SOCW 6311 WK 2 Discussion: Generating Support for Evidence-Based Practices

Mechanisms of Change in Prolonged Exposure Therapy for PTSD: Implications for Clinical Practice

Lily A. Brown, Laurie J. Zandberg, and Edna B. Foa University of Pennsylvania

Prolonged exposure therapy (PE) is a highly efficacious and effective treatment for posttraumatic stress disorder (PTSD). In addition to reducing PTSD symptoms, PE ameliorates a wide-variety of related symptoms, including anxiety, depression, func- tional impairment, mild suicidal ideation, and anger. Furthermore, PE is effective in patients with comorbid conditions, including dissociation, substance use, borderline personality disorder and psychosis. How does PE achieve these outcomes? Emotional processing theory (EPT) is the conceptual model from which PE was derived. Three key concepts were originally proposed as indicators that emotional processing, the mechanism underlying symptom reduction via exposure therapy, including PE, had occurred. The three indicators are fear activation, within-session habituation, and between-session habituation, all of which were proposed to reduce symptoms of PTSD. In addition to these indicators, EPT posits that changes in cognitive evaluations about the self and the world are also involved in successful emotional processing, the mechanism underlying symptom reduction. Since its emergence in 1986, EPT has been updated and modified to incorporate emerging empirical findings and conceptual developments. We first review recent empirical support for, and refutation of, various hypotheses derived from EPT, including the importance of fear activation, between- session habituation, and cognitive change. We then provide a clinical case study to highlight strategies to promote emotional processing and the resultant long-term symptom reduction. This case example highlights three common obstacles to success in PE: namely underengagement, insufficient homework compliance, and the presence of PTSD-related negative cognitions.

Keywords: posttraumatic stress disorder, prolonged exposure therapy, emotional processing theory, mechanisms, case example

Emotional Processing Theory

Emotional processing theory (EPT) explains the development, maintenance and updating of emotional structures, or networks of emotion- ally salient associations (Foa & Kozak, 1986). According to EPT and consistent with experi- mental analogue studies of associative learning, emotions such as fear indicate the activation of an emotional structure, a cognitive network that contains information about stimuli, responses, and the meaning of stimuli and responses. Em-

bedded within the emotional structure are asso- ciations between aversive unconditioned stimuli (US) and neutral conditioned stimuli (CS). Thus, pairing a dark alley (CS) and assault (US) results in an association that is represented in the emotional structure. The structure includes CS elements (e.g., the gender or race of the assailant, dark alleys, music heard in the back- ground of the assault), US elements (e.g., the physical assault itself), conditioned response el- ements (CR; e.g., fear, shame, avoiding dark alleys or people who resemble the assailant), and unconditioned response elements (UR; e.g., the physical pain of the assault). Stimuli and response elements, in turn, are associated with new meaning (e.g., dark alleys mean “danger”).

Associations embedded in emotional struc- tures can be either accurate or inaccurate. Ac- cording to EPT, associations represented within the emotional structure are maintained until

Lily A. Brown, Laurie J. Zandberg, and Edna B. Foa, Department of Psychiatry, Center for the Treatment and Study of Anxiety, University of Pennsylvania.

Correspondence concerning this article should be addressed to Lily A. Brown, Market Street Suite 600 North, Philadelphia, PA 19104. E-mail: [email protected]

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Journal of Psychotherapy Integration © 2019 American Psychological Association 2019, Vol. 29, No. 1, 6 –14 1053-0479/19/$12.00 http://dx.doi.org/10.1037/int0000109

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new, inconsistent information becomes avail- able and is embedded in the structure. Thus, a woman who has experienced an assault may perceive individuals who resemble the perpetra- tor as dangerous until she encounters neutral or positive experiences with such individuals. Un- fortunately, CRs (e.g., fear, avoidance) that are evoked in response to CS maintain the errone- ous predictions of “danger” in the face of safe stimuli. For example, if the woman described above feels anxious around and therefore avoids men who resemble the perpetrator, she will not have the opportunity to learn that these men are not dangerous. Thus, fear of safe stimuli ele- ments is maintained indefinitely through avoid- ance.

