Ninety-one-year-old “Charles” was really looking forward to his 70th class reunion at Dartmouth College. But one of his classmates, an old friend, died from a heart attack during the reunion, leaving Charles feeling not only very depressed, but very lonely. What is the point of reaching 100 if your spouse and friends are no longer living to share it with you?, he thought. Five months later, he died as well.
Did depression or lonesomeness trigger Charles' demise? It is possible that the combination of the two did, a study reported in the January American Journal of Psychiatry suggests. It appears to be the first prospective investigation of the relationship between depression, loneliness, and death in the oldest old in the community.
The lead scientist was Max Stek, M.D., Ph.D., a geriatric psychiatrist and senior lecturer at Leiden University in the Netherlands.
There are strong indications that depression can hasten the death of people via various routes, notably suicide or cardiovascular disease. There are some reasons to suspect, however, that the link between depression and death in the oldest old might be unique—for example, because the oldest old are survivors, depression might not impact their health in the same way that it does that of younger people. Also, depression in old age has been found to be coupled often with feelings of loneliness, yet the effects of such feelings on human health are obscure. So Stek and his coworkers decided to explore the impact of depression, perceived loneliness, and the two combined on mortality in very old people in a study called the Leiden 85-Plus Study.
All Leiden residents born from 1912 to 1914 were enrolled in the study on their 85th birthday, that is, from 1997 to 1999. After that, each subject annually had a structured face-to-face interview. The interviews included the 15-item Geriatric Depression Scale to measure depression and the Loneliness Scale to measure perceived loneliness. The latter instrument was developed especially for use in the elderly. Because the validity and reliability of these scales may be reduced in subjects with impaired cognitive function, they were given only to the 500 subjects with a Mini-Mental State Examination score above 18. Out of the 500 subjects, 476 completed the scales, and 141 subjects in that group died during follow-up.
Stek and his colleagues then used results from the scales completed by the 476 subjects to determine whether there was any link between depression and death, perceived loneliness and death, or depression plus perceived loneliness and death. Neither depression alone nor perceived loneliness alone appeared to have any significant effect on mortality, they found. However, a combination of both depression and loneliness did.
These results remained the same after the researchers assessed possibly confounding factors such as gender, marital status, living arrangement, education, smoking, alcohol consumption, and chronic diseases.
“Thus, in the oldest old, depression is associated with mortality only when feelings of loneliness are present,” Stek and his colleagues concluded.
The reason for this finding, they speculated, may be “that depression with feelings of loneliness leads to more pronounced motivational depletion and to `giving up.'”
“Further exploration of the clinical features of depression in the oldest old,” they added, “could lead to a better understanding of `how depression kills' in order to develop possible interventions.”
The study was funded by the Netherlands Organization of Scientific Research and the Ministry of Health, Welfare, and Sports.
Am J Psychiatry 2005 162 178