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Prolonged Exposure Therapy (PET)

What is Prolonged Exposure Therapy?

Prolonged Exposure Therapy (PET) is a specialized form of psychotherapy designed to help individuals suffering from post-traumatic stress disorder (PTSD). PTSD can develop after a person experiences or witnesses a traumatic event, leading to symptoms such as unwanted thoughts, disturbing nightmares, feelings of hopelessness, depression, and hypervigilance. PET aims to help individuals re-engage with life by gradually confronting and processing trauma-related memories, thoughts, and stimuli, thereby reducing PTSD symptoms and distinguishing between safety and danger.

When is Prolonged Exposure Therapy Used?

PET is suitable for individuals diagnosed with PTSD resulting from traumatic experiences such as accidents, assaults, natural disasters, or combat. It's particularly beneficial for those who avoid thoughts, feelings, or situations that remind them of their trauma, causing significant distress and impairment in daily functioning. However, PET is not necessary for individuals who have experienced trauma but do not exhibit PTSD symptoms.

What to Expect in Prolonged Exposure Therapy

Session Structure: PET is conducted one-on-one with a trained therapist. Sessions typically last about 90 minutes and occur weekly over the course of two to three months, though the duration can vary based on individual needs.

Key Components:

  • Imaginal Exposure: This involves recounting the traumatic event in detail during therapy sessions, helping to process and reduce the distress associated with these memories.

  • In Vivo Exposure: Patients gradually confront and engage with avoided situations or stimuli in real life, based on a hierarchy of distress they create with their therapist.

  • Psychoeducation: Patients learn about PTSD and how PET can help alleviate their symptoms.

  • Breathing Retraining: Techniques such as belly breathing are taught to help manage anxiety and promote relaxation.


For example, a mother who avoids driving after losing her daughter in a car accident might work with her therapist to gradually reintroduce driving into her routine, starting with less distressing tasks like sitting in a parked car.

How Prolonged Exposure Therapy Works

PET is grounded in associative learning theory, which explains how the brain links certain stimuli with traumatic events. Ivan Pavlov's classical conditioning experiments illustrate this concept: his dogs learned to associate a bell with food, eventually salivating at the sound alone. Similarly, people with PTSD may associate certain smells, sights, or sounds with their trauma, triggering fear and anxiety. PET helps "unlearn" these associations by repeatedly exposing individuals to these stimuli without the traumatic outcome, thereby reducing their fear response.

Techniques Used in PET


  • Imaginal Exposure: Patients vividly recall the traumatic event in a safe therapeutic environment, helping to reduce the power of these memories over time.

  • In Vivo Exposure: Gradual exposure to real-life situations that are avoided due to trauma-related fear. For instance, a veteran might slowly reintroduce activities like attending crowded events.

  • Breathing Retraining: Teaching patients to breathe deeply and slowly from the belly rather than the chest, which can help reduce anxiety and improve relaxation.

Understanding the Subjective Units of Distress Scale (SUDS)

The Subjective Units of Distress Scale (SUDS) is a tool used in PET to measure a person's distress levels. This self-assessment scale ranges from 0 (no distress) to 100 (extreme distress), helping therapists and patients track progress and adjust exposure exercises accordingly.



Prolonged Exposure Therapy is a powerful treatment for PTSD, helping individuals confront and process their trauma in a structured and supportive environment. Through techniques like imaginal and in vivo exposure, along with breathing retraining, PET aims to reduce PTSD symptoms and improve overall functioning. If you or someone you know is struggling with PTSD, PET might be a valuable path to recovery.

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