Washington: Researchers have linked feeling of loneliness to an increased risk of developing dementia in later life.
The researchers tracked the long-term health and wellbeing of more than 2000 people with no signs of dementia and living independently for three years.
All the participants were taking part in the Amsterdam Study of the Elderly (AMSTEL), which is looking at the risk factors for depression, dementia, and higher than expected death rates among the elderly.
At the end of this period, the mental health and wellbeing of all participants was assessed using a series of validated tests. They were also quizzed about their physical health, their ability to carry out routine daily tasks, and specifically asked if they felt lonely. Finally, they were formally tested for signs of dementia.
At the start of the monitoring period, around half the participants were living alone and half were single or no longer married. Around three out of four said they had no social support. Around one in five said they felt lonely.
Among those who lived alone, around one in 10 had developed dementia after three years compared with one in 20 of those who lived with others.
Among those who had never married or were no longer married, similar proportions developed dementia and remained free of the condition.
But among those without social support, one in 20 had developed dementia compared with around one in 10 of those who did have this to fall back on.
And when it came to those who said they felt lonely, more than twice as many of them had developed dementia after three years compared with those who did not feel this way.
Further analysis showed that those who lived alone or who were no longer married were between 70 percent and 80 percent more likely to develop dementia than those who lived with others or who were married.
And those who said they felt lonely were more than 2.5 times as likely to develop the disease. And this applied equally to both sexes.
When other influential factors were taken into account, those who said they were lonely were still 64 percent more likely to develop the disease, while other aspects of social isolation had no impact.
“These results suggest that feelings of loneliness independently contribute to the risk of dementia in later life,” the authors wrote.
“Interestingly, the fact that ‘feeling lonely’ rather than ‘being alone’ was associated with dementia onset suggests that it is not the objective situation, but, rather, the perceived absence of social attachments that increases the risk of cognitive decline,” they added.
They suggested that loneliness may affect cognition and memory as a result of loss of regular use, or that loneliness could itself be a sign of emerging dementia, and either be a behavioural reaction to impaired cognition or a marker of undetected cellular changes in the brain.
The finding was published online in the Journal of Neurology Neurosurgery and Psychiatry.