Dr Foa is a world-renowned expert in the treatment of post-traumatic stress disorder (PTSD) and the developer of prolonged exposure (PE) therapy. We discussed what PE is, how it has changed over time, and Dr Foa’s current research.

According to the World Health Organization (WHO), around 3.9% of people will suffer from PTSD at some point in their lives. Prolonged exposure (PE) therapy is one of the most effective treatments for these people. Clients are helped to gradually approach the memories, feelings, and situations that they have been avoiding because they remind them of the trauma and cause them severe distress. By repeatedly approaching these situations and memories, they emotionally process their trauma and recover from their PTSD symptoms. Numerous studies show PE is effective for 65% to 80% of people.

In the early days, though, not everyone in the therapy community was on board with the treatment. “There were many reactions in the beginning,” says Dr Foa. “Some people said that talking about the trauma would make their patient worse.” 90 studies conducted in various countries have since demonstrated that’s not the case. She continues: “Therapists are now interested in learning how to do PE. Whenever I announce that my collaborators and I are going to do a workshop, a lot of people register to attend. People want to learn it because it’s so simple, makes sense and is effective.”

Dr Foa’s idea for PE emerged around the time that PTSD was being officially recognized. She and her colleagues had been using exposure therapy to help people confront their fears, but she realized that the exposure needed to be combined with a way of emotionally processing the trauma memories. “The idea is that the traumatic memories are haunting the person because they were not sufficiently processed. The client with PTSD is trying to avoid thinking about the trauma and by doing that, they’re not finding out what happened during the trauma and organizing the memory.”

PTSD was entered into DSM-III in 1980, following research with veterans of the Vietnam War, as well as people who had been sexually assaulted. The condition was initially listed in the category of anxiety disorders. Dr Foa recalls: “We kind of thought, ‘well it looks like an anxiety disorder’, but it was always coming after a traumatic event, which is not the case with other anxiety disorders. Also, the symptoms of remembering and having intrusive thoughts about a traumatic event were different.” In 2013, it was moved to a new category: trauma and stressor-related disorders.

Emotional processing

In the imaginal exposure part of PE, the client is asked to choose the memory that is haunting them the most (in terms of it coming back to them as intrusive thoughts and flashbacks) and then describe it aloud, in the present tense. Dr Foa says: “People with PTSD don’t want to remember. It’s very painful, so they try to avoid thinking about it. When the memory comes to mind, they immediately try to think about something else, so they never get to actually be in touch with what really happened there. It’s like they’re staying at the door in front of a room full of furniture. They peek at the door but they never get to see what’s happening in the room. When we do the imaginal exposure, we help them go into the room, look at the furniture, and see what really happened.”

Clients then spend time discussing with their therapist what happened in the imaginal exposure. “We process it with them: how did you feel, did you learn anything new… any new perceptions?”

For the in vivo (i.e., real life) exposure, the therapist helps the client make a list of the trauma-associated places, people, or things that they have been avoiding. The client then starts visiting them as homework outside of the treatment session. This is reviewed when the client and therapist meet again.

Researching prolonged exposure therapy

Dr Foa, who is now a professor of psychiatry at the University of Pennsylvania, published her first study on PE, involving 45 women who had PTSD after being raped, in 1991.

The research, published in the Journal of Consulting and Clinical Psychology, found that those who received PE or stress-inoculation therapy (SIT; a type of cognitive behavioral therapy), and to a lesser extent those who received supportive counseling, significantly improved, while those on the wait list did not. At a one-year follow-up, those who received PE continued to improve, while the other groups only maintained their gains.

Her next, larger study (published in the same journal in 1999) found that PE was more successful than SIT: after treatment, only 35% of the women receiving PE retained a diagnosis of PTSD, compared with 42% of those receiving SIT (For those receiving a combination of PE and SIT, 46% retained a diagnosis. One possible explanation is that using both techniques may have overwhelmed the patient).

When Dr Foa was starting out with PE, exposure sessions were fairly long, but studies have now found they can be much shorter. In fact, Dr Foa now regrets the naming of her treatment. “I wouldn’t call it prolonged exposure now. I would call it emotional processing therapy because I think that is what we are doing. At the time, we were all thinking about anxiety and exposure therapy, and the studies were showing that longer exposures were better than shorter exposures. We’ve now found out that we don’t need 40 minutes to imagine the traumatic event; it’s sufficient to do it in 15 or 20 minutes.”

Cognitions and symptoms

As well as intrusive memories, avoidance, and high arousal or fear, people with PTSD experience negative cognitions about themselves, the world, and other people. Dr Foa explains that it is these negative cognitions that drive the other symptoms: “The main cognitions in people with PTSD are that the world is extremely dangerous, and there is just no place where it’s safe. They also think ‘I’m extremely weak, I’m extremely incompetent, I’m not the person I was before.’ When we measure the PTSD symptoms and the cognitions weekly to see how they change over time, we’re finding in several studies that the cognitions change first and then the symptoms.”