Emotional structures are updated through the presentation of information that is incompatible with erroneous associations represented in the structure. This information allows for the for- mation of new associations (i.e., not all men who resemble the perpetrator are dangerous). For new information to become embedded in and update an emotional structure, two con- ditions are necessary. First, the emotional structure must be activated so it becomes available to incorporate new information. Thus, fear activation is both a mechanism through which an emotional structure is primed for updating as well as an indicator that emotional processing is taking place. Second, information that directly competes with the erroneous, pathological associations must be available. For example, the trauma- tized woman described above will eventually learn that not all men who resemble the per- petrator are dangerous if: (a) she encounters men who resemble the perpetrator, initially resulting in a fear response (fear activation), during exposure therapy; and (b) she is not assaulted by these men, thus promoting ex- tinction learning. According to EPT, two ad- ditional indicators of emotional processing are (a) decreased emotional responding (e.g., fear) within an exposure (i.e., within-session habituation) and (b) decreased emotional re- sponding across sessions (i.e., between- session habituation). These principles of EPT form the basis of prolonged exposure therapy (PE) for posttraumatic stress disorder (PTSD).

Prolonged Exposure Therapy (PE)

PE is an evidence-based manualized treat- ment for PTSD with numerous randomized con- trolled trials supporting its efficacy and effec- tiveness (Cusack et al., 2016). There are four components of PE: (1) in vivo exposure; (2) imaginal exposure/processing; (3) psychoedu- cation; and (4) breathing retraining (Foa, Hem- bree, & Rothbaum, 2007). In vivo exposure involves the gradual confrontation of anxiety- provoking but objectively safe trauma-remind- ers, including people, places, objects and situa- tions. In vivo exposure promotes: (a) reduction in negative trauma-related cognitions; (b) learn- ing that the feared situation is not dangerous; (c) learning that fear and arousal do not last indef- initely; and (d) learning about the ability to tolerate anxiety. Imaginal exposure and pro- cessing involve the revisiting of the trauma memory aloud coupled with discussing core cognitions and beliefs about the self, others and the world related to the trauma. By repeatedly confronting the memory of the trauma, pa- tients can learn that: (a) the memory itself is not dangerous; (b) the distress associated with thinking about what happened declines over time; and (c) some of the faulty perceptions they may hold about their own and other’s behavior are not accurate. Psychoeducation involves the provision of didactic information about PTSD, common reactions to trauma, and the role of avoidance in maintaining PTSD. In breathing retraining, patients learn to slow their breathing to regulate distressing emotions.

Mechanisms of Change in PE

EPT principles are embedded in PE for PTSD. First, both in vivo exposure and imagi- nal exposure exercises involve emotional acti- vation. This emotional activation allows for the incorporation of new information into the emo- tion structure. Fear activation has been found to predict treatment response for anxiety disorders (e.g., Jaycox, Foa, & Morral, 1998; Norton, Hayes-Skelton, & Klenck, 2011; Peterman, Carper, & Kendall, 2016; Phelps, Delgado, Nearing, & LeDoux, 2004), though some stud- ies contradict these findings, including a recent meta-analysis (e.g., Baker et al., 2010; Rupp, Doebler, Ehring, & Vossbeck-Elsebusch,

7MECHANISMS OF PROLONGED EXPOSURE

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2017). Additionally, within-session habituation is encouraged in PE. Patients are commonly encouraged to continue in vivo exposures until their fear reduces by 50%. Similarly, patients engage in extended imaginal exposure exer- cises, often about 40 min in length, in part to promote within-session habituation. However, evidence about the relationship between within- session habituation and symptom reduction is mixed. Although a recent meta-analysis found that within-session habituation was associated with outcome of exposure therapy (Rupp et al., 2017), several studies have not found a relation- ship between within-session habituation and outcome (Baker et al., 2010; Harned, Ruork, Liu, & Tkachuck, 2015; Nacasch et al., 2015; Peterman et al., 2016; Sripada & Rauch, 2015; van Minnen & Foa, 2006). Finally, between- session habituation, or the reduction of anxiety from one session to the next, is promoted in PE through exposure homework assignments. Most studies have found that between-session habit- uation is related to symptom reduction (e.g., Rupp et al., 2017; Sripada & Rauch, 2015; van Minnen & Hagenaars, 2002), though some stud- ies have not (Peterman et al., 2016).

