Systematic Desensitization

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systematic desensitisation

Systematic desensitization is a type of behavioral therapy based on the principle of classical conditioning. It was developed by Wolpe during the 1950s. This therapy aims to remove the fear response of a phobia, and substitute a relaxation response to the conditional stimulus gradually using counter conditioning. There are three phases to the treatment:

First, the patient is taught a deep muscle relaxation technique and breathing exercises. E.g. control over breathing, muscle detensioning or meditation. This step is very important because of reciprocal inhibition, where once response is inhibited because it is incompatible with another. In the case of phobias, fears involves tension and tension is incompatible with relaxation.

Second, the patient creates a fear hierarchy starting at stimuli that create the least anxiety (fear) and building up in stages to the most fear provoking images. The list is crucial as it provides a structure for the therapy.

Third, the patient works their way up the fear hierarchy, starting at the least unpleasant stimuli and practising their relaxation technique as they go. When they feel comfortable with this (they are no longer afraid) they move on to the next stage in the hierarchy. If the client becomes upset they can return to an earlier stage and regain their relaxed state.

The client repeatedly imagines (or is confronted by) this situation until it fails to evoke any anxiety at all, indicating that the therapy has been successful. This process is repeated while working through all of the situations in the anxiety hierarchy until the most anxiety-provoking.

Thus, for example, a spider phobic might regard one small, stationary spider 5 meters away as only modestly threatening, but a large, rapidly moving spider 1 meter away as highly threatening. The client reaches a state of deep relaxation, and is then asked to imagine (or is confronted by) the least threatening situation in the anxiety hierarchy.

The number of sessions required depends on the severity of the phobia. Usually 4-6 sessions, up to 12 for a severe phobia. The therapy is complete once the agreed therapeutic goals are met (not necessarily when the person’s fears have been completely removed).

Exposure can be done in two ways:

    · In vitro – the client imagines exposure to the phobic stimulus.

    · In vivo – the client is actually exposed to the phobic stimulus.

Research has found that in vivo techniques are more successful than in vitro (Menzies & Clarke, 1993). However, there may be practical reasons why in vitro may be used.

Example

Wolpe (1964) successfully used the method to treat an 18 year old male with a severe handwashing compulsion. The disorder involved a fear of contaminating others with urine. After urinating, the patient felt compelled to spend 45 minutes cleaning his genitalia, two hours washing his hands, and four hours showering.

Treatment involved placing the young man in a state of relaxation and then asking him to imagine low anxiety scenes (such as an unknown man touching a trough of water containing one drop of urine). As the patient’s anxiety gradually dissipated, Wolpe gradually increased the imaginary concentration of urine. In addition, a real bottle of urine was presented at a distance and moved closer to the patient in gradual steps. Finally Wolpe could apply drops of diluted urine to the back of the patient’s hand without evoking anxiety. A follow-up 4 years later revealed complete remission of the compulsive behaviors.

Critical Evaluation

Practical Issues

The fact that the SD technique can be applied in images means that many of the practical disadvantages involved in in vivo exposition with this type of phobia can be eliminated.

One weakness of in vitro exposition is that it relies on the client’s ability to be able to imagine the fearful situation. Some people cannot create a vivid image and thus systematic desensitization is not always effective (there are individual differences).

Systematic desensitization is a slow process, taking on average 6-8 sessions. Although, research suggests that the longer the technique takes the more effective it is.

The progressive structure of SD allows the patient to control the steps he/she must make until fear is overcome. This absence of disturbing elements makes this technique less likely to provoke abandonment of the therapy.

Theoretical Issues

Systematic desensitization is highly effective where the problem is a learned anxiety of specific objects/situations, e.g. phobias (McGrath et al., 1990) . However, SD is not effective in treating serious mental disorders like depression and schizophrenia.

Studies have shown that neither relaxation nor hierarchies are necessary, and that the important factor is just exposure to the feared object or situation.

Systematic desensitization is based on the idea that abnormal behaviour is learned. The biological approach would disagree and say we are born with a behaviour and therefore it must be treated medically.

Treats the symptoms not the cause(s) of the phobia. SD only treats the observable and measurable symptoms of a phobia. This is a significant weakness because cognitions and emotions are often the motivators of behaviour and so the treatment is only dealing with symptoms not the underlying causes.

Social phobias and agoraphobia do not seem to show as much improvement. Could it be that there are other causes for phobias than classical conditioning? For example, if a fear of public speaking originates with poor social skills then phobic reduction is more likely to occur in a treatment which includes learning effective social skills than systematic desensitization alone.

Empirical Evidence

Lang et al. (1963) used SD with a group of college students who were all suffering from a snake phobia. They underwent 11 sessions to work through a hierarchy. Hypnosis was used to assist in the maintenance of relaxation. The P’s fear rating fell and improvements were still evident 6 months later.

Rothbaum et al. (2000) used SD with participants who were afraid of flying. Following treatment 93% agreed to take a trial flight. It was found that anxiety levels were lower than those of a control group who had not received SD and this improvement was maintained when they were followed up 6 months later.

Capafons et al. (1998) recruited 41 aerophobia sufferers for a media campaign in Spain and treated 20 of them with SD, and had 21 members of a control group. The treatment group was given 2x1 hour sessions of in vivo and in vitro techniques a week over a 12-15 week period. During a flight simulation, self-reports and physiological measures of anxiety were used. The results showed all but two those who had SD treatment reported lower levels of fear and were seen to have less anxiety, and one member of the control group showed signs of improvement. While SD is effective it was not 100% effective

Ethical Issues

SD is a treatment method that increases the feeling of self-control; that is, the therapist suggests, guides or helps, but does not represent the nucleus of the treatment. The risk of dependence upon the therapist or of perceiving improvements as being external to the patient are thus minimised in this technique.

References

Lang, P. J., & Lazovik, A. D. (1963). Experimental desensitization of phobia. The Journal of Abnormal and Social Psychology, 66(6), 519.

McGrath, T., Tsui, E., Humphries, S., & Yule, W. (1990). Successful Treatment of a Noise Phobia in a Nine‐year‐old Girl with Systematic Desensitisation in vivo. Educational Psychology, 10(1), 79-83.

Menzies, R. G., & Clarke, J. C. (1993). A comparison of in vivo and vicarious exposure in the treatment of childhood water phobia. Behaviour Research and Therapy, 31(1), 9-15.

Rothbaum, B. O., Hodges, L., Smith, S., Lee, J. H., & Price, L. (2000). A controlled study of virtual reality exposure therapy for the fear of flying. Journal of consulting and Clinical Psychology, 68(6), 1020.

Wolpe, J. (1958). Psychotherapy by reciprocal inhibition. Stanford, CA: Stanford University Press.

Wolpe, J. (1964). Behaviour therapy in complex neurotic states. The British Journal of Psychiatry, 110(464), 28-34.

How to cite this article:

McLeod, S. A. (2008). Systematic Desensitization. Retrieved from www.simplypsychology.org/Systematic-Desensitisation.html

Further Information

Classical Conditioning

Behavior Therapies

Abnormal Psychology