Delusion: Not a Symptom or Sign, but a Pathology of the Human Mind

Abstract Delusion has long been considered a core feature of psychiatric disorders, especially psychoses. Conventionally, psychiatry has debated whether delusions should be understood as a symptom, reported by the patient, or as a sign, observed and inferred by the physician. In this article, the author argues that delusion cannot be reduced to either category alone. Symptoms such as suspiciousness, irritability, and aggression often accompany delusional states, but they are not sufficient to establish the presence of a delusion. Conversely, signs such as fixedness, bizarreness, and acting-out behaviors, while crucial for identification, require subjective corroboration. The author proposes that delusion is best conceptualized as a descriptive psychopathological entity (equivalent to pathology of medicine), emerging from the integration of both symptoms and signs. This interpretation strengthens the conceptual foundations of clinical psychiatry within the disease model of medicine.