That's because parkisons drugs can upregulate a certain protein that is implicated in all forms of addiction that feature that kind of "seeking" behavior and modification of the reward system!
We found that if you give an addicted rat a chemical which suppresses the expression of this gene, it will improve their addiction situation, reduce seeking behaviors, etc.
https://en.wikipedia.org/wiki/FOSB#Role_in_addiction
We found that if you give an addicted rat a chemical which suppresses the expression of this gene, it will improve their addiction situation, reduce seeking behaviors, etc.
We found that in 2015.