Infant care is a challenge for any new mother, but it may be more of a challenge for women suffering from postnatal depression (PND).

PND is a common disorder that reportedly affects 10 to 20 percent of mothers. Onset occurs the first six weeks after giving birth, but can go present itself up to six months later. And women who suffer from the condition often display poorer parenting behaviors, according to the results of 33 studies analyzed in a recent review. "Compared to [non-depressed] controls, mothers with PND interact with their infants less sensitively, report feeling less competent, and less often choose recommended practical parenting strategies," writes Dr. Beth L Mah, leader of the research review and of the Mothers and Babies Research Centre, Hunter Medical research Institute, in the study.

According to the review, which examined all current evidence on PND and parenting, intervention programs may help to improve PND-parenting behaviors. Specifically, hormone therapy with oxytocin may be especially helpful, though more research is needed to determine its benefits and risks.

While the review examined studies that varied in terms of types of treatment and assessment of results, the general consensus was "psychological interventions for mothers with postnatal depression generally have positive effects on mother-infant interactions," according to Mah.

It's been suggested before that oxytocin could positively influence mothers with PND — in 13 studies, higher levels of the hormone were associated with parental behaviors more likely to promote bonding; mothers were more affectionate with their baby. So far, though, only four studies have examined the relationship between PND and oxytocin.

Two studies showed mothers with lower oxytocin levels were more likely to have depressive symptoms, and two other studies were randomized trials of oxytocin treatment: one in women with PND and one in women with dysfunctional labor. Somewhat unexpectedly, the latter studies showed oxytocin therapy increased depressive symptoms.

Overall, the review yielded divergent results. It seemed women with naturally higher oxytocin levels had better moods, but the administration of oxytocin resulted in a more negative mood.

"Oxytocin is potentially useful in improving parental behaviors of mothers with postnatal depression," the review states, "but more research is needed to establish its safety because of the uncertain impact of oxytocin upon maternal mood."

Dr. Mah highlighted the importance of future research, with priorities including better diagnostic tools for postnatal depression and higher-quality data on how PND affects parenting.

"Perhaps the most important challenge is to determine whether oxytocin could be used as an adjunctive treatment to improve mother-infant relationships that are affected by the mother’s postnatal depression or other psychiatric conditions." Mah concludes.

Source: Mah, B. Oxytocin, Postnatal Depression, and Parenting: A Systematic Review. Harvard Review of Psychiatry. 2016.