Several studies have shown the anti-depressant drug fluoxetine, sold as Prozac, has positive effects on the brains of mice with Down syndrome, and parents have shared anecdotal evidence that their children have also seen the benefits.
The University of Texas Southwestern Medical Center will start enrolling pregnant women whose fetuses have been diagnosed with Down syndrome in a trial to test whether the drug can prevent babies from being born with symptoms of the condition, or improve brain development to lessen the condition’s effects.
The study was crowdfunded by Paul Watson, a commercial pilot with a 14-year-old son who has Down syndrome. Watson told the MIT Technology Review he has been giving his son the drug for three years and said he is “doing pretty well cognitively.”
“Other parents whose kids are taking Prozac also feel that their kids are performing ahead of their peers with Down syndrome,” Watson said. “But we don’t really know. That’s why we want a drug trial. We wanted to legitimize it with a formal study.”
Down syndrome is caused by an extra copy of chromosome 21, which leads to fewer neurons in the brain, a smaller brain, and lower cognitive abilities. Many parents treat their children with Prozac after hearing about it anecdotally from other parents, though eight studies with mice, including one in 2014, show giving pregnant mice the drug caused their babies to be born with a normal number of neurons and no indications of Down syndrome.
“Since brain alterations in Down syndrome start to be present prenatally, the prenatal period represents an optimum window of opportunity for therapeutic interventions,” researchers in Italy and France wrote in a study on the importance of timing for drug treatment of the condition. “Importantly, recent studies clearly show that treatment during the prenatal period can rescue overall brain development and behavior and that this effect outlasts treatment cessation.
The study at the University of Texas is set to run about three years, starting with the recruitment of pregnant women who have already received a fetal diagnosis of Down syndrome. Women will be treated with Prozac during the remainder of their pregnancies, and their babies will receive the drug for their first two years of life.
Some concern has been raised about potential side effects of taking Prozac during pregnancy. A 2015 study found the drug can increase the risk for birth defects such as heart wall defects and irregular skull shape, but researchers in the Down syndrome study said the risk for side effects is small.
Matt Byerly, a psychiatry professor formerly at the University of Texas who helped design the trial, said testing the drug prenatally is important based on the previous studies with mice.
“What I found is that there are significant effects evident in the brain by the end of the second trimester and certainly by birth,” Byerly said. “I felt that to take advantage of what fluoxetine could potentially do, we needed to intervene before these changes occur.”