This study examined the effects of maternal sertraline treatment on serotonin transport in 14 breastfeeding mother-infant pairs. The researchers found that mothers receiving sertraline experienced substantial declines in platelet serotonin levels, indicating blockade of serotonin transporters. In contrast, the infants exposed to sertraline through breastfeeding showed little to no changes in platelet serotonin levels, suggesting their peripheral and central serotonin transport was not appreciably affected. The results indicate that mothers can safely take sertraline while breastfeeding without negatively impacting serotonin transport in their infants.