A new study has uncovered a reason why some people taking some medications for Parkinson’s disease develop harmful addictive behaviors.
Compulsive behaviors are a common side effect of a particular type of dopamine replacement therapy for Parkinson’s known as dopamine agonists (brand names Parlodel, Requip and Mirapex). People using this class of medications have a higher likelihood of developing problem gambling, binge eating, hypersexuality and excessive shopping – even if they’ve had no prior tendency to do so.
The researchers used a method of magnetic resonance imaging to develop individualized brain pathway diagrams for each study participant. Participants were also asked to gamble in a virtual casino, providing a readout of impulsive and risk-taking behavior in real time.
Taking these observations and the effects of dopamine agonists into account, the researchers were able to identify which participants were most susceptible to impulse-control behaviors, reported neuropsychiatrist Phil Mosley, M.D., of the QIMR Berghofer Medical Research Institute, Australia.
The investigation revealed a clear link between the strength of certain brain connections and impulsive behavior, even in people without clinically significant impulse-control problems. The findings suggest that brain imaging and computer-based testing could be used to better identify people at risk of developing these behaviors when treated with dopamine-replacement drugs, the researchers wrote.
“We could offer targeted education to at-risk individuals, or adapt their treatment regimen to minimize the potential harms from these therapies,” Mosely concluded.
The study was published this week in the journal Brain.
