Women who do not breastfeed their babies are at a higher risk of postnatal depression, according to a major study of more than 10,000 mothers.
The study revealed a complex relationships between mothers' intentions and their ability to breastfeed, and their risk of developing depression after their child's birth - a condition which affects around one in 10 women.
Mothers who breastfed their baby were 50 per cent less likely to suffer postnatal depression than those who chose not to. However, the women most at risk of developing the condition were those who had planned to breastfeed their babies but were unable to.
This group was twice as likely to suffer depression than mothers who simply chose not to breastfeed.
The researchers said that more support needed to be given, both to encourage mothers to breastfeed, and also support those women who find they are unable to.
"Breastfeeding has well established benefits to babies, in terms of their physical health and cognitive development; our study shows that it also benefits the mental health of mothers," said Cambridge University's Dr Maria Iacovou, who coauthored the study. "In fact, the effects on mothers' mental health are also likely to have an impact on babies, since maternal depression has previously been shown to have negative effects on many aspects of children's development."
The study is published in the journal Maternal and Child Health today.
According to Department of Health figures, almost three quarters of UK mothers began breastfeeding their babies at birth in 2012/13, but only 47 per cent continued breastfeeding until the baby was between six and eight weeks old.
Rosemary Dodds, senior policy adviser at the National Childbirth Trust said: "Mothers often experience pressures after the birth such as pain, shortage of sleep and anxiety. Breastfeeding can help to relax mothers and reduce stress, so it might play a part in preventing mental health issues developing. We welcome further research into this subject as perinatal mental health is a huge issue for many mothers."