Women who live in large urban areas are more likely to develop postnatal depression than their peers in more rural areas, according to new research from Canada.
That's largely because risk factors for postnatal depression – such as having low levels of social support, and being born in a different country – are more common among women living in urban areas, according to researchers from Toronto’s Women's College Research Institute.
Many women may feel moody, anxious and tearful in the first couple of weeks after having a baby, thanks to hormonal shifts, lack of sleep and new-parent stress. When these symptoms get better on their own in a few days, they're known as "the baby blues".
But between 10 and 15 per cent of women develop persistent, serious depression during the first year after their baby's birth.
The team, lead by Dr Simone Vigod, looked at data from a 2006 survey of 6126 new mothers.
About 7.5 per cent of all women surveyed reported depression symptoms that put them above the cut-off for postnatal depression, according to findings published in the medical journal CMAJ.
Just over 9 per cent of women living in cities of 500,000 people or more had postnatal depression, versus 6 per cent of women living in rural areas (described as towns of less than 1000 people).
Between five and 7 per cent of women living in suburban areas reported being depressed after giving birth.
"That's a pretty big difference at the population level," Dr Vigod told Reuters Health.
"It's not the air that you breathe in an urban area that makes you depressed - it's actually that the population characteristics of people living there are different.”
Specifically, Dr Vigod and her colleagues found that urban women were less likely to report having adequate social support during pregnancy and after the birth, and were also less likely to say they were in excellent or very good health. By taking these and other differences into account, the researchers were able to explain the higher depression risk among the urban women.
Women in the study were surveyed at five to 14 months after their child’s birth, Dr Vigod noted, so they weren't just suffering from a brief bout of baby blues. Ideally, she added, doctors would be able to identify at-risk women during pregnancy, in order to prevent them from becoming depressed after delivery.
"Perhaps social support should be assessed a little bit more explicitly than it is now," she said. "For women at risk it's such a strong variable. Perhaps it's worth the cost of trying to increase social support systems."
Doctors could also go beyond simply asking pregnant women about their marital status, she added, and ask them in more detail about who will be on hand for them once the baby is born, and what the nature of that support will be.
Women in the study who were born outside Canada may also face language and cultural barriers to accessing care during pregnancy, Dr Vigod pointed out.
"We live in a really multicultural society, people from all over the world live in Canada, and maybe there has to be special attention to the cultural context in order to really target depression," she said.
Visit beyondblue.org.au to learn more about postnatal depression, how to get help, and how to recognise PND in others.