Abstract
Methylphenidate (MPH) is a stimulant that increases extracellular levels of dopamine and noradrenaline. It can diminish risky decisionmaking
tendencies in certain clinical populations. MPH is also used, without license, by healthy adults, but the impact on their decisionmaking
is not well established. Previous work has found that dopamine receptor activity of healthy adults can modulate the influence of
stake magnitude on decisions to persistently gamble after incurring a loss. In this study, we tested for modulation of this effect by MPH
in 40 healthy human adults. In a double-blind experiment, 20 subjects received 20 mg of MPH, while 20 matched controls received a
placebo. All were provided with 30 rounds of opportunities to accept an incurred loss from their assets or opt for a “double-or-nothing”
gamble that would either avoid or double it. Rounds began with a variable loss that would double with every failed gamble until it was
accepted, recovered, or reached a specified maximum. Probability of recovery on any gamble was low and ambiguous. Subjects receiving
placebo gambled less as the magnitude of the stake was raised and as the magnitude of accumulated loss escalated over the course of the
task. In contrast, subjects treated with MPH gambled at a consistent rate, well above chance, across all stakes and trials. Trait reward
responsiveness also reduced the impact of high stakes. The findings suggest that elevated catecholamine activity by MPH can disrupt
inhibitory influences on persistent risky choice in healthy adults.
tendencies in certain clinical populations. MPH is also used, without license, by healthy adults, but the impact on their decisionmaking
is not well established. Previous work has found that dopamine receptor activity of healthy adults can modulate the influence of
stake magnitude on decisions to persistently gamble after incurring a loss. In this study, we tested for modulation of this effect by MPH
in 40 healthy human adults. In a double-blind experiment, 20 subjects received 20 mg of MPH, while 20 matched controls received a
placebo. All were provided with 30 rounds of opportunities to accept an incurred loss from their assets or opt for a “double-or-nothing”
gamble that would either avoid or double it. Rounds began with a variable loss that would double with every failed gamble until it was
accepted, recovered, or reached a specified maximum. Probability of recovery on any gamble was low and ambiguous. Subjects receiving
placebo gambled less as the magnitude of the stake was raised and as the magnitude of accumulated loss escalated over the course of the
task. In contrast, subjects treated with MPH gambled at a consistent rate, well above chance, across all stakes and trials. Trait reward
responsiveness also reduced the impact of high stakes. The findings suggest that elevated catecholamine activity by MPH can disrupt
inhibitory influences on persistent risky choice in healthy adults.
| Original language | English |
|---|---|
| Pages (from-to) | 13032–13038 |
| Number of pages | 7 |
| Journal | The Journal of neuroscience : the official journal of the Society for Neuroscience |
| Volume | 32 |
| Issue number | 38 |
| Publication status | Published - 2012 |
| Externally published | Yes |
Keywords
- Methylphenidate
- decision support
- decision making