Finally, changes in PTSD-related negative cognitions are associated with symptom reduc- tion. PE significantly reduces negative cogni- tions (Foa & Rauch, 2004; McLean, Yeh, Rosenfield, & Foa, 2015; Nacasch et al., 2015; Zalta et al., 2014). Furthermore, reductions in negative cognitions precede reductions in PTSD symptoms in adults (Kumpula et al., 2017) and adolescents (McLean et al., 2015). Thus, changes in negative cognitions are a mechanism of symptom improvement for PE.

Enhancing PE per EPT Principles of Change

To illustrate the use of these putative mech- anisms to enhance PE outcomes, we present the case of Alice. We focus herein on fear activa- tion, between-session habitation, and cognitive change. We do not emphasize within-session habituation because it is not related to treatment outcome.

Alice is a 40-year old Latina female who presented to treatment with longstanding PTSD symptoms related to the traumatic death of her mother. Alice’s mother developed an addiction to opiates following a knee injury during Alice’s adolescent years. In the decade

following, Alice endured countless episodes of emo- tional abuse from her mother, particularly when her mother needed assistance in obtaining additional med- ications. Alice found her mother’s dead body on a day when Alice had chosen to stay at work, rather than rushing home when her mother had called her to re- quest medications. The exact cause of her mother’s death remains unknown. Many years after her mother’s passing, Alice continued to experience nightmares, in- trusive memories, and (occasional) dissociative flash- backs about finding her mother’s body. Whenever pos- sible, she avoided talking about her mother or about the general topic of drug use; similarly, she had not visited her mother’s grave since the funeral. Alice endorsed beliefs that she was responsible for her mother’s death, that she was a bad and uncaring daughter, and—in her worst moments—that she “killed her mother.” Her heightened anxiety, hypervigilance, and intermittent panic attacks compromised her daily functioning. Thus, she made the difficult decision to take a medical leave of absence to obtain PE treatment.

Enhancing Initial Activation of the Emotional Structure: Addressing Under

Engagement

Imaginal exposure is designed to help pa- tients systematically approach their trauma memory—to narrate in detail what occurred and emotionally process the trauma. To improve symptoms of PTSD, it is necessary to activate the emotional network related to PTSD symp- toms. During imaginal exposure for PE, patients revisit the memory for approximately 40 min per session. To enhance activation, patients are instructed to close their eyes and recall the memory in present tense, describing what they were thinking, feeling, and doing at the time of the trauma. In the following text, we describe Alice’s difficulty in initially achieving appropri- ate activation of the trauma emotional structure in imaginal exposure.

In her first few imaginal exposures, Alice exhibited “under-engagement.” She complied with the instruc- tions for exposure, but retold the events of the trauma in an unemotional and detached manner. The therapist made several notes: (1) Alice narrated logistical details very specifically, as if she were reading a police report, but did not comment on her personal thoughts and feelings; (2) The moments where Alice discovered her mother’s body were recounted very quickly, with lim- ited detail; and (3) Alice frequently lapsed into tangen- tial or reflective commentary (e.g., “see that’s the kind of thing that happens when a family member is an addict”). While pertinent to the processing of the ex- perience following the imaginal exposure, it was pos- ited that this kind of editing during the imaginal expo- sure served to distance Alice from the trauma imagery. Each of these observations suggested that Alice may be

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titrating her experience by engaging in subtle forms of protective avoidance.

Alice’s therapist made several modifications to en- hance activation and emotional engagement. First, she revisited the imaginal exposure rationale (originally presented in Session 3). She emphasized the impor- tance of emotional engagement with the trauma mem- ory to promote Alice’s processing of her feelings. Second, she used open-ended questioning to explore whether Alice might have concerns about engaging with the memory. These questions revealed that Alice was quite concerned that if she envisioned all the trauma details, she might get so upset that she would “lose it.” She felt like she was “on the brink of falling apart as it was,” and was not sure she could afford to take this risk. Alice’s therapist provided reassurance that her distress will likely decrease rather than in- crease if she allows herself to stick with her feelings. Additionally, the therapist reminded Alice that fully experiencing her emotions will allow her to digest and process the trauma and gain control over the memory. The therapist validated that the experience may be distressing in the first few sessions while also high- lighting that this short-term pain may be necessary for healing.

