Systematic Desensitisation (aka Graduated Exposure Therapy) is a technique used to treat phobias and other extreme or erroneous fears based on principles of B of Classical Conditioning, The technique, based on counterconditioning, was developed by South African psychiatrist Joseph Wolpe (1958). He was clearly  influenced by the 1924 experiment of Mary Cover Jones, a student of John B Watson, who found that a child being given fed candy would accept a feared object (in this case, a rabbit) being brought gradually closer.

The theoretical base for Systematic Desensitisation is that the phobia has developed from pairing what is now the phobic stimulus (NS/CS) with a fear-provoking stimulus (UCS) to develop the phobic fear (UCR/CR); now the phobic stimulus (CS) is paired with the relaxation technique (UCS) to develop the relaxed feeling response (UCR/CR).

Some of the most common fears treated with Systematic Desensitisation include fear of public speaking, fear of flying, stage fright, elevator phobias, driving phobias and animal phobias.

Systematic Desensitisation is used to help the client cope with phobias and other fears, and to induce relaxation. In progressive relaxation, one first tightens and then relaxes various muscle groups in the body. During the alternating clenching and relaxing, the client should be focusing on the contrast between the initial tension and the subsequent feelings of relaxation and softening that develop once the tightened muscles are released. After discovering how muscles feel when they are deeply relaxed, repeated practice enables a person to recreate the relaxed sensation intentionally in a variety of situations. Progressive Relaxation Training was developed by Edmund Jacobson during the 1930s. Alternatives to progressive relaxation include meditation and imagining happy scenarios.

After learning relaxation skills, the client and therapist create an ‘anxiety hierarchy’. The hierarchy is a catalogue of anxiety-provoking situations or stimuli arranged in order from least to most distressing. It is important that the client is fully involved in creating the hierarchy as it has to be meaningful to them. For a person who is frightened by snakes, the anxiety hierarchy might start with seeing a picture of a snake, eventually move to viewing a caged snake from a distance, and culminate in actually handling a snake. With the therapist's support and assistance, the client proceeds (at their own pace) through the anxiety hierarchy, responding to the presentation of each fearful image or act by producing the state of relaxation. The person undergoing treatment stays with each step until a relaxed state is reliably produced when faced with each item. As tolerance develops for each identified item in the series, the client moves on to the next. In facing more menacing situations progressively, and developing a consistent pairing of relaxation with the feared object, relaxation rather than anxiety becomes associated with the source of their anxiety. Thus, a gradual desensitisation occurs, with relaxation replacing alarm.

Several means of confronting the feared situations can be used. In the pre-computer era, the exposure occurred either through imagination and visualisation (imagining a plane flight) or through actual real-life — or so-called in vivo — encounters with the feared situation (going on an actual plane flight). More recently, during the 1990s, virtual reality or computer-simulated exposure has come to be utilised in lieu of in vivo exposure. Research findings indicate that mental imagery is the least effective means of exposure; in vivo and virtual reality exposure appear to be indistinguishable in terms of effectiveness.

Systematic desensitisation is a therapeutic intervention that reduces the learned link between anxiety and objects or situations that are typically fear-producing. The aim of systematic desensitisation is to reduce or eliminate fears or phobias that sufferers find are distressing or that impair their ability to manage daily life. By substituting a new response to a feared situation — a trained contradictory response of relaxation which is irreconcilable with an anxious response (reciprocal inhibition, according to Wolpe — phobic reactions are diminished or eradicated.

Because of the potential for extreme panic reactions to occur, which can increase the phobia, this technique should only be conducted by a well-qualified, trained professional. Also, the relaxation response should be thoroughly learned before confronting the anxiety-provoking hierarchy.

Evaluation of Systematic Desensitisation

Desensitisation is an effective form of therapy. Individuals who have a positive response are enabled to resume daily activities that were previously avoided. The majority of persons undergoing this treatment show symptom reduction.

Juan Capafons, Carmen Sosa & Pedro Avero (1998) demonstrated that Systematic Desensitisation was successful in overcoming fear of flying. 20 clients were taught first to relax and to imagine, then the hierarchy for travelling by plane was set up and finally the hierarchy was presented along with the focus on stopping negative thoughts.  Success was measured by self-report, interview and recording biological factors when the clients were in a simulated situation. The 20 showed significantly reduced fear compared to 21 people in a control group.

T McGrath, E Tsui, S Humphries & Yule (1990) claimed that Systematic Desensitisation is effective for around 75% of people with specific phobias. M G Craske & D H Barlow (1993). D H Barlow & C L Lehman confirmed this kind of effectiveness in 1996.

Lars-Goran Ost, PM Salskovskis & K Hellstrom (1991) presented the whole  hierarchy of feared stimuli were presented in a single session over several hours for 20 clients with spider phobias. Ost et al found that, no matter how severe the phobia had been, 90% were much improved on a 4-year follow-up.

Edwin de Beurs, A J L M van Balkom, Alfred Lange & Richard van Dyck (1995) compared Systematic Desensitisation with Cognitive-Behavioural Therapy and pharmacological treatments. Their sample of 96 clients was randomly assigned into 4 groups:-

1. medication, followed by Systematic Desensitisation
2. placebo medication, followed by Systematic Desensitisation
3. CBT (n the form of panic management, followed by Systematic Desensitisation
4. Systematic Desensitisation alone

Clients in the groups were each given 12 weekly sessions. All 4 groups made progress in decreasing agoraphobic avoidance; but treatment 1 - medication, followed by Systematic Desensitisation - proved to be twice as effective as the other 3 (which were more or less equal).M Burke, L M Drummond & D W Johnston (1997) similarly  found Systematic Desensitisation equally effective for phobias whether in combination with medication or CBT.

While Systematic Desensitisation is effective for treating specific phobias, it is not as effective in dealing with social phobias and is as good as useless in dealing with major mental illnesses such as psychotic disorders. M G Craske & D H Barlow (1993) found the therapy did facilitate improvements in 60-80% of clients suffering from Agoraphobia - but improvements were only partial and a full 50% of cases experienced relapse.

Although the Classical Conditioning rationale of Systematic Desensitisation appears clear enough, it can be argued that there are elements of Operant Conditioning in the process as the client effectively avoids the unpleasant/fear-invoking stimulus - ie: negative reinforcement. It also can be argued that Systematic Desensitisation also involves an element of the Cognitive approach as progressive relaxation requires the client to think differently about the phobic stimulus in a different way. Indeed, in their critique of the therapy, Terence Wilson & Daraiel O’Leary (1978) point out that it requires imagination.

In 1975 John Lick told his clients that he was presenting them with subliminal phobic stimuli and that repetition of these stimuli reduced their physiological fear responses. Somewhat to Lick’s surprise, this worked very well for his clients - as he was not following the ‘correct’ procedure. He was not presenting them at all with phobic stimuli of any kind and the feedback about physiological responses was fake! It seems in this case to have been good rapport between therapist and  client and the power of suggestion which made the difference..

Developed initially from work by Ali Standen