Two studies are making a splash this week with findings linking depression to heart disease — a risk correlation indicated in a growing list of studies from the past decade.
The first of the latest two, presented at the American Psychosomatic Society meeting this week in Chicago, explored the depression-heart disease link from the standpoint of genetic influence by following 1200 middle-aged men, but with a twist — they were all twins.
Using twins in the study allowed researchers to tease apart the genetic from the non-genetic influences on heart disease (identical twins share 100% of their genes, fraternal twins share 50%; the study included both), and the results put the spotlight squarely on non-genetic influences: according to the study, depression almost doubles the risk of developing heart disease over a 12-year period.
The second study (also presented at the APS meeting) investigated whether marital stress increases the risk of heart disease via depression. 276 couples married for at least 20 years completed self-reporting questionnaires on the quality of their marriages, and were sent to labs for a range of blood tests to screen for pre-existing heart disease and determine disposition for developing heart disease.
The results: women in strained marriages were more depressed and had more metabolic syndrome symptoms (precursors for heart disease). Men in strained marriages, on the other hand, were also depressed, but did not show more metabolic syndrome symptoms. The results suggest that men and women are both psycho-emotionally affected by marital stress, but women more often evidence the effects physiologically as well.
Moral of the story: depression left untreated can break your heart.
It’s worth noting, however, that there have also been previous studies, like this one in JAMA, that do not bear out the depression-heart disease link. Because depression often accompanies inactivity and an unhealthy diet, it’s not easy to determine whether it’s depression or associated behaviors–or both–that bring on the heartache.
Link to LiveScience article on marriage and depression
Link to story on twins study