During imaginal exposure, the therapist facilitated greater engagement by asking prompting questions to draw out detail about the trauma, especially about Alice’s thoughts and feelings. Prompts were brief and delivered in the present tense, such as “what do you feel in your body?” and “what’s going through your mind?” When Alice reached the part of the memory where she found her mother’s body, the therapist prompted her to “stay here—what are you seeing?” In so doing, Alice described details she had been avoid- ing, and her emotions broke through to the surface. She was appropriately tearful during subsequent exposures, and her body showed signs of heightened anxiety (e.g., sweating, shaky voice). As predicted by EPT, however, the more Alice retold the memory in this connected way, the easier she could speak about it. Alice realized that she did not “lose it,” and was in fact stronger than she had predicted.

Enhancing Between-Session Habituation: Homework Compliance

As noted earlier, between-session habituation is a well-established marker of long-term main- tenance of gains in exposure therapy for anxiety disorders (Rupp et al., 2017). Mechanisms driv- ing between-session habituation are currently unknown, but homework compliance may pro- mote between-session habituation. Indeed, higher compliance with imaginal exposure homework is associated with greater reductions in PTSD symptom severity (Cooper et al., 2017). How should clinicians manage issues related to homework compliance to optimize

outcomes in PE? We revisit the case of Alice to demonstrate.

Alice presented to her fourth session of PE appearing forlorn and anxious. When her therapist asked how she was doing, she reported feeling guilty that she had not listened to her imaginal exposure tape. While she had agreed to complete an in vivo exposure exercise daily, she had only completed one in vivo exposure exercise in the past week.

When the therapist inquired about the completed in vivo assignment, Alice revealed that she went to the grocery store after work once. She reported that she remained at the store for about 30 min despite feeling quite anxious (pre-SUDS: 60, post-SUDS: 70, peak SUDS: 85). The therapist praised Alice’s effort and asked her “How did you convince yourself to go to the store in the first place?” Alice revealed that she was worried about breaking her commitment to her thera- pist. The therapist then asked Alice “Was there any- thing that you said to yourself as you were driving to the store or walking inside?” Alice had reminded her- self about the rationale for PE; she remembered that if she avoided the store, she would continue to feel anx- ious. The therapist praised Alice and agreed with the utility of this strategy.

The therapist then asked, “How were you able to stay in the store even though you were very anxious?” Alice reported that when she was at the store, she reminded herself that if she left right away, she would be giving into her anxiety. She reported thinking that if she left right away, it might even make her anxiety worse. Again, the therapist praised Alice for having the cour- age to fight through her anxiety.

Once the therapist felt that she had thoroughly praised Alice for the completed assignment, she turned her attention briefly to the incomplete assignment. The therapist said, “I think it’s wonderful that you were able to complete that first exposure this week. It’s going to be important for us to collaboratively choose assignments that you can repeat. Repetition is a critical component for success in PE. The more that you repeat the exposures, the less anxiety that you will feel. Do you have any questions about that? At the end of the session, we’ll make sure to spend time on planning for the week for in vivo exposures.”

Then, the therapist explored noncompliance with ima- ginal exposure homework. “What do you think got in the way of imaginal exposure homework this week? I’m really worried about this. We’ve found that listen- ing to the tape helps to relieve suffering. I’m worried that if you don’t listen to the tape, you’re not going to get the most out of this treatment. Does that make sense? At the end of the session, we’ll spend some time trouble-shooting ways to overcome urges to avoid lis- tening to the tape this week. For right now, I think we should start another imaginal exposure.”

After the patient completed the imaginal exposure and processing, the therapist opened another conversation about homework compliance concerns. “Alice, you

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have done an exceptional job with your imaginal ex- posure and processing today. You should be very proud of yourself. It’s going to be extremely important for you to listen to the tape this week—you discussed important information and it’s essential for you to hear it repeatedly. Would you be willing to commit to listening to the tape at least three times this week? Could I call you at a scheduled time, perhaps right after you listen to the tape for the first time this week? In terms of the in vivo exposure homework for this week, let’s build on momentum from last week. Can you foresee any difficulties in completing these assign- ments in the coming week? Is there anything that we can do to make them more likely to be accomplished? Would you be willing to commit to doing these assign- ments this week? Just remember, the more that you do this now, the faster your symptoms are going to improve.”

