In this case, I would have rather seen the link to the article posted as a comment in the other thread about Provigil. A lot of discussion has already centered around it; there's no sense in starting up a second thread on it, and fragmenting the discussion.
Personally, I'm glad this was posted separately. It was much more informative and better written than the first article, and I would not have been likely to see it if it was added now as a comment in the first post.
You meant to add a comment here: http://news.ycombinator.com/item?id=190676