Successful applications of systematic desensitization have been reported when patients controlled tape recorders that presented relaxation instructions and descriptions of scenes on the hierarchy (Migler & Wolpe, 1967). More recently, a computer program was designed to deliver systematic desensitization, and a pilot study with an agoraphobic client produced encouraging data (Chandler, Burck, & Sampson, Jr., 1986). In addition, clients experiencing the same fears have been successfully treated in group sessions; examples include fear of public speaking (Paul & Shannon, 1966); test anxiety (Ihli & Garlington, 1969), and spider phobias (Robinson & Suinn, 1969). Finally, manuals have been written outlining the steps involved for performing systematic self-desensitization (e.g., see Martin & Pear (1998, Chapter 25).
One variant of systematic desensitization is called in vivo desensitization (or contact desensitization: Miltenberger, 1997). It is similar to systematic desensitization except that rather than imagining the scenes on the hierarchy, the client experiences them in reality. Wolpe (1982) recommends this procedure when imaginal stimuli do not elicit the same types of emotional reactions as the feared stimulus itself; he estimated that this occurs for about 15-20% of patients.
The main advantage of in vivo desensitization is that generalization from experiencing no anxiety while visualizing a feared situation to experiencing no anxiety while making actual contact with it is no longer a issue because the behavior of concern is trained in the situation of concern. A disadvantage stems from the fact that the therapist has to leave the office in order to help the client confront his or her actual fears, making the procedure potentially more time consuming and more costly than systematic desensitization. Another drawback is that the therapist's presence is not always possible in certain anxiety-provoking situations (e.g., sexual acts with spouse).