IMO adderall's mechanism is much more severe on neurons than methylphenidate. It's very well proven that amphetamine/methamphetamine increases the level of free dopamine in the cytosol which are prone to auto-oxidation to quinones. This wreaks all sort of havoc over the long-term.
Methylphenidate(ritalin) and its stereoisomer stay cleanly outside the presynaptic neurons and only blocks NET and DAT from pumping NE and DA back inside the cell. Unlike amphetamine, it doesnt disrupt the pH gradient of the vesicle membrane and cause an abnormal amount of dopamine to leak and accumulate in the cytosol.
Personally, I would never take adderall/vyvanse/dexedrine.
As a counterexample, let me give you my experience. After being prescribed focalin, my gpa shot through the roof. This stuff actually improved my health.
How?
Instead of pulling all nighters and procrastinating like I used to, this stuff allows me to get work done weeks early and go to sleep on time.
I learned calculus in 1 week, bought a piano and taught myself how to play moonlight sonata 1st mvt and kiss the rain in 3 weeks (working on bach air in d major at the moment).
Oh yea, I also read the entire lehninger biochem book and bernard milller's advanced organic chemistry for fun in my own time. Then a whole world of research papers were discovered through the uni library subscription :>
This stuff allows you to learn at an alarming rate if used properly.
I don't drink alcohol on days of studying because it prevents LTM formation, you're basically wasting your time studying if you do this. Also I never waste my time with people while medicated. This stuff can make you socially awkward and kill your sense of humor. Take it only for the singular purpose of learning and getting work done.
I took extra care with my health, ate blueberries, avocado, eggs, brocoli, meat, etc., lots of lycopene, astaxanthin, R-lipoic acid, melatonin and 8 hours of sleep.
Tolerance will go up very slowly with frequent breaks and essentially goes back to zero with a month break. For adderall, this will take much longer, some people will even develop permanent tolerance that will never go away.
On days when I dont take focalin, I sit around, sip on a beer and browse HN ;)