Strategies to prevent dementia apply before the first symptoms develop.  They aim at a lifestyle-related reduction of risk factors or improvement of protective factors and at intervention in molecular processes in order to reduce the number of new cases. Prevention studies may for instance investigate drug interventions that can reduce amyloid plaques before the onset of first symptoms and the possible positive effects of lifestyle adjustments, including social and cognitive activities, nutrition and sleeping habits. It is not possible to influence all risk factors, including genetic predisposition or age. In contrast, cognitive, social and physical activity can be influenced and is currently being investigated for its preventative effect. Furthermore, research into the prevention of dementia differentiates between life stages in which different factors can pose risks.