People who feel lonely are at an increased risk of developing dementia later in life, the results of a new study indicate.

According to Dutch scientists, a number of factors are known to be linked to the development of dementia, including age, genes and depression. However until now, the impact of loneliness has not been studied in great detail.

For the purpose of this study, loneliness was defined as living alone, not having a partner and having few friends and/or social interactions.

The scientists monitored the health and wellbeing of over 2,000 people who were living independently for a three-year period. None showed any signs of dementia at the start of the study.

Their mental and physical health was assessed, which included formal tests for dementia. They were also questioned about feelings of loneliness.

At the start of the study, almost half of the participants were living alone and half did not have a partner. Three-quarters said they had no social support and one in five admitted to feeling lonely.

The scientists found that when it came to loneliness, more than twice as many people who admitted to being lonely went on to develop dementia compared to people who did not feel this way - 13% versus 5%. These figures applied to both men and women.

Meanwhile, an analysis of the figures also showed that people who lived alone or who were no longer married were up to 80% more likely to go on to develop dementia compared to people who were married or lived with others.

According to the team from Free University Medical Centre, these findings ‘suggest that feelings of loneliness independently contribute to the risk of dementia in later life'.

"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 said.

Details of these findings are published in the Journal of Neurology Neurosurgery and Psychiatry.

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