A recent study used a Parkinson’s disease drug to try and regulate impulsive behavior. Results showed that people who were naturally impulsive were less so after taking tolcapone.
"Talk to your doctor about your impulsive tendencies."
Andrew Kayser, PhD, assistant professor of neurology at the University of California at San Francisco, led an investigation into dopamine’s effect on impulse behavior.
For the study, 23 adults were given tolcapone, which is a dopamine-degrading enzyme, or a placebo. The test subjects were then asked to choose a small amount of money now or a larger amount later.
Each subject was tested at baseline, after taking a placebo and after taking tolcapone. Magnetic resonance imaging (MRI) scans were done during the test to see the frontal cortex both on and off the drug.
Impulse behavior can come from a person not wanting a delayed reward. This need for more immediate reward can come from frontal lobe damage or a behavioral disorder.
Subjects were less impulsive in their decision making after taking tolcapone, even those deemed impulsive before taking the drug.
Dr. Keyser said, “Impulsivity is a risk factor for addiction to many substances, and it has been suggested that people with lower dopamine levels in the frontal cortex tend to be more impulsive.”
“We wanted to see if we could decrease impulsivity by raising dopamine, and it seems as if we can.”
“Most, if not all, drugs of abuse, such as cocaine and amphetamine, directly or indirectly involve the dopamine system.”
Further studies will be necessary to determine whether tolcapone will work in ‘real world’ situations, such as under the influence of alcohol, not just a fictitious money-reward scenario.
This was a small study and further trials will be necessary to test its efficacy.
Tolcapone is on the market as a treatment drug for Parkinson’s disease.
This study was published in July by the Journal of Neuroscience. The study was funded by the Wheeler Center for the Neurobiology of Addiction, the US Army Telemedicine and Advanced Technology Research Center and The Foundation for Alcohol Research and the State of California, no conflicts of interest were found.