Note that the therapist used several strate- gies throughout this example to maintain rap- port, improve Alice’s sense of mastery and self-efficacy, and improve homework compli- ance. First, she praised Alice for completing one homework component. Second, she reit- erated the rationale for repetition of exposure practice. Third, she expressed care and con- cern for the patient, as well as described re- search suggesting the link between homework compliance and improvement. Fourth, she en- gaged in problem solving with the patient to enhance compliance by planning for midweek check-in calls and helping the patient antici- pate obstacles. Fifth, she used scaffolding to gradually increase homework compliance; the therapist may have assumed that listening to the imaginal exposure tape daily was too overwhelming for the patient and therefore decreased the frequency to three times. Fi- nally, she used the power of public commit- ment to encourage the patient to vocalize her commitment to the assignments.

Enhancing Cognitive Change: Techniques Used in Processing of Imaginal Exposure

Many patients with PTSD harbor exagger- ated or distorted perceptions of their respon- sibility for the trauma. Excessive guilt or self- blame is common. Avoidance of the trauma memory prevents direct confrontation of the details of the trauma. As a result, these neg- ative perceptions go unchallenged. Imaginal exposure promotes cognitive change by high- lighting the context in which the trauma oc- curred. In many cases, imaginal exposure

alone leads to changes in perception of cul- pability. In other cases, processing of the ima- ginal exposure allows for in depth discussion of these beliefs, and facilitates change in neg- ative cognitions.

Alice reported strong beliefs that she was a disgusting and unfeeling person who was responsible for her mother’s death. She believed that if only she had returned home earlier, when her mom first called her, her mother might still be alive. To Alice, the fact that she had chosen to ignore her mother’s pleas demon- strated that she was “no good”, and that she may have wanted her mom to die. She was, after all, very angry with her mom at this point in her life because of the culmination of years of verbal abuse.

To better evaluate these cognitions, Alice’s therapist probed the “choice point” driving her shame and guilt: When Alice’s mother called and decided to stay at work instead of returning home immediately. The goal was to reveal influential contextual details. What did Alice’s mom say? How did she sound? What was Alice thinking? Alice verbalized her anguish at the time of the event. Rather than being cold and unfeeling, she had gone to the break-room and cried. There was nothing in the phone message that was different than the hundreds of prior calls her mom had made. This time, Alice decided she could not afford to lose her job, and delayed checking on her mom until after her shift.

During processing, the therapist helped Alice reevalu- ate her reasons for making the difficult decision of staying at work on the day her mother died. This reevaluation was facilitated by questioning, but with- out any formal cognitive exercises (as you might see in other PTSD treatments, such as Cognitive Processing Therapy). Questions were posed to help Alice explore inconsistencies between her stated beliefs and the de- tails that emerged in the imaginal exposure. For exam- ple, “Help me understand: you think that you should have known your mother really needed you that day. How did her voicemail compare to her other mes- sages?” Alice could think of no differences. Her ther- apist replied, “So it sounds like there was no way to tell a difference from the voicemail. What usually hap- pened when you got home?” Alice recognized that all her previous experiences suggested her mom would be sick from withdrawal, but otherwise fine. The therapist wondered “What do you make of that?” Alice realized that there was no real difference between that day and the many other times when her mother asked Alice to leave her work.

Over 15 sessions of PE, Alice’s beliefs about her direct responsibility for her mom’s death softened greatly. She still wished that she had gone home that day, but did not view herself as responsible for her mother’s death. Instead, she understood the com- plexity of the circumstances that led her to stay at work, and the lack of certainty that her mother would have survived even if she had gone home immediately.

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Managing Treatment Refusal, Nonresponse, and Symptom Exacerbation

Unfortunately, not all patients who are of- fered PE respond as well as Alice. A full discussion of strategies to manage treatment refusal, nonresponse, and symptom exacerba- tion is beyond the scope of this article. In brief, common strategies include exploring and validating ambivalence about exposures, revisiting the treatment rationale, altering the intensity of exposures, and increasing thera- pist support by engaging in check-in phone- calls between sessions. When these and other strategies have not increased treatment en- gagement or response, several considerations may be appropriate.

