New research finds that feeling lonely increases the rate of cognitive decline, independently of depression. Share on Pinterest If you’re older and you’re lonely, chances are your mental faculties will decline at a quicker rate. That’s the conclusion from new research presented today at the Alzheimer’s Association International Conference 2015 in Washington, D.C. In their study, researchers said they discovered that loneliness can be a key predictor of the rapid progression of dementia-related diseases. Learn More: Loneliness Is a Serious Health Risk for Seniors »

With Loneliness in Mind More than 45 million people worldwide are living with dementia today. One of the earliest symptoms of dementia is cognitive decline, a gradual reduction in high-level functions like memory and problem-solving. Although social isolation has long been linked with cognitive decline, it’s been unclear which causes which. Or if both are caused by a third factor, such as depression. The study released today examined 8,300 adults age 65 or older over the course of 12 years. Every two years, the participants came in for a memory test. The researchers also measured age, sex, race, wealth, income, health conditions, strength of social network, and levels of depression. One in six of the participants reported feeling lonely much of the time. Of these lonely individuals, nearly half experienced high levels of depression. Over the 12 years, researchers said people who were lonely experienced cognitive decline at a 20 percent faster rate than people who were not lonely. This is the same rate of cognitive decline associated with high levels of depression itself. Even having a single symptom of depression was enough to cause an 8 percent increase in cognitive decline. “We found that those effects were overlapping. In those analyses it looked like loneliness and depression were operating under the same mechanism, so we think that they’re related risk factors, but we also believe that loneliness or even one or two depressive symptoms in and of themselves represent a risk factor,” said Dr. Nancy Donovan, associate psychiatrist at Brigham and Women’s Hospital, in an interview with Healthline. Related Reading: New Brain Scan Technique Captures Early Signs of Dementia »