The psyche should also benefit from a bond for life. Researchers have now noticed a certain degree of protection against depression. However, this is by no means true for everyone.
With a marriage certificate, life becomes more relaxed. Anyone who is in a relationship crisis and tired of eternal quarrels may only smile mildly about it. Medically, however, there is much to suggest that marriage offers advantages.
It has long been described in numerous studies that lasting relationships are healthier than being single and that a marriage certificate could have a positive effect on various complaints, from high blood pressure and elevated cholesterol to blood sugar in diabetes (1). Spouses even have a better prognosis for serious diseases such as cancer (2).
Now a study of 1600 twins shows that marriage also affects depressive symptoms. Other researchers have already discovered that there is a connection between marriage, stress, and depression. Married people, for example, often report less stress and depressive symptoms than those who are divorced or have never married. Researchers led by Christopher Beam (3) now wanted to know whether men or women benefit equally and whether there are any genetic explanations. The variant of a gene that regulates the serotonin balance (5-HTTLPR), for example, is already known to increase both the perception of stress and the risk of depressive symptoms in carriers.
For their study, the scientists examined only twins. Since they not only grow up in the same environment in the first years of their lives but are also genetically similar to either almost 100 (identical twins) or 50 percent (fraternal twins), they can provide important answers to the researchers’ questions. If, for example, the identical twins differ from the fraternal twins in a trait studied, this indicates a strong genetic influence.
The researchers compared married twins with divorced twins and with twins who had never married. About half of the twins were married, while about nine percent said they were divorced. In their analysis, the researchers found evidence that marriage reduces the influence of genes on depressive symptoms. According to the theory, the presence of a spouse reduces emotional reactions to stress. However, to the surprise of the researchers, this was particularly true for women. The heritability of depressive symptoms caused by stress was smaller in women than in male twins. A divorce caused the opposite effect.
It is possible that women with such a predisposition benefit more from marriage than men. But what about other factors that affect the risk of depression? According to the data of these researchers, marriage did not diminish the effect of environmental factors that lead to depressive symptoms through stress. But why is that? The authors suggest that marriage reduces biological susceptibility to stress. The daily problems in a marriage or the additional tasks in the family could, however, favor depressive problems, which would not have been apparent so quickly in singles. It is also known that unmarried women usually have access to a larger social network. So the ultimate impact of marriage on women seems to depend heavily on how much support they get from their partner. But this also needs to be checked.
This is part 32 of a series covering twin health provided by Paul Enck from the Tübingen University Hospital and science writer Nicole Simon. Further studies in twin research can be found at TwinHealth website. Translation was done with the assistance of DeepL translator.
- Martínez ME, Anderson K, Murphy JD, Hurley S, Canchola AJ, Keegan TH, et al. Differences in marital status and mortality by race/ethnicity and nativity among California cancer patients. Cancer. 2016 May 15;122(10):1570-8.
- Beam CR, Dinescu D, Emery R, Turkheimer E. A Twin Study on Perceived Stress, Depressive Symptoms, and Marriage. J Health Soc Behav. 2017 Mar;58(1):37-53.