CHICAGO, Feb. 6 (UPI) -- Lonely people may be twice as likely to develop dementia linked to Alzheimer's disease late in life than those who are not lonely, says a U.S. study.
Robert S. Wilson of Rush University Medical Center in Chicago analyzed the association between loneliness and Alzheimer's disease in 823 individuals with an average age of 80.7.
Loneliness was measured on a scale of one to five, with higher scores indicating more loneliness. The data were collected between November 2000 and May 2006.
At the first examination, participants' average loneliness score was 2.3, but during the study period, 76 individuals developed dementia that met criteria for Alzheimer's disease. Risk for developing Alzheimer's disease increased approximately 51 percent for each point on the loneliness score, so that a person with a high loneliness score -- 3.2 -- had about 2.1 times the risk of developing Alzheimer's disease than a person with a low score -- 1.4. The findings did not change significantly when the researchers factored in markers of social isolation, such as a small social network and infrequent social activities, according to the study published in the Archives of General Psychiatry.