Marriage is indeed a double-edged sword. It is good for mental health, but the flip side is that breakdown of marriage can cause severe depression.
A major international study across 15 countries and 34 493 people, shows getting married is positive for the mental health of both men and women, resulting in reduced risks of the likelihood of most mental disorders such as depression, anxiety and substance abuse.
By contrast, ending marriage through separation, divorce or being widowed, is associated with substantially increased risk of mental health disorders in both genders; particularly substance abuse for women and depression for men.
The wide-ranging study led by clinical psychologist Dr Kate Scott from the University of Otago Wellington is based on the WHO World Mental Health (WMH) surveys across developing and developed countries in the past decade. This world first study has been recently published in the UK journal Psychological Medicine
"There have been a number of international studies about the impact of marriage on the mental health of men and women and this is quite a controversial area because of the gender politics involved," says Dr Scott.
"But what makes this investigation unique and more robust is the sample is so large and across so many countries and the fact that we have data not only on depression, which has been much studied in the past, but also on anxiety and substance use disorders. In addition we were able to look at what happens to mental health in marriage, both in comparison with never getting married, and with ending marriage."
She says this allows much better contextualization of gender differences in the relationship between marital status and mental health than has been previously possible, and more sophisticated and detailed conclusions.
"One of the more important findings is that in recent years it has been asserted that marriage is better for men than for women in terms of mental health. This study does not agree with that position.
"We found that compared to never getting married, getting married is good for both men and women in terms of most mental health disorders."
However the study did find that men are less likely to become depressed in their first marriage than women. The study comments that this may be linked to traditional gender roles in the home. Dr Scott says significant gender role differences in the home can have an effect on mental health problems for married women.
Other studies based on the WMH surveys have shown that as gender roles have become less traditional over time, for example as women have worked more and become better educated, female depression tends to fall.
The other gender difference the study found is that getting married reduces risk of substance use disorders more for women than for men. Dr Scott says that this may be explained by the fact that women are usually the primary caregiver for young children. A number of international studies have shown that women's consumption of alcohol drops sharply when they become pregnant, and this restraint often continues into early child care.
At the same time ending marriage can increase the risk of mental health problems. Being previously married (i.e. being separated, divorced, widowed) is associated with increased risk of all mental health disorders in both men and women; particularly with depression in men and substance abuse (drugs and alcohol) in women.
"What our study points to is that the marital relationship offers a lot of mental health benefits for both men and women, and that the distress and disruption associated with ending marriage can make people vulnerable to developing mental disorders".
This study has been funded in New Zealand by the Ministry of Health, the Health Research Council and the Alcohol Advisory Council and carried out in association with the WHO, Harvard University and a number of other organizations internationally.