A drug that boosts memory for Alzheimer's patients may also augment the performance of airplane pilots, according to a study published in the July 9 issue of Neurology, the scientific journal of the American Academy of Neurology.
The study involved 18 pilots with an average age of 52. First, the pilots conducted seven practice flights on a flight simulator training them to perform a complex series of instructions. Then half of them took the drug donepezil for 30 days and half took a placebo. They then took the flight simulator test twice more to see if they had retained the training. The pilots who had taken the drug retained the training better than those who had taken placebo.
Researchers were testing the theory that declines in cognitive abilities due to aging are caused in part by loss of functioning of acetylcholine. Acetylcholine is a neurotransmitter that relays messages between cells in areas of the brain important for memory and thought. Donepezil is a cholinesterase inhibitor, which blocks the action of an enzyme responsible for breaking down acetylcholine.
Pilots make good test subjects because flight simulators provide reliable, objective data, according to study author Jerome Yesavage, M.D., of Stanford University and the Palo Alto VA Health Care System in California.
During the 75-minute flight simulations, the pilots received new air traffic control commands every three minutes with a new heading, altitude, radio frequency, and, on 50 percent of the legs, a new transponder code that they had to remember and dial into the cockpit panel. They were also confronted with three emergency situations during each flight.
The researchers caution that the results need to be confirmed in larger studies. "These results don't mean that use of donepezil is recommended for healthy people," Yesavage said. "For one thing, side effects may show up when larger numbers of people take the drug."
If the results are confirmed with larger studies, many legal, regulatory and ethical issues will arise, Yesavage said.
"Many older adults who will never develop Alzheimer's have cognitive impairments that impact their day-to-day functioning, and the demand is increasing for therapies to address this," Yesavage said. "Many questions will come up. How will we pay for these therapies? Will it worsen the gap between the haves and have-nots when the rich are cognitively enhanced not only through better education, but also through drugs or other technologies? And how should the use of these therapies be regulated in settings beyond aviation or normal aging, such as chess matches or test-taking among college students?"
The study was supported by grants from the National Institute of Mental Health, the National Institute on Aging, the Sierra-Pacific Mental Illness Research, Education, and Clinical Center and the Department of Veterans Affairs.