What is systematic desensitisation ?

Systematic desensitisation (SD) is a psychotherapeutic technique based on behavioural principles. SD involves the patient being deeply relaxed and then exposed to a negative trigger whilst in that relaxed state. Through a process known as reciprocal inhibition the old response is overwritten with a new one. The key to success is the patient being sufficiently relaxed that they can experience the trigger whilst retaining their state of relaxation. To this end a process of graded exposure is used to keep the trigger mild.

Systematic desensitisation – Key features and terms

Trigger.

In this context, a trigger is anything which initiates an emotional or state change. The trigger could be;

• External, like seeing or hearing something,
• Internal, such as imagining or remembering something.

The change induced by the trigger is perceived as swift and automatic.

Relaxation.

In systematic desensitisation relaxation is a deliberately created state. It is common for a therapist to teach relaxing exercises or use a guided relaxation technique to produce relaxation. This kind of relaxation allows the patient to retain a sense of  control and personal agency.

Reciprocal inhibition.

Reciprocal inhibition is the idea that a person can only really experience a single emotional/physical state at one time. This means that if you are anxious you will experience things as anxious. eventually you will come to associate everything experienced with anxiety. Conversely, if you experience something in a relaxed state you will begin to associate that with being  relaxed. So, if relaxation is induced by a therapist and then the anxiety inducing trigger experienced, a new relaxed response will be learnt. This new response will override (inhibit) the previous one.

Graded exposure.

Also called graduated exposure, graded exposure is a process of gentle exposure to trigger stimuli. The triggers are organised in a progressively more challenging way. Normally to achieve this a hierarchy of disturbance is created which is then worked through.

Hierarchy of disturbance.

This is a list of all the elements of a trigger which a person can identify. These are organised from leash difficult to most challenging. An example for a spider phobic might look like this;

1. Knowing there is a small spider in an adjacent room. (least difficult for this hypothetical patient).
2. Seeing a small spider on the far wall (staying still).
3. Seeing a small spider on the far wall (moving slowly).
4. Seeing a medium sized spider on the far wall (staying still).
5. Seeing a medium sized spider on the far wall (moving slowly).
6. Seeing a large spider on the far  wall (staying still).
7. Seeing a large spider on the far wall (moving slowly).
8. A large spider on the floor about 1.5 metres away (staying still).
9. A large spider on the floor about 1.5 metres away (moving slowly).
10. A large spider on the floor about 1 metre away (moving slowly).
11. A large spider on the floor about half a metre away (moving slowly).
12. Touching a spider whilst wearing a thick gardening glove.
13. Touching a spider whilst wearing a plastic glove.
14. Touching a spider. (Most challenging for this hypothetical patient) .

The job of the therapist is then to help create a list of situations of progressively more intense triggers to be worked through.

In life / In the imagination.

The exposure to triggers which is required for systematic desensitisation to work can be done in two ways;

• In real life with the trigger stimulant being either; present in the therapist office or by going out into the world to encounter it.
• In the imagination of the patient.

Both methods have their strengths and limitations. Desensitization in real life is almost certainly the best way but the resources to do it are expensive, time consuming, often specific and difficult to manage. The imagination by contrast is usually very good at conjuring up the required resources but at some point this will have to be consolidated into real life with some real world practice.

Systematic desensitization – uses and limitations.

Systematic desensitization is frequently used by therapists for anxiety responses where the trigger is specific and the reaction is disproportionate to the level of threat. A typical example of this would be a phobia or anxiety induced response like psychological erectile dysfunction or vaginisimus  like . However, frequently the anxiety trigger will have a reason to have come into existence, which may limit progress with systematic desensitization alone. Typical reasons for this are;

• The fear is secondary to another fear. For example a fear of insects can sometimes be a fear of contamination or a fear of heights will often be the result of having the wooziness caused by  vertigo.
• The fear is related to post traumatic stress disorder (PTSD). At some point a powerful experience resulted in an anxiety, it may be that the originating experience needs to be treated before the anxiety can be desensitised.
• Neurological sensitivity to the trigger. Not every bodies sensory experience is the same, substantial numbers of people have a visual or auditory sensitivity which results in apparently normal situations being uncomfortable. Over time the effect of this, combined with other people’s lack of awareness or comprehension of the problem, result in a build-up of tension around it. Overall this means that at best systematic desensitisation will help deal with the build up of tension.

The Author

Dr Matt Krouwel PhD is a hypnotherapist in Birmingham (UK) with over 25 years experience of working with anxieties, panic and related disorders. He is a a member of the BSCH and NCH.