New research has shown that people with Alzheimer's may not always experience memory loss as their first symptom of the disease, with younger people more likely to have problems with judgement, language or visual and spatial awareness than older people. The study of 7,815 people - one of the largest of its kind to date - suggests a need for greater awareness of the different symptoms of Alzheimer's disease, the most common cause of dementia. Led by a researcher at UCL (University College London) and part-funded by Alzheimer's Research UK, the UK's leading dementia research charity, the research is published in the journal Alzheimer's & Dementia.
Alzheimer's disease, which currently affects half a million people in the UK, causes the death of brain cells and leads to a range of symptoms, including problems with thinking and memory and changes in behaviour. While memory loss is a typical early symptom of Alzheimer's disease, some people can experience other, very different symptoms in the early stages of the disease. The researchers set out to investigate how a person's age might affect the first symptoms they experience, looking at both cognitive symptoms - problems with thinking skills - and behavioural symptoms.
The team analysed data from 7,815 people in the US National Alzheimer Coordinating Center (NACC) database, which includes records on people attending Alzheimer's disease centres across the US. Each participant had a diagnosis of Alzheimer's, and a record had been made of the symptoms they had first noticed in the early stages of the disease. The average age of the group was 75, with the youngest person aged 36 and the oldest aged 110.
Although memory loss was the most common first symptom in all age groups, the results showed younger people were more likely than their older counterparts to report 'non-memory' problems first - including difficulty with judgement or problem-solving, problems with language, or a loss of visual or spatial awareness. In people under 60, a quarter reported that their first symptom was not memory loss, while one in five people in their 60s first had symptoms other than memory loss. This number fell to one in ten for people in their 70s, and one in 15 for those 80 years or older.
When the researchers compared the people's first reported behavioural symptoms, they also found age differences. The most common behavioural symptom was apathy or withdrawal, but compared to older age groups, younger people were more likely to experience depression or other behavioural symptoms such as anxiety. In contrast, older people were more likely to have had psychosis, or no behavioural symptom at all, compared to those who were younger.
Dr Jo Barnes, Alzheimer's Research UK Senior Research Fellow at UCL and the study's lead author, said: "Our results highlight the many different ways Alzheimer's can affect the brain, causing problems with several different cognitive processes, not just memory. Brain imaging studies have suggested that the disease may be more likely to affect different parts of the brain in younger people, and this may help to explain some of the different symptoms seen in our study. Importantly, however, even in older groups not all people with Alzheimer's report memory loss as their first warning sign of the disease.
"An awareness of symptoms other than memory loss is vital for helping to diagnose Alzheimer's, particularly for those people whose early symptoms are not typical of the disease. Our findings suggest a need for doctors to use tests that do not solely or disproportionately focus on memory, but which also take into account some of the different ways that Alzheimer's can manifest."
Dr Eric Karran, Director of Research at Alzheimer's Research UK, said: "All too often Alzheimer's is thought of as being a disease characterised only by memory loss, but this study shines a light on some of the other distressing symptoms people with the disease can experience. A greater understanding of these symptoms could not only help people receive a diagnosis earlier, but could also aid public awareness of the disease and help improve support services. Further research to investigate why younger people are more likely to experience different symptoms in the early stages of Alzheimer's could provide useful insights into the disease. It's worth noting that some of the people in this study may have been wrongly diagnosed with Alzheimer's, and these results highlight the need to develop more accurate tests for the disease. If we are to find better ways of diagnosing Alzheimer's early and new ways to treat the disease, continued investment in research is vital."