I've seen quite a few folks here say that being medicated as a kid is protective for developing substance abuse later as a teen or adult. A randomized trial just published (the gold standard), which followed kids for more than 15 years says it makes no difference either way.
https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2806881
(I do not have a dog in this fight -- my kid is quite possibly inattentive ADHD but does not have a solid diagnosis)