We started difficult child 3 on stimulants when he was 3 years old. People were scandalised, but the improvement was dramatic and fast.
What we saw - he was able to stay focussed on topic even in a distracting environment. For him, this also meant he could focus on the spoken word much better and his gains in language development were astonishing.
Secondary benefits - as the child realises he can stay focussed, the resistance to taking medications can plummet. They improve self-esteem ("Hey, I'm not a bad kid, after all - I can be good so easily on the medications, the teacher likes me again, I find everyone else is being nice to me, I like going to school, I enjoy learning, I love the lessons.")
Tics - are they real tics, or are they stims (as in self-stimulatory behaviours)? We found that some stims increased, some decreased. Over time the type of stims we have observed have trended to more socially acceptable, less obvious ones. They have some control, although less control when anxious. The stims (behaviours) are calming, are themselves a coping strategy.
We tried to eliminate stimming behaviour only to find that if you block one behaviour, another one breaks out to replace it. So we herded our kids towards more acceptable ones.
The medications and addiction - it's not a problem when taken according to prescription. The medications (like so many of them) are only addictive when seriously abused. Our kids, despite having been taking these medications for over a decade each (decade and a half, at least) literally can (and sometimes do) stop taking medications 'cold turkey' and the main problem we have is a desire to throttle the unmedicated child. From the kid's point of view, there is no problem.
easy child 2/difficult child 2 only takes her medications these days when she's working a shift at the store, or has a college class. College is two nights a week. Her shifts are erratic. Other days - no medications. And she has no problem taking her medications this way.
The only people to get addicted to this stuff are people who seriously work at developing an addiction, who take this because their usual 'speed' is not so available. In other words - I think you have to be already addicted to something else.
I have heard of parents getting addicted to taking their kids' medications (which I think is utterly irresponsible, to even take your kids' medications in the first place).
Don't worry about addiction. But keep the pills safe from other already-addicts from getting access to them. Your child, if he does well on these medications, will want to guard every pill for the improvement it gives his life.
Marg