The best treatment is prevention: prevention of cognitive decline and dementia - current state, gaps and next steps.

The World Health Organization (WHO) recognises dementia as a public health priority. Currently, more than 55 million people live with dementia, and this figure is expected to almost triple to 139 million by 2050. Alzheimer’s disease is the most common cause of dementia, and there is still no cure. Despite the availability of symptomatic and first disease-modifying treatments, effective treatment remains limited. This makes it even more important to be aware that it is estimated that nearly half of all dementia cases could be prevented by eliminating 14 major risk factors. Consequently, the role of these modifiable risk factors has been the subject of research to inform effective preventive strategies. This narrative review summarises the current evidence on the prevention of cognitive decline and dementia. First, we provide an overview of the current state on risk factors, multimodal clinical controlled trials for slowing down or preventing dementia and primordial, primary, secondary, tertiary and quaternary prevention of cognitive decline and dementia. Second, we evaluate knowledge and action gaps in the field. Finally, we discuss how to address these gaps and what the next steps should be. Overall, to accelerate progress, the following key calls to action are paramount: (1) making prevention of cognitive decline and dementia a priority; (2) promoting brain health throughout the lifespan through coordinated intersectoral action targeting key risk factors; (3) improving access to diagnosis and treatment for patients with cognitive decline and dementia; and (4) encouraging research on prevention and how to translate knowledge into action.