Nearly 2 million people in the United States and many more in the world are impacted by divorce each year. There have been a variety of studies that have hinted that divorce may be linked to the increased chance of an early death, but overall the evidence has been mixed.
David Sbarra, Rita Law, and Robert Portley from the University of Arizona recently published a study to summarize the evidence on the link between divorce and early death. They gathered data from 32 studies involving more than 6.5 million people in 11 countries that included 755,000 divorces and 160,000 deaths.
In general, the researchers found that adults who were divorced were 23% more likely to die younger than their married counterparts. Men had almost twice as high a risk of early death compared to women. People younger than 65 years of age were more at risk following divorce than older people. This pattern was consistent regardless of what country people lived in.
The next question asked by the researchers was whether divorce "caused" death. Now this may seem obvious, but even with prospective data, it is not always the case that correlation mean causation. One important consideration is a selection effect that accounts for both divorce and death. The authors write, "social selection holds that some people possess characteristics that increase risk for both separation/divorce and poor health outcomes. Hostility, depression and substance abuse are just a few examples of the many processes that can increase the likelihood of future divorce...and are unique predictors of early death..." In other words, some common characteristic is causing both divorce and death. These data do not allow us to test the selection hypothesis and therefore, we cannot rule out this selection effect.
The authors conclude their study with a thoughtful analysis of the mechanisms through which divorce might lead to early death. Their first idea is that because divorce often reduces the financial status of both husbands and wives, this may impact health. In general, we know that individuals with lower economic means are more at-risk of health problems. Another consequence of divorce is that people's social ties are disrupted. Divorced men and women are less likely to maintain ties to neighbors, churches, clubs and so forth. Again we know that strong social relationships benefit health and well-being.
Another possible way in which divorce influences well-being is through health habits. There is some strong evidence that following divorce, women in particular are more likely to resume smoking. There is some evidence to suggest that eating habits and sleeping patterns are also disrupted.
Finally, there is the possibility that the stress of divorce disrupts biological functions which puts people more at risk. In a previous study, Sbarra demonstrated that divorced people who reported more difficulty handling their emotions following divorce had higher blood pressure. This finding suggests that stress-related difficulties brought on by divorce may contribute to poorer health.
Despite the general finding that divorce increases the risk of early death, the authors urge caution in the interpretation of these findings. They note that many people remarry and this was not taken into account in this study. They also suggest that until more work is done that controls for selection factors and includes the various mechanisms, it would be unwise to base too much on the findings of this one study. Although the findings from this study remain open to further exploration, the analysis by these authors is a welcome reminder of the complexities of understanding the effects of divorce.