Maternal depression and a common class of antidepressants can alter a crucial period of language development in babies, according to a new study by researchers at the University of British Columbia, Harvard University and the Child & Family Research Institute (CFRI) at BC Children's Hospital.
Published today in the Proceedings of the National Academy of Sciences, the study finds that treatment of maternal depression with serotonin reuptake inhibitors (SRIs) can accelerate babies' ability to attune to the sounds and sights of their native language, while maternal depression untreated by SRIs may prolong the period of tuning.
"This study is among the first to show how maternal depression and its treatment can change the timing of language development in babies," says Prof. Janet Werker of UBC's Dept. of Psychology, the study's senior author. "At this point, we do not know if accelerating or delaying these milestones in development has lasting consequences on later language acquisition, or if alternate developmental pathways exist. We aim to explore these and other important questions in future studies."
The study followed three groups of mothers - one being treated for depression with SRIs, one with depression not taking antidepressants and one with no symptoms of depression. By measuring changes in heart rate and eye movement to sounds and video images of native and non-native languages, the researchers calculated the language development of babies at three intervals, including six and 10 months of age. Researchers also studied how the heart rates of unborn babies responded to languages at the age of 36 weeks in the uterus.
"The findings highlight the importance of environmental factors on infant development and put us in a better position to support not only optimal language development in children but also maternal well-being," says Werker, who adds that treatment of maternal depression is crucial. "We also hope to explore more classes of antidepressants to determine if they have similar or different impacts on early childhood development."
High resolution photos of Werker (reading to children) and co-author Tim Oberlander are available upon request.