Abstract
Case complexity and reduced treatment outcomes have been reported in patients with anxiety disorders and comorbid cluster C personality disorders (PD). This chapter reviews the effect of PD on presentation, course, and treatment of individual anxiety disorders. Additionally, two personality models are presented to explain the underlying mechanisms of these cases. Moreover, treatment approaches are discussed that are able to manage a comorbid cluster C PD, as seen in a case study of treating anxiety in a patient with comorbid obsessive–compulsive PD. However, further research is needed to develop more effective interventions for patients with this comorbidity.