According to a new study, Danish scientists have calculated the risk of death from all causes for more than seven million people with different psychiatric diagnoses. They found that in such patients the risk of death is two to seven times higher than in average Danes, and this dependence is true for almost all types of mental disorders and any causes of death.
Mental disorders are far from always associated with physiological disorders, so it is still not known for certain whether they shorten life, and if so, how much. The easiest way to find out is to compare the life expectancy of people with and without mental illness. Such calculations have already been carried out before: it turned out that for women, such diseases shorten their lives by about 12 years, and for men by almost 16.
However, this method does not take into account the age at which people develop the disorder. Therefore, a more accurate parameter appeared – the number of years lost. Researchers note the age of onset of the disease, record the expected life expectancy for people of this age, and then subtract from it the number of actually lived years. The data obtained in this way are “softer”: they promise men a reduction in life by about 10 years and women by 7.
A group of scientists led by Professor Thomas Laursen from Aarhus University decided to make an even more accurate calculation and find out the number of years lost for people with different diagnoses, as well as compare mortality from different causes.
Researchers analyzed mortality for 7369926 patients with mental disorders who lived in Denmark between 1995 and 2015. It turned out to be twice as high as the population average: 28.7 people a year versus 12.95. This dependence was true for any diagnosis and any cause of death in both women and men, although the latter died on average more often.
As expected, mortality increased with age. However, the difference in mortality in patients with diagnoses and healthy people varied unevenly: the peak of differences occurred at 33 years – at this age, people with disorders had a seven-fold higher risk of death than normal. And then the differences were smoothed out and by the age of 80, the difference was two-fold.
According to scientists, the number of years lost was similar to the calculations of their predecessors: about 10 for men and 7 for women. On average, patients lost more years of life because of their psychiatric diagnoses than their peers due to physiological problems. There was only one exception to this dependence: men with any type of mental disorder lost fewer years than men with cancer. However, one can hardly talk about some kind of “protective property” of mental disorders here – rather, the fact is that healthy mental men more often die from cancer.
Thus, researchers have confirmed that a wide variety of mental disorders shorten years of life and increase the risk of dying from any cause. However, for different diagnoses, these risks turned out to be different – and this can be used by doctors in the future to better understand what might threaten their patients.