First, some patients may refuse to engage in PE. After the rationale is revisited and general motivational enhancement strategies have been engaged, potentially borrowing from the motivational interviewing literature (Miller & Rollnick, 2013), some patients may refuse PE in part or whole. For example, one study reported that about 17% of patients refused to engage in imaginal exposure exer- cises (Schottenbauer, Glass, Arnkoff, Ten- dick, & Gray, 2008). There is no evidence to support the efficacy of delivering piecemeal components of PE in the absence of the full package. In fact, a few studies have demon- strated that in vivo or imaginal exposures alone are not sufficient to reduce symptoms of PTSD (Bryant et al., 2008). Therefore, rather than agreeing to continue with one treatment component in the absence of the full PE pack- age, it is recommended that the therapist and patient make a clear transition toward another treatment package or modality altogether in the event of patient refusal.

Second, patients may not benefit from PE, as approximately 50% of patients do not respond clinically to empirically supported treatments for PTSD (Schottenbauer et al., 2008). The full PE treatment package should be continued at least for several sessions even in the event of initial nonresponse. In fact, prior research has suggested differential patterns of response, such that some participants respond more quickly than others (Clapp, Kemp, Cox, & Tuerk, 2016; Foa, Zoellner, Feeny, Hembree, & Alvarez- Conrad, 2002). Therefore, nonresponse early in treatment should not be cause for alarm. If a

participant continues the treatment for several sessions without responding, changing the treat- ment plan may be warranted. Rather than sup- plementing PE with alternative treatment pro- cedures in PE sessions, one option is for the therapist and patient to consciously shift to an alternate evidence-based treatment modality (e.g., Cognitive Processing Therapy; Interper- sonal Psychotherapy). A thorough evaluation of the impediments to success may guide the se- lection of alternative treatments. For instance, a patient who has panic attacks that interfere with PE engagement may benefit from panic disorder treatment prior to returning to PE. A second option is to supplement PE with attendance in a complementary therapy. For example, patients with symptoms of borderline personality disor- der may benefit from attendance in dialectical behavior therapy (DBT; Linehan, 1993) group sessions in addition to individual PE sessions. However, therapists should be cautious about this approach, as there is limited data to support its efficacy (for an example, see Harned et al., 2014). While the concurrent delivery of two empirically supported treatments may improve treatment outcome, it may also dilute treatment effects (Foa et al., 1999). A third option is to deliver additional treatment sessions beyond the traditional recommendation of 12 sessions. This may be a useful approach when patients have shown some improvement but have not reached full treatment response. However, we are not aware of any research on this topic in PTSD.

Third, some patients receiving PE experience symptom exacerbation. Approximately 3–15% of patients report a reliable exacerbation in symptoms (Foa et al., 2002). This exacerbation has been detected most commonly between Ses- sions 3 and 4, following the introduction of imaginal exposure. Fortunately, symptom exac- erbation is not associated with worsened treat- ment outcome (Foa et al., 2002). Therefore, in the absence of acute safety concerns, clinicians should not deviate from the PE protocol despite symptom exacerbation. Indeed, the possibility of symptom exacerbation is frequently dis- cussed as part of preparation for PE. This facil- itates appropriate expectations for the treatment and mitigates demoralization following symp- tom exacerbation. If symptom exacerbation continues for several weeks, the therapist may consider many of the options described for nonresponse. Many of the listed options for

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treatment nonresponse are also relevant for symptom exacerbation. Specifically, therapists should consider stopping treatment and initiat- ing a new treatment modality or supplementing treatment with a concurrent treatment option (e.g., group therapy).

Conclusion

In summary, PE is a very effective treatment for PTSD. When the therapist bases treatment decision in EPT, outcomes are enhanced, as demonstrated by the evidence in support of fear activation, between-session habituation, and cognitive change. In PE, therapists should en- sure that fear is appropriately activated, home- work is completed, and negative cognitions are identified and modified. We have described sev- eral strategies for promoting each of these mechanisms in clinical practice.

