• By Laura Whybra
  • Posted on Wednesday 18th September, 2013

Extra doses of hormone make depressed mothers’ emotions more extreme

strong>When new mothers are depressed, the impact on their kids can be lasting. Giving depressed mothers oxytocin, a hormone involved in mother-infant bonding, sounds like a promising treatment. But a new study raises warning flags.Oxytocin plays a major role in childbirth and breastfeeding. It is also involved in processes involving bonding and trust. So a team of Australian and Dutch researchers wanted to know whether extra doses of oxytocin could help mothers with postnatal depression to improve the way they bond with their babies. While some of the results looked promising, others raised serious concerns about side effects. Mothers were alternatively given oxytocin or a placebo via a nasal spray. After they took the drug, they described their relationship with their babies in a more positive way. But at the same time, they reported sadder moods and tended to open the conversation by describing their babies as more difficult. It seems that what the oxytocin did was to increase the salience of participants’ emotional states, for better and for worse.Why mix oxytocin and depression?Mothers with depression are more likely to be self-critical and emotionally over-involved with their children, which in turn can affect the relationship they form with their babies. More unstable moods and greater sadness also alter both their parenting and relations with other family members. Oxytocin has been extensively researched over the last few years. But although research has established that this hormone is linked to mother-infant bonding, no one had yet tested whether extra doses of oxytocin could provide beneficial effects for mothers with postnatal depression.The research team recruited 25 mothers diagnosed with postnatal depression, with babies between three and 12 months. The mothers received two nasal spray treatments a week apart. Half were randomly assigned to get the oxytocin first and placebo second; the other half received a placebo first and oxytocin second. A nasal spray of oxytocin gives a two-hour boost to hormone levels. On each of the two visits, after receiving the treatment or placebo, mothers were videotaped interacting with their babies, rated their mood, and described their babies and their relationship with them. Promise and riskOxytocin had effects, but not entirely good ones. It made mothers sadder. Although researchers had expected mothers who took oxytocin to describe their babies in more positive terms, just the opposite happened; after receiving the drug, mothers were more likely to be critical (saying that their babies were poor sleepers, for instance). On the positive side, mothers did report a better quality of relationship with their infants after they received the oxytocin than they did after receiving the placebo: they were more likely to talk about how close they felt with their babies. Overall, their emotional responses seemed stronger while taking the oxytocin – both more strongly positive and more strongly negative. The authors speculate that the mothers’ reports may have been complicated by how much they trusted the researchers. Some studies have found that oxytocin helps subjects trust an interviewer more; some show just the opposite. This research suggests new directions in the postnatal depression field. Is there any way to draw on the positive effects of oxytocin without tapping the negative ones? How could the side-effects of the hormone be handled in a clinical setting? *********Reference: Mah, B.L., Van IJzendoorn, M.H., Smith, R., Bakermans-Kranenburg, M.J. (2013). Oxytocin in postnatally depressed mothers: Its influence on mood and expressed emotion. Progress in Neuro-Psychopharmacology & Biological Psychiatry 40, 267–272.

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