Despite greater awareness of mental illness, there remains a very strong link between depression and the risk of early death, with a particularly significant increase among women in recent years, according to a new study published in CMAJ (Canadian Medical Association Journal).
“There is less stigma associated with depression, better treatments are available, but depression’s link to mortality still persists,” said Dr. Stephen Gilman of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the National Institutes of Health in Bethesda, MD. “At first, the association was limited to men, but in later years it was seen for women as well.”
The researchers believe that societal change may be one reason for the increased risk of death among women with depression.
“During the last 20 years of the study in which women’s risk of death increased significantly, roles have changed dramatically both at home and in the workplace, and many women shoulder multiple responsibilities and expectations,” said Dr. Ian Colman, Canada Research Chair in the School of Epidemiology, University of Ottawa, Ottawa, Ontario.
The findings come from the well-known Stirling County Study in Canada, one of the first community-based studies on mental illness. An international team of researchers reviewed 60 years of mental health data on 3,410 adults during three time periods (1952-1967, 1968-1990, and 1991-2011) from a region in Atlantic Canada and linked the data to deaths in the Canadian Mortality Database. The mean age of participants at enrollment was about 49 years.
The researchers found that the relationship between depression and an increased risk of death occurred in all decades of the study among men, whereas it emerged among women beginning in the 1990s. The risk of death appeared strongest in the years following a depressive episode, leading the researchers to speculate that this risk could be reversed if depression is successfully treated.
“The lifespan for young adults with depression at age 25 was markedly shorter over the 60-year period, ranging from 10 to 12 fewer years of life in the first group, four to seven years in the second group and seven to 18 fewer years of life in the 1992 group,” Colman said.
“Most disturbing is the 50 percent increase in the risk of death for women with depression between 1992 and 2011.”
While depression has also been linked with a poor diet, lack of exercise, smoking, and alcohol consumption — all factors that can result in chronic health problems — these did not explain the increased risk of death associated with depression in this study.
The researchers suggest that family physicians watch patients for mood disturbances, especially recurrent episodes of depression, so that they may offer treatment and support.
Limitations of the study include a long period of time between participant interviews which prevented determining the exact timing of depression, and the participants’ experiences of recurrent episodes of depression between interviews.