By Ann Quigley, Contributing Writer
Health Behavior News Service
Depression is more dangerous for elderly men than women, with depression starting in old age representing the greatest risk for men, according to a long-term study.
“Depression may be an early sign of impending physical decline,” says study author Kaarin Anstey, Ph.D., of the Center for Mental Health Research at Australian National University in Canberra, Australia. “Or it may incur a physiological response that predisposes individuals to cardiovascular disease or cancer.”
Anstey and co-author Mary A. Luszcz, Ph.D., of the School of Psychology and Center for Aging Studies at Flinders University in Adelaide, South Australia, analyzed data from the Australian Longitudinal Study of Aging, focusing on individuals aged 70 or older. More than 1,900 participants completed a questionnaire measuring depression in 1992; a subset of these participants completed it in 1994. The researchers tracked the health of the participants until 2000.
Participants were classified as having “incident depression” if their questionnaire scores indicated they were depressed the second time they took the test but not the first time. They received a classification of “remitted depression” if their depression had relented the second time they took the test and “chronic depression” if their scores were high on both occasions.
After taking into account factors such as smoking, alcohol and medical conditions, depression was associated with mortality for men but not women, the researchers found.
“Our findings confirm previous studies showing that late-life depression occurs more often in women, but has greater negative outcomes for men,” says Anstey.
The significant effect of depression on male mortality was small but “robust,” suggesting that depression may play a role in causing health changes in men, according to the study. Incident depression had the strongest association with death for men. The effects of chronic and remitted depression were not statistically significant when the researchers took medical conditions into account.
The lack of a statistically significant association between chronic depression and mortality may relate to chronically depressed participants skewing results by dropping out between the first and second questionnaires. The effects of chronic depression in this study are probably underestimated because of these dropouts, according to the study.
The finding that remitted depression was not associated with mortality “suggests that treating depression in very old adults may reduce the risk of mortality,” says Anstey. The study results are published in the November/December issue of Psychosomatic Medicine.
The researchers suggest that depression may be a precursor of cardiovascular disease or dementia, or may occur in concert with these conditions.
This study was partly funded by a National Health and Medical Research Council of Australia Clinical Research Fellowship, the South Australian Health Commission, the Australian Rotary Health Research Fund and by a grant from the U.S. National Institutes of Health.