Ritalin is a drug prescribed to help people with attention deficit hyperactivity disorder, or ADHD. It can help these people think more clearly. But recently scientists found that the drug may have a different, surprising effect when taken by healthy people: It can make them reckless.
In a study published in September, scientists gave 40 healthy women either a single standard dose of Ritalin or a placebo. (A placebo is a fake: It looks just like the drug being tested, but it doesn’t do anything.) Scientists then asked the women to play a gambling game while the researchers took notes on game strategy. Previous studies in people with ADHD had indicated that Ritalin encouraged less risky behavior. The surprise here: Healthy women who took Ritalin took greater risks than usual. When most people would see that they were losing and throw in the towel, people who took Ritalin kept gambling.
Players gambled with fake money, but the researchers had promised real money to the overall winner. The game was also designed to make people lose, so players lost their (fake) money soon after they started gambling. At this point, they were given a choice: Double or nothing. They could quit the game — and admit a loss from their holdings — or invest more money for a chance to try and win big. They didn’t know that winning could never happen — that the game had been purposefully designed to see how much they were willing to lose.
“That’s the sad part of the game,” Daniel Campbell-Meiklejohn told Science News. In this experiment, “you really can’t win.”
Campbell-Meiklejohn, a neuroscientist now at New York University, worked on the new study when he was at Aarhus University in Denmark. Neuroscientists often work to link human behavior to brain function.
People with attention deficit hyperactivity disorder aren’t the only ones using Ritalin. Many people, including some college students, inappropriately (and illegally) take the drug with the intention of boosting their thinking ability, such as when they’re cramming before tests. A doctor would never prescribe the drug for this use.
Ritalin causes the brain to release more than usual amounts of two chemicals: dopamine and noradrenaline. But research has not shown how or why boosting brain levels of those chemicals might encourage a person to take risks. The scientists working on this study suspect Ritalin may cause a person to focus on the good reward, even if getting it is unlikely. Or the drug may lessen warning signals in the body normally associated with risk.
What scientists do know is that every day, people face an endless stream of decisions — and drugs like Ritalin may lead people to choose badly.
dopamine A chemical present in the body that helps send messages between brain cells. Dopamine also helps form other substances like epinephrine, a hormone involved in stress.
noradrenaline A chemical present in the body that helps send messages between brain cells, also used as a drug to raise blood pressure.
neuroscience Any of the sciences that deal with the structure or function of the nervous system and brain.
strategy The method or design of a plan or behavior to achieve something. Strategies may be developed with the aim of winning a battle, winning a game, overcoming some obstacle or achieving some challenging goal.