التعرض الداخلي

Summary

Interoceptive exposure is a specific exposure technique, used primarily in CBT for panic disorder. It follows the same basic principles of all exposure, but instead of seeking out the phobic stimulus in the real world (as during in-vivo exposure) or in an inner memory or mental image (as during imaginal exposure) the focus of interoceptive exposure are inner stimuli in the bodily symptoms (such as the heart palpitations or shortness of breath).

Principles and practice

As with all types of exposure, interoceptive exposure is preceded by functional analysis (see separate article). Before starting any exposure therapy, the therapist needs to have a clear enough assessment of what the patient is avoiding and what stimuli are conditioned to fear. This may include external stimuli (for which exposure in-vivo is used, see specific article), inner stimuli in form of memories or mental images (for which imaginal exposure is used, see specific article), but it may also include inner stimuli in form of aversive bodily sensations: shortness of breath, dizziness, heart palpitations and physical stimuli. For anxiety related to this type of physical sensations, as in panic disorder, interoceptive exposure is used.

The five principles of exposure

As with all exposure, interoceptive exposure as a specific therapeutic intervention follows 5 principles. For it to be effective, all exposure should be:

• planned and structured (by the therapist, in collaboration with the patient)

• gradual (by way of a exposure hierarchy, in collaboration with the patient)

• prolonged (that is, be sufficiently long as to enable new non-fearful experiences)

• repeated (that is, be done a sufficient number of times, which also enables experiencing something new over time)

• without safety behaviours (that is, without the patient trying to distract him or herself or seeking other forms of temporary safety or temporary relief during exposure) (see separate article).

Specific principles of interoceptive exposure

Interoceptive exposure starts with trying out different interoceptive exercises to see which that actually trigger fear. That is, which exercises that then are helpful to be used in repeated exposure. As a therapist, before one performs interoceptive exposure with a patient, it is important to ensure that the patient has gone through a recent health check by a medical doctor. It is very rare that any of these exercises pose any kind of health problem; but in some cases (such as when the patient with panic disorder has a comorbid cardiovascular problem) it is particularly important with the medical doctor’s clearance (or proposed modification) of the interoceptive exercises.

Examples of interoceptive exercises are:

• Hyperventilation: To trigger shortness of breath and dizziness.

• Running in place: To trigger heart palpitations (the heart racing).

• Breathing through a straw: To trigger shortness of breath and chest discomfort.

• Spinning (while standing up or on a spinning chair): To trigger dizziness or vertigo.

• Lightly shaking one’s head: To trigger light-headedness and dizziness.

The patient is instructed to rate his or her degree of anxiety/subjective units of distress (0-10 or 0-100, see separate article) for every exercise listed above, and an exposure hierarchy is construed, including the exercises that triggered some anxiety, to be able to plan the forthcoming phase of exposure. In describing the “anxiety scale” (0-100) it is very important to explain to the patient that what he or she should rate is specifically the fear or anxiety, _not_ the intensity of the physical sensation in itself. All of us, irrespective if we have panic disorder or not, feel (more or less) of dizziness when we spin ourselves on a spinning chair for example. But for most of us, even with very high dizziness, our anxiety level is very low or zero. It is not the intensity of the dizziness that the anxiety scale shall reflect, but specifically the intensity of fear/anxiety.

Thereafter, the exposure starts with the interoceptive exercise that is somewhere in the middle of the hierarchy.

And as in all other exposure, during interoceptive exposure, the therapist will ask questions like “What goes through your mind right now” (to help identifying safety behaviours). The therapist will also guide the patient by asking him or her to focus on the anxiety provoking stimulus (“Try to stay with the feeling”). The therapist also wants to continually assess the patient’s level of anxiety (“What is your level of anxiety at this moment?”) and provide support (“I can see how difficult this is for you, you are so brave!”).

The specific interoceptive exercise is worked through and repeated as many times as needed, until the patient’s anxiety is lower or until he or she has experienced something new.

The interoceptive exposure session should end with an evaluation: The therapist asks the patient what he or she has learned from the interoceptive exposure, and is asked to define a homework to do for the next session that ideally is construed as a repetition of the actual exposure done with the therapist during the session. That is, after the therapist-guided exposure, the ideal is that the patient does the same exposure exercise that she did with the therapist, but this time by herself, as a homework exercise until the next session (see separate article on Homework).