They found that treatment of maternal depression with a class of anti-depressants, known as selective serotonin re-uptake inhibitors (SSRIs), can speed up babies' ability to attune to the sounds and sights of their native language.
Such depression if untreated by SSRIs may prolong the period of tuning, according to researcher at the University of British Columbia, Harvard University and the Child & Family Research Institute (CFRI).
SSRIs are a class of anti-depressants that work by blocking the reabsorption of serotonin in the brain, raising their levels.
"This study is among the first to show how maternal depression and its treatment can change the timing of language development in babies," says senior study author Janet Werker, professor of psychology at the University of British Columbia.
The study followed three groups of mothers -- one being treated for depression with SRIs, one with depression not taking anti-depressants and one with no symptoms of depression, according to a British Columbia statement.
Researchers calculated the language development of babies at three intervals, including six and 10 months of age by measuring changes in heart rate and eye movement to sounds and video images of native and non-native languages,
They studied how the heart rates of unborn babies responded to languages at the age of 36 weeks in the uterus.
"We also hope to explore more classes of anti-depressants to determine if they have similar or different impacts on early childhood development," said Werker in a statement.
"These findings once again remind us that poor mental health during pregnancy is a major public health issue for mothers and their infants," co-author Tim Oberlander, professor of developmental paediatrics at UBC, said.
The study findings are published in the journal Proceedings of the National Academy of Sciences.
