I'll offer a slightly different twist on this, not that I think it is 5% but it is amazing how fucked up parents are these days. I know working professional adults who have kids (pre-teens) that have them on rigourous diets and "supplements". They are getting them getting cosmetic surgery in the teen years. They spend too much time at work that their only outlet is their kids (and the sports they are involved with).
Teenage girls are now getting cosmetic surgery, but I went to a big high school and that was unheard of back then yet I knew kids taking AAS.
Therefore, I would not be surprised that pre-teens are taking AAS....but it is not because of the media but because of their loser-parents that think they are doing them a favor.