[A brief historical approach about the concept of paranoia].

From the ancient Greeks (V to III centuries BC), through Hippocrates to the Roman physician Aulo Cornelius Celso (I century), the term paranoia has been used as a manifestation of mental illness. After many centuries, Robert Burton in 1621 introduces the concept with a more modern meaning. Only with Heinroth (1818) the syndrome enters into the psychiatric nosology as a disorder of thought with unaltered perceptions. French and German psychiatry agree on the concept of paranoia as a partial psychosis with a maintained level of functioning and absence of deterioration. With this meaning the term is introduced in the modern psychiatry in Kahlbaum's work (1863). Jasper contributes with the introduction of paranoid development that can be influenced by the environment or previous experiences (1910). But to Kraepelin (1921) is owed the most precise description in a specifc essay based on his clinical experience. The German psychiatrist speaks of both a psychogenic and a more biological component. In modern psychiatric classifcations gradually the syndrome has disappeared and encompassed in the generic delusional disorder, clearly distinct from schizophrenia, and only if the delusions are understandable. The consequences of the absence of a diagnostic recognition implies that there is no specific research on this syndrome with difficulties in developing psychotherapeutic and pharmacological treatments.