Farah said there have been no studies that establish the long-term effects of brain function in children who take Ritalin to control hyperactivity or in people who take medication for depression. It could be that drugs alter the way the brain works, fundamentally changing personality. The drugs may even have unanticipated consequences such as speeding the brain’s decline with old age.

The question becomes more complicated for drugs such as modafinil, which can improve memory or the ability to concentrate. These have obvious appeal for professionals wanting an edge, but at what cost? “I think it is important for science to move forward,” Illes said. “I worry about how the science will be conveyed to the public. Will it play on fears of not having a competitive edge?”

If the answer is yes, Illes brings up a few hypothetical situations. What if some people in a given field take a drug to make themselves doubly productive? Will their productivity put pressure on colleagues to use the drugs, much like some professional athletes feel competitive pressure to take steroids? Would differences in productivity cause conflicts between colleagues or inequalities in pay?

These scenarios raise issues about what scientists should do to prevent the abuse of brain enhancement research. In their review, Illes and her colleagues quote Francis Fukuyama, the Omer L. and Nancy Hirst Professor of Public Policy at the Institute of Public Policy at George Mason University, who has called for legislation to control the use of drugs or devices that alter the way the brain functions.

Legislation isn’t necessary, according to the group, but caution is. Illes and Farah argue that by being proactive in thinking about ethical issues, ethicists, neurologists and physicians can develop guidelines to aid decisions about how research findings are used and communicated to the public.

Robert Cook-Deegan, MD, director of Duke Institute for Genome Sciences and Policy’s Center for Genome Ethics, Law and Policy, hopes that such guidelines will distinguish between potentially harmful brain alterations and the type of brain-altering activities that have taken place since the dawn of civilization. Every time a person smokes a cigarette, drinks a glass of wine or wakes up with a cup of coffee, the workings of that person’s brain are being changed, he said, so how is taking a drug any different?

“Caffeine then modafinil; what is next?” said Cook-Deegan, a co-author of the paper. Cook-Deegan said drug treatments follow a well-trammeled path from development for treating a disease such as depression, Alzheimer’s or narcolepsy, to use for less established medical conditions. The drug Ritalin, used to treat children with attention deficit hyperactivity disorder, is a classic example. Where it was once a welcome relief to those rare parents with hard-to-manage kids, the drug is now widely prescribed and is even taken by college students needing help focusing before exams.

In addition to drugs, Illes said that modern brain imaging techniques may reveal aspects of personality such as a tendency to lie or be aggressive. As the technology improves doctors must decide who should have access to this information and whether they should treat a neural tendency rather than an actual behavior.

Illes said the panel’s discussion was limited to examples of what neuroscientists may be able to detect or treat in the future. Through such meetings, she hopes the medical community will be poised to act responsibly when those future technologies become a reality.