HealthDay News — High levels of dopamine may increase risk-taking behaviors in healthy people — mimicking results seen in people with Parkinson’s disease — according to research published in the Journal of Neuroscience.

Previous research has linked drugs that increase dopamine, such as L-DOPA, with compulsive gambling in Parkinson’s disease patients. The new study included 30 individuals without Parkinson’s disease. The participants were asked to choose between safe and risky gambling options that resulted in monetary gains and losses. They did this after receiving L-DOPA and again after receiving an inactive placebo.

The participants took more risks to get bigger rewards after receiving L-DOPA, but not the placebo. However, L-DOPA did not affect how often the study volunteers took risks if there was a potential loss, the investigators found. After receiving L-DOPA, the participants took more risks regardless of how much larger the potential reward was than the safer option. Participants were happier to win a small reward while on L-DOPA than on the placebo. They were happier to win a large reward than a small reward while on the placebo, but were equally happy about small rewards and large rewards while on L-DOPA, the findings showed.

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L-DOPA made potential rewards more appealing but did not affect the participants’ perception of possible losses, according to study leader Robb Rutledge, PhD, of University College London, and his colleagues. The study authors also suggested that while on L-DOPA, the participants might have had similar amounts of dopamine release for all gambling rewards, which may explain why they were equally happy after small and large wins.


  1. Rutledge RB et al. J Neurosci. 2015; doi:10.1523/JNEUROSCI.0702-15.2015.