An antibiotic used to treat teen acne also helps increase attention spans and communication while decreasing anxiety in people with fragile X syndrome, preliminary research suggests.

In a paper published in the September issue of the American Journal of Intellectual and Developmental Disabilities, researchers report that parents observed improvements while their children were taking the drug minocycline. The results were promising enough to prompt the National Fragile X Foundation to fund a placebo-controlled clinical trial.

The initial feedback comes from parents of a group of 53 people with fragile X ages 4 months to 25 years who were prescribed the medication by researchers at the University of California, Davis MIND Institute, some for just a couple of weeks and others for as long as 20 months. In at least half of cases, parents said that their children’s use of language or attention spans improved while on the drug. What’s more, 30 percent reported a decrease in anxiety.

On average, parents reported seeing results after about three months on the medication. However, three children did drop out of the study because of side effects and several participants experienced upset stomach.

A genetic disorder, fragile X is the most common form of inherited intellectual disability. It affects about one in 3,600 males and one in 4,000 females in the United States.

Researchers are now moving forward with a two-year, $100,000 pilot study of minocycline in kids with fragile X ages 4 to 16.