Antidepressants Like Prozac, Sarafem Can Affect Fetal Brain Development During Pregnancy: Study

A chemical used in these antidepressants not only crosses the placenta but also passes into breast milk, the study found.

NEW YORK - JANUARY 4: Two bottles of Prozac are seen on a pharmacy shelf January 4, 2005 in New York City. Photo by Stephen Chernin/Getty Images

The use of antidepressants during pregnancy could affect brain development of the fetus and potentially lead to mental health disorders later in life, according to a recent study.

The peer-reviewed study, published in Nature Communications journal on Feb. 16, looked into the effects of fluoxetine, an antidepressant, on a fetus when taken by pregnant women. Fluoxetine is commonly used in drugs like Sarafem and Prozac to treat perinatal depression, a mood disorder that occurs during pregnancy and following childbirth. Fluoxetine raises serotonin levels in the brain, a chemical produced by nerve cells, and is considered a natural mood stabilizer.

Researchers analyzed how serotonin impacts prefrontal cortex development in a fetus, a region of the brain that modulates higher-order cognitive processes. To do so, they looked at how a deficiency or a surplus of serotonin affects brain development in mice.

The study found that serotonin influences how individual connections between neurons adapt and change, thus playing a role in the brain’s ability to learn and adjust.

Serotonin had a direct influence on some of the nascent and immature synaptic connections in the prefrontal cortex. When this influence is disrupted or dysregulated during the early development of a fetus, it can lead to various mental health disorders, the study found.

“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. The prefrontal cortex, the most evolved brain region, plays a central role in highest-order cognition, which is why we focused our study on finding the answer from this brain area,” said lead author Won Chan Oh.

Mr. Won pointed out that they were the first to provide “experimental evidence” of serotonin having a direct impact on prefrontal cortex development when fluoxetine is taken during pregnancy. “Fluoxetine not only crosses the placenta but also passes into breast milk,” he said.

“Understanding this correlation has the potential to help with early intervention and the development of new therapeutics for neurodevelopmental disorders involving serotonin dysregulation,” he stated.

Researchers proposed that healthcare professionals should be involved in decision-making when it comes to pregnant women, discussing the benefits and side effects of antidepressants as well as potential non-pharmacological interventions to deal with depression.

The research was funded by multiple sources, including the Brain and Behavior Research Foundation, Brain Research Foundation, CSU/CU-Pilot Collaboration Award, and the Ludeman Family Center Research Award. The authors declared they have no competing interests in the study.

Serotonin and Depression

The use of serotonin to treat depression is driven by the theory that the condition is caused due to a chemical imbalance, specifically that a deficit in brain serotonin is responsible for the illness.

However, a July 2022 paper questioned this assumption. It reviewed multiple studies on serotonin and concluded that “there is no convincing evidence that depression is associated with, or caused by lower serotonin concentrations or activity.”

“Most studies found no evidence of reduced serotonin activity in people with depression compared to people without,” it said.

The paper pointed out that the chemical imbalance theory of depression is still being put forward by professionals. The public now “widely believes” that depression is the result of serotonin or other chemical abnormalities.

“This belief shapes how people understand their moods, leading to a pessimistic outlook on the outcome of depression and negative expectancies about the possibility of self-regulation of mood,” the paper said.

“The idea that depression is the result of a chemical imbalance also influences decisions about whether to take or continue antidepressant medication and may discourage people from discontinuing treatment, potentially leading to lifelong dependence on these drugs,” it warned.

In an August 2022 post at the Brownstone Institute, Joanna Moncrieff, an author of the paper, revealed that the research had triggered several responses from psychiatric experts who “desperately tried to put the genie back in the bottle.”

Some experts claim there are many trials showing that these antidepressants work. However, Ms. Moncrieff points out that such claims were based on randomized trials showing that “antidepressants are marginally better than a placebo at reducing depression scores over a few weeks.”

“The difference is so small that it is not clear it is even noticeable, and there is evidence that it may be explained by artefacts of the design of the studies rather than the effects of the drugs,” she wrote.

Some argue that the mechanism of how antidepressants work is irrelevant. They insisted that since it is not exactly known how every medical drug functions, the mechanism of antidepressants should also not be an issue.

Ms. Moncrieff said that such arguments are based on “a deep-seated assumption” about depression and the actions of antidepressants.

“These psychiatrists assume that depression must be the result of some specific biological processes that we will eventually be able to identify and that antidepressants must work by targeting these,” she wrote. “These assumptions are neither supported nor helpful.”

Rather than resort to chemical antidepressants, there are natural solutions available for depression. For instance, a nutritious diet, especially whole foods, has been found to contribute to good mood. Some researchers have also found that certain combinations of bacteria in the gut can affect mood.

Spending some time in sunshine and nature has been shown to ease depression. People who have meaningful relationships and engage in helping others may also see their depression recede.