My insurance won't cover Vyvanse (brand) after Oct. 1

Just got a letter from Aetna yesterday stating that after Oct. 1st my plan will no longer cover Vyvanse because "there's another covered medication that's safe and effective for your condition and may cost less."

I find it hard to believe that these insurance companies do not know how inconsistent the effectiveness of these generics are. But everyone is so concerned about mental health right now though, right?

I don't know how many generic versions of Vyvanse I have tried but I know that they have all been less effective than the brand. I also take Adderall IR and have only found 2 generics that work. The other 3 or 4 that I have tried have little to no effect.