Aims The consortium aims to identify effective prevention strategies for dementia and Alzheimer disease (AD). We intend to harmonise and optimise methodologies for multinational, multimodal prevention trials across the entire spectrum of AD, and provide guidelines and recommendations for effective interventions tailored to different risk groups. Research questions Main research questions addressed in this project are: A) In at-risk community dwelling older adults: A.1) efficacy and mechanisms of multimodal preventive interventions; A.2) facilitators and barriers to participation in and adherence to multimodal interventions. B) In memory clinic patients with prodromal AD: B.1) implementation of the new diagnostic criteria for prodromal AD: feasibility and impact; B.2) feasibility of and adherence to a multi-modal intervention for preventing cognitive decline/dementia. Working hypothesis Given the multifactorial aetiology of late-onset AD, multimodal preventive interventions targeting several risk factors and disease mechanisms simultaneously are the most likely to be effective. In addition, effective prevention depends on the availability of a range of multimodal interventions that can be tailored to different at-risk groups. Methodology The project is based on the synergistic use of data from 5 AD/dementia prevention trials ongoing in Europe, with over 10 000 participants. With 2 additional sub-studies within ongoing trials (HATICE, LipiDiDiet). Data analyses will allow A) identification of the most effective components of multimodal interventions and methods of delivery; B) definition of the most efficient recruitment strategies in varying settings and target populations; C) definition of an intervention protocol for prodromal AD, which will be used in a proof-of-concept multinational pilot trial (MIND-ADMINI). Overall generated data will allow formulation of recommendations and guidelines for AD prevention in community and clinical settings (immediate action); recommendations and guidelines for conducting multinational multimodal preventive trials for AD; design large pan-European prevention trials (MIND-ADMAXI) carried out by the consortium. Added value The consortium is unique worldwide in providing extensive practical experience and expertise covering AD/dementia risk reduction and prevention from community to the clinic. We will combine and optimise existing infrastructures based on 5 ongoing AD/dementia prevention trials, creating an outstanding opportunity for rapid integration of knowledge, and harmonisation of methods and outcome measures across Europe. The novel approach consists of multimodal interventions, the inclusion of novel modes of delivery (e.g. computerbased cognitive training, medical food), the inclusion of feed-back from the users (trial participants), and combining data from several European countries with over 10 000 participants. Keywords Alzheimer’s disease, dementia, prevention, intervention, multimodal, multinational, populationbased, clinic-based, adherence, harmonisation