If lyrica have addiction possibility so is it feasible for patient who takes it for rls to stay on this medicine long term? or should be switched to neurontin instead? asking in terms of dependency factor of both drugs?

Lyrica and neurontin are not interchangeable so you'd have to work with your prescribing physician if you're interested in changing. Lyrica is more apt to cause significant withdrawal symptoms than neurontin, but the latter has more side effect potential. It's feasible to take lyrica longterm but it must be taken strictly according to instructions, not off & on.

Lyrica can be taken twice daily, but Neurontin requires thrice daily dosing. Side effect profile is lower with Lyrica. If you have concerns, a dopamine agonist might be a better choice to manage your RLS.