He has only just graduated from drama school (he went to RADA - the Royal Academy of Dramatic Arts in London (alumni e.g. Kenneth Branagh, Ralph Fiennes, Anthony Hopkins) ), and he is in his mid-20s; I think it is highly unlikely that he is the same Adam Campbell who wrote an episode of "I shrunk...," as he would have been 10 at the time.

Also: interesting piece of trivia: he used to share a flat with Will Young, who's the winner of the first season of Pop Idol (the British ORIGINAL of American Idol)