Sleeping problems were the most frequent health problem in the study, affecting 22 per cent of children living only with one parent and 19 per cent of kids who lived mostly with one parent. (iStock)

The constant moving back and forth between two homes may not harm the mental health of kids in joint-custody arrangements as much as some experts feared, according to a new study.

Researchers in Sweden found that while children whose parents don't live together have more psychosomatic health problems than kids in nuclear families, the kids in joint custody arrangements had fewer issues than those living with a single parent.

"We have looked at quality of life, health, and mental health and it seems like both children and parents fare better when children are taken care of alternately by the parents after the separation," lead study author Malin Bergstrom, of the Center for Health Equity Studies at Stockholm University and the Karolinska Institute, said by email.

Bergstrom and her colleagues analyzed data from a survey of about 150,000 sixth and ninth graders in Sweden to see how their family living arrangements might influence the development of psychosomatic conditions, which occur when mental factors lead to physical symptoms despite a lack of underlying disease.

Past research has established that children whose parents are separated are at higher risk for emotional problems and social maladjustments than those in two-parent households, the study team writes in the Journal of Epidemiology and Community Health. Some experts have suspected that "living in two worlds," and even the logistics of moving back and forth between two homes may cause stress for kids in joint custody arrangements, they note.

Bergstrom and colleagues reviewed records from a national classroom survey taken in 2009 and found that 69 percent of the 147,839 children lived with both parents in so-called nuclear families, while 8 percent lived mostly with one parent and 13 percent lived only with one parent.

Most children living with one parent lived with their mothers, while about one sixth of them lived with their fathers.

Children were more likely to live with a single parent in ninth grade than in sixth grade.

Overall, children who lived only with one parent reported the most psychosomatic health problems, and more of them also said that they experienced these issues constantly or frequently.

Sleeping problems were the most frequent, affecting 22 per cent of children living only with one parent and 19 per cent of kids who lived mostly with one parent. Just 14 per cent of children in joint custody had sleep problems, as did 13 per cent of kids in nuclear families.

Amicable separations

Headaches followed a similar trend, afflicting 19 per cent of children living with only one parent, 14 per cent of kids in joint custody and 12 per cent of children in nuclear families.

One limitation of the study, the researchers acknowledge, is its lack of data on families' socioeconomic status or the level of conflict or cooperation in the relationship between parents. The study also lacked details on when the children's parents separated.

Because psychosomatic health problems can be related to stress, the researchers had expected to see more symptoms among children in joint custody, Bergstrom said.

"It was surprising that children who move frequently and have two homes experience less stress than those in one stable setting," she said.

But it's possible that families with joint custody arrangements might involve parents who separated more amicably, said Philip Cohen, a sociology professor at the University of Maryland in College Park.

"The joint custody arrangement may be an indicator of a less acrimonious relationship or breakup between the parents, which we would expect to have fewer negative consequences for the children in subsequent years than a more conflict filled family life," Cohen, who wasn't involved in the study, said by email.

At the same time, the findings from Sweden — where unmarried or separated parents are quite normal and there is a relatively generous social safety net — might not apply to other countries such as the U.S. where single parenthood can be associated with lower economic status and lack of social support in terms of childcare, healthcare and housing, he said.