Web edition: September 18, 2012
Print edition: October 20, 2012; Vol.182 #8 (p. 20)
A dose of Ritalin makes healthy women more reckless in a gambling game. After taking the stimulant, participants in an experiment shifted their betting strategy and kept playing even when faced with stakes too high for most folks.
Though solid numbers are scarce, evidence suggests that many healthy people turn to Ritalin (also known as methylphenidate) and other stimulants to boost mental capacity. Some college students, for instance, rely on these “smart pills” to focus attention in cram sessions before tests.
The new results, published in the Sept. 19 Journal of Neuroscience, suggest that the drugs might have unanticipated consequences for these people, says study coauthor Daniel Campbell-Meiklejohn of New York University.
Scientists have known that the very same drug has an opposite effect in people with attention deficit hyperactivity disorder and a kind of dementia, normalizing these people’s risky behavior. Scientists can’t yet explain Ritalin’s divergent effects, but they suspect that variations in how the brain handles the chemical messenger dopamine may be involved.
Researchers enlisted 40 healthy women to take either Ritalin or a placebo, and later play a gambling game. The game was rigged so that the players would quickly rack up a loss and then have to choose whether to double-down in the hopes of recovering their money. “That’s the sad part of the game,” says Campbell-Meiklejohn, who conducted the study while at Aarhus University in Denmark. “You really can’t win.”
Usually, when the stakes get too high, most people bow out and accept their loss. Women who took the placebo behaved this way in a gambling game that used fake money and awarded a real cash prize to the overall winner. But women who got Ritalin kept betting, even when the stakes reached 1,600 Kroner, or about $280. These women seemed inured to the fear of losing a big pot of money.
More studies are needed to know exactly how Ritalin, which boosts levels of dopamine and another chemical messenger called noradrenaline in the brain, influences risky behavior. Ritalin and other drugs like it might shift people so that they are more focused on the potential reward at the expense of thinking about the consequences. Or the drugs might impair a person’s ability to recognize a risky situation or learn from a loss.
Other drugs like amphetamines and cocaine, which behave similarly to Ritalin in the brain, might also increase aspects of risky behavior, says cognitive neuroscientist Trevor Robbins of the University of Cambridge. And these changed behaviors, which could include drug-seeking and using, could lead to addiction.
The influence of these drugs isn’t restricted to illicit drug use or gambling, says Campbell-Meiklejohn. A shift in decision-making strategy would reverberate in everyday life, whether you’re deciding if you should stick it out through a rough patch at a job or to run for the bus rather than walk.
D. Campbell-Meiklejohn et al. In for a penny, in for a pound: Methylphenidate reduces the inhibitory effect of high stakes on persistent risky choice. Journal of Neuroscience, Vol. 32, September 19, 2012, p. 13032. doi:10.1523/JNEUROSCI.0151-12.2012
B. Bower. Stimulant Inaction: ADHD drug's mental lift proves surprisingly weak. Science News, Vol. 172, November 3, 2007, p. 277. Available online: [Go to]