I'm aware, and I was hesitant to use it when the doc first prescribed it. Personally I'm not so worried about this anymore, there are days when I don't take it (either forget or wake up too late in the day) and I don't feel any different. I never felt like I craved it or had any sort of rewarding feeling upon taking it. I never took Adderall so I can't compare, but from what I know the mental effects of Phentermine are much weaker.

Usually it's prescribed for no more than 3 months, but the doc recommended taking it for longer. He mentioned that addiction risk is negligible for most people. Very solid doctor who specializes in those thing, so I took his word for it after a bit of Googling.