Exposure hierarchy

Summary

An exposure hierarchy is a clinical tool used in exposure therapy for planning exposure exercises. Its goal is to help create a “road map” for the therapy, helping the therapist and the patient see where to start and collaboratively establishing the outline and the goals of the therapy.

Principles and practice

Creating an exposure hierarchy is an important part of preparing for exposure exercises during an exposure therapy. The idea behind it is the principle of gradual exposure – that the chances of the patient being able to perform an exposure exercise is higher if the task does not constitute one of the most difficult things he or she can imagine, but rather something more reasonable. In this regard, it is also a way of structuring the therapy, and for the patient getting a sense of control of the process – getting an outline or “road map” for the entire therapy.

After the therapist has explained the treatment rationale (see separate article) of exposure therapy and the patient having agreed to trying it out, and after the therapist has been able to get an overview of the patient’s anxiety related situations and stimuli, the task is to order these situations and stimuli, from the least anxiety provoking to the most anxiety provoking.

Sometimes, all elements related to the patient’s fear doesn’t fit into one exposure hierarchy, and the therapist needs to prepare several different exposure hierarchies, simply because there are so many different stimuli that they cannot practically be listed in one single exposure hierarchy (which often is the size of an A4 paper sheet, see the Clinical tool Exposure hierarchy). If one needs several hierarchies, it can be good to divide them in terms of themes. For the patient with social anxiety, it could for example be one hierarchy for all the different anxiety provoking situations at work, and another hierarchy for non-work related social situations. Or for the patient with OCD, for example, one hierarchy could be for contamination OCD :

“Touching the seat in the public bus without washing my hands afterwards - 80

Touching my child’s jacket that he has worn outside without washing my hands afterwards 50”

Touching the handle of the door to our house without washing my hands afterwards – 30”

etc

Whereas the same patient, if he also suffers from religious obsessions, another hierarchy could be:

“Staying inside the mosque even if I have a blasphemous thought, and not neutralizing – 70"

“Not repeating the ablution (wudu) even if I get the obsession ‘What if I forgot to say Bismillah?’ – 40”

etc

The above examples are from hierarchies while working with exposure in-vivo. For other forms of exposure, the same principles apply. Normally, different domains of exposure are however not mixed in one single hierarchy (that is, in-vivo is not mixed with imaginal exposure in the same hierarchy), for the same reasons as discussed further below: The exposure hierarchy should be a pragmatic, practical blueprint for therapy, and if very different stimuli are mixed in the same hierarchy, it tends to become less clear and less practical.

The anxiety scale

The therapist introduces the patient to a scale (from 0-100 or 0-10) and defines the maximum point (100 or 10) as “the highest level of anxiety you have ever felt”, and then defines the lowest point (0) as having no anxiety or discomfort at all (see separate article on Subjective Units of Distress). The therapist then goes with the patient through the different anxiety related situations or stimuli that they have identified together, and asks “if you did an exposure for that, how much anxiety do you think it would evoke?”, and then they write this situation down, together with the expected degree of anxiety.

When doing an exposure hierarchy, it is important to explain to the patient the he or she should imagine the degree of anxiety _without doing any safety behavior_ (see separate article on Safety behaviors). Otherwise, the hierarchy risks not be very helpful.

The rule of thumb is then to start the exposure for something roughly in the middle of the hierarchy. That is, not to start too low (if it hardly evokes any anxiety, it won’t enable the patient to get the important experience of having challenged the anxiety and experiencing something new) and not too high (if risks to evoke too high levels of anxiety, there is a greater risk that the patient won’t be able to go through with the exercise).

The exposure hierarchy as a pragmatic tool

In modern exposure therapy, the role of the actual level of anxiety is also played down. Through research, we now know that exposure therapy fundamentally doesn’t work through the habituation of anxiety. It rather works through what is called inhibitory learning (see separate article), which shortly put, means that exposure works because the patient experiences something new, rather than by getting rid of anxiety. This means that the most important thing is not the actual level of anxiety (and it is not necessary that it goes down during an exposure session). The most important is that the patient, in presence of anxiety, flexibly is able to do what he or she wants to do, and not letting the anxiety take control.

The role of the exposure hierarchy is primarily to be a pragmatic tool to help structure the start of exposure exercises and to structure the therapy, giving an overview and a sense of control to the patient. Its role is not to constitute a “true” or “perfect” representation of the patient’s anxiety. Quite often, when the exposure exercises are actually done, the patient realises that the _expected_ level of anxiety (what was defined in the hierarchy) didn’t actually correspond to the _actual_ level of anxiety felt during the exposure.

See Exposure hierarchy under Clinical tools.