and about 15 minutes of in-depth discussion of the in vivo homework assignments. As treatment advances, encourage the patient to describe the trauma in greater detail during the imaginal revisiting and recounting and to focus progressively more on the most distressing aspects of the trauma experience, or memory “hot spots.” In later sessions, as the patient improves, imaginal exposure may become shorter, to about 30 minutes.

Session 10 (or Final Session) includes homework review, 15–25 minutes of recounting the entire trauma memory only once, discussion of this exposure with emphasis on how the experience has changed over the course of therapy, and a detailed review of the patient’s progress in treatment. The final part of the session is devoted to discussing continued application of all that the patient has learned in treatment, relapse prevention, and treatment termination.

Use of the Patient Workbook

The patient workbook will aid you in delivering this treatment. It contains brief information and instructions to patients that follow the format of this guide, as well as blank versions of all forms used during the treatment sessions and for homework assignments. These include forms for creating an exposure hierarchy (Handout 4) and tracking imaginal and in vivo exposure homework (Handouts 5 and 7). Patients will find it extremely helpful to use the workbook to review treatment (p. 21) rationales (Handout 1), record observations during homework exercises (Handouts 5 and 7), and reinforce what they have learned in session. You may photocopy forms from the workbook or download multiple copies from the Treatments ThatWork Web site at

Some of the forms used in PE therapy are also included in this therapist guide. You may photocopy other necessary forms (e.g., exposure homework recording forms, Common Reactions to Trauma information) from the workbook or download multiple copies from the Treatments ThatWork Web site. (p. 22)