[Psychiatry and neurology: a commitment with obligations]

Neurology and psychiatry differ from the other branches of medicine by their narrow implication with the nervous system. However, owing to the quantitative importance of neuroses in daily practice, an unbridgeable gap might appear between psychiatry, concerning the mind, and neurology, concerning the body. That gap cannot be justified, because the most psychogenic mental disease is associated with organic components and, on the other side, the most organic mental disorder is associated with psychological components; failing to appreciate purely psychical disturbances as preliminary symptoms of certain organic brain-disorders may have a fatal issue for the patient. Only the organic investigation, in the broadest sense of the term, of the nervous system may, in our time, allow an always closer approach to the background of psychiatric diseases that were considered, in earlier times, as purely psychogenic. The author chose Alzheimer's disease as an instance of the necessary intercourse between psychiatry and neurology. The author discusses the epidemiology, the symptomatology, the anatomopathology, the biochemistry and the therapy of this disease. In comparison with the course of things concerning Parkinson's disease, we may be sure that our knowledge concerning Alzheimer's disease will depend upon a narrow collaboration between psychiatry and the different branches of neurology.