Revisionist historians who would date Merriman’s decline to his failed drug test have yet to adequately account for his success later that season or his 12½ sacks in 2007.
Steroids are not like direct acting drugs such as methamphetamines or cocaine, which take effect immediately and wear off promptly when you stop using them. Steroids are taken for the indirect effect of building muscle mass and strength, which requires using them for some time. The muscle and strength does not disappear immediately when one stops taking the steroids that created them, it can take quite a while for them to atrophy.
A side effect of steroid use, one that I suspect is significant in Merriman’s situation, is that it seriously compromises the immune system and the body’s ability to heal after injury. That’s one of the reasons that their use is banned, and not only in professional sports.
I am not without sympathy for Shawne Merriman, but he chose to use steroids to enhance his performance. There is no question that he did so, he tested positive for them and his denials are as meaningful as those of Roger Clemons. He had a difficult childhood, but so did millions of other kids, and they grew up in far more productive ways than he chose to do. The bed he sleeps in is of his own making.