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Mecanismos de cambio en la terapia de exposición prolongada para el TEPT: implicaciones para la práctica clínica

La terapia de exposición prolongada (EP) es un tratamiento altamente eficaz y eficaz para el trastorno de estrés postraumático (TEPT). Además de reducir los síntomas de trastorno de estrés postraumático, la EP mejora una amplia variedad de síntomas relacionados, que incluyen ansiedad, depresión, deterioro funcional, ideación suicida leve y enojo. Además, la EP es efectiva en pacientes con condiciones comórbidas, que incluyen disociación, uso de sustancias, trastorno límite de la personalidad y psicosis. ¿Cómo logra la EP estos resultados? La teoría del procesamiento emocional (EPT por sus siglas en inglés) es el modelo conceptual del cual se derivó la EP. Tres conceptos clave se propusieron originalmente como indicadores de que el procesamiento emocional, el mecanismo subyacente a la reducción de los síntomas mediante la terapia de exposición, incluida la EP, había ocurrido. Los tres indicadores son la activación del miedo, la habituación dentro de la sesión y la habituación entre sesiones, todos los cuales se propusieron para reducir los síntomas del TEPT. Además de estos indicadores, EPT postula que los cambios en las evaluaciones cognitivas sobre el yo y el mundo también están involucrados en el procesamiento emocional exitoso, el mecanismo subyacente en la reducción de los síntomas. Desde su aparición en 1986, el EPT se ha actualizado y modificado para incorporar hallazgos empíricos emergentes y desarrollos conceptuales. Primero, revisamos el apoyo empírico reciente y la refutación de varias hipótesis derivadas del EPT, incluida la importancia de la activación del miedo, entre la habituación de la sesión y el cambio cognitivo. Luego proporcionamos un estudio de caso clínico para resaltar estrategias para promover el procesamiento emocional y la reducción de síntomas a largo plazo resultante. Este ejemplo de caso destaca tres obstáculos comunes para el éxito en la educación física: la falta de participación, el cumplimiento insuficiente de la tarea y la presencia de cogniciones negativas relacionadas con el trastorno de estrés postraumático.

13MECHANISMS OF PROLONGED EXPOSURE

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trastorno de estrés postraumático, terapia de exposición prolongada, teoría del procesamiento emocional, mecanismos, ejemplo de caso

针对创伤性应激障碍的延迟暴露疗法中的改变机制：临床实践的意义 延迟暴露疗法（PE）是一项针对创伤性应激障碍（PTSD）具有高度实验效力和临床功效的治疗方式。并且，为 了减少创伤性应激障碍的症状（PTSD），延迟暴露疗法（PE）缓解了多种相关症状，包括：焦虑，抑郁，功能性 失调，轻度自杀意念和愤怒。并且，延迟暴露疗法（PE）对于有并发症的病人非常有效，包括解离（症状），药 物成瘾，边缘型人格障碍以及精神病。那么延迟暴露疗法（PE）是怎样获得这些效果的呢？情绪处理理论（EPT） 作为一种核心模型，延迟暴露疗法即由此发展而来。三个核心概念作为指标最先被提出来， 即：情绪处理作 为通过暴露疗法获得症状缓解的机制（包括：长期暴露疗法 PE）已然发生。这三个指标就是恐惧的触发，治 疗中的习惯化，以及治疗期间的习惯化，这三个指标都被视为能够够缓解创伤性应激障碍（PTSD）的症状。连同 这些指标一起，情绪处理理论（EPT）认为在关于自我及世界的认知评断上发生的改变都伴随着成功的情绪处理 ----即让症状获得缓解的机制。自从1986年情绪处理理论（EPT）产生至今，它有数次更新和调整，以便引进不 断更新的实证发现和概念发展。我们首先回顾了最近的实证支持，以及对从情绪处理理论（EPT）发展而来的许 多假设的驳斥，包括恐惧触发、治疗期间的习惯化、还有认知的改变的重要性。我们接下来再提供临川实例研究 去强调一些策略，以便能够推进情绪处理理论（EPT）（的发展）并带来长期症状减缓的结果。这些案例突出了三 个阻碍延迟暴露疗法（PE）成功的因素，即：低参与度、不充分的作业遵从，以及存在创伤应激障碍相关的负面 认知。

创伤性应激障碍, 延迟暴露疗法, 情绪处理理论, 机制, 案例

Received August 4, 2017 Revision received December 14, 2017

Accepted December 17, 2017 �

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