Despite careful planning, it is inevitable that a number of issues will arise during the course of the intervention that will affect progress. The clinician needs to be prepared for this eventuality. Adopting such an expectation acknowledges both the reality and the complexity of therapy. Problems are challenges to be overcome rather than indications that CBT has failed or is not working. While it is not possible to prepare for all eventualities, the following presents some of the more common problems that are encountered during the course of CBT.