BEWARE: Why Loneliness Could be a Behavioral Symptom of Preclinical Alzheimer's Disease

A new study revealed that loneliness, characterized by social detachment, could be considered as a behavioral symptom of preclinical Alzheimer's disease, prior to mild cognitive impairment.

The study, published in the journal JAMA Psychiatry, suggests that the experience of loneliness in older adults may play a causative role in the development of Alzheimer's disease. Furthermore, the study also provides evidence supporting the role of loneliness as a neuropsychiatric symptom relevant to preclinical Alzheimer's disease.

"We are interested in the possibility that early brain changes due to Alzheimer's disease may be associated with subtle changes in social perception or social reward that could predispose to feelings of loneliness," explained Nancy J. Donovan, MD, an associate psychiatrist at the Center for Alzheimer Research and Treatment at Brigham and Women's Hospital in Boston and lead author of the study, in a report from Medscape Medical News.

For the study, the researchers recruited 79 cognitively normal, community-dwelling adults involved in the Harvard Aging Brain Study. The researchers tested the Alzheimer's risk of each participant by identifying their APOEε4 genotype, the genetic risk for Alzheimer's, and measuring their fibrillar amyloid burden. The loneliness levels of the participants were measured using the 3-item version of the UCLA Loneliness Scale.

The researchers found that 28 percent of the participants possess APOEε4 and 32 percent of them had cortical amyloid burden. The overall mean loneliness score among the participants was 5.3.

Among the participants, the ones with the higher levels of cortical amyloid burden were 7.5 times more likely to be classified as lonely. Furthermore, the link between the levels of cortical amyloid burden and loneliness were significantly stronger to those participants classified as APOEε4 carriers.

Dr. Donovan noted that more research is needed to confirm the causative relationship of Alzheimer's and loneliness. However, the researchers suggests that clinicians should consider loneliness as a potential symptom for Alzheimer's, especially when reported with other behavioral symptoms such as mood changes.