first, it works great for a while ... then very gradually it starts to wear off and you need more.
growth hormone drops - or growth hormone receptors get blocked
your adrenals wear out - heart doesn't pump as hard (lower stroke volume)
somewhere in there your testosterone drops to extreme low normal after ~1 year.
no interest in sex - or you always have a softie.
no desire to exercise - you stay focused on school, work, etc. no need to "run around"
when your adrenals burn out, you end up tired, unmotivated, depressed and soft - no muscle.
long term adderall use is bad news, don't take it unless your adhd is causing you a lot of trouble.