Billions of dollars have been spent trying to find a treatment for Alzheimer’s disease over the decades, but those efforts have stubbornly fallen short − at least until recently. US authorities have authorised the test since May, but Europe has not yet approved any Alzheimer’s blood test, one of which is the subject of a recently launched national clinical trial in Britain. One area of consensus is what makes people more at risk of getting Alzheimer’s disease and dementia more broadly. A recent JAMA study found that the cognitive decline of Alzheimer’s patients slowed slightly after undergoing two years of intensive support to be healthier. But for people suffering from Alzheimer’s and their families, this kind of progress may not look like much, French epidemiologist Cecilia Samieri acknowledged at a conference this month.