ABSTRACT
The present clinical study was aimed at investigating predictors of treatment success, attrition and the extent of treatment needed to achieve clinically significant improvement in spider phobic patients. A total of 103 patients were included in the study after a detailed screening interview. There were four treatment conditions; self-help manual, video, group, and individual treatment, which the patients received in a hierarchical order providing they were not clinically significantly improved after the previous treatment. Pre and post each treatment the patients went through a behavioral approach test and filled in a number of self-report questionnaires. The results showed that 38 patients dropped out during the manual treatment, and 59 fulfilled the treatments to become clinically improved. The patients achieving clinical improvement after the two self-help treatments were significantly predicted, as was the extent of treatment needed. The significant predictors were credibility of the manual treatment and motivation for psychotherapy in general.