A patient holds a persecutory belief. Before revealing the answer, decide what distinguishes a delusion of persecution from delusional perception.

Ask whether you are describing the content of the belief itself, or the specific mechanism by which it arose from a normal perception. A delusion of persecution is a content category: a fixed conviction of being watched, followed, plotted against, or otherwise deliberately targeted for harm, regardless of how that conviction came about. Delusional perception is a mechanism, not a content category: it describes a normal perception of a real object or event to which a delusional, and often persecutory, meaning is suddenly attached. In practice, a delusion of persecution can arise through delusional perception, or through many other routes, so the two concepts operate at different levels — one describes what is believed, the other describes one particular way a belief (of any content, persecutory or otherwise) can form.