Some parents of children with Down's syndrome are giving them Prozac after tests showed that brain chemistry-altering drugs could boost intelligence.

Several drugs have been shown to improve memory and learning in the mouse version of the condition.

As a result, some families have started to give their children drugs such as Prozac - usually used to treat depression - despite the need for more studies on humans to be carried out to make sure it is safe.

Mara Dierssen, from the Centre for Genomic Regulation in Barcelona, Spain, said the evidence so far showed promise, but warned "more studies have to be done first".

Down's syndrome occurs when a fertilised egg has an extra chromosome. It affects every cell in a baby's body and increases the risk of heart disease and early onset dementia.


People with the genetic condition generally have an IQ around 50 points lower than the average.

Scientists have found that reducing levels of a molecule called KKCC1 in mice makes them sprout more connections between neurons.

A team from the Institute of Technology in Genoa used a drug called bumetanide to block the molecule.

Prozac has also been shown to boost memory in mice with the equivalent of Down's syndrome.

Carol Tamminga from Texas University said some parents have decided to give such drugs to their children based on the early evidence, while some women are choosing to take Prozac while pregnant with a baby that has Down's syndrome.

"Those who are potentially interested in doing this are doing it anyway," she said.

Disabled activist Tom Shakespeare told the New Scientist that more evidence about such drugs' safety was needed.

He said: "There's a lot of hype. We have seen with autism that parents will do anything to enhance the cognitive ability of their child."