Noticing that you've forgotten something, sometimes called 'a senior moment' can be frustrating, but new research suggests the fact that you're aware of your forgetfulness may be a good thing.
A US study has found that older adults who go on to develop dementia may begin to lose their awareness of memory problems up to 3 years before being diagnosed with dementia.
Rush University Medical Center in Chicago analysed data from 3 continuing studies involving more than 2,000 participants with an average age of 76 at the start of the research.
At the beginning of the trial, the volunteers had no signs of memory or brain problems called cognitive impairment.
Memory and thinking ability tests were given every year, and the volunteers were also asked how often they had trouble remembering things. They were also asked to rate their current memory compared with how it was 10 years earlier.
During the study, published in the journal Neurology, 239 people were diagnosed with dementia. The researchers found that awareness of memory ability was stable until it dropped sharply on average 2.6 years before the dementia started.
In a statement, study author Dr Robert Wilson says: "Our findings suggest that unawareness of one’s memory problems is an inevitable feature of late-life dementia, driven by a build-up of dementia-related changes in the brain.
"Lack of awareness of memory loss is common in dementia, but we haven’t known much about how common it is, when it develops or why some people seem more affected than others. Most studies of memory unawareness in dementia have focused on people who have already been diagnosed. In contrast, this new study began following older adults before they showed signs of dementia."
Although there were individual differences in when the unawareness started and how fast it progressed, "virtually everyone had a lack of awareness of their memory problems at some point in the disease," Dr Wilson says.
One surprise finding was that memory unawareness began earlier in younger people than in older adults. However, this may be because older people are more likely to think memory loss is a normal part of getting older.
Dr Wilson says the findings stress the importance of family members and friends getting help for someone they suspect of developing dementia, "since people may be unable to give reliable reports about the history of their own memory and thinking abilities."
UK dementia experts have been reacting to the findings in statements.
Dr Laura Phipps from Alzheimer’s Research UK says: "This study presents interesting insights into the changes taking place in the early stages of the condition. The findings show that it’s common for people to lose the ability to recognise the memory difficulties they’re experiencing in the lead-up to a diagnosis and suggests that this is driven by underlying damage in the brain. The findings highlight the importance of testimony from relatives and close friends at the point of diagnosis to help doctors to gain a clearer picture of someone's memory problems."
Dr Clare Walton, research manager at the Alzheimer’s Society says: "This study shows that people are not always aware of changes to their memory in the early stages of the condition. Often, friends and family are the first to recognise the warning signs. People who are concerned about the memory of someone close to them should encourage that person to visit their GP. A diagnosis can help people with dementia plan for the future and get access to vital care and support."