For more than 60 years, researchers have been interested in determining the impact of expectations on treatment outcome. Earlier studies mostly focused on two types of expectations: prognostic and process expectations. Aims: To review how four different types of expectations (prognostic, process, anxiety expectancy and anxiety sensitivity) contribute to psychotherapy outcome, and to the development of clinical disorders, especially anxiety. Conclusions: First, the role of process and prognostic expectancies in clinical disorders and psychotherapy outcome should be clarified by addressing the methodological flaws of the earlier expectancy studies. Second, studies, especially those on anxiety disorders, may benefit from evaluating the four different types of expectations to determine their relative impact on outcome, and on the development and maintenance of these disorders. Third, possible links with other clinical disorders should be further explored. Finally, expectancies should be assessed prior to treatment and after several sessions to determine the extent to which the treatment's failure in modifying initial low expectancies contribute to a poor outcome.
Part of the book: A Fresh Look at Anxiety Disorders