dopamine dysregulation syndrome (wanting to take more and more of the medicine) has been reported for co-careldopa, but it is quite rare. it is more common for dopamine dysregulation syndrome to happen with dopamine agonists.
co-careldopa sometimes exacerbates or causes addictions to other behaviors, e.g., gambling, sex, etc. in my case, the problematic behaviors are reading, computer programming, and just plain thinking. i try to keep my co-careldopa at the minimum, but then i lose time to the tremor. it’s a choice of which way i want to lose control. 
again, dopamine agonists have a higher likelihood of causing this kind of trouble.
hope this information helps!
best wishes,
joe