By Nelson Binggeli, PhD

Introduction

This is the third in a series of four articles describing the primary techniques of Cognitive Behavioral Therapy (CBT).  Prior to reading this article, please read my Introduction to CBT and my disclaimer regarding information provided on this website.  

This article focuses on a set of techniques called “exposure therapy,” which help people overcome anxiety by learning to face their fears in a systematic way.  Exposure therapy been shown to be very effective in treating anxiety disorders, including Generalized Anxiety Disorder, Obsessive Compulsive Disorder, Panic Disorder, Posttraumatic Stress Disorder, Social Anxiety Disorder, and Specific Phobia.  This article first describes how anxiety disorders develop at least partially through classical conditioning and avoidance.  It then presents the principles of exposure therapy.  

Classical conditioning

In order to understand why exposure therapy works, it helps to understand classical conditioning and its role in the anxiety disorders.  Classical conditioning was first demonstrated by Ivan Pavlov, a Russian physiologist, in his famous experiments with dogs around the turn of the 20th century.  Pavlov showed that if you repeatedly ring a bell right before giving food to a dog, it will eventually come to salivate upon hearing the bell only.  The general principle that Pavlov discovered was that if you repeatedly present a stimulus that naturally causes a reaction (e.g., food causing salivation) right after presenting a previously neutral stimulus (i.e., the bell), an animal will come to react to the previous neutral stimulus in a similar way.  

Classical conditioning forms part of the basis for anxiety disorders.  People with anxiety disorders have come to associate non-threatening neutral stimuli with either traumatic experiences or imagined future catastrophes.  They have learned to react to a previously neutral stimulus as if it were an actual threat.  For example someone with a phobia of dogs may experience a stress reaction just by looking at a picture of a dog.  They may rationally know that the picture cannot hurt them, but nevertheless their brain triggers the release of adrenaline to help their body either fight or flee.  This illustrates how classical conditioning is an automatic emotional response that bypasses rational thought. 

Classically conditioned responses are recorded deep in the emotional centers of the brain (i.e., the limbic system).  When we perceive that something is threatening, our emotional centers send out an alarm.  It takes a few more milliseconds for the rational centers of our brain to process what is happening.  When we are afraid, our body responds more strongly to the alarm from the emotional centers of the brain than to our rational thoughts.  This is responsible for the phenomenon of knowing that something isn’t threatening and yet still feeling afraid. 

In Panic Disorder, people come to fear body sensations that actually are not harmful.  In Generalized Anxiety Disorder, people react to thoughts and images of possible future negative events almost as strongly as if they were actually occurring.  In Posttraumatic Stress Disorder, people react to things that remind them of a traumatic event almost as if the event were actually occurring in the present. In Social Anxiety Disorder, people come to associate social situations with visions of being humiliated.  In Obsessive Compulsive Disorder, people develop an exaggerated fear of not doing something to remove a possible threat, no matter how unlikely this threat may be.

The role of avoidance

Typically, people tend to avoid these stimuli as much as possible.  While this is understandable, it prevents the emotional centers of their brain from learning that these stimuli actually are not threatening.  This maintains and may even strengthen the perception that these stimuli are something to be feared.  Over time, avoidance behavior can become stronger and more pervasive because it provides relief from anxiety (thought a process called negative reinforcement).  Accordingly, in order to overcome anxiety and its limiting effect on one’s life, one must learn to stop avoiding.

Exposure therapy

Exposure therapy is a technique for reducing classically conditioned responses.  In exposure therapy, clients voluntarily agree to be exposed to the very stimuli that trigger the anxiety response.  When people repeatedly expose themselves to stimuli that they fear and nothing bad happens, the emotional centers of the brain learn that they can relax in the presence of this stimuli. 

The stimuli may be actual or imagined and it may be confronted in the therapist’s office or in real life.  Often, people find it more acceptable to begin with exposure to imagined objects or events before confronting actual ones.  Typically, the exposure exercises begin with stimuli that might arouse only mild to moderate levels of anxiety.  After several successful exposures, people often are ready to confront things that are even more anxiety provoking.  Often, the therapist helps the client to develop coping strategies for managing the anxiety-provoking situation, which can include relaxation skills, assertive communication skills, and more rational ways of thinking about situation (see cognitive restructuring).

Exposure therapy can be challenging for both clients and for therapists.  Confronting stimuli that causes feelings of fear, helplessness, shame, disgust, or horror is not easy.  However, there is a lot of scientific evidence that it works, and most people find that ultimately the short-term pain caused by exposure is greatly outweighed by becoming liberated from classically conditioned fear responses.  In addition, the graduated nature of the exposures (i.e., starting with less fearful stimuli) and the use of improved coping strategies make it somewhat less challenging than it might otherwise be.

There are several theories about why exposure works.  The one that has the most research support is that it works primarily through the mechanism of habituation.  Habituation occurs when the repeated exposure to a stimulus decreases our responsiveness to it.  For example, we may come to “tune out” the noise of a loud fan after being in a room with it for a while.  It is also possible that we replace one form of conditioning for another (this has been called counterconditioning).  Because an anxiety response cannot continue indefinitely, eventually anxiety decreases during exposure.  When this happens, the association between the stimulus and the anxiety response is weakened and replaced with an association with a more relaxed state.  Theorists who emphasize cognitive factors argue that (a) safe exposure may help people think about the stimuli more objectively, (b) people come to expect that they’ll be less anxious in the presence of the stimuli, and (c) exposure may strengthen the person’s beliefs that they are capable of coping with their anxiety. 

Creating an anxiety hierarchy

The first step in conducting exposure therapy is creating what is called an “anxiety hierarchy.”  This is a list of the stimuli that causes an anxiety reaction arranged in a hierarchy according to how much anxiety each stimuli causes.  For example, stimuli that cause only mild anxiety are listed at the bottom of the list.  

More specific information about how to create an anxiety hierarchy will be provided here soon.

Conducting exposure exercises

More specific information about this will be provided soon.

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Websites for more information

Center for the Treatment and Study of Anxiety, at the University of Pennsylvania, directed by Edna Foa, PhD

More about Cognitive Behavioral Therapy (CBT)

An Introduction to Cognitive-Behavioral Therapy (CBT)

     CBT techniques part 1:  Cognitive restructuring

     CBT techniques part 2:  Behavioral activation

     CBT techniques part 3:  Exposure therapy (you are on this page)

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Last updated 02.05.11

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