> But I think it's pretty well understood that taking amphetamines is a net-negative for individuals and society.

Depends on the amphetamine. They are not made equal. It's absolutely possible to maximize benefits and minimize risks. Remember that this stuff treats attention deficit disorder.

He was just taking adderall-level doses, no recreational doses. Basically in line with ADHD treatment. Not sure how that level for those who need it would be net negative

While reading the article, you found some evidence contradicting a firmly held belief, and decided to keep the belief and discard the new evidence.

I would have stopped reading your comment after realising this, but I was already at the end.

A single anecdote about having ideas while taking amphetamines is hardly evidence.

It's not a large or high-quality piece of evidence, but it is most definitely a nonzero amount of evidence.

The evidence provided by any observational study is no more than the sum of many small pieces of evidence exactly like this one.