I can speak to the long-term effects of two people taking adderall/ritalin.
I started taking them about 14 years ago, when I was in early 30s. Being raised by my great depression era grandparents, I was extremely anti-medication. In general, I still am, for myself. It's not right to impose that view on others. You'll see why in a couple of paragraphs.
I've been technically focused, on a daily basis, since I was a kid, starting in the late 1970s, and that translated into a very successful career, even before I started taking the meds.
But I definitely have ADHD, and I always have.
What does that mean specifically, in my case? It means that it takes an enormous amount of energy to focus. Indeed, in the decade I was getting paid before taking the meds, I created many things, big, small, alone, in groups, terrible and awesome, in a variety of environments and backgrounds.
But after a long day of work, where I'd used all of my mental energy to focus, I would end up having to take an hour nap. Note, I wasn't sleep deprived. Via my grandparents, I've always valued getting enough sleep.
But the mental drain was enormous, doing software/technology for 8 or so hours every day.
My new wife at the time, who has a mental health background, suggested I get evaluated for ADHD. I resisted for a long time, but finally I did and brought home some adderall.
Me being me, I wanted to approach this very carefully and rigorously.
Despite a good diet, plenty of sleep and exercise, my pulse rate was always a bit high, as was my blood pressure. Subclinical, but notably elevated.
Something interesting happened after I took adderall the first time: my BP and pulse rate were lower. And please note that this has been clinically noted and recorded on my medical record over the years as I've gotten my vitals checked from time to time. The meta-data before each check was when I last took the med.
When I take adderall, concentrating isn't a struggle, it just happens when I want it to. This has the effect of lowering my vitals, even though adderall is, as stated elsewhere, a very smooth version of speed.
Over the years, I've alternated between adderall and ritalin at first and now concerta, which is, of course, 'ritalin extended release'.
I don't take the meds every day, and I've had the two prescribing doctors over the years give me high dosing flexibility. In other words, lots of small dosage tablets, giving me the ability to dose as I see fit.
Here are my general rules for dosing, in order of precedence:
1. work days
2. dose strongly biased toward the AM
3. lower or zero dose on work days where I need to be 'scattered' and do a lot of shallow things
4. rarely non-work days, usually with a lesser dose, where I need to do some deeper focus
I feel absolutely no 'pull' from these meds. I have gone months not taking them, and they have improved my life notably. They are a tool, and I use them as such.
The other person is my son. I must be briefer here because my day must begin shortly.
He is now a teenager, and started showing signs of clinical autism before his 2nd birthday. Further, he is even more ADHD than I am.
We were told he would never speak. Further, we resisted giving him any meds, for years. This was a mistake.
We finally started him on Concerta when he was six years old. The difference is profound.
ADHD and autism together in a single mind is quite a curious combination.
Briefly: without the meds, his mind races in so many directions, in so many deep 'autistic rabbit holes', that he can hardly string together a clear sentence, even today. Only after he started taking the meds was he able to start learning in a relatively normal way.
He is effectively dependent on the meds to function in a relatively normal way. And, with his mom's amazing, devoted and miraculous effort and attention these past 14 years, he is at mainstream class levels (but one year behind) in every subject except math.
ramblerman, I am the one who has rambled this morning (my time). I am well known for creating walls of text, so please accept my apology for that.
As you say, adderall isn't magically different. It is in fact speed.
But our brains and bodies are amazing, and amazingly variant.
I suspect that most of the people who take adderall and concerta don't need it as my son needs it. And perhaps we need more rigorous clinical protocols, but who knows. It's all pretty complicated.
PS: I have to leave this message unedited, so please pardon the roughness of it. I have to get ready for work, and the train waits on nobody.