Both reports, published in the Jan. 16 online edition of BMJ, find that talk therapy and caring communication can help new mothers deal with their depression without the need for antidepressants.

"Approximately 13 percent of women will experience postpartum depression," said Cindy-Lee Dennis, an associate professor at the University of Toronto and lead researcher on one of the studies. "There are significant consequences of this condition for the mother, the infant and the family."

Once a woman has had postpartum depression, she is more likely to have future bouts of depression, Dennis said, and that puts infants and children at risk for cognitive, behavioral and social problems.

"For the family, often you see with postpartum depression [that] the partner can also experience depression," she said. "We know that this leads to marital conflict and potentially divorce."

People need to understand what the signs and symptoms of postpartum depression are and seek help, Dennis said.

Jane Morrell, research leader at the University of Huddersfield in the U.K. and an author of the other study, agreed.

"Women need to be encouraged not to bottle up their feelings and talk to other people, including their partners and health-care professionals," she said.

Morrell and her colleagues randomly assigned 418 mothers with postpartum depression to have one-hour weekly visits for up to eight weeks from a health-care worker who delivered counseling, cognitive behavioral therapy (sometimes called talk therapy) or traditional postnatal care.

The researchers found that at six months and 12 months, mothers who had received counseling or therapy had greater reductions in depression than did mothers who had received usual care.

In fact, mothers who were depressed at six weeks were 40 percent less likely to be depressed at six months if they had gotten counseling or therapy, the researchers found.

Morrell's team also found that this method of dealing with depression was cost-effective. "There is no stronger evidence of an intervention to help women who have depression postnatally," she said.

In the other report, Dennis's group studied the benefit of telephone support to prevent postpartum depression in high-risk women.

In this case, 701 women who were at high risk of postpartum depression were randomly assigned to standard postnatal care or to standard care plus telephone support from women who had experienced postpartum depression themselves.

The researchers found that women who received peer support were 50 percent less likely to develop postpartum depression 12 weeks after giving birth than were women who didn't get the support. In addition, more than 80 percent of the women who got telephone support said they would recommend this type of support to a friend.

For any new mother with symptoms of depression, "providing her with telephone-based support from another mother who has experienced postpartum depression and has recovered, and has been trained, might be able to prevent the development of postpartum depression," Dennis said.

William S. Meyer, an associate clinical professor in the departments of psychiatry and obstetrics/gynecology at Duke University Medical Center, said that both reports highlight what people who work with women suffering postpartum depression see.

"These papers provide further support for what those of us who work in the field learn every single day," Meyer said. "The support of new mothers is the single best deterrent of postpartum depression."

Study upon study demonstrates that the most severe risk factor for postpartum depression is the mother who does not feel supported, Meyer said. "Is it any wonder then that providing support from mothers, even fairly minimal support, even by modestly trained lay people, would not mitigate the incidence and severity of depression in the postpartum period?" he asked.

But Dr. Kimberly Yonkers, an associate professor of psychiatry at Yale University School of Medicine and an expert in treating postpartum depression, said that for many women with severe depression, these treatments aren't enough.

"Modest forms of psychotherapy are helpful for mild to modest forms of depression," Yonkers said. "These therapies can be administered by trained paraprofessionals or lay personnel. These interventions decrease the burden of depressive symptoms in postpartum women."

"But there are still substantial numbers of women who seem to require stepped-up treatment," she said.

References

Dennis CL, Hodnett E, Kenton L, Weston J, Zupancic J, Stewart DE, Kiss A. Effect of peer support on prevention of postnatal depression among high risk women: multisite randomised controlled trial. BMJ. 2009 Jan 15;338:a3064. doi: 10.1136/bmj.a3064.