NEW YORK — Healthy older adults and those with mild cognitive impairment who received a drug that spurs hormones important to normal brain function had improved concentration, decision-making skills and verbal memory, a study found.

The healthy adults given Theratechnologies' Egrifta, a drug that spurs the release of human growth hormone, had executive-function improvements that were more than 100 percent greater than those in a placebo group, while verbal memory improvements were 50 percent greater, said Laura Baker, lead author of Monday's study in the Archives of Neurology.

The growth hormone is released from the brain and stimulates others that are important for normal brain function, Baker said. The body's hormones decline as people age.

Monday's findings offer a possible new treatment for the aging brain of healthy older adults as well as those with mild cognitive impairment, who are at an increased risk of developing Alzheimer's disease, she said.

"Very few other strategies to improve cognition in these adults have demonstrated success," Baker, an associate professor of psychiatry and behavioral sciences at the University of Washington School of Medicine in Seattle, said Monday in an email. "This strategy of supplementing one hormone that can then impact several other hormones represents a new approach that targets an entire biological system to restore function to that of a younger adult."

More studies are needed to look at the safety and efficacy of long-term use on cognitive function in older adults before doctors can start prescribing it as a treatment, she said.

About 5.4 million Americans have Alzheimer's, the most common type of dementia, and by 2050 that number is expected to grow to as many as 16 million, according to the Alzheimer's Association. The number of people worldwide with the condition is expected to swell to 115 million by 2050.

Egrifta, marketed in the United States by Merck of Darmstadt, Germany, is used to reduce excess abdominal fat in HIV patients.

The study was supported by the National Institutes of Health and the Department of Veterans Affairs.