Delusions across and beyond diagnoses

In this chapter, our main goal is to explore the heterogeneity of delusions. In the second section, we look at definitions of delusions. The concept of “delusion” can be very elusive, given the difficulty in establishing the necessary and sufficient conditions that a belief must meet to count as a delusion. In the third section, we focus on the clinical characteristics of delusions. Clinically, delusions differ both in form and content, and can be found in the context of a number of mental disorders. In the fourth section, we discuss how clinical delusions share some features with everyday beliefs—which suggests that there is a sense of “delusions” that cuts across the clinical and non-clinical divide. That is the sense of delusions that focuses on its epistemic features.