A new study published in Nature Communications suggests that antidepressant use can impact early post-natal brain development.
The study, led by researchers at the University of Colorado Anschutz Medical Campus, focused on the effect of fluoxetine, commonly used in medications such as Prozac and Sarafem for treating depression and perinatal depression, on the developing prefrontal cortex of mice.
Since fluoxetine works by increasing the levels of serotonin in the brain, the researchers looked at the impact serotonin has on prefrontal cortex development.
“While it is known that serotonin plays a role in the brain development, the mechanisms responsible for this influence, specifically in the prefrontal cortex, have been unclear, ” said lead author Won Chan Oh, PhD, assistant professor in the Department of Pharmacology at CU Anschutz.
Oh and his student, Roberto Ogelman, a neuroscience PhD candidate, found serotonin directly influences nascent and immature excitatory synaptic connections in the prefrontal cortex, which if disrupted or dysregulated during early development can contribute to various mental health disorders. 
Oh and Ogelman in their lab at the CU Anschutz Medical Campus
“Our research uncovers the specific processes at the synaptic level that explain how serotonin contributes to the development of this important brain region during early-life fluoxetine exposure,” adds Oh. “We are the first to provide experimental evidence of the direct impact of serotonin on the developing prefrontal cortex in mice."
To study the effect, the researchers looked at the impact of deficiency and surplus of serotonin on brain development in mice. They discovered that serotonin is not just involved in overall brain function but also has a specific role in influencing how individual connections between neurons change and adapt, contributing to the brain's ability to learn and adjust.
“Understanding this correlation has the potential to help with early intervention and the development of new therapeutics for neurodevelopmental disorders involving serotonin dysregulation,” said Oh.
The researchers plan to continue studying the impact of fluoxetine, next examining its impact on a developing brain later in life.
