This is definitely not true. Like any medication, they have risks, but they’re generally safe. As for dependence, there’s a difference between dependence and addiction. Dependence on ADHD meds is the same as dependence on needing glasses to see. Addiction is using them excessively to the point it is a problem. And ADHDers without treatment actually have a higher risk of addiction to other substances.
That said, not all ADHDers need medication. I personally do. But they aren’t a magic pill that make all ADHD symptoms go away. Managing also involves therapy and skillbuilding. Meds are just a tool. I was diagnosed with ADHD when I was 6 and I’ve learned several things over the years.
Maybe the ADHD meds are making things worse in this case, but they are certainly not the root of the problem. That is entirely up to the parents to consider and neither you nor I know enough to say they are or aren’t helping. I can say ADHD meds alone have never caused this kind of behavior.
Blaming it on ADHD meds isn’t helpful and potentially harmful. There’s quite clearly something more serious at play.