Researchers examined six decades of mental health and mortality data on 3,410 adults during three time periods: 1952 to 1967, 1968 to 1990 and 1991 to 2011. Depression was associated with an increased risk of premature death in every decade of the study for men, and starting in the 1990s for women.
The connection between depression and a shorter lifespan appeared strongest in the years following a depressive episode, leading the researchers to conclude that at least part of the risk might be reversed by effectively treating the mental illness.
In the current study, however, researchers found a link between depression and premature death even after accounting for things like obesity, smoking and drinking habits.
“It is known that depression is associated with an increased risk of death from heart disease,” said Dr. Ralph Stewart, a researcher at the University of Auckland in New Zealand who wasn’t involved in the study.”
“This study suggests that this increased risk of death extends to other causes of premature death and persists over decades,” Stewart said by email.
The researchers examined data from the Stirling County Study, which began in 1952 in Canada and is one of the first community-based studies on mental illness.
People were about 50 years old on average when they joined the study. Across the three time periods examined, researchers followed half of the participants for at least 19 years.
Researchers calculated life expectancies at age 25 for men and women with and without depression in each wave of the study.