A paper in the journal Nature, written by seven authors from the United States and Britain, backs the use of brain-enhancing drugs like Ritalin, Adderall and Provigil to boost performance, if people using them are healthy.

These drugs are usually prescribed for hyperactive kids or memory-impaired older people, as they can help people focus their attention and handle information in their heads. But college students are already illegally taking prescription stimulants like Ritalin to help them study. Therefore, scientists fear the demand for such drugs is likely to grow among middle-aged people as well, as they want youthful memory powers to help them answer multitasking jobs.

“They are abused for a variety of reasons including the fact that people want to get high, but there is the realization that they are being increasingly utilized to improve cognitive performance,” Dr. Nora Volkow, director of the National Institute of Drug Abuse, said.

She cited annual reports from a narcotics control board in the United Nations noting a 300 percent increase in the production and supply of stimulants in the United States between 1995 and 2006.

The paper supports the use of brain stimulants by healthy people but at the same time, it recommends more research into the benefits and risks of such drugs. The risk of dependency is high when they are used for this purpose, the scientists warned. Many people became addicted decades ago when these drugs were widely prescribed for a variety of disorders. Also, the paper calls for action by doctors, educators and others to develop policies on the use of such drugs by healthy people.