I was first prescribed Adderall for about three years, taking usually 90mg instant release tablets. He was experiencing recreational effects up to three to four hours with little comedown. Then later in his life was taking 60mg of Dexedrine instant release tablets with exceptional recreational effects. Now he has been taking up to 100mg of Metadate CD with very little recreational effects and nasty comedowns. Even now when he takes his old familiar friend Dexedrine and Adderall the effects are nearly the same as his Metadate CD. Has SWIM burnt him self out on Amphetamine like substances? I have taken long sessions of abstinence from all stimulants, but still gains very little from any of these chemicals. Can anyone relate to this? Is it possible to gain a permanent tolerance to stimulants even after a long hiatus? I have noticed the same thing with heroin.