People with early signs of Alzheimer's more than seven times more likely to be lonely

Researchers say their findings could lead to greater understanding of the 'neurobiology of loneliness'

Loneliness has been linked to other health problems such as heart disease and stroke (Cultura/Getty Creative)

Loneliness could be a factor in Alzheimer’s disease, according to new research.

Researchers used brain-imaging techniques to determine levels of amyloid – a protein associated with the disease – in the brains of a group of 79 apparently healthy people with an average age of 76.

They then compared this to a test designed to find out how lonely someone is.

After controlling for factors such as age, sex, genetics, depression, anxiety, socio-economic status and the participants' social networks, they concluded that people with preclinical Alzheimer’s were 7.5 times more likely to feel lonely compared to people who did not have any early warning signs of the disease.

While the study found evidence of a correlation between loneliness and early signs of the disease, it was unclear whether social isolation might actually be one of the reasons why Alzheimer’s develops or if it was simply one of the symptoms.

Writing in the journal JAMA Psychiatry, the researchers said their findings might help spot the condition more quickly.

“We report a novel association of loneliness and cortical amyloid burden in cognitively normal adults and present evidence for loneliness as a neuropsychiatric symptom relevant to pre-clinical Alzheimer’s disease,” they wrote.

“This work will inform new research into the neurobiology of loneliness and other socio-emotional changes in late life and may enhance early detection and intervention research in Alzheimer’s disease.”

Alzheimer’s disease tends to get progressively worse from the preclinical stage through to mild cognitive impairment, dementia and then significant functional declines.

The researchers, led by Dr Nancy Donovan, of Brigham and Women's Hospital and Harvard Medical School, Boston, cautioned that their findings might have been affected by the better mental and physical health of participants in the study, compared to the general population of about the same age.

They also did not seem to be particularly lonely with an average score in the tests of 5.3 on a scale of three to 12.

However the association between high amyloid levels and loneliness was stronger than the association with a known genetic risk factor.

Dr Clare Walton, research manager at the Alzheimer’s Society, said: “This study didn’t involve people with Alzheimer’s, but it looked at a protein called amyloid in the brain which is known to build up many years before dementia is detected.

"Those who had high levels of amyloid were much more likely to say they felt lonely, even when the quality of their social environment was taken into account. These findings suggest that loneliness could be an early predictor of developing Alzheimer’s disease, but as it was a small study, more research is needed to cement these claims.

“Loneliness is a growing concern for our ageing population and we know that too often dementia and loneliness come hand in hand.

"No one should feel alone but if people are not properly supported, dementia can be an incredibly isolating experience. It is essential people with dementia are supported to maintain meaningful social connections and continue living their life as they want.”