Dementia Clues Appear Almost a Decade Before Diagnosis

Memory loss and cognitive impairment may be detectable up to nine years before an official dementia diagnosis, according to research offering some hope for early intervention. Alzheimer's and dementia are hard to treat, as diagnosis usually comes after symptoms appear, at which point it may be too late to alter the course of the disease, reports the Guardian. However, "when we looked back at patients' histories, it became clear that they were showing some cognitive impairment several years before their symptoms became obvious enough to prompt a diagnosis," Cambridge University doctor Nol Swaddiwudhipong says in a release. "The impairments were often subtle, but across a number of aspects of cognition."

Researchers used the UK Biobank biomedical database to collect health histories for participants, which included tests on problem-solving, memory, and reaction times, and data on the number of falls they suffered. The team found those who went on to develop Alzheimer's and a rare form of dementia called frontotemporal dementia five to nine years later had poorer results in reaction times and in problem-solving and memory tasks, including number recall, than those individuals who remained healthy. Those later diagnosed with Alzheimer's were also more likely to have suffered a fall in the previous year. The findings could help doctors identify high-risk individuals well before a diagnosis is made.

They could "intervene at an earlier stage to help them reduce their risk," says Swaddiwudhipong, lead author of the study published Wednesday in the Alzheimer's & Dementia journal of the Alzheimer's Association. The findings could also help identify individuals suitable for trials of new treatments. "If we can find these individuals early enough, we'll have a better chance of seeing if the drugs are effective," says senior author Dr. Tim Rittman, noting patients with a diagnosis "are already some way down the road and their condition cannot be stopped." However, "health services don't routinely offer the tests needed to detect changes in brain function that happen before symptoms are noticeable," David Thomas of Alzheimer's Research UK tells Bloomberg. (More dementia stories.)