What is Prolonged Exposure Therapy?

Prolonged Exposure therapy (PE) is an evidence-based psychological technique used to treat individuals who have experienced severe trauma and who are not able to recover without directed psychological intervention. Prolonged exposure makes use of the principle of systematic desensitization in behavioral therapy in which continued exposure to a feared stimulus over time (while preventing avoidance and escape behaviors) reduces distress and anxiety. This method employs both imaginal exposure (the client is asked to think about some aspect of the feared event) and in vivo exposure (the client is directly presented with the feared event or stimulus), or a combination of the two types of exposure to gradually lessen anxieties and fears. According to Foa and Jaycox (1998), prolonged exposure to reminders and/or thoughts of the traumatic event while in a setting in which the client feels safe has the following important outcomes:

  • Reminds the client that remembering the trauma is not dangerous.
  • Helps client understand that remembering things about the trauma is not the same as re-experiencing it.
  • Lets client know that anxiety does not remain high forever, but decreases over time without suppressing or avoiding the memories/thoughts/feelings.
  • Teaches client that experiencing the symptoms of PTSD does not lead to loss of control.

Why use this strategy?

Post Traumatic Stress Disorder (PTSD) and Acute Traumatic Stress Disorder are anxiety disorders. Behavioral and Cognitive Behavioral Therapy, which often include graduated exposure to stressful, anxiety-provoking or traumatic events, have proven to be effective across a wide variety of anxiety disorders such as social phobia, simple phobias, and obsessive compulsive disorder. Prolonged exposure therapy is recommended as a first choice of treatment for PTSD to address the following key target symptoms:

  • Intrusive thoughts
  • Flashbacks
  • Avoidance and numbing
  • Trauma related fearfulnesss, panic, generalized anxiety, hyperarousal, hypervigilance, and exaggerated startle responses
    (Foa, Davidson, and Frances, 1999)

Whom to use it with?

Prolonged Exposure therapy can be used with clients of all ages expiencing traumatic stress disorders including rape, assault, and battlefield trauma. Some useful principles and important environmental and client characteristics:

It is unwise to provide a formal psychological intervention within 30 days of the traumatic event- watchful waiting and monitoring would be recommended. Because a large number of individuals recover naturally, providing early treatment is wasteful and possibly harmful in that it may retraumatize the individual.

  • In order to benefit from treatment, the client must currently be in a safe environment, and not be constantly re-exposed to the traumatic stressors.
  • The client must be able to tolerate the increased anxiety that is temporarily produced by exposure therapy.
  • The client must have the ability to recall details of the event.

When to use this procedure

It is important to remember that not all people exposed to an extreme stressor will develop PTSD, and that some PTSD sufferers may be difficult to identify. Although most people may experience distressing symptome shortly after a traumatic stressor has occurred, only a small percentage will go on to develop PTSD. Before embarking on a program of exposure therapy, it is important to develop a collaborative psychoeducational approach in which you engage your client about the rationale for this procedure and review their readiness.

How to use this procedure

When a client constantly avoids anxiety provoking situations, a vicious cycle occurs in which avoidance is reinforced, the client never learns that dreaded emotions, thoughts, memories and images are not dangerous and, as a result, anxiety never lessens. The original sense of fear and unhelpful beliefs related to the trauma (“I’m weak. It’s my fault”. I should have tried harder. The world is dangerous.”) are never fully and consciously processed. As a result many of the memories, dreams, feelings and thoughts and related associations can never be fully addressed and resolved through new learning. The use of imaginal and in vivo exposure helps clients reactivate the original trauma memory and any problematic beliefs; these can then be challenged and the related anxiety and avoidance diminished.

Some of the techniques of prolonged exposure therapy are listed below, along with examples.

Psychoeducation and normalizing symptoms

Initially, it is important to help the client understand their distressing experiences and reduce their level of distress and anxiety through educating them about common PTSD symptoms (intrusive thoughts, memories, images) and reassure them that they are not actually "going crazy" or "losing control". It is important to normalize these symptoms and concerns.

Take the time to explain to the client the rationale for undergoing prolonged exposure therapy, focus on how and why this method will help to reduce anxiety levels and distress. This provides a clear framework for therapy by telling the client what to expect during the course of the therapy, overall, and at the beginning of each session.

"Today we’re going to talk about some of the reactions people can have to a stressful life event. People often feel that they are 'going crazy' or 'losing control' when they begin to experience distressing thoughts, images or feelings related to a traumatic experience. This reaction can cause even more distress and anxiety. Sometimes people try to block out their distressing thoughts, images and feelings and this can lead to a feeling of being numb and 'not really being there'.

