Fig. (2) Virtual graph (*) of the possible effects of suspending a treatment with symptomatic effect. *: In reality, the natural evolution of impairment is not lineal and varies according to the stage of the disease; however, the lineal diagram facilitates the conceptual understanding of the action of the drugs.1: Cognitive decline related to ageing. 2: Cognitive and functional loss due to an untreated progressive disease. 3: Improvement produced by treatment. 4: If a treatment is only symptomatic, its action is lost when it is suspended and the patient follows the evolution of untreated patients. 5: If the treatment, apart from being symptomatic, also modifies the course of the disease, its symptomatic action is lost when it is suspended, but the modification already achieved is held and the patient follows a progression line that does not overlap that of untreated patients.