She cites the example of a female soldier who had been raped by colleagues. She had suffered from PTSD for nine years and her distorted memories were fuelling her misplaced guilt. “We had a patient who was in the military and during a holiday she invited a lot of her army friends round. They were all drunk and they started to rape her; there were eight of them. When she described it, it was so sad and so awful [but] she said, ‘They were my friends and if they knew I hated what they were doing, they wouldn’t do it. It’s all my fault because I didn’t make it clear to them that I didn’t enjoy the rape.’ After several sessions of asking her to imagine what had happened there, what she remembered changed. She remembered that they knew she didn’t want it. She described fighting like a lioness and specific parts of the memory came back to her. For example, she remembered biting one of them when he tried to force her and he screamed. She didn’t remember those things [at first], so her perception at the end of treatment changed. She said ‘they knew I didn’t want it, they were awful.’ So there was a shift that changed completely.”

Prolonged exposure and other therapies

Most studies show that PE not only reduces PTSD but also other trauma-related problems, including depression, general anxiety, anger, self-injury, and guilt. One of PE’s particular strengths is that it may be easier for a client to follow than other types of therapy. Dr Foa elaborates, “For cognitive behavioral therapy (CBT), for example, you need to be able to think rationally: if A, then B. We know that most people don’t think rationally, so it is pretty difficult.

“I like PE because it doesn’t require a lot of metacognitions. I always say, if the client has legs and is motivated to get well, and you give them homework to go to the places that they avoid, they can go and do it. In order to do imaginal exposure they only need a tongue. If they have a memory of what happened, they can tell you a story. In fact, one of the ways that people in many cultures get over a traumatic memory is by sharing it as a story.”

That’s not to say PE is not emotionally demanding. Dr Foa says people need to accept that, as with physical conditions, sometimes the treatments are painful: “Imagine you broke your leg and you went to a surgeon who told you ‘If I do surgery, I can set the bone to where it was, and you will heal better than if I just put a cast on it. The surgery is more painful, and the recovery is longer, but if you don’t do the surgery you are probably going to limp for life.’ What would you decide to do? It's the same situation here. When it comes to physical issues, people understand that they have to suffer in the short run in order to heal. In psychology, we feel ‘oh I don’t want to suffer, be nice to me’, and then we have patients who are treated with counseling, supportive services, and all of that, but who keep on having PTSD for years and years. I don’t think it’s justified to help people avoid [processing the trauma] and then be stuck with PTSD symptoms for life.”

Another treatment for PTSD is eye movement desensitization and reprocessing (EMDR) therapy, which uses bilateral stimulation (e.g., eye movements, tapping, sounds) to process memories that are ‘stuck’ in the memory network. Unlike PE, EMDR doesn’t require the client to describe traumatic experiences in great detail. Both treatments are highly recommended treatments for PTSD, with strong evidence bases. Innovative recent research by a Dutch group has even combined prolonged exposure and EMDR in an effective intensive treatment program for PTSD (Van Minnen et al 2020).

But for Dr Foa, a benefit of PE over EMDR is that the patient gets to really tell their story: “Nobody likes to listen to traumas: friends will say ‘oh it happened so long ago, try to get over it.’ I think it’s useful for the therapist to listen to them, to what happened. They have somebody to work it out with them.”

What next?

Dr Foa is now investigating whether giving people undertaking PE the hormone estrogen – which studies show can improve learning and memory – influences how they respond to treatment. “The mechanism underlying PE is learning, so [an] increased ability to learn via estrogen should increase the efficacy of PE,” she concludes.

If you’d like to hear more of Dr Foa’s ideas, she is the co-author of Prolonged Exposure Therapy for PTSD, which is part of the Treatments That Work^TM series available through Psychology Tools.

References

• Foa, E. B., Hembree, E. A., Rothbaum, B. O., & Rauch, S. A. M. (2019). Prolonged exposure therapy for PTSD: Emotional processing of traumatic experiences: Therapist guide (2nd ed.). Oxford University Press.
• Foa, E. B., Rothbaum, B. O., Riggs, D. S., & Murdock, T. B. (1991). Treatment of posttraumatic stress disorder in rape victims: a comparison between cognitive-behavioral procedures and counseling. Journal of consulting and clinical psychology, 59(5), 715.
• Foa, E. B., Dancu, C. V., Hembree, E. A., Jaycox, L. H., Meadows, E. A., & Street, G. P. (1999). A comparison of exposure therapy, stress inoculation training, and their combination for reducing posttraumatic stress disorder in female assault victims. Journal of consulting and clinical psychology, 67(2), 194.
• Van Minnen, A., Voorendonk, E. M., Rozendaal, L., & de Jongh, A. (2020). Sequence matters: Combining prolonged exposure and EMDR therapy for PTSD. Psychiatry Research, 290, 113032.