I think it is useful to separate out the concepts of substance abuse from substance addiction. If the article just dealt with who experience powerful cravings

I think it is useful to separate out the concepts of substance abuse from substance addiction. If the article just dealt with who experience powerful cravings and withdrawals (the most common definition of addiction, and the most useful as far as I can tell) then it would be much more insightful. Instead it seems to equate addiction with heavy use and recklessness.