TUESDAY, Aug. 30, 2011 (HealthDay News) -- Nearly one in 10 women in the United States were married before the age of 18, a new study finds, and they could face a slightly higher risk of mental illness than other married women.
The research doesn't prove that so-called "child marriage" causes the increased risk of mental problems, the authors noted in the report published in the September issue of the journal Pediatrics.
Still, the findings are enough for its lead author to call for the end of child marriage in the United States.
"People should ask their politicians to adopt a law to ban it. It should be avoided by families, and teenagers willing to be married should delay marriage to adulthood," said Dr. Yann Le Strat, a psychiatrist at Louis-Mourier Hospital of Paris in Colombes, France, and an adjunct scientist at the Centre for Addiction and Mental Health in Toronto.
The study authors analyzed the results of a 2001-02 national survey designed to understand alcoholism and other conditions. A total of 24,575 women took part; the researchers focused on the 18,645 who were married or had been married.
The goal of the research was to understand how child marriage affects mental health in women, Le Strat explained. The researchers didn't look at how it might affect men.
"Studies in India and Africa have shown that child marriage is known to be associated with elevated risks of HIV transmission, unwanted pregnancy [and] death from childbirth," Le Strat said. "But surprisingly, the impact of child marriage on mental health had never been studied."
Of the nearly 19,000 women in the U.S. study, close to 9 percent had been married before the age of 18. They were more likely to be black or American Indian/Alaska Native, poorer and less educated than women who married later. They were also more likely to live in the South and in rural areas, and much more likely to be older than 65 (of whom about 13 percent were married as children) than aged 18 to 29 (of whom 3.4 percent married as children).
It's not clear why the women in the study chose to get married before adulthood, but pregnancy seems to have played a role. Almost half of the women who married as children were pregnant before adulthood, compared to just 3 percent of those who got married as adults, the authors noted.
The researchers found that slightly more women who'd married as children had suffered from mental disorders throughout their lifetimes, compared those who'd married as adults -- 53 vs. 49 percent, respectively
Specifically, major depressive disorder and nicotine dependence were the most common disorders among those married as children. There wasn't a big difference in terms of alcohol and illegal drug abuse, although those women married as children were much more likely to smoke cigarettes (the study classified tobacco addiction as a mental illness).
The study found that a higher risk of most mental disorders was common in women married as children. After adjusting for other factors, the researchers found that antisocial personality disorder was the most common disorder.
Nevertheless, it's difficult, and perhaps impossible, to know for sure if child marriage was behind a higher rate of mental illness, since other factors could be part of the picture.
"What we have here is only an indirect proof that child marriage may have negative effects on mental health," Le Strat stressed.
One alternative possibility is that something about these women could make them more likely to get married as children and to suffer from mental illness, the researchers asserted.
One fact is clear, though, said Linda J. Waite, a professor of sociology at the University of Chicago who studies marriage. Both men and women who marry young are more likely than other people to get divorced, she said, although Latino women are an exception to the rule.
Those higher divorce rates only disappear when people reach their mid-20s, she noted.
Why are marriages at younger ages so much more fragile? "One of the arguments is that testosterone levels in young men are too high," Waite said, "and they're related to all sorts of behaviors that make men bad husbands -- infidelity, abuse, difficulty getting along with people. Another argument is that young people are still sorting things out, getting settled and figuring out who they are. If you marry quite young, you don't know who you're marrying and that person will probably change."
As for the idea of limiting child marriage, Waite said that "the issue is when women are forced or pressured to marry early," such as in the South and in religious communities. "It's a real problem."
For more on mental illness, visit the U.S. National Library of Medicine.