"We are going to help you get through the scary feelings about your assault by talking about it together. At first, it may seem very frightening to you to even consider discussing this with me. We are going to make sure that you are in a safe place before we start and that you feel in control of the process. You will be able to tell be whenever you wnat to slow down or stop."

"I’ll help you with some relaxation techniques so that talking about what happened won’t feel so scary."

Imaginal Exposure procedures

The client's readiness to undergo this procedure will depend upon effective psychoeducation, the strength of your therapeutic alliance, the client's sense of 'control' over the process and other factors. Depending upon the level of engagement, the client should be ready to attempt an imaginal exposure to the event that caused their PTSD after an initial three to four sessions of assessment and psychoeducation.

Before starting PE, train the client in identify their SUDS level (Subjective Units of Distress) (see below) and determine their personal comfort zone and the level at which they feel anxiety would be intolerable. The goal of PE is to keep the client outside their comfort zone but below the level of intolerable or unmanageable distress. Clients who become too distressed may begin to dissociate in the session. Be aware of signs of dissociation including 'spacing out', 'feeling numb', 'zong out' and 'not really being here'.

"Before we start I am going to ask you to rate the amount of distress you are feeling on a scale of 0 to 100, where "0" is no distress at all and "100" is the highest level of distress you can imagine. Our goal is to have you be able to rate your distress at any given moment in the session, so that I can know how you are feeling and whether or not to slow down or speed up the exposure. This means that you get to be in control of the pace of this therapy- it’s up to you."

This procedure involves having the client imagine the event again, while describing it in as much detail as possible to the therapist. With progressive retelling of the event, the client is encouraged to recall more specific memories, feeling, sensations and thoughts. Encourage the client to use the present tense while relating their story, as this enables them to encounter the most intense emotions surrounding the event.

Allow sufficient time for the client to process the experience prior to the end of the treatment session. This may require extended sessions of 60-90 minutes. Be very careful not to terminate PE prematurely as this is likely to reinforce escape-anxiety responses. De-briefing the client and getting feedback at the end of the procedure is a very important tool in terms of modifying procedures and optimizing treatment. Always modify your procedure based upon client feedback.

Repeat the exposure until anxiety is consistently reduced.

Handy Tips

Assume a nonjudgmental attitude, especially with victims of physical abuse or rape. These clients may be experiencing intense feelings of shame and guilt about what happened to them, and the therapist must create an environment in which the client feels safe and accepted.

Normalize the client’s responses to the trauma. Many people feel as if they are “losing it” or “going crazy” because of their symptoms. Be certain to explain, in simple terms, how pathological fear is created, and that many people experience the same things that they are dealing with in response to an extreme stressor.

Express confidence in your knowledge of traumatic stress disorders and in the treatment you are delivering. Take an active stance in this therapy; be directive with the client. Your client may be very hesitant to follow through on the therapy once the exposure starts. It is critical to have the client complete the full course of treatment.

Take notice of and let the client know about strengths and personal resources that you have identified. This will go a long way towards instilling a belief that the therapy will work, and that the client can handle the full course of treatment.

Possible Pitfalls

Be careful not to terminate exposure procedures while anxiety is high. This will have the effect of increasing anxiety and reinforcing avoidance. Always allow sufficient time for the client to process the experience fully and watch for a lowering of anxiety before stopping.

It is easy to misdiagnose clients who are suffering from PTSD, as many of the symptoms included can look like an explosive anger problem, depression, and sometimes even a psychotic disorder. Be certain to take a thorough history of the client’s symptoms and problem behaviors.

Check for the presence of suicidality, current traumatic stressors, and substance abuse. These must be addressed first.


Suggested Readings
National Institute for Clinical Excellence (2005). Post-traumatic stress disorder: The management of PTSD in adults and children in primary and secondary care. (PDF Format)

Key References
Ehlers, A. and Clark, D.M. (2000). A cognitive model of post traumatic stress disorder. Behaviour Research and Therapy, 38, 319-345. (PDF Format)

Foa, E.B., Davidson, JRT, Frances, A. (1999). Expert Consensus Guide: Treatment of traumatic stress disorder. Journal of Clinical Psychiatry, 60 (Suppl. 16). (PDF Format)

Foa, E.B. and Rothbaum, B.O. (1998). Treating the Trauma of Rape: Cognitive –Behavioral Therapy for PTSD. New York: Guilford Press. (PDF Format)