In your opinion, is it safe to take it basically forever,as prescribed, because I understand that symptoms usually return when especially adults stop taking CNS stimulants. In fact, I'm really not. Also, I'm no expert in these matters. I just draw on my own personal experiences. As always, medicine, when used within the proper perspective works wonders.
Drugs work on an individual to individual basis.
What I think you're doing is worrying about this too much, and you shouldn't. Take the medicine the way the doctor wants you to and keep him informed of any changes in your behavior that may cause you to do otherwise. You